lipoteichoic-acid and Hypersensitivity

Topics: Animals; Bronchoalveolar Lavage Fluid; Cytokines; Female; Hypersensitivity; Inflammation; Intracellular Signaling Peptides and Proteins; Lipopolysaccharides; Mice; Mice, Inbred C57BL; NF-kappa B; Ovalbumin; RAW 264.7 Cells; Teichoic Acids; Toll-Like Receptor 2

Binding of allergen to IgE on basophils positively affects allergic inflammation by releasing inflammatory mediators. Recently, basophils were shown to express pattern-recognition receptors, such as toll-like receptors (TLRs), for recognizing microbe-associated molecular patterns (MAMPs) that are independent of allergen-IgE binding. In this study, we investigated whether MAMP alone can induce IL-6 production in a human basophil cell line, KU812. Stimulation with flagellin in the absence of allergen-IgE association induced IL-6 expression in KU812 cells, while stimulation with lipoteichoic acid, peptidoglycan, or poly I:C did not under the same condition. Flagellin-induced IL-6 expression was also observed in human primary basophils. Flow cytometric analysis showed that KU812 cells expressed flagellin-recognizing TLR5 both on the cell surface and in the cytoplasm while TLR2 and TLR3 were observed only in the cytoplasm. We further demonstrated that although flagellin augmented the phosphorylation of mitogen-activated protein kinases including p38 kinase, ERK, and JNK, flagellin-induced IL-6 production was attenuated by inhibitors for p38 kinase and ERK, but not by JNK inhibitors. In addition, flagellin enhanced phosphorylation of signaling molecules including CREB, PKCδ, and AKT. The inhibitors for PKA and PKC also showed inhibitory effects. Interestingly, flagellin-induced IL-6 production was further enhanced by pretreatment with inhibitors for PI3K, implying that PI3K negatively affects the flagellin-induced IL-6 production. Furthermore, DNA binding activities of NF-κB, AP-1, and CREB, which play pivotal roles in the induction of IL-6 gene expression, were increased by flagellin. These results suggest that flagellin alone is sufficient to induce IL-6 gene expression via TLR5 signaling pathways in human basophils.

Topics: Allergens; Basophils; Cell Line; Cyclic AMP Response Element-Binding Protein; Cyclic AMP-Dependent Protein Kinases; DNA-Binding Proteins; Extracellular Signal-Regulated MAP Kinases; Flagellin; Humans; Hypersensitivity; Immunoglobulin E; Inflammation; Interleukin-6; Interleukin-8; JNK Mitogen-Activated Protein Kinases; Lipopolysaccharides; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Peptidoglycan; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Poly I-C; Protein Kinase C-delta; Proto-Oncogene Proteins c-akt; Receptors, Pattern Recognition; RNA, Messenger; Teichoic Acids; Toll-Like Receptor 2; Toll-Like Receptor 3; Toll-Like Receptor 5; Transcription Factor AP-1

It was established in a mouse model that the cowshed Gram-positive bacterium Lactococcus lactis G121 modulates the immune system resulting in allergy protection. However, the molecules and mechanisms involved in this process have not been elucidated yet. Lipoteichoic acids (LTAs) represent one major cell envelope component of Gram-positive bacteria that is considered a pathogen-associated molecular pattern. In the investigations presented here, the isolation as well as the structural and functional analyses of the LTA of L. lactis G121 were performed. Extraction with butan-1-ol and purification by hydrophobic interaction chromatography yielded pure LTA. Structural investigations included chemical analytical methods, nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization Fourier-transformed ion cyclotron mass spectrometry. LTA comprised a heterogeneous mixture of molecules composed of a 1,3-linked poly(glycerol phosphate) backbone which was randomly substituted at C-2 by D-alanine and α-D-galactopyranose. The lipid anchor constituents were kojibiose linked to a heterogeneous diglyceride comprising in total six different fatty acid compositions. This LTA preparation possesses Toll-like receptor 2- (TLR2) and TLR4-independent cytokine-inducing activities in human mononuclear cells.

