lipid-a and lipoteichoic-acid

Topics: Animals; Antigens, Bacterial; Binding Sites; Cell Wall; Cytokines; Gene Expression Regulation; Gram-Positive Bacteria; Humans; Ligands; Lipid A; Lipopolysaccharide Receptors; Lipopolysaccharides; Macrophage Activation; Macrophages; Mice; Mycobacterium; Peptidoglycan; Protein Binding; Signal Transduction; Teichoic Acids; Transcription Factors

Topics: Acetylmuramyl-Alanyl-Isoglutamine; Adjuvants, Immunologic; Animals; Bacteria; Carbohydrate Sequence; Cytokines; Guinea Pigs; Immunologic Factors; Influenza Vaccines; Lipid A; Lipopolysaccharides; Mice; Molecular Sequence Data; Neoplasms, Experimental; Plasmodium falciparum; Teichoic Acids

Previous studies have shown that ELAVL1 plays multiple roles, but its overall biological function remains ill-defined. Here we clearly demonstrated that zebrafish ELAVL1a was a lipoteichoic acid (LTA)- and LPS-binding protein abundantly stored in the eggs/embryos of zebrafish. ELAVL1a acted not only as a pattern recognition receptor, capable of identifying LTA and LPS, as well as bacteria, but also as an effector molecule, capable of inhibiting the growth of Gram-positive and -negative bacteria. Furthermore, we reveal that the C-terminal 62 residues of ELAVL1a positioned at 181-242 were indispensable for ELAVL1a antibacterial activity. Additionally, site-directed mutagenesis revealed that the hydrophobic residues Val192/Ile193, as well as the positively charged residues Arg203/Arg204, were the functional determinants contributing to the antimicrobial activity of rELAVL1a. Importantly, microinjection of rELAVL1a into embryos markedly promoted their resistance against pathogenic Aeromonas hydrophila challenge, and this pathogen-resistant activity was considerably reduced by co-injection of anti-ELAVL1a antibody or by knockdown with morpholino for elavl1a. Collectively, our results indicate that ELAVL1a is a maternal immune factor that can protect zebrafish embryos from bacterial infection. This work also provides another angle for understanding the biological roles of ELAVL1a.

Topics: Animals; ELAV Proteins; Gene Expression Regulation, Developmental; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Lipid A; Lipopolysaccharides; Mutation; Phylogeny; Protein Binding; Teichoic Acids; Zebrafish; Zebrafish Proteins

Previous research established different interactions of the insect pathogen, Xenorhabdus nematophila and nonpathogen, Bacillus subtilis, with antimicrobial hemocytes and humoral factors of larval Malacosoma disstria [Giannoulis, P., Brooks, C.L., Dunphy, G.B., Mandato, C.A., Niven, D.F., Zakarian, R.J., 2007. Interaction of the bacteria Xenorhabdus nematophila (Enterobacteriaceae) and Bacillus subtilis (Bacillaceae) with the hemocytes of larval Malacosoma disstria (Insecta: Lepidoptera: Lasicocampidae). J. Invertebr. Pathol. 94, 20-30]. The antimicrobial systems were inhibited by X. nematophila and stimulated by B. subtilis. The bacterial surface antigens participating in these reactions were unknown. Thus, herein the effects of lipopolysaccharide (endotoxin) from X. nematophila and lipoteichoic acid from B. subtilis on the larval M. disstria immune factors, the hemocytes and phenoloxidase, were determined. Endotoxin elevated the level of damaged hemocytes limiting the removal of X. nematophila from the hemolymph and enhancing the rapid release of bacteria trapped by nodulation. Similar effects were observed with the lipid A moiety of the endotoxin. The effects of lipopolysaccharide and lipid A on the hemocyte activities were abrogated by polymyxin B (an antibiotic that binds to lipid A) confirming lipopolysaccharide as the hemocytotoxin by virtue of the lipid A moiety. Lipoteichoic acid elicited nodulation and enhanced phenoloxidase activation and/or activity. Although lipoidal endotoxin and lipid A inhibited phenoloxidase activation they enhanced the activity of the enzyme. Apolipophorin-III precluded the effects of lipopolysaccharide, lipid A, and lipoteichoic acid on the hemocytes and prophenoloxidase until the antigens exceeded a critical threshold.

