lipoteichoic-acid and Disease-Models--Animal

Lipoteichoic acid (LTA) is a surface-associated adhesion amphiphile from Gram-positive bacteria and regulator of autolytic wall enzymes (muramidases). It is released from the bacterial cells mainly after bacteriolysis induced by lysozyme, cationic peptides from leucocytes, or beta-lactam antibiotics. It binds to target cells either non-specifically, to membrane phospholipids, or specifically, to CD14 and to Toll-like receptors. LTA bound to targets can interact with circulating antibodies and activate the complement cascade to induce a passive immune kill phenomenon. It also triggers the release from neutrophils and macrophages of reactive oxygen and nitrogen species, acid hydrolases, highly cationic proteinases, bactericidal cationic peptides, growth factors, and cytotoxic cytokines, which may act in synergy to amplify cell damage. Thus, LTA shares with endotoxin (lipopolysaccharide) many of its pathogenetic properties. In animal studies, LTA has induced arthritis, nephritis, uveitis, encephalomyelitis, meningeal inflammation, and periodontal lesions, and also triggered cascades resulting in septic shock and multiorgan failure. Binding of LTA to targets can be inhibited by antibodies, phospholipids, and specific antibodies to CD14 and Toll, and in vitro its release can be inhibited by non-bacteriolytic antibiotics and by polysulphates such as heparin, which probably interfere with the activation of autolysis. From all this evidence, LTA can be considered a virulence factor that has an important role in infections and in postinfectious sequelae caused by Gram-positive bacteria. The future development of effective antibacteriolitic drugs and multidrug strategies to attenuate LTA-induced secretion of proinflammatory agonists is of great importance to combat septic shock and multiorgan failure caused by Gram-positive bacteria.

Topics: Adhesins, Bacterial; Animals; Arthritis; Bacterial Infections; Bacteriolysis; Cytokines; Disease Models, Animal; Drosophila Proteins; Encephalomyelitis; Gram-Positive Bacteria; Humans; Lipopolysaccharide Receptors; Lipopolysaccharides; Macrophages; Membrane Glycoproteins; Nephritis; Neutrophils; Reactive Oxygen Species; Receptors, Cell Surface; Teichoic Acids; Toll-Like Receptors; Uveitis; Virulence

Topics: Actins; Animals; Cell Line; Cell Wall; Disease Models, Animal; Female; Fibroblasts; Fibrosis; Hot Temperature; Humans; Lactobacillus; Lipopolysaccharides; Male; Matrix Metalloproteinase 1; Mice, Inbred BALB C; Probiotics; Signal Transduction; Skin; Smad Proteins; Tail; Teichoic Acids; Transforming Growth Factor beta; Wound Healing

Shikonin is the major active component in

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Bronchoalveolar Lavage Fluid; Caspase 3; Cytokines; Disease Models, Animal; DNA Fragmentation; Inflammation; Lipopolysaccharides; Male; Mice, Inbred C57BL; Myeloid Cell Leukemia Sequence 1 Protein; Naphthoquinones; Neutrophil Infiltration; Neutrophils; Poly(ADP-ribose) Polymerases; Teichoic Acids; Tumor Suppressor Protein p53

Patients with prior illness are more vulnerable to heat stroke-induced injury, but the underlying mechanism is unknown. Recent studies suggested that NLRP3 inflammasome played an important role in the pathophysiology of heat stroke.. In this study, we used a classic animal heat stroke model. Prior infection was mimicked by using lipopolysaccharide (LPS) or lipoteichoic acid (LTA) injection before heat stroke (LPS/LTA 1 mg/kg). Mice survival analysis curve and core temperature (T. Prior infection simulated by LPS/LTA injection resulted in latent inflammation status presented by high levels of cytokines in peripheral serum. However, LPS/LTA failed to cause any change in animal survival rate or body temperature. In the absence of LPS/LTA, heat treatment induced heat stroke and animal death without significant systemic or neuroinflammation. Despite a decreased level of IL-1β in hypothalamus, Nlrp3 knockout mice demonstrated no survival advantage under mere heat exposure. In animals with prior infection, their heat tolerance was severely impaired and NLRP3 inflammasome induced neuroinflammation was detected. The use of Nlrp3 knockout mice enhanced heat tolerance and alleviated heat stroke-induced death by reducing mice hypothalamus IL-1β production with prior infection condition. Furthermore, IL-1β neutralizing antibody injection significantly extended endotoxemic mice survival under heat stroke.. Based on the above results, NLRP3/IL-1β induced neuroinflammation might be an important mechanistic factor in heat stroke pathology, especially with prior infection. IL-1β may serve as a biomarker for heat stroke severity and potential therapeutic method.

Topics: Animals; Antibodies, Neutralizing; Brain; Disease Models, Animal; Heat Stroke; Inflammasomes; Interleukin-1beta; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Neuroinflammatory Diseases; NLR Family, Pyrin Domain-Containing 3 Protein; Signal Transduction; Teichoic Acids; Thermotolerance

Previously, we generated and screened a panel of monoclonal antibodies (mAbs) against methicillin-resistant Staphylococcus aureus (MRSA) to identify protective mAbs in mouse infection models. One of these mAbs, ZBIA3H, bound to lipoteichoic acid (LTA) and exerted protective effects in a mouse sepsis model. To reinforce the ability of the mAb to protect against infection, combination therapies with the mAb and antibiotics need to be examined. Therefore, herein, we studied the efficacy of ZBIA3H (in combination or alone) in a mouse sepsis model. ZBIA3H improved the survival rate in the mouse models of sepsis induced by highly virulent or refractory S. aureus (community-acquired MRSA strain MW2, vancomycin-intermediate S. aureus strain Mu3, or vancomycin-resistant S. aureus strain VRS1). Furthermore, ZBIA3H remarkably improved the survival rate in combination with antimicrobial agents (vancomycin, daptomycin, or linezolid) in mouse sepsis models. From these results we conclude that anti-LTA mAb ZBIA3H or its humanized form is a promising mAb individually, or in combination with antibiotics, against clinical refractory infection of S. aureus.

Topics: Animals; Anti-Bacterial Agents; Antibodies, Bacterial; Antibodies, Monoclonal; Daptomycin; Disease Models, Animal; Drug Therapy, Combination; Humans; Linezolid; Lipopolysaccharides; Methicillin-Resistant Staphylococcus aureus; Mice; Sepsis; Staphylococcal Infections; Staphylococcus aureus; Teichoic Acids; Vancomycin

Intestinal radioprotection was modelled in vitro with cell lines and enteroids as well as in vivo by assaying clinical outcomes and crypt survival. Fractionated abdominal and single dose radiation were used along with syngeneic CT26 colon tumour grafts to assess tumour radioprotection.. LGG with a mutation in the processing of lipoteichoic acid (LTA), a TLR2 agonist, was not radioprotective, while LTA agonist and native LGG were. An agonist of CXCR4 blocked LGG-induced MSC migration and LGG-induced radioprotection. LGG given by gavage induced expression of CXCL12, a CXCR4 agonist, in pericryptal macrophages and depletion of macrophages by clodronate liposomes blocked LGG-induced MSC migration and radioprotection. LTA effectively protected the normal intestinal crypt, but not tumours in fractionated radiation regimens.. LGG acts as a 'time-release capsule' releasing radioprotective LTA. LTA then primes the epithelial stem cell niche to protect epithelial stem cells by triggering a multicellular, adaptive immune signalling cascade involving macrophages and PGE2 secreting MSCs.. NCT01790035; Pre-results.

Topics: Animals; Cell Movement; Cells, Cultured; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Immunohistochemistry; Intestinal Mucosa; Lacticaseibacillus rhamnosus; Lipopolysaccharides; Macrophage Activation; Mesenchymal Stem Cells; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Probiotics; Radiation Injuries; Radiation-Protective Agents; Reference Values; Sensitivity and Specificity; Teichoic Acids

Topics: Animals; Animals, Outbred Strains; Bacterial Outer Membrane Proteins; Candida albicans; Candidiasis; CD5 Antigens; Cytokines; Disease Models, Animal; Disease Susceptibility; Interferon-gamma; Lipopolysaccharides; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mycoses; Sepsis; Species Specificity; Spleen; Teichoic Acids; Zymosan

Staphylococcus aureus is a significant bacterial pathogen that may penetrate through the barrier into the epidermis and dermis of the skin. We hypothesized that the S. aureus cell wall product lipoteichoic acid (LTA) may contribute to the development of inflammation and skin barrier defects; however, the effects of LTA in vivo are not well understood. In this study, we examined the effects induced by intradermal S. aureus LTA. We found that keratinocytes in LTA-treated skin were highly proliferative, expressing 10-fold increased levels of Ki67. Furthermore, we observed that LTA caused damage to the skin barrier with substantial loss of filaggrin and loricrin expression. In addition, levels of the IL-1 family of inflammatory cytokines, as well as the neutrophil-attracting chemokines Cxcl1 and Cxcl2, were increased. Concomitantly, we observed significant numbers of neutrophils infiltrating into the epidermis. Finally, we determined that LTA-induced signals were mediated in part through IL-1, because an IL-1 receptor type 1 antagonist ameliorated the effects of LTA, blocking neutrophil recruitment and increasing the expression of skin barrier proteins. In summary, we show that S. aureus LTA alone is sufficient to promote keratinocyte proliferation, inhibit expression of epidermal barrier proteins, induce IL-1 signaling, and recruit cells involved in skin inflammation.

Topics: Animals; Cell Wall; Cells, Cultured; Cytoprotection; Disease Models, Animal; Epidermis; Filaggrin Proteins; Humans; Interleukin 1 Receptor Antagonist Protein; Interleukin-1; Keratinocytes; Ki-67 Antigen; Lipopolysaccharides; Mice; Neutrophil Infiltration; Neutrophils; Primary Cell Culture; Receptors, Interleukin-1 Type I; Staphylococcal Skin Infections; Staphylococcus aureus; Teichoic Acids

Endometritis is one of the main diseases that causes great economic losses in the dairy industry. Recent studies have shown that matrine extracted from the traditional Chinese herb Sophora flavescens is an alkaloid with a broad range of bioactivities. Here, we aimed to investigate the protective effects of matrine on Staphylococcus aureus lipoteichoic acid (LTA)-induced endometritis in mice and elucidate the possible molecular mechanisms in vitro. Histopathological changes showed that matrine remarkably attenuated the uterus injury in a mouse model of LTA-induced endometritis. qPCR and ELISA results showed that matrine dose-dependently reduced the expression of pro-inflammatory cytokines (TNF-α and IL-1β). To further elucidate the underlying mechanisms of this protective effect of matrine, LTA-stimulated bovine endometrial epithelial cells (bEECs) were employed in this study. The results demonstrated that TLR2 expression and its downstream nuclear factor (NF)-κB activation were both suppressed by matrine treatment. Furthermore, a small interference RNA targeting TLR2 gene mimicked matrine in its inhibition on LTA-induced activation of TLR2 and NF-κB. In conclusion, these findings suggest the protective effect of matrine against LTA-induced endometritis through negative regulation of TLR2-mediated NF-κB pathway.