Topics: Cytokines; HEK293 Cells; Humans; Hypersensitivity; Lactococcus lactis; Leukocytes, Mononuclear; Lipopolysaccharides; Teichoic Acids; Toll-Like Receptor 2

Selected lactic acid bacteria were reported to prevent atopic dermatitis and experimental asthma but the mechanisms of their immunomodulatory effects are not fully elucidated. In this study, the signaling pathways triggered by Lactobacillus plantarum NCIMB8826 were investigated and the potential use of this strain producing a variant of the mite allergen Der p 1 as live vaccine vehicle was evaluated.. Mouse bone marrow-derived dendritic cells were stimulated with wild-type or a L. plantarum teichoic acid mutant to evaluate the secretion of cytokines. A recombinant L. plantarum expressing Der p 1 was engineered, its in vitro immunomodulatory properties were characterized and its prophylactic potential was evaluated in a Der p 1-sensitization murine model.. Mouse dendritic cells stimulated by L. plantarum triggered the release of interleukin-10 (IL-10), IL-12 p40, IL-12 p70 and tumor necrosis factor-alpha (TNF-alpha). IL-12 p40 secretion was dependent on nuclear factor-kappaB (NF-kappaB), mitogen-activated protein (MAP) kinases, Toll-like receptor 2 (TLR2), TLR9 and on the bacterial teichoic acid composition. Recombinant L. plantarum producing Der p 1 exhibited similar immunostimulatory properties as wild-type. Prophylactic intranasal pretreatment of mice with this recombinant strain prevented the development of the typical Th2-biased allergic response by a drastic reduction of specific IgE and the induction of protective allergen-specific IgG2a antibodies. Moreover, both wild-type or recombinant L. plantarum reduced airway eosinophilia following aerosolized allergen exposure and IL-5 secretion upon allergen restimulation.. By combining both Th1-type immunostimulatory properties and an efficient allergen delivery capacity, recombinant L. plantarum producing Der p 1 represents a promising vaccine against house dust mite allergy.

Topics: Animals; Antigens, Dermatophagoides; Arthropod Proteins; Cysteine Endopeptidases; Dendritic Cells; Humans; Hypersensitivity; Immunoblotting; Lactobacillus plantarum; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Mites; Signal Transduction; Teichoic Acids; Toll-Like Receptor 2; Toll-Like Receptor 9; Transfection; Vaccines, Synthetic

Prospective cohort studies suggest that children hospitalized in early life with severe infections are significantly more likely to develop recurrent wheezing and asthma.. Using an inhalational mouse model of allergic airways inflammation, we sought to determine the effect of viral and bacterial-associated molecular patterns on the magnitude of the allergic inflammatory response and whether this effect was age dependent.. BALB/c mice were sensitized by intranasal administration of endotoxin(low) ovalbumin (OVA) in the absence or presence of viral single-stranded (ss)RNA, lipoteichoic acid or flagellin as neonates (within the first 24 h of life) or as weanlings (4 weeks of age). Mice were challenged four times with OVA at 6 weeks of age and end-points (bronchoalveolar lavage cytology, histology, antigen-specific T and B cell responses) determined at 7 weeks of age.. Inhalational sensitization (<24 h or 4 weeks of age) and challenge with OVA induced a mild allergic inflammatory response in the airways as indicated by increased numbers of eosinophils and mucus cells, elevated serum OVA-specific IgG1, and production of T helper 2 (Th2) cytokines. Mice sensitized to endotoxin(low) OVA at birth in the presence of ssRNA or lipoteichoic acid, but not flagellin, showed an increase in the numbers of airway and tissue eosinophils, mucus producing cells and antigen-specific production of IL-13 as compared with mice exposed only to endotoxin(low) OVA. By contrast, all three TLR ligands failed to increase the magnitude of OVA-induced allergic inflammation in mice sensitized as weanlings.. Recognition of distinct microbial-associated patterns in early life may preferentially promote the de novo differentiation of bystander, antigen-specific CD4(+) T cells toward a Th2 phenotype, and promote an asthma-like phenotype upon cognate antigen exposure in later life.