Topics: Animals; Antigens, Surface; Apolipoproteins; Bacillus subtilis; Cell Count; Dose-Response Relationship, Immunologic; Hemocytes; Host-Pathogen Interactions; In Vitro Techniques; Larva; Lipid A; Lipopolysaccharides; Monophenol Monooxygenase; Moths; Teichoic Acids; Xenorhabdus

Mouse Paneth cells respond to bacteria and bacterial cell surface antigens by discharging secretory granules into the lumen of small intestinal crypts (T. Ayabe et al., Nat. Immunol. 1:113-118, 2000). To investigate mechanisms regulating these responses, purified surface glycolipid molecules with known acyl chain modifications and attenuated properties were tested for the ability to stimulate Paneth cell secretion. The antigens included lipopolysaccharide (LPS) from wild-type and msbB-null Escherichia coli and phoP-null and phoP-constitutive Salmonella enterica serovar Typhimurium strains, as well as LPS, lipid A, and lipoteichoic acid from Pseudomonas aeruginosa and Listeria monocytogenes grown in Mg2+-limited media. Measurements of total secreted protein, secreted lysozyme, and the bactericidal peptide activities of collected secretions showed that the purified antigens elicited similar secretory responses from Paneth cells in mouse crypts ex vivo, regardless of glycolipid acyl chain modification. Despite their impaired Tlr4 pathway, Paneth cells in ex vivo C3H/HeJ mouse crypts released equivalent amounts of bactericidal peptide activity in response to purified bacterial antigens, including lipid A. Thus, mouse Paneth cells respond equivalently to purified bacterial cell envelope glycolipids, regardless of functional Tlr4, the structural properties of glycolipid acyl chains, or their association with virulence in humans.

Topics: alpha-Defensins; Animals; Antigens, Bacterial; Antigens, Surface; Calcium; Glycolipids; Lipid A; Lipopolysaccharides; Mice; Mice, Inbred C3H; Paneth Cells; Receptors, Cell Surface; RNA, Messenger; Teichoic Acids; Toll-Like Receptor 4; Virulence

Paneth cells in mouse small intestinal crypts secrete granules rich in microbicidal peptides when exposed to bacteria or bacterial antigens. The dose-dependent secretion occurs within minutes and alpha-defensins, or cryptdins, account for 70% of the released bactericidal peptide activity. Gram-negative bacteria, Gram-positive bacteria, lipopolysaccharide, lipoteichoic acid, lipid A and muramyl dipeptide elicit cryptdin secretion. Live fungi and protozoa, however, do not stimulate degranulation. Thus intestinal Paneth cells contribute to innate immunity by sensing bacteria and bacterial antigens, and discharge microbicidal peptides at effective concentrations accordingly.

Topics: Animals; Escherichia coli; Intestine, Small; Lipid A; Lipopolysaccharides; Matrix Metalloproteinase 7; Mice; Mice, Knockout; Paneth Cells; Protein Precursors; Salmonella typhimurium; Staphylococcus aureus; Teichoic Acids

CD14 has been implicated as a receptor of lipoteichoic acid (LTA) and other bacterial components as well as lipopolysaccharide (LPS). Since the structures of LTAs from various gram-positive bacteria are heterogeneous, we analyzed the effects of LTAs on the secretion of interleukin-8 (IL-8) by high- and low-CD14-expressing (CD14(high) and CD14(low)) human gingival fibroblasts (HGF). While Bacillus subtilis LTA had an IL-8-inducing effect on CD14(high) HGF which was considerably weaker than that of LPS, Streptococcus sanguis and Streptococcus mutans LTAs had practically no effect on the cells. B. subtilis LTA had only a weak effect on CD14(low) HGF, as did LPS. S. sanguis and S. mutans LTAs at a 1,000-fold excess each completely inhibited the IL-8-inducing activities of both LPS and a synthetic lipid A on CD14(high) HGF. The effect of LPS was also inhibited by the presence of an LPS antagonist, synthetic lipid A precursor IVA (LA-14-PP), with a 100-fold higher potency than S. sanguis and S. mutans LTAs and by anti-CD14 monoclonal antibody (MAb). S. sanguis and S. mutans LTAs, LA-14-PP, and anti-CD14 MAb had no significant effect on phorbol myristate acetate-stimulated IL-8 secretion by HGF. These LTAs also inhibited the IL-8-inducing activity of B. subtilis LTA on CD14(high) HGF, as did LA-14-PP and anti-CD14 MAb. The antagonistic and agonistic functions of LTAs were also observed with human monocytes. Binding of fluorolabeled LPS to human monocytes was inhibited by S. sanguis LTA, although the inhibition was 100 times weaker than that of LPS itself, and anti-CD14 MAb inhibited fluorolabeled LPS and S. sanguis LTA binding. Binding of LTAs to CD14 was also observed with nondenaturing polyacrylamide gel electrophoresis. These results indicate that LTAs act as antagonists or agonists via a CD14-dependent mechanism, probably due to the heterogeneous structure of LTAs, and that an antagonistic LTA might be a useful agent for suppressing the periodontal disease caused by gram-negative bacteria.