Topics: Alkaloids; Animals; Anti-Inflammatory Agents; Disease Models, Animal; Down-Regulation; Endometritis; Female; Humans; Interleukin-1beta; Lipopolysaccharides; Matrines; Medicine, Chinese Traditional; Mice; NF-kappa B; Quinolizines; RNA, Small Interfering; Signal Transduction; Sophora; Staphylococcus aureus; Teichoic Acids; Toll-Like Receptor 2; Tumor Necrosis Factor-alpha; Uterus

Despite extensive investigation focused on both the molecular characteristics and the expression level of Toll-like receptors (TLRs) during the inflammatory response in vertebrates, few data are available in the literature on the role of these proteins in invertebrate's immune response. Here, we propose the medicinal leech as a valuable model to better elucidate the role of TLR4 and its related products, such as tumor necrosis factor (TNF-α), after activation of the leech peripheral immune system with the endogenous medicinal leech recombinant allograft inflammatory factor-1 (rHmAIF-1) or with an exogenous stimulus, such as lipopolysaccharide (LPS). Our results indicate that activated macrophages (HmAIF-1

Topics: Animals; Calcium-Binding Proteins; Disease Models, Animal; Granulocytes; Inflammation; Leeches; Leeching; Lipopolysaccharide Receptors; Lipopolysaccharides; Macrophages; Microfilament Proteins; Teichoic Acids; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Host-to-host transmission is a necessary but poorly understood aspect of microbial pathogenesis. Herein, we screened a genomic library of mutants of the leading respiratory pathogen

Topics: Alanine; Animals; Animals, Newborn; Bacterial Proteins; Bacterial Shedding; Disease Models, Animal; DNA Transposable Elements; Genomic Library; Host-Pathogen Interactions; Inflammation; Lipopolysaccharides; Mice; Mice, Inbred C57BL; Mutagenesis; Pneumococcal Infections; Respiratory System; Streptococcus pneumoniae; Teichoic Acids

Enterococcus faecium (E. faecium) has emerged as one of today's leading causes of health care-associated infections that is difficult to treat with the available antibiotics. These pathogens produce capsular polysaccharides on the cell surface which play a significant role in adhesion, virulence and evasion. Therefore, we aimed at the identification and characterization of bacterial polysaccharide antigens which are central for the development of vaccine-based prophylactic approaches. The crude cell wall-associated polysaccharides from E. faecium, its mutant and complemented strains were purified and analyzed by a primary antibody raised against lipoteichoic acid (LTA) and diheteroglycan (DHG). The resistant E. faecium strains presumably possess novel capsular polysaccharides that allow them to avoid the evasion from opsonic killing. The E. faecium U0317 strain was very well opsonized by anti-U0317 (~95%), an antibody against the whole bacterial cell. The deletion mutant showed a significantly increased susceptibility to opsonophagocytic killing (90-95%) against the penicillin binding protein (anti-PBP-5). By comparison, in a mouse urinary tract and rat endocarditis infection model, respectively, there were no significant differences in virulence. In this study we explored the biological role of the capsule of E. faecium. Our findings showed that the U0317 strain is not only sensitive to anti-LTA but also to antibodies against other enterococcal surface proteins. Our findings demonstrate that polysaccharides capsule mediated-resistance to opsonophagocytosis. We also found that the capsular polysaccharides do not play an important role in bacterial virulence in urinary tract and infective endocarditis in vivo models.

Topics: Animals; Anti-Bacterial Agents; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Capsules; Cell Wall; Disease Models, Animal; Drug Resistance, Bacterial; Endocarditis, Bacterial; Enterococcus faecium; Female; Gram-Positive Bacterial Infections; Humans; Leukocytes, Mononuclear; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Opsonin Proteins; Penicillin-Binding Proteins; Phagocytosis; Polysaccharides, Bacterial; Primary Cell Culture; Rats; Rats, Wistar; Teichoic Acids; Urinary Tract Infections

Lipoteichoic acid (LTA), a major component of the cell wall of Staphylococcus aureus (S. aureus), is not generally considered as an ideal vaccine candidate since it is a thymus-independent antigen. In this study, we screened a 12-mer phage peptide library and identified a series of peptide sequences that can mimic the epitope of LTA. A tetra-branched multiple antigenic peptide, named MAP2-3, comprising one of the positive peptide sequences (GHKEDRQWCQHS), was synthesized. Immunization with MAP2-3 induced LTA-specific IgG antibodies, prolonged the survival time, and decreased the bacterial burden in organs of mice infected with S. aureus. Moreover, passive immunization with polyclonal anti-MAP2-3 sera reduced bacterial load in organs of mice with bacteremia, alleviated acute lung injury in mice with pneumonia, and decreased the size of lesions in mice with skin infection. The number of LTA-specific antibody-secreting cells in the spleen of MAP2-3 immunized mice were significantly higher than that in the control mice. In summary, as a surrogate of LTA, vaccination with MAP2-3 elicited humoral immune response and protected mice from S. aureus infection. This study provides a new option to design vaccines against S. aureus.

Topics: Animals; Antibodies, Bacterial; Antibody Specificity; Antigens, Bacterial; Cell Surface Display Techniques; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Immunization; Immunoglobulin G; Lipopolysaccharides; Mice; Molecular Mimicry; Peptide Library; Peptides; Rabbits; Staphylococcal Infections; Staphylococcal Vaccines; Staphylococcus aureus; Teichoic Acids

Topics: Allergens; Animals; Cell Movement; Chronic Disease; Disease Models, Animal; Enterotoxins; Eosinophils; Humans; Lipopolysaccharides; Male; Nasal Mucosa; Neutrophil Infiltration; Ovalbumin; Rabbits; Rhinitis; Sinusitis; Staphylococcus aureus; Teichoic Acids

Bacterial infections are the most prevalent etiological factors of epididymitis, a commonly diagnosed inflammatory disease in the investigation of male infertility factors. The influence of early pathogenic mechanisms at play during bacterial epididymitis on reproductive outcomes is little understood. We report here that experimental epididymitis induced in rats by Gram-negative (LPS) and Gram-positive (LTA) bacterial products resulted in differential patterns of acute inflammation in the cauda epididymis. LPS elicited a strong inflammatory reaction, as reflected by upregulation of levels of mRNA for seven inflammatory mediators (Il1b, Tnf, Il6, Ifng, Il10, Nos2 and Nfkbia), and tissue concentration of six cytokines/chemokines (IL1A, IL1B, IL6, IL10, CXCL2 and CCL2) within the first 24 h post-treatment. Conversely, LTA induced downregulation of one (Nfkbia) and upregulation of six (Il1b, Il6, Nos2, Il4 Il10 and Ptgs1) inflammatory gene transcripts, whereas increased the tissue concentration of three cytokines/chemokines (IL10, CXCL2 and CCL2). The stronger acute inflammatory response induced by LPS correlated with a reduction of epididymal sperm count and transit time that occurred at 1, 7, and 15 days post-treatment. Our study provides evidence that early epididymal inflammatory signaling events to bacterial activators of innate immunity may contribute to the detrimental effects of epididymitis upon male fertility.

Topics: Acute Disease; Animals; Biomarkers; Chemokines; Cytokines; Disease Models, Animal; Epididymis; Epididymitis; Gene Expression; Lipopolysaccharides; Male; Rats; RNA, Messenger; Sperm Count; Spermatozoa; Teichoic Acids; Testosterone

Infective endocarditis is usually caused by Streptococcus sanguinis and characterized by inflammatory responses in the endocardium. This study aimed to investigate if the new compound (3R)-5,6,7-trihydroxy-3-isopropyl-3-methylisochroman-1-one (TIM) isolated from Alpinia katsumadai Hayata could provide protection against lipoteichoic acid (LTA)-induced cell damage in embryonic rat heart cells (H9c2).. LTA-induced cell damage was established in H9c2, and the protective effects of TIM against the cell damage were examined at different concentrations (0.1-2.5 µM). The inflammatory response and oxidative stress in H9c2 cells were also measured.. Treatment with TIM (0.1-2.5 µM) significantly decreased LTA-induced toxicity in H9c2 cells, which was indicated by increase in cell viability, elevation in the mitochondrial membrane potential, decrease in the release of cytochrome-c and DNA damage, inhibition of caspase-3/9 activities, and change in apoptosis-related protein expression in LTA-treated H9c2 cells. TIM treatment also significantly attenuated the redox imbalance in H9c2 cells by decreasing malondialdehyde and intracellular reactive oxygen species levels as well as by enhancing superoxide dismutase activities and glutathione levels by increasing nuclear factor (erythroid-derived 2)-like 2 protein expression. Moreover, TIM treatment decreased interleukin 1 ß, interleukin 12, and tumor necrosis factor α levels by inhibiting nuclear factor kappa B protein expression.. Our data indicated that TIM protected H9c2 cells against LTA-induced toxicity, at least partially through inhibiting the inflammatory response and oxidative stress, providing scientific rational to develop TIM to treat infective endocarditis.

Topics: Animals; Antioxidants; Cardiotoxicity; Cell Line; Chromans; Disease Models, Animal; Endocarditis, Bacterial; Lipopolysaccharides; Myoblasts, Cardiac; Rats; Streptococcus; Teichoic Acids

Lipoteichoic acid (LTA)-induced acute lung injury (ALI) is an experimental model for mimicking Gram-positive bacteria-induced pneumonia that is a refractory disease with lack of effective medicines. Here, we reported that costunolide, a sesquiterpene lactone, ameliorated LTA-induced ALI. Costunolide treatment reduced LTA-induced neutrophil lung infiltration, cytokine and chemokine production (TNF-α, IL-6 and KC), and pulmonary edema. In response to LTA challenge, treatment with costunolide resulted less iNOS expression and produced less inflammatory cytokines in bone marrow derived macrophages (BMDMs). Pretreatment with costunolide also attenuated the LTA-induced the phosphorylation of p38 MAPK and ERK in BMDMs. Furthermore, costunolide treatment reduced the phosphorylation of TAK1 and inhibited the interaction of TAK1 with Tab1. In conclusion, we have demonstrated that costunolide protects against LTA-induced ALI via inhibiting TAK1-mediated MAPK signaling pathway, and our studies suggest that costunolide is a promising agent for treatment of Gram-positive bacteria-mediated pneumonia.

Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Chemical and Drug Induced Liver Injury; Cytokines; Disease Models, Animal; Extracellular Signal-Regulated MAP Kinases; Gram-Positive Bacteria; Humans; Inflammation Mediators; Lipopolysaccharides; Lung; Macrophages; Male; MAP Kinase Kinase Kinases; Mice; Mice, Inbred C57BL; Neutrophil Infiltration; Pneumonia, Bacterial; Pulmonary Edema; Sesquiterpenes; Signal Transduction; Teichoic Acids

(Aim) Bacterial infection underlies the pathogenesis of many human diseases, including acute and chronic inflammation. Here, we investigated a possible role for bacterial infection in the progression of chronic pancreatitis. (Materials and Methods) Pancreatic juice was obtained from patients with pancreatic cancer (n = 20) or duodenal cancer/bile duct cancer (n = 16) and subjected to PCR using universal primers for the bacterial 16S ribosomal RNA gene. Bacterial species were identified by PCR using bile samples from four pancreatic cancer patients. PCR products were subcloned into T-vectors, and the sequences were then analyzed. Immunohistochemical and serologic analyses for Enterococcus faecalis infection were performed on a large cohort of healthy volunteers and patients with chronic pancreatitis or pancreatic cancer and on mice with caerulein-induced chronic pancreatitis. The effect of E. faecalis antigens on cytokine secretion by pancreatic cancer cells was also investigated. (Results) We found that 29 of 36 pancreatic juice samples were positive for bacterial DNA. Enterococcus and Enterobacter species were detected primarily in bile, which is thought to be a pathway for bacterial infection of the pancreas. Enterococcus faecalis was also detected in pancreatic tissue from chronic pancreatitis and pancreatic cancer patients; antibodies to E. faecalis capsular polysaccharide were elevated in serum from chronic pancreatitis patients. Enterococcus-specific antibodies and pancreatic tissue-associated E. faecalis were detected in mice with caerulein-induced chronic pancreatitis. Addition of Enterococcus lipoteichoic acid and heat-killed bacteria induced expression of pro-fibrotic cytokines by pancreatic cancer cells in vitro. (Conclusion) Infection with E. faecalis may be involved in chronic pancreatitis progression, ultimately leading to development of pancreatic cancer.

Topics: Adenocarcinoma; Animals; Antibodies, Bacterial; Bacterial Infections; Disease Models, Animal; Enterococcus; Female; Gene Expression Regulation, Neoplastic; Hot Temperature; Humans; Interleukin-8; Lipopolysaccharides; Male; Middle Aged; Pancreatic Juice; Pancreatic Neoplasms; Pancreatitis, Chronic; RNA, Messenger; RNA, Ribosomal, 16S; Teichoic Acids; Vascular Endothelial Growth Factor A

Innate defense regulator (IDR) peptide-1002 is a synthetic host defense peptide derivative with strong anti-inflammatory properties. Extending previous data, IDR-1002 suppressed in vitro inflammatory responses in RAW 264.7 murine monocyte/macrophage cells challenged with the TLR4 agonist LPS and TLR2 agonists lipoteichoic acid and zymosan. To investigate the anti-inflammatory mechanisms of IDR-1002 in vivo, the PMA-induced mouse ear inflammation model was used. Topical IDR-1002 treatment successfully dampened PMA-induced ear edema, proinflammatory cytokine production, reactive oxygen and nitrogen species release, and neutrophil recruitment in the ears of CD1 mice. Advanced RNA transcriptomic analysis on the mouse ear transcriptome revealed that IDR-1002 reduced sterile inflammation by suppressing the expression of transmembrane G protein-coupled receptors (class A/1 rhodopsin-like), including receptors for chemokines, PGs, histamine, platelet activating factor, and anaphylatoxin. IDR-1002 also dampened the IFN-γ response and repressed the IFN regulatory factor 8-regulated network that controls central inflammatory pathways. This study demonstrates that IDR-1002 exhibits strong in vitro and in vivo anti-inflammatory activities, informs the underlying anti-inflammatory mechanisms, and reveals its potential as a novel therapeutic for inflammatory diseases.

Topics: Animals; Anti-Inflammatory Agents; Antimicrobial Cationic Peptides; Disease Models, Animal; Ear; Female; Humans; Immunity, Innate; Inflammation; Interferon-gamma; Lipopolysaccharides; Mice; Mice, Inbred Strains; RAW 264.7 Cells; Teichoic Acids; Tetradecanoylphorbol Acetate; Toll-Like Receptor 2; Toll-Like Receptor 4

Teichoic acid (TA), a crucial cell wall constituent of the pathobiont Streptococcus pneumoniae, is bound to peptidoglycan (wall teichoic acid, WTA) or to membrane glycolipids (lipoteichoic acid, LTA). Both TA polymers share a common precursor synthesis pathway, but differ in the final transfer of the TA chain to either peptidoglycan or a glycolipid. Here, we show that LTA exhibits a different linkage conformation compared to WTA, and identify TacL (previously known as RafX) as a putative lipoteichoic acid ligase required for LTA assembly. Pneumococcal mutants deficient in TacL lack LTA and show attenuated virulence in mouse models of acute pneumonia and systemic infections, although they grow normally in culture. Hence, LTA is important for S. pneumoniae to establish systemic infections, and TacL represents a potential target for antimicrobial drug development.

Topics: Animals; Cell Line; Cell Wall; Disease Models, Animal; Humans; Ligases; Lipopolysaccharides; Male; Mice; Microscopy, Electron; Mutagenesis; Peptidoglycan; Pneumonia, Pneumococcal; Sepsis; Streptococcus pneumoniae; Teichoic Acids; Virulence

We wished to examine the effects of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome on periapical periodontitis induced by Enterococcus faecalis and to investigate the molecular mechanisms of lipoteichoic acid (LTA) derived from E. faecalis on the expression of the NLRP3 inflammasome.. A model of periapical periodontitis by sealing E. faecalis into the pulp chambers of rats was established. We then examined the relationship between the expression, location, distribution, and concentration of NLRP3, caspase-1, and interleukin 1β with the inflammatory progression by immunohistochemistry and undertook correlation analyses. RAW264.7 cells were cultured in the absence or presence of LTA together with or without nuclear factor kappa B (NF-κB) inhibitor BAY 11-7082; NLRP3 inflammasome expression was measured by Western blotting, the enzyme-linked immunosorbent assay, and real-time quantitative polymerase chain reaction. An immunofluorescence study was conducted to further detect whether NF-κB can be completely inhibited by BAY 11-7082 or activated by LTA.. An animal model of periapical periodontitis was established successfully. Expression of NLRP3, caspase-1, and interleukin 1β protein was observed in the inflamed area. The expression of these 3 proteins had a significant positive correlation (P < .05). Overall, our results showed that, compared with the negative control group, LTA could directly activate expression of messenger RNA and protein of the NLRP3 inflammasome (P < .05), whereas BAY 11-7082 inhibited it (P < .05).. Our results suggested that LTA can act as a directly stimulating factor associated with expression of the NLRP3 inflammasome during periapical periodontitis, which is mainly linked with the NF-κB signaling activation pathway.

Topics: Animals; Disease Models, Animal; Disease Progression; Enterococcus faecalis; Immunohistochemistry; Inflammasomes; Lipopolysaccharides; Male; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Periapical Periodontitis; Phagocytes; Rats; Rats, Sprague-Dawley; Teichoic Acids

Kupffer cells (KCs), the vast pool of intravascular macrophages in the liver, help to clear blood-borne pathogens. The mechanisms by which KCs capture circulating pathogens remain unknown. Here we use intra-vital imaging of mice infected with Staphylococcus aureus to directly visualize the dynamic process of bacterial capture in the liver. Circulating S. aureus were captured by KCs in a manner dependent on the macrophage complement receptor CRIg, but the process was independent of complement. CRIg bound Staphylococcus aureus specifically through recognition of lipoteichoic acid (LTA), but not cell-wall-anchored surface proteins or peptidoglycan. Blocking the recognition between CRIg and LTA in vivo diminished the bacterial capture in liver and led to systemic bacterial dissemination. All tested Gram-positive, but not Gram-negative, bacteria bound CRIg in a complement-independent manner. These findings reveal a pattern recognition role for CRIg in the direct capture of circulating Gram-positive bacteria from the bloodstream.

Topics: Animals; Disease Models, Animal; Intravital Microscopy; Kupffer Cells; Lipopolysaccharides; Liver; Macrophages; Mice; Protein Binding; Receptors, Complement; Receptors, Pattern Recognition; Staphylococcal Infections; Staphylococcus aureus; Teichoic Acids

The Acute Respiratory Distress Syndrome (ARDS), remains a significant source of morbidity and mortality in critically ill patients. Pneumonia and sepsis are leading causes of ARDS, the pathophysiology of which includes increased pulmonary microvascular permeability and hemodynamic instability resulting in organ dysfunction. We hypothesized that N-ethylmaleimide sensitive factor (NSF) regulates exocytosis of inflammatory mediators, such as Angiopoietin-2 (Ang-2), and cytoskeletal stability by modulating myosin light chain (MLC) phosphorylation. Therefore, we challenged pulmonary cells, in vivo and in vitro, with Gram Positive bacterial cell wall components, lipoteichoic acid (LTA), and peptidoglycan (PGN) and examined the effects of NSF inhibition.. Mice were pre-treated with an inhibitor of NSF, TAT-NSF700 (to prevent Ang-2 release). After 30min, LTA and PGN (or saline alone) were instilled intratracheally. Pulse oximetry was assessed in awake mice prior to, and 6 hour post instillation. Post mortem, tissues were collected for studies of inflammation and Ang-2. In vitro, pulmonary endothelial cells were assessed for their responses to LTA and PGN.. Pulmonary challenge induced signs of airspace and systemic inflammation such as changes in neutrophil counts and protein concentration in bronchoalveolar lavage fluid and tissue Ang-2 concentration, and decreased physiological parameters including oxygen saturation and pulse distention. TAT-NSF700 pre-treatment reduced LTA-PGN induced changes in lung tissue Ang-2, oxygen saturation and pulse distention. In vitro, LTA-PGN induced a rapid (<2 min) release of Ang-2, which was significantly attenuated by TAT-NSF700 or anti TLR2 antibody. Furthermore, TAT-NSF700 reduced LTA-PGN-induced MLC phosphorylation at low concentrations of 1-10 nM.. TAT-NSF700 decreased Ang-2 release, improved oxygen saturation and pulse distention following pulmonary challenge by inhibiting MLC phosphorylation, an important component of endothelial cell retraction. The data suggest that inhibition of NSF in pneumonia and sepsis may be beneficial to prevent the pulmonary microvascular and hemodynamic instability associated with ARDS.

Topics: Angiopoietin-1; Animals; Bacterial Infections; Blood Vessels; Cell Line; Cell Wall; Cytoskeleton; Disease Models, Animal; Exocytosis; Gram-Positive Bacteria; Humans; Inflammation; Lipopolysaccharides; Lung; Male; Mice; Mice, Inbred BALB C; Microcirculation; N-Ethylmaleimide-Sensitive Proteins; Oxygen; Peptidoglycan; Phosphorylation; Pneumonia; Respiratory Distress Syndrome; Sepsis; Teichoic Acids; Vascular Diseases

Hypernomic secretion of epithelial cytokines has several effects on stromal cells. The contributions of inflammatory epithelial cells to stromal fibroblasts in bovine mammary glands with mastitis remain poorly understood. Here, we established an inflammatory epithelial cell model of bovine mastitis with gram-negative lipopolysaccharide (LPS) and gram-positive lipoteichoic acid (LTA) bacterial cell wall components. We characterized immune responses of mammary stromal fibroblasts induced by inflammatory epithelial cells. Our results showed that inflammatory epithelial cells affected stromal fibroblast characteristics by increasing inflammatory mediator expression, elevating extracellular matrix protein deposition, decreasing proliferation capacity, and enhancing migration ability. The changes in stromal fibroblast proliferation and migration abilities were mediated by signal molecules, such as WNT signal pathway components. LPS- and LTA-induced inflammatory epithelial cells triggered different immune responses in stromal fibroblasts. Thus, in mastitis, bovine mammary gland stromal fibroblasts were affected by inflammatory epithelial cells and displayed inflammation-specific changes, suggesting that fibroblasts play crucial roles in bovine mastitis.