Topics: Adjuvants, Immunologic; Animals; Animals, Newborn; Eosinophilia; Flagellin; Gene Expression; Hyperplasia; Hypersensitivity; Immunoglobulin G; Interferon-gamma; Interleukin-13; Interleukin-4; Interleukin-5; Lipopolysaccharides; Lung; Lymph Nodes; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mucous Membrane; Ovalbumin; RNA, Viral; Teichoic Acids; Th2 Cells; Toll-Like Receptor 2; Toll-Like Receptor 7; Vaccination

Allergic diseases are reported to be caused by a skew in the balance between T helper type 1 and 2 cells. Because some lactic acid bacteria have been shown to stimulate IL-12 (p70) production, which in turn shifts the balance between the T helper type 1 and 2 cell response from the latter to the former, they have the potential to either prevent or ameliorate disease conditions or both. They have therefore been extensively studied in the recent past for their probiotic activities. Nevertheless, much less information is available concerning the microbial factors that determine the strain-dependent ability to affect the production of cytokines. The objectives of our study were first to select potentially probiotic lactobacilli that strongly stimulate cytokine production in vitro, and then to determine whether the selected Lactobacillus strains could suppress antigen-specific IgE production in vivo by using allergic model animals. Finally, our investigation was extended to analyze which bacterial components were responsible for the observed biological activity. Twenty strains of heat-killed lactobacilli isolated from humans were screened for their stimulatory activity for the production of IL-12 (p70) by murine splenocytes in vitro. The results showed that some strains of Lactobacillus plantarum and Lactobacillus gasseri had a higher stimulatory activity for IL-12 (p70) production than the other lactobacilli tested; however, this effect was strain dependent rather than species dependent. Oral administration of the heat-killed strains that showed higher stimulatory activity for IL-12 (p70) production tended to reduce the serum antigen-specific IgE levels in ovalbumin-sensitized BALB/c mice compared with the controls. Among the lactobacilli tested, L. gasseri OLL2809 showed the highest activity in reducing the level of antigen-specific IgE. Furthermore, the stimulatory activity for IL-12 (p70) production was found to be reduced after treating the lactobacilli with N-acetyl-muramidase and to be positively correlated with the amount of peptidoglycan in the cells. The present data suggest that L. gasseri OLL2809 is a good candidate for potential probiotics in terms of either the prevention or amelioration of allergic diseases or both. In addition, the strain-dependent stimulatory activity for IL-12 (p70) production was found to be due, at least in part, to the amount of peptidoglycan present in the cells.

Topics: Animals; Cytokines; Endopeptidases; Freeze Drying; Hot Temperature; Hypersensitivity; Immunoglobulin E; Interleukin-12; Lactobacillus; Lipopolysaccharides; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Peptidoglycan; Probiotics; Spleen; Teichoic Acids

Regimens of intravenous injections of saline-washed Lactobacillus fermentum elicited hypersensitivity reactions in rabbits. Pathological investigation revealed evidence consistent with induction of aggregate anaphylaxis, characterised by acute cor pulmonale. Additional evidence of similar tissue injury was observed in livers of rabbits which had received several intravenous injections of L. fermentum. Deposition of immune complexes in kidney glomeruli was demonstrated in only 1 out of 11 animals. Skin testing experiments revealed that lipoteichoic acid was involved in type I and type II antibody-mediated hypersensitive states. The involvement of bacterial cell surface components and extracellular products in such reactions implies a potential role in host tissue injury.

Topics: Animals; Hypersensitivity; Kidney Glomerulus; Lactobacillus; Lipopolysaccharides; Liver Diseases; Lung Diseases; Male; Phosphatidic Acids; Rabbits; Teichoic Acids; Vasculitis