Topics: Animals; Cattle; Cell Movement; Cell Proliferation; Coculture Techniques; Disease Models, Animal; Epithelial Cells; Extracellular Matrix Proteins; Female; Fibroblasts; Inflammation; Inflammation Mediators; Lipopolysaccharides; Mastitis, Bovine; RNA, Messenger; Stromal Cells; Teichoic Acids; Tumor Necrosis Factor-alpha

Pneumococcal asymptomatic colonization of the respiratory tracts is a major risk for invasive pneumococcal disease. We have previously shown that pneumococcal wall teichoic acid (WTA) was involved in pneumococcal infection of sepsis and adherence to epithelial and endothelial cells. In this study, we investigated the contribution of pneumococcal WTA to bacterial colonization and dissemination in murine models. The result showed that nasopharynx colonizing D39 bacterial cells have a distinct phenotype showing an increased exposure of teichoic acids relative to medium-grown bacteria. The WTA-deficient mutants were impaired in their colonization to the nasopharynx and lungs, and led to a mild inflammation in the lungs at 36 h post-inoculation. Pretreatment of the murine nares with WTA reduced the ability of wild type D39 bacteria to colonize the nasopharynx. In addition, the WTA-deficient strain was impaired in its ability to invade the blood and brain following intranasal administration. WTA-deficient D39 strain was reduced in C3 deposition but was more susceptible to the killing by the neutrophils as compared with its parent strain. Our results also demonstrated that the WTA enhanced pneumococcal colonization and dissemination independently of the host strains. These results indicate that WTA plays an important role in pneumococcal pathogenesis, both in colonization and dissemination processes.

Topics: Animals; Bacterial Proteins; Complement C3; Disease Models, Animal; Female; Flow Cytometry; Lipopolysaccharides; Lung; Mice; Mice, Inbred BALB C; Mutation; Nasopharynx; Phenotype; Pneumococcal Infections; Streptococcus pneumoniae; Teichoic Acids; Virulence

Acute lung injury (ALI) is a significant source of morbidity and mortality in critically ill patients. Age is a major determinant of clinical outcome in ALI. The increased ALI-associated mortality in the older population suggests that there are age-dependent alterations in the responses to pulmonary challenge. The objective of this observational study was to evaluate age-dependent differences in the acute (within 6 hours) immunological and physiological responses of the heart and lung, to pulmonary challenge, that could result in increased severity.. Male C57Bl/6 mice (young: 2-3 months, old: 18-20 months) were challenged intratracheally with cell wall components from Gram-positive bacteria (lipoteichoic acid and peptidoglycan). After 6 hours, both biochemical and physiological consequences of the challenge were assessed. Alveolar infiltration of inflammatory cells and protein, airspace and blood cytokines, cardiac function and myocardial proteasome activity were determined.. In young mice, there was a dose-dependent response to pulmonary challenge resulting in increased airspace neutrophil counts, lung permeability, and concentrations of cytokines in bronchoalveolar lavage fluid and plasma. A midrange dose was then selected to compare the responses in young and old animals. In comparison, the old animals displayed increased neutrophil accumulation in the airspaces, decreased arterial oxygen saturation, body temperatures, plasma cytokine concentrations, and a lack of myocardial proteasome response, following challenge.. Age-dependent differences in the onset of systemic response and in maintenance of vital functions, including temperature control, oxygen saturation, and myocardial proteasome activation, are evident. We believe a better understanding of these age-related consequences of ALI can lead to more appropriate treatments in the elderly patient population.

Topics: Acute Lung Injury; Age Factors; Aging; Animals; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Hemodynamics; Inflammation Mediators; Lipopolysaccharides; Lung; Male; Mice, Inbred C57BL; Myocardium; Neutrophil Infiltration; Peptidoglycan; Pneumonia; Proteasome Endopeptidase Complex; Risk Factors; Severity of Illness Index; Teichoic Acids; Time Factors

Nerve injury-induced protein (Ninjurin [Ninj]) 1 is an adhesion molecule originally identified in Schwann cells after nerve injury, whereas it is also expressed in leukocytes, epithelium, endothelium, and various organs, and is induced under inflammatory conditions. Its contribution to inflammation was so far restricted to the nervous system and exclusively attributed to its role during leukocyte migration. We hypothesized a proinflammatory role for Ninj1 also outside the nervous system. To elucidate its impact during inflammation, we analyzed expression levels and its contribution to inflammation in septic mice and studied its effect on inflammatory signaling in vitro. The effect on inflammation was analyzed by genetic (only in vitro) and pharmacologic repression in septic mice (cecal ligation and puncture) and cell culture, respectively. Repression of Ninj1 by an inhibitory peptide or small interfering RNA attenuated LPS-triggered inflammation in macrophages and endothelial cells by modulating p38 phosphorylation and activator protein-1 activation. Inhibition of Ninj1 in septic mice reduced systemic and pulmonary inflammation as well as organ damage, and ameliorated survival after 24 hours. Ninj1 is elevated under inflammatory conditions and contributes to inflammation not only by mediating leukocyte migration, but also by modulating Toll-like receptor 4-dependent expression of inflammatory mediators. We assume that, owing to both mechanisms, inhibition reduces systemic inflammation and organ damage in septic mice. Our data contribute to a better understanding of the complex inflammatory mechanisms and add a novel therapeutic target for inflammatory conditions such as sepsis.

Topics: Animals; Cell Adhesion Molecules, Neuronal; Cell Movement; Disease Models, Animal; Endothelial Cells; Gene Expression Regulation; Humans; Leukocytes, Mononuclear; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Nerve Growth Factors; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Poly I-C; Primary Cell Culture; Sepsis; Signal Transduction; Systemic Inflammatory Response Syndrome; Teichoic Acids; Toll-Like Receptor 4; Transcription Factor AP-1; Tumor Necrosis Factor-alpha

Few drugs have been found satisfactory in the treatment of nonsteroidal anti-inflammatory drugs (NSAIDs)-induced enteropathy. Toll-like receptor (TLR) 4 and aberrant leukocyte migration to the intestinal mucosa are reported to be involved in the pathology of intestinal enteropathy and TLR2 agonists have been found to evoke hyposensitivity to TLR4 stimulation in vitro. In this study, we investigated whether and how lipoarabinomannan (LAM) or lipoteichoic acid (LTA), TLR2 agonists, attenuated indomethacin (IND)-induced intestinal damage.. LAM (0.5 mg/kg) or LTA (15 mg/kg) was administered intraperitoneally to mice before IND (10 mg/kg) administration. Disease activity was evaluated macroscopically and histologically. In the migration analysis, fluorescence-labeled leukocyte movement in the intestinal microvessels was observed by intravital microscopy. Expression of P-selectin, MAdCAM-1, TLR2, TLR4, and F4/80 was observed immunohistochemically. In the in vitro analysis, RAW264.7 macrophage cells were preincubated with LAM and stimulated with lipopolysaccharide (LPS), and the mRNA expression levels of TLR4, tumor necrosis factor-α, and interleukin-12p40 were measured.. Pretreatment with LAM or LTA significantly decreased IND-induced injury as well as decreased leukocyte infiltration. Pretreatment with LAM decreased IND-induced TLR4 expression on F4/80(+) macrophages, the level of P-selectin expression, and leukocyte migration in the small intestinal vessels. In the in vitro study, a single administration of LAM decreased TLR4 mRNA expression and inhibited the increase in mRNA expression of inflammatory cytokines by LPS in a dose-dependent manner.. TLR2 agonists attenuated IND-induced small intestinal lesions and leukocyte infiltration probably by suppressing the TLR4 signaling pathway in tissue macrophages.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Migration Assays, Leukocyte; Cell Movement; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression; Ileitis; Indomethacin; Inflammation Mediators; Injections, Intraperitoneal; Leukocytes; Lipopolysaccharides; Mice; RAW 264.7 Cells; RNA, Messenger; Signal Transduction; Teichoic Acids; Toll-Like Receptor 2; Toll-Like Receptor 4

The incidence of multidrug-resistant Enterococcus faecium hospital infections has been steadily increasing. With the goal of discovering new vaccine antigens, we systematically fractionated and purified four distinct surface carbohydrates from E. faecium endocarditis isolate Tx16, shown previously to be resistant to phagocytosis in the presence of human serum. The two most abundant polysaccharides consist of novel branched heteroglycan repeating units that include signature sugars altruronic acid and legionaminic acid, respectively. A minor high molecular weight polysaccharide component was recognized as the fructose homopolymer levan, and a glucosylated lipoteichoic acid (LTA) was identified in a micellar fraction. The polysaccharides were conjugated to the CRM197 carrier protein, and the resulting glycoconjugates were used to immunize rabbits. Rabbit immune sera were evaluated for their ability to kill Tx16 in opsonophagocytic assays and in a mouse passive protection infection model. Although antibodies raised against levan failed to mediate opsonophagocytic killing, the other glycoconjugates induced effective opsonic antibodies, with the altruronic acid-containing polysaccharide antisera showing the greatest opsonophagocytic assay activity. Antibodies directed against either novel heteroglycan or the LTA reduced bacterial load in mouse liver or kidney tissue. To assess antigen prevalence, we screened a diverse collection of blood isolates (n = 101) with antibodies to the polysaccharides. LTA was detected on the surface of 80% of the strains, and antigens recognized by antibodies to the two major heteroglycans were co-expressed on 63% of these clinical isolates. Collectively, these results represent the first steps toward identifying components of a glycoconjugate vaccine to prevent E. faecium infection.

Topics: Animals; Anti-Bacterial Agents; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Load; Bacterial Proteins; Bacterial Vaccines; Carbohydrate Sequence; Disease Models, Animal; Drug Resistance, Multiple, Bacterial; Enterococcus faecium; Female; Fructans; Gram-Positive Bacterial Infections; Humans; Immune Sera; Lipopolysaccharides; Mice; Molecular Sequence Data; Opsonin Proteins; Rabbits; Sialic Acids; Teichoic Acids; Uronic Acids; Vaccines, Conjugate

The cutaneous inflammation associated with acne vulgaris is caused by the anaerobic bacterium Propionibacterium acnes through activation of the innate immune system in the skin. Current standard treatments for acne have limitations that include adverse effects and poor efficacy in many patients, making development of a more effective therapy highly desirable. In the present study, we demonstrate the protective effects of a novel customized α-helical cationic peptide, P5, against P. acnes-induced inflammatory responses in vitro and in vivo. Application of P5 significantly reduced expression of two inflammatory cytokines IL-8 and TNF-α in P. acnes-treated primary human keratinocytes, where P5 appeared to act in part by binding to bacterial lipoteichoic acid, thereby suppressing TLR2-to-NF-κB signaling. In addition, in a mouse model of acne vulgaris, P5 exerted both anti-inflammatory and antimicrobial effects against P. acnes, but exerted no cytotoxic effects against skin cells. These results demonstrate that P5, and perhaps other cationic antimicrobial peptides, offer the unique ability to reduce numbers P. acnes cells in the skin and to inhibit the inflammation they trigger. This suggests these peptides could potentially be used to effectively treat acne without adversely affecting the skin.

Topics: Acne Vulgaris; Animals; Anti-Inflammatory Agents; Antimicrobial Cationic Peptides; Cells, Cultured; Disease Models, Animal; Gene Expression Regulation; Gram-Positive Bacterial Infections; Humans; Interleukin-8; Keratinocytes; Lipopolysaccharides; Mice; Propionibacterium acnes; Signal Transduction; Teichoic Acids; Tumor Necrosis Factor-alpha

Sepsis, a life-threatening syndrome with increasing incidence worldwide, is triggered by an overwhelming inflammation induced by microbial toxins released into the bloodstream during infection. A well-known sepsis-inducing factor is the membrane constituent of Gram-negative bacteria, lipopolysaccharide (LPS), signalling via Toll-like receptor-4. Although sepsis is caused in more than 50% cases by Gram-positive and mycoplasma cells, the causative compounds are still poorly described. In contradicting investigations lipoproteins/-peptides (LP), lipoteichoic acids (LTA), and peptidoglycans (PGN), were made responsible for eliciting this pathology. Here, we used human mononuclear cells from healthy donors to determine the cytokine-inducing activity of various LPs from different bacterial origin, synthetic and natural, and compared their activity with that of natural LTA and PGN. We demonstrate that LP are the most potent non-LPS pro-inflammatory toxins of the bacterial cell walls, signalling via Toll-like receptor-2, not only in vitro, but also when inoculated into mice: A synthetic LP caused sepsis-related pathological symptoms in a dose-response manner. Additionally, these mice produced pro-inflammatory cytokines characteristic of a septic reaction. Importantly, the recently designed polypeptide Aspidasept(®) which has been proven to efficiently neutralize LPS in vivo, inhibited cytokines induced by the various non-LPS compounds protecting animals from the pro-inflammatory activity of synthetic LP.

Topics: Animals; Anti-Bacterial Agents; Cytokines; Disease Models, Animal; Endotoxemia; Endotoxins; Female; Gram-Negative Bacteria; HEK293 Cells; Humans; Leukocytes, Mononuclear; Lipopolysaccharides; Lipoproteins; Macrophages; Mice; Peptides; Peptidoglycan; Sepsis; Staphylococcus aureus; Teichoic Acids

The current epidemic of infections caused by antibiotic-resistant gram-positive bacteria requires the discovery of new drug targets and the development of new therapeutics. Lipoteichoic acid (LTA), a cell wall polymer of gram-positive bacteria, consists of 1,3-polyglycerol-phosphate linked to glycolipid. LTA synthase (LtaS) polymerizes polyglycerol-phosphate from phosphatidylglycerol, a reaction that is essential for the growth of gram-positive bacteria. We screened small molecule libraries for compounds inhibiting growth of Staphylococcus aureus but not of gram-negative bacteria. Compound 1771 [2-oxo-2-(5-phenyl-1,3,4-oxadiazol-2-ylamino)ethyl 2-naphtho[2,1-b]furan-1-ylacetate] blocked phosphatidylglycerol binding to LtaS and inhibited LTA synthesis in S. aureus and in Escherichia coli expressing ltaS. Compound 1771 inhibited the growth of antibiotic-resistant gram-positive bacteria and prolonged the survival of mice with lethal S. aureus challenge, validating LtaS as a target for the development of antibiotics.

Topics: Acyltransferases; Animals; Anti-Bacterial Agents; Catalytic Domain; Disease Models, Animal; Drug Resistance, Microbial; Enzyme Inhibitors; Lipopolysaccharides; Mice; Microbial Sensitivity Tests; Mutation; Phosphatidylglycerols; Sepsis; Small Molecule Libraries; Staphylococcal Infections; Staphylococcus aureus; Structure-Activity Relationship; Survival Analysis; Teichoic Acids

Type 1 lipoteichoic acid (LTA) is present in many clinically important gram-positive bacteria, including enterococci, streptococci, and staphylococci, and antibodies against LTA have been shown to opsonize nonencapsulated Enterococcus faecalis strains. In the present study, we show that antibodies against E. faecalis LTA also bind to type 1 LTA from other gram-positive species and opsonized Staphylocccus epidermidis and Staphylcoccus aureus strains as well as group B streptococci. Inhibition studies using teichoic acid oligomers indicated that cross-reactive opsonic antibodies bind to the teichoic acid backbone. Passive immunization with rabbit antibodies against E. faecalis LTA promoted the clearance of bacteremia by E. faecalis and S. epidermidis in mice. Furthermore, passive protection also reduced mortality in a murine S. aureus peritonitis model. The effectiveness of rabbit antibody against LTA suggests that this conserved bacterial structure could function as a single vaccine antigen that targets multiple gram-positive pathogens.

Topics: Adult; Animals; Antibodies, Bacterial; Antigens, Bacterial; Bacteremia; Disease Models, Animal; Enterococcus faecalis; Female; Glycerophosphates; Human Experimentation; Humans; Immunization, Passive; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Opsonin Proteins; Peritonitis; Phagocytosis; Rabbits; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus epidermidis; Streptococcus agalactiae; Survival Analysis; Teichoic Acids

Neuronal injury in pneumococcal meningitis is a consequence of microglial activation and direct toxicity by bacterial products and systemic inflammation.. The treatment effect of the TEPC-15 antibody recognizing teichoic and lipoteichoic acids was investigated in murine microglial cells and in a rabbit model of pneumococcal meningitis.. In vitro, the TEPC-15 antibody recognizing teichoic and lipoteichoic acids increased Streptococcus pneumoniae phagocytosis by murine microglial cells. In rabbit ceftriaxone-treated S. pneumoniae meningitis, intracisternal TEPC-15 reduced the density of apoptotic neurons in the hippocampal dentate gyrus (116 ± 70 vs. 221 ± 132/mm(2); p = 0.03). Cerebrospinal fluid inflammatory parameters (protein, lactate, leukocytes, prostaglandins) were not reduced in TEPC-15-treated rabbits.. Intracisternal treatment with the TEPC-15 antibody reduced neuronal damage probably by promoting rapid phagocytosis of bacterial products.

Topics: Animals; Anti-Bacterial Agents; Antibodies, Monoclonal; Ceftriaxone; Cells, Cultured; Dentate Gyrus; Disease Models, Animal; Lactic Acid; Leukocytes; Lipopolysaccharides; Meningitis, Pneumococcal; Mice; Mice, Inbred C57BL; Microglia; Phagocytosis; Prostaglandins; Proteins; Rabbits; Streptococcus pneumoniae; Teichoic Acids

A group of synthetic antimicrobial oligomers, inspired by naturally occurring antimicrobial peptides, were analyzed for the ability to modulate innate immune responses to Toll-like receptor (TLR) ligands. These synthetic mimics of antimicrobial peptides (SMAMPs) specifically reduced cytokine production in response to Staphylococcus aureus and the S. aureus component lipoteichoic acid (LTA), a TLR2 agonist. Anti-inflammatory SMAMPs prevented the induction of tumor necrosis factor (TNF), interleukin 6 (IL-6), and IL-10 in response to S. aureus or LTA, but no other TLR2 ligands. We show that these SMAMPs bind specifically to LTA in vitro and prevent its interaction with TLR2. Importantly, the SMAMP greatly reduced the induction of TNF and IL-6 in vivo in mice acutely infected with S. aureus while simultaneously reducing bacterial loads dramatically (4 log(10)). Thus, these SMAMPs can eliminate the damage induced by pathogen-associated molecular patterns (PAMPs) while simultaneously eliminating infection in vivo. They are the first known SMAMPs to demonstrate anti-inflammatory and antibacterial activities in vivo.

Topics: Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Bacterial Load; Cytokines; Disease Models, Animal; Lipopolysaccharides; Mice; Mice, Inbred C57BL; Peptides; Protein Binding; Staphylococcal Infections; Staphylococcus aureus; Teichoic Acids; Toll-Like Receptor 2

In a typing system based on opsonic antibodies against carbohydrate antigens of the cell envelope, 60% of Enterococcus faecalis strains can be assigned to one of four serotypes (CPS-A to CPS-D). The structural basis for enterococcal serotypes, however, is still incompletely understood. Here we demonstrate that antibodies raised against lipoteichoic acid (LTA) from a CPS-A strain are opsonic to both CPS-A and CPS-B strains. LTA-specific antibodies also bind to LTA of CPS-C and CPS-D strains, but fail to opsonize them. From CPS-C and CPS-D strains resistant to opsonization by anti-LTA, we purified a novel diheteroglycan with a repeating unit of →6)-β-Galf-(1→3)- β-D-Glcp-(1→ with O-acetylation in position 5 and lactic acid substitution at position 3 of the Galf residue. The purified diheteroglycan, but not LTA absorbed opsonic antibodies from whole cell antiserum against E. faecalis type 2 (a CPS-C strain) and type 5 (CPS-D). Rabbit antiserum raised against purified diheteroglycan opsonized CPS-C and CPS-D strains and passive protection with diheteroglycan-specific antiserum reduced bacterial counts by 1.4-3.4 logs in mice infected with E. faecalis strains of the CPS-C and CPS-D serotype. Diheteroglycan-specific opsonic antibodies were absorbed by whole bacterial cells of E. faecalis FA2-2 (CPS-C) but not by its isogenic acapsular cpsI-mutant and on native PAGE purified diheteroglycan co-migrated with the gene product of the cps-locus, suggesting that it is synthesized by this locus. In summary, two polysaccharide antigens, LTA and a novel diheteroglycan, are targets of opsonic antibodies against typeable E. faecalis strains. These cell-wall associated polymers are promising candidates for active and passive vaccination and add to our armamentarium to fight this important nosocomial pathogen.

Topics: Animals; Antibodies, Bacterial; Antibody Specificity; Antigens, Bacterial; Bacteremia; Bacterial Capsules; Cell Wall; Cross Reactions; Disease Models, Animal; Enterococcus faecalis; Genetic Loci; Lipopolysaccharides; Magnetic Resonance Spectroscopy; Mice; Opsonin Proteins; Phagocytosis; Polysaccharides; Rabbits; Structural Homology, Protein; Teichoic Acids; Vaccination

Peptidoglycan recognition proteins (PGRPs) are involved in the recognition of pathogen-associated molecular patterns. The well known pathogen-associated molecular patterns include LPS from Gram-negative bacteria and lipoteichoic acid (LTA) from Gram-positive bacteria. In this work, the crystal structures of two complexes of the short form of camel PGRP (CPGRP-S) with LPS and LTA determined at 1.7- and 2.1-Å resolutions, respectively, are reported. Both compounds were held firmly inside the complex formed with four CPGRP-S molecules designated A, B, C, and D. The binding cleft is located at the interface of molecules C and D, which is extendable to the interface of molecules A and C. The interface of molecules A and B is tightly packed, whereas that of molecules B and D forms a wide channel. The hydrophilic moieties of these compounds occupy a common region, whereas hydrophobic chains interact with distinct regions in the binding site. The binding studies showed that CPGRP-S binds to LPS and LTA with affinities of 1.6 × 10(-9) and 2.4 × 10(-8) M, respectively. The flow cytometric studies showed that both LPS- and LTA-induced expression of the proinflammatory cytokines TNF-α and IL-6 was inhibited by CPGRP-S. The results of animal studies using mouse models indicated that both LPS- and LTA-induced mortality rates decreased drastically when CPGRP-S was administered. The recognition of both LPS and LTA, their high binding affinities for CPGRP-S, the significant decrease in the production of LPS- and LTA-induced TNF-α and IL-6, and the drastic reduction in the mortality rates in mice by CPGRP-S indicate its useful properties as an antibiotic agent.

Topics: Adult; Animals; Anti-Bacterial Agents; Binding Sites; Camelus; Carrier Proteins; Crystallography, X-Ray; Disease Models, Animal; Female; Humans; Hydrophobic and Hydrophilic Interactions; Inflammation; Interleukin-6; Lipopolysaccharides; Male; Mice; Protein Structure, Tertiary; Teichoic Acids; Tumor Necrosis Factor-alpha

Mastitic milk is associated with increased bovine protease activity, such as that from plasmin and somatic cell enzymes, which cause proteolysis of the caseins and may reduce cheese yield and quality. The aim of this work was to characterize the peptide profile resulting from proteolysis in a model mastitis system and to identify the proteases responsible. One quarter of each of 2 cows (A and B) was infused with lipoteichoic acid from Staphylococcus aureus. The somatic cell counts of the infused quarters reached a peak 6h after infusion, whereas plasmin activity of those quarters also increased, reaching a peak after 48 and 12h for cow A and B, respectively. Urea-polyacrylamide gel electrophoretograms of milk samples of cow A and B obtained at different time points after infusion and incubated for up to 7 d showed almost full hydrolysis of β- and α(S1)-casein during incubation of milk samples at peak somatic cell counts, with that of β-casein being faster than that of α(S1)-casein. Two-dimensional gel electrophoretograms of milk 6h after infusion with the toxin confirmed hydrolysis of β- and α(S1)-casein and the appearance of lower-molecular-weight products. Peptides were subsequently separated by reversed-phase HPLC and handmade nanoscale C(18) columns, and identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. Twenty different peptides were identified and shown to originate from α(s1)- and β-casein. Plasmin, cathepsin B and D, elastase, and amino- and carboxypeptidases were suggested as possible responsible proteases based on the peptide cleavage sites. The presumptive activity of amino- and carboxypeptidases is surprising and may indicate the activity of cathepsin H, which has not been reported in milk previously.

Topics: Animals; Cattle; Disease Models, Animal; Female; Lipopolysaccharides; Mastitis, Bovine; Milk; Milk Proteins; Peptide Hydrolases; Peptides; Proteomics; Staphylococcus aureus; Teichoic Acids

Preconditioning with bacterial wall fragments lipopolysaccharide (LPS) or lipoteichoic acid (LTA) reduce myocardial infarct size after ischaemia and reperfusion (I/R) in rats. Preconditioning with LTA reduces neutrophil accumulation during reperfusion and thereby ameliorates one of myocardial reperfusion injury's most important mechanisms. In this study, we use an ex vivo model of regional myocardial I/R to investigate LTA versus LPS induced preconditioning in a system devoid of leukocytes.. Rats were subjected to LTA or LPS with or without dexamethasone pre-treatment. Twenty-four hours after LTA or LPS challenge, hearts were removed and retrogradely perfused in a Langendorff set-up. Hearts underwent 20 min of regional ischaemia followed by 2 h of reperfusion. Ischaemic preconditioning (IPC) was performed as a positive control. Myocardial infarct size was determined as the primary end-point.. LTA and LPS preconditioning both lead to a marked reduction in infarct size similar to IPC, however, no significant differences were found between LTA and LPS. The reduction in infarct size was abrogated by dexamethasone pre-treatment.. We conclude that preconditioning with LTA and likewise with LPS confers myocardial protection in an ex vivo setting devoid of leukocytes. Dexamethasone inhibits preconditioning, suggesting that the underlying mechanism is dependent upon induction of a systemic inflammatory response to a LTA or LPS stimulus.

Topics: Animals; Anti-Inflammatory Agents; Dexamethasone; Disease Models, Animal; Endotoxins; Ischemic Preconditioning, Myocardial; Lipopolysaccharides; Male; Myocardial Infarction; Neutrophils; Rats; Rats, Wistar; Systemic Inflammatory Response Syndrome; Teichoic Acids

In severe acute pancreatitis (SAP), immunologic impairment in the early phase may be linked to subsequent infectious complications that are main contributor to the high mortality. Toll-like receptors (TLRs) recognize microorganisms as the innate immune system, and are involved in host defense mechanism. TLR2 recognizes lipoteichoic acid (LTA) of gram-positive bacteria, and TLR4 recognizes lipopolysaccharide (LPS) of gram-negative bacilli. This study aimed to investigate the expression of TLRs on macrophages and their TLRs-mediated cytokine production in rat SAP. SAP was induced by retrograde injection of 3% sodium deoxycholate into the biliopancreatic duct in male Wistar rats. Macrophages were isolated from bronchoalveolar lavage fluid 6 hours after induction of SAP. The expression of TLR2 and TLR4 was analyzed by real-time RT-PCR and western blotting. TNF-alpha release from macrophages was estimated after 4-hour stimulation of LTA or LPS. Endotoxin/bacterial translocation (E/BT) was also evaluated in this model. The expression of TLR2 (mRNA and protein) and LTA-mediated TNF-alpha production were significantly decreased in SAP compared with control. The expression of TLR4 (mRNA and protein) and LPS-mediated TNF-alpha production was also significantly decreased in SAP compared with control. E/BT occurred 18 hours after induction of SAP. These results suggest that the impaired responsiveness to LTA and LPS of macrophages is derived from decreased expression of TLR2 and TLR4, respectively. This suppression of immune response in the early phase may be implicated in the mechanism of infectious complications.

Topics: Acute Disease; Animals; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Down-Regulation; Lipopolysaccharides; Macrophages, Alveolar; Male; Pancreatitis; Protein Transport; Rats; Rats, Wistar; RNA, Messenger; Teichoic Acids; Toll-Like Receptor 2; Toll-Like Receptor 4

New peptides for lipopolysaccharide (LPS) and lipoteichoic acid (LTA) neutralization in upper respiratory tract infections were developed and evaluated in terms of efficacy and safety for application in humans. Based on the sequence of the human antimicrobial peptide LL-37 we developed and investigated length variants, substitution analogues and modifications to stabilize the peptides to prevent enzymatic degradation and to improve efficacy. The most promising peptide appears P60.4, a 24 amino acid peptide with similar efficacy as LL-37 in terms of LPS and LTA neutralization and lower pro-inflammatory activity. In addition, the acetylated and amidated version of this peptide shows no toxicity and displays higher or equal antimicrobial activity compared to LL-37.

Topics: Amino Acid Sequence; Animals; Anti-Infective Agents; Antimicrobial Cationic Peptides; Cathelicidins; Disease Models, Animal; Guinea Pigs; Lipopolysaccharides; Male; Microbial Sensitivity Tests; Molecular Sequence Data; Peptides; T-Lymphocytes; Teichoic Acids

A mouse model of staphylococcal sepsis was used to evaluate the efficacy of RNAIII-inhibiting peptide (RIP) combined with the cathelicidin BMAP-28. Preliminary in vitro studies showed that both peptides, alone or combined, were able to inhibit the lipoteichoic acid-induced production of tumor necrosis factor alpha and nitric oxide by RAW 264.7 cells. For in vivo experiments, the main outcome measures were lethality, quantitative blood cultures, and detection of tumor necrosis factor alpha and interleukin 6 plasma levels. BALB/c mice were injected i.v. with 2.0 x 10(6) colony-forming units of live Staphylococcus aureus ATCC 25923 or with 5.0 x 10(8) heat-killed cells of the same strain. All animals were randomized to receive i.v. isotonic sodium chloride solution, 10-mg/kg RIP, alone or in combination with 2-mg/kg BMAP-28, 7-mg/kg imipenem, or 7-mg/kg vancomycin, immediately and at 6 hours after bacterial challenge. In in vivo experiments performed with live bacteria, all compounds reduced lethality rates and bacteremia when compared with controls. In general, combined-treated groups had significantly lower bacteremia when compared with single-treated groups. Lowest lethality rates and bacteremia were obtained when RIP was administered in combination with BMAP-28 or vancomycin. In the experiments performed using heat-killed organisms, only BMAP-28 demonstrated significant efficacy on lethality rates and cytokines plasma levels when compared with controls. RIP combined with BMAP-28 exhibited the highest efficacy on all main outcome measurements. These data were observed on both immediate and delayed treatments. These results highlight the capacity of RIP and BMAP-28 to reduce the septic effects of bacterial cell components and exotoxins, and suggest their potential use in the treatment of severe staphylococcus-associated sepsis.

Topics: Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Cell Line, Tumor; Disease Models, Animal; Drug Therapy, Combination; Interleukin-6; Lipopolysaccharides; Macrophages; Male; Mice; Mice, Inbred BALB C; Nitric Oxide; Oligopeptides; Proteins; Staphylococcal Infections; Staphylococcus aureus; Survival Analysis; Teichoic Acids; Tumor Necrosis Factor-alpha

Based on a wealth of in vitro macrophage studies, immunity to Staphylococcus aureus cell wall-derived peptidoglycan (PGN) and lipoteichoic acid has been attributed to TLR2. We investigated whether the in vitro paradigm of TLR2 dominance would hold true in vivo. Using an experimental peritonitis model, we challenged mice with PGN or lipoteichoic acid and found that only PGN resulted in significant leukocyte (primarily neutrophil) accumulation in the peritoneum at 4 h. PGN-mediated leukocyte recruitment was P-/E-selectin dependent but only partially TLR2 dependent, and also involved the C5aR. Concomitant inhibition of TLR2 and C5aR resulted in a further reduction in PGN-induced peritonitis. Peritoneal neutrophilia was partially mast cell dependent; however, the defect could not be reconstituted with TLR2(-/-) or C5aR(-/-) mast cells. Interestingly, macrophage-deficient mice did not have defective neutrophil recruitment. By 24 h, the response to PGN involved primarily monocytes and was TLR2 and C5aR independent. Finally, we challenged mice with live S. aureus and found a similar degree of TLR2 involvement in leukocyte recruitment to that observed with PGN. Most importantly, bacterial clearance from the spleen and peritoneum was not altered in TLR2(-/-) mice vs wild-type mice. Morbidity was only significantly increased in S. aureus-infected mice treated with a blocking Fab against C5aR. Taken together, these studies indicate that in vivo responses to prototypic TLR2 ligands do not necessarily recapitulate the absolute necessity for TLR2 observed in vitro, and additional receptors contribute, in a significant manner, to PGN and S. aureus-mediated immune responses.

Topics: Animals; Antigens, Bacterial; Chemotaxis, Leukocyte; Complement C5a; Disease Models, Animal; E-Selectin; Ligands; Lipopolysaccharides; Macrophages; Mast Cells; Mice; P-Selectin; Peptidoglycan; Peritonitis; Staphylococcal Infections; Staphylococcus aureus; Teichoic Acids; Toll-Like Receptor 2; Toll-Like Receptor 4

Lipoteichoic acid (LTA) represents a major virulence factor in gram-positive sepsis.. In the present study we perfused isolated rat hearts for 180 minutes with highly purified LTA from Staphylococcus aureus. A progressive decline of left ventricular contractile function paralleled by the expression of myocardial tumor necrosis factor-alpha (TNF-alpha) mRNA and protein as well as the release of TNF-alpha into the perfusate was observed in LTA-perfused hearts. Employment of an anti-TNF-alpha antibody completely prevented the loss in contractile function. When CD14, a prominent pathogen recognition receptor, was blocked by a specific antibody, induction of TNF-alpha mRNA and protein release as well as the associated cardiodepression was diminished in response to LTA. Synthesis of TNF-alpha protein was located to interstitial cells of LTA-challenged hearts as detected by immunohistochemistry. Besides progressive cardiodepression, coronary perfusion pressure (CPP) was moderately increased in LTA-perfused hearts. This was accompanied by the release of thromboxane A2 (TXA2) into the perfusate and the induction of cyclooxygenase (Cox)-2 mRNA and protein in the myocardium. Blocking of TXA2 by the nonspecific Cox inhibitor indomethacin, the thromboxane receptor antagonist daltroban, or the selective Cox-2 inhibitor NS-398 prevented the increase in CPP.. LTA causes cardiac depression by activating myocardial TNF-alpha synthesis via CD14 and induces coronary vascular disturbances by activating Cox-2-dependent TXA2 synthesis. These phenomena may contribute to cardiac depression in gram-positive sepsis.

Topics: Animals; Disease Models, Animal; Gene Expression Regulation; Heart; Heart Failure; In Vitro Techniques; Lipopolysaccharides; Male; Rats; Rats, Wistar; RNA, Messenger; Staphylococcus aureus; Teichoic Acids; Tumor Necrosis Factor-alpha

We have established a mouse model for fatal postoperative enteritis due to Staphylococcus aureus to analyze mechanisms of bacterial translocation and determine reasons for the lethality of this infection. In the present study the role of macrophages was ascertained in protection against S. aureus induced enteritis.. Mice were pretreated with cyclophosphamide (CY), an immunosuppressant, and then infected directly into the jejunum with methicillin-resistant S. aureus (MRSA) isolated from a patient. In other groups of mice liposome-encapsulated dichloromethylene diphosphate (Cl2MDP) was administered to deplete macrophages in vivo. Other experimental groups received lipoteichoic acid (LTA), which was used to inhibit the ability of macrophages to bind MRSA, and additionally, to analyze dependence of bacterial clearance on the macrophage scavenger receptor. The ability of macrophages to bind MRSA was compared with survival rates in this mouse model of fatal postoperative enteritis.. Injection of liposome-encapsulated Cl2MDP decreased survival rate of mice infected intraintestinally with MRSA in a dose-dependent manner. Cyclophosphamide also decreased survival rate of MRSA-infected mice and was found to correlate with its ability to decrease the number of macrophages in the spleen. Intravenous LTA administration did not affect total splenocyte numbers or the number of splenic macrophages but decreased the ability of macrophages to bind MRSA and adversely affected survival of mice infected with MRSA.. Macrophages play a critical role in protection against MRSA administered directly into the jejunum. LTA recognition sites (probably type A scavenger receptors) on macrophages are required for binding and phagocytosing MRSA.

Topics: Animals; Antimetabolites; Clodronic Acid; Cyclophosphamide; Disease Models, Animal; Enteritis; Immunosuppressive Agents; Lipopolysaccharides; Macrophages, Peritoneal; Male; Methicillin Resistance; Mice; Mice, Inbred BALB C; Phagocytosis; Postoperative Complications; Specific Pathogen-Free Organisms; Staphylococcal Infections; Teichoic Acids

Whether nitric oxide (NO) protects or impairs the liver function and structure during the early phase of sepsis is still controversial. The aim of this study is to evaluate the effect of NO on lipopolysaccharide (LPS) or lipoteichoic acid (LTA) induced liver injury in rats.. One hundred twenty-six Wistar rats were assigned randomly and equally to LTA and LPS groups. Each group was divided into three subgroups which received saline, L-Arginine (L-Arg) or NG-nitro-L-arginine methylester (L-NAME) consecutively, one hour prior to either 5 mg/kg LPS or 3 mg/kg LTA injection. Plasma nitrite plus nitrate [NOx] were measured. Liver injury was assessed by measuring the rises in circulating liver enzymes and by scoring the extent of liver necrosis.. Administration of L-NAME+LPS not only reduced [NOx] production but also enhanced liver damage. LNAME+ LTA caused an increase in the plasma levels of [NOx] (p=0.0006), and produced sinusoidal enlargement in liver. L-Arg protected the hepatocytes against LPS injury, whereas, enhanced the liver damage in the LTA group.. Our data indicated that overproduction of NO exerts detrimental effect on LTA-treated rats while providing a protective function in LPS group.

Topics: Animals; Arginine; Disease Models, Animal; Enzyme Inhibitors; Lipopolysaccharides; Liver; Liver Function Tests; Male; NG-Nitroarginine Methyl Ester; Nitrates; Nitrites; Random Allocation; Rats; Rats, Wistar; Shock, Septic; Teichoic Acids

Staphylococcus aureus is an important pathogen in nosocomial pneumonia. Lipoteichoic acid (LTA) and peptidoglycan (PepG) are part of the staphylococcal cell wall. Here we show that LTA and PepG act in synergy to cause polymorphonuclear cell recruitment in the pulmonary compartment during S. aureus pneumonia.

Topics: Animals; Antigens, Bacterial; Bronchoalveolar Lavage Fluid; Cell Movement; Disease Models, Animal; Drug Synergism; Enzyme-Linked Immunosorbent Assay; Immunohistochemistry; Lipopolysaccharides; Lung; Mice; Mice, Inbred BALB C; Neutrophils; Peptidoglycan; Pneumonia, Staphylococcal; Staphylococcus aureus; Teichoic Acids

Streptococcus (S.) pyogenes is common cause of acute tonsillitis. Lipoteichoic acid (LTA), which is a common constitute of the cell surface of most gram positive bacteria, is known to act as a substance of bacterial site for adherence to epithelium and antiserum to LTA is reported to inhibit bacterial attachment to epithelial cells in vitro. Cholera toxin subunit B (CT-B) is known to be a mucosal adjuvant. The purpose of this study is to investigate whether intranasal immunization with LTA and CT-B may be a possible candidate for vaccine formulation.. Six-week-old male BALB/c mice were assigned to three experimental groups, mice immunized with LTA and CT-B, with LTA alone and with phosphate buffered saline (PBS) as a control. Immunizations were performed intranasally every 2 days for 2 weeks in every group. At the 21 days after immunization, sera, pharyngeal washings and pharyngeal epithelial cells were taken. The levels of serum IgG and pharyngeal IgA antibodies to LTA were measured by enzyme-linked immunosorbent assay (ELISA). The adherence rates of S. pyogenes pretreated by pharyngeal washings to pharyngeal epithelial cells from the mice were determined by in vitro adherence assay.. The serum anti-LTA IgG antibody levels of either mice immunized with LTA and CT-B or mice immunized with LTA alone were significantly higher than those of mice administered with PBS alone. The pharyngeal anti-LTA IgA antibody levels of the mice immunized with LTA and CT-B were significantly higher than those of either mice with LTA alone or mice with PBS alone. The streptococcal adherence rates to pharyngeal epithelial cells were significantly decreased by pretreatment with pharyngeal washings from the mice immunized with LTA and CT-B as compared with pretreatment with those from either mice with PBS or mice with LTA alone.. These data shows that intranasal immunization with LTA and CT-B evokes a good pharyngeal IgA response as well as systemic IgG response to LTA and inhibits streptococcal adherence to pharyngeal epithelial cells, suggesting that intranasal immunization with LTA and CT-B may be an effective approach to prevent streptococcal tonsillitis.

Topics: Administration, Intranasal; Animals; Antibodies, Bacterial; Bacterial Adhesion; Cholera Toxin; Disease Models, Animal; Immunoglobulin A; Immunoglobulin G; Lipopolysaccharides; Male; Mice; Mice, Inbred BALB C; Nasal Mucosa; Streptococcus pyogenes; Teichoic Acids; Tonsillitis

Lipoteichoic acids (LTA) and peptidoglycans (PepG) are major components of the cell walls of gram-positive bacteria that trigger inflammatory responses in vitro. To study the in vivo effects of LTA and PepG from Staphylococcus aureus in lungs and to determine the role of interleukin (IL)-6 herein, these compounds were intranasally administered to IL-6 gene deficient (IL-6(-/-)) and wild type (IL-6(+/+)) mice. In IL-6(+/+) mice, LTA and PepG induced acute pulmonary inflammation in a dose-dependent way, characterized by neutrophilic influx and IL-6 production in the bronchoalveolar lavage fluid. Endogenously produced IL-6 attenuated inflammation induced by 10 microg LTA, as reflected by enhanced neutrophil influx, and increased tumor necrosis factor-alpha, macrophage inflammatory protein-1-alpha, and cytokine-induced neutrophil chemoattractant (KC) release into bronchoalveolar lavage fluid of IL-6(-/-) mice, compared with IL-6(+/+) mice. By contrast, pulmonary inflammation induced by 100 microg LTA was similar (neutrophil influx) or even tended to be attenuated (cytokine and chemokine release) in IL-6(-/-) mice. Endogenous IL-6 increased inflammation induced by PepG, as reflected by decreased neutrophil influx into lungs of IL-6(-/-) mice, compared with IL-6(+/+) mice. These data suggest that IL-6 plays an anti-inflammatory role during LTA-induced pulmonary inflammation, which is dependent on the severity of the inflammatory challenge, and a proinflammatory role in peptidoglycan-induced acute lung inflammation. Thus, the contribution of IL-6 to lung inflammation may vary with the stimulus used.

Topics: Administration, Intranasal; Animals; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Dose-Response Relationship, Drug; Immunohistochemistry; Interleukin-6; Lipopolysaccharides; Macrophages; Mice; Mice, Inbred BALB C; Peptidoglycan; Pneumonia, Staphylococcal; Probability; Sensitivity and Specificity; Staphylococcus aureus; Statistics, Nonparametric; Teichoic Acids

The inflammatory response following initiation of antibiotic therapy and parameters of neuronal damage were compared during intravenous treatment with quinupristin/dalfopristin (100 mg/kg as either a short or a continuous infusion) and ceftriaxone (10 mg/kg/h) in a rabbit model of Streptococcus pneumoniae meningitis. With both modes of administration, quinupristin/dalfopristin was less bactericidal than ceftriaxone. However, the concentration of proinflammatory cell wall components (lipoteichoic acid (LTA) and teichoic acid (TA)) and the activity of tumour necrosis factor (TNF) in cerebrospinal fluid (CSF) were significantly lower in the two quinupristin/dalfopristin groups than in ceftriaxone-treated rabbits. The median LTA/TA concentrations (25th/75th percentiles) were as follows: (i) 14 h after infection: 133 (72/155) ng/mL for continuous infusion of quinupristin/dalfopristin and 193 (91/308) ng/mL for short duration infusion, compared with 455 (274/2042) ng/mL for ceftriaxone (P = 0.002 and 0.02 respectively); (ii) 17 h after infection: 116 (60/368) ng/mL for continuous infusion of quinupristin/dalfopristin and 117 (41/247) ng/mL for short duration infusion, compared with 694 (156/2173) ng/mL for ceftriaxone (P = 0.04 and 0.03 respectively). Fourteen hours after infection the median TNF activity (25th/75th percentiles) was 0.2 (0.1/1.9) U/mL for continuous infusion of quinupristin/dalfopristin and 0.1 (0.01/3.5) U/mL for short duration infusion, compared with 30 (4.6/180) U/mL for ceftriaxone (P = 0.02 for each comparison); 17 h after infection the TNF activity was 2.8 (0.2/11) U/mL (continuous infusion of quinupristin/dalfopristin) and 0.1 (0.04/6.1) U/mL (short duration infusion), compared with 48.6 (18/169) U/mL for ceftriaxone (P = 0.002 and 0.001). The concentration of neuron-specific enolase (NSE) 24 h after infection was significantly lower in animals treated with quinupristin/dalfopristin: 4.6 (3.3/5.7) microg/L (continuous infusion) and 3.6 (2.9/4.7) microg/L (short duration infusion) than in those treated with ceftriaxone (17.7 (8.8/78.2) microg/L) (P = 0.03 and 0.009 respectively). In conclusion, antibiotic treatment with quinupristin/dalfopristin attenuated the inflammatory response within the subarachnoid space after initiation of antibiotic therapy. The concentration of NSE in the CSF, taken as a measure of neuronal damage, was lower in quinupristin/dalfopristin-treated rabbits than in ceftriaxone-treated rabbits.

Topics: Animals; Anti-Bacterial Agents; Ceftriaxone; Cerebrospinal Fluid Proteins; Disease Models, Animal; Inflammation; Lactic Acid; Lipopolysaccharides; Meningitis, Pneumococcal; Microbial Sensitivity Tests; Neurons; Phosphopyruvate Hydratase; Rabbits; Streptococcus pneumoniae; Subarachnoid Space; Teichoic Acids; Tumor Necrosis Factor-alpha; Virginiamycin

In the rabbit model of Streptococcus pneumoniae meningitis, treatment with rifabutin, quinupristin-dalfopristin, moxifloxacin and trovafloxacin led to smaller increases of the CSF concentrations of the pro-inflammatory cell wall components lipoteichoic and teichoic acids (LTA and TA) than did treatment with ceftriaxone. Low doses of moxifloxacin were associated with higher LTA and TA concentrations in CSF than were high doses.

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Aza Compounds; Ceftriaxone; Cephalosporins; Disease Models, Animal; Fluoroquinolones; Immunoenzyme Techniques; Lipopolysaccharides; Meningitis, Pneumococcal; Moxifloxacin; Naphthyridines; Polysaccharides, Bacterial; Quinolines; Rabbits; Reference Values; Rifabutin; Teichoic Acids; Virginiamycin

To examine the capacity of lipoteichoic acid (LTA) to induce intraocular inflammation in the rat.. LTA obtained from Staphylococcus aureus and three different streptococcal species were suspended in saline solution in various concentrations and were injected into one footpad of female Lewis rats. The uveitic changes were assessed by conventional clinical and histopathologic procedures, whereas the intensity of inflammation in the anterior chamber (AC) was evaluated by the measurement of protein concentration and cell density in the aqueous humor (AH).. LTA from S. aureus induced a strong intraocular inflammation between 24 and 30 hours after injection. The inflammatory reaction was observed in a dose-dependent manner. At a dose of 15 mg/kg LTA, the protein concentration and cell counts in the AH were 5.6 +/- 0.5 mg/ml and 4075 +/- 1193 cells/microl, respectively. When LTAs of streptococcal origin were used, cells were undetected in the AH and protein concentration increased only two- or threefold compared with the control group. In pathologic examination, inflammatory cells were found in the AC and posterior chamber only after the injection of S. aureus LTA. In systemic evaluations of the liver, kidney, spleen, heart, lung, gut, brain, joint, and eye performed 6, 24, and 48 hours after the challenge, inflammatory lesions were found only in the eye.. LTA, especially of S. aureus origin, induces anterior uveitis in the rat. This model may be useful for investigation of Gram-positive bacterial infection and uveitis.

Topics: Acute Disease; Animals; Anterior Chamber; Aqueous Humor; Cell Count; Disease Models, Animal; Dose-Response Relationship, Drug; Eye Proteins; Female; Lipopolysaccharides; Rats; Rats, Inbred Lew; Staphylococcus aureus; Streptococcus; Teichoic Acids; Time Factors; Uveitis, Anterior

The purpose of this study was to determine whether or not lipoteichoic acid (LTA) could induce preterm delivery in mice. On days 15 and 17 of pregnancy, female C3H/HeN mice impregnated by male B6D2F1 mice were given intraperitoneal injections of LTA (12.5-75 mg/kg, single dose or repeated doses at a 3-h interval). We examined the changes in cervix, placental trophoblasts, and plasma and amniotic fluid concentrations of interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) after dosing with LTA. In addition, the effect of LTA on the contraction of isolated uterine muscle from pregnant mice was also measured. The incidence of preterm delivery was highest (100%), when the pregnant animals were treated with 75 mg/kg LTA twice on day 15 of pregnancy or with 25 mg/kg LTA twice on day 17 of pregnancy. LTA-accelerated cervical ripening and placental abruption preceding the onset of preterm delivery, as well as increased plasma and amniotic fluid concentrations of IL-1alpha, IL-6, and TNF-alpha. Also, LTA increased contraction of uterine muscle strips. In conclusion, LTA induced preterm delivery in mice in the same manner as lipopolysaccharide (LPS), but the effective dose of LTA was larger than that of LPS.

Topics: Amniotic Fluid; Animals; Cervical Ripening; Cytokines; Disease Models, Animal; Female; Lipopolysaccharides; Male; Mice; Mice, Inbred C3H; Obstetric Labor, Premature; Placenta; Pregnancy; Teichoic Acids; Uterine Contraction

The effect of penicillin treatment of Streptococcus sanguis in vitro, on subsequent bacterial density in the bloodstream and on cardiac valves in the rabbit model of endocarditis was studied. As experimental tools for this study, isogenic pairs of S. sanguis differing in resistance to streptomycin or rifampin were prepared by genetic transformation. Rabbits with traumatized heart valves received an intravenous inoculation of penicillin treated (1 mug/ml) and untreated S. sanguis, each marked by resistance to either streptomycin or rifampin. The number of penicillin-treated and untreated bacteria attached to the valvular surfaces was determined by differential counting on streptomycin or rifampin containing media. Penicillin pretreatment reduced cardiac valve colonization 5 min after inoculation ("adherence ratio" x 10(8) was 4.11 for the control and 3.66 for the penicillin-treated bacteria, P < 0.001). The results were not due to differences in serum killing or bacterial densities in the bloodstream. There was no difference in valvular bacterial densities 24 h after bacterial inoculation (adherence ratio x 10(8), 7.26 untreated vs. 6.34 penicillin-pretreated, P > 0.10). In vitro experiments were performed using platelet-fibrin surfaces to test the possibility that penicillin-induced loss of lipoteichoic acid was responsible for decreased streptococcal adherence. Pretreatment of S. sanguis cultures with inhibitory concentrations of penicillin or with antiserum against lipoteichoic acid and precoating of the platelet-fibrin surfaces with lipoteichoic acid, all caused reduction in bacterial adherence. The findings are interpreted as support for the role of lipoteichoic acid as an adhesin in S. sanguis interactions with particular host tissue surfaces.

Topics: Adhesiveness; Animals; Disease Models, Animal; Endocarditis, Bacterial; Heart Valves; Lipopolysaccharides; Microbial Sensitivity Tests; Penicillins; Phosphatidic Acids; Rabbits; Streptococcal Infections; Streptococcus sanguis; Teichoic Acids

An animal model of maternal-newborn transmission of group B streptococci (GBS) was developed. Pregnant Swiss-Webster mice were colonized by applying 10(8) GBS to the oral cavity, vagina, and nipples daily for 3 days before delivery. Lipoteichoic acid (LTA) from type III GBS or phosphate buffered saline was applied topically to the oral cavity, perineum or nape of newborn mice. Cultures of newborn mice at 3 days of age revealed 35 of 75 (47%) controls and 0 of 79 animals given 2 doses of LTA (2 mg/ml) were positive for GBS at one or more sites. One to two% of control and LTA-treated mice remained culture positive at 7 days of age. None developed GBS disease and no obvious toxicity was noted. This is the first in vivo evidence that colonization with GBS can be prevented by interfering with their adherence to epithelial surfaces. LTA also prevented colonization by 60,000 GBS in the oral cavity of 1-day-old newborn mice. A minimum concentration of 0.5 mg LTA/ml was required and similar dose response curves were obtained in preventing maternal-newborn transmission or oral newborn colonization. LTA from type III GBS also protected against types Ia and II. Only 6 of 15 (40%) vaginally colonized, nonpregnant mice became noncolonized 3 days after LTA treatment. Topically applied lipoteichoic acid from group B streptococci may be a useful method of preventing GBS colonization and/or disease in human infants at birth if it is nontoxic. The method avoids the problems associated with antibiotic prophylaxis and vaccine development.

Topics: Animals; Disease Models, Animal; Humans; Infant, Newborn; Infant, Newborn, Diseases; Lipopolysaccharides; Mice; Phosphatidic Acids; Streptococcal Infections; Streptococcus agalactiae; Teichoic Acids