Topics: Antibodies, Monoclonal; Bacillus subtilis; Fibroblasts; Gingiva; Humans; Interleukin-1; Interleukin-8; Lipid A; Lipopolysaccharide Receptors; Lipopolysaccharides; Monocytes; Streptococcus mutans; Streptococcus sanguis; Teichoic Acids

Toll-like receptor (TLR) 2 and TLR4 are implicated in the recognition of various bacterial cell wall components, such as lipopolysaccharide (LPS). To investigate in vivo roles of TLR2, we generated TLR2-deficient mice. In contrast to LPS unresponsiveness in TLR4-deficient mice, TLR2-deficient mice responded to LPS to the same extent as wild-type mice. TLR2-deficient macrophages were hyporesponsive to several Gram-positive bacterial cell walls as well as Staphylococcus aureus peptidoglycan. TLR4-deficient macrophages lacked the response to Gram-positive lipoteichoic acids. These results demonstrate that TLR2 and TLR4 recognize different bacterial cell wall components in vivo and TLR2 plays a major role in Gram-positive bacterial recognition.

Topics: Animals; Antigens, Bacterial; Cell Wall; Corynebacterium diphtheriae; Drosophila Proteins; Escherichia coli; Female; Gram-Negative Bacteria; Gram-Positive Bacteria; Interleukin-1 Receptor-Associated Kinases; Lipid A; Lipopolysaccharides; Macrophages, Peritoneal; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Nocardia; Peptidoglycan; Protein Isoforms; Protein Kinases; Receptors, Cell Surface; Salmonella; Signal Transduction; Species Specificity; Staphylococcus aureus; Teichoic Acids; Toll-Like Receptor 2; Toll-Like Receptor 4; Toll-Like Receptors

Our purpose was to determine whether cultured human decidual cells produce chemokines in response to different strains of group B streptococci and purified bacterial cell wall components.. Human decidual cells were cultured from term placentas by standard techniques. Different strains of group B streptococci were isolated from neonates with early-onset group B streptococci sepsis. Confluent cell monolayers were incubated with these different strains of group B streptococci and various concentrations of purified bacterial cell wall components (including lipoteichoic acid, sialic acid, lipopolysaccharide, and lipid A) for 16 hours at 37 degrees C. Culture supernatants were collected and assayed for macrophage inflammatory protein-1 alpha and interleukin-8. Statistical analysis was by analysis of variance.. We found that cultured human decidual cells produced significant amounts of the two chemokines macrophage inflammatory protein-1 alpha and interleukin-8 in a strain-specific fashion to the various different strains of group B streptococci tested, from 215% to 421% over baseline production (p < 0.05 by analysis of variance). Also, we found that incubation of decidual cells with various concentrations of lipoteichoic acid, sialic acid, lipopolysaccharide, and lipid A resulted in significant concentration-dependent increases in decidual cell macrophage inflammatory protein-1 alpha and interleukin-8 production (p < 0.05.). Decidual cells produced significant amounts of the chemokines macrophage inflammatory protein-1 alpha and interleukin-8 in response to intact group B streptococci in a strain-specific fashion and in response to various concentrations of different bacterial cell wall components. Because chemokines are important mediators signaling migration of different immune effector cells into areas of inflammation, we suggest that decidual cell chemokine production in response to bacteria and bacterial cell wall components may be a key early event in the pathogenesis of infection-associated preterm labor.

Topics: Analysis of Variance; Cell Wall; Cells, Cultured; Chemokine CCL4; Cytokines; Decidua; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Female; Humans; Interleukin-8; Lipid A; Lipopolysaccharides; Macrophage Inflammatory Proteins; N-Acetylneuraminic Acid; Pregnancy; Streptococcus agalactiae; Teichoic Acids

To determine whether cultured human decidual cells and chorion cells produce interleukin-10 (IL-10) after incubation with purified bacterial products.. Decidual cell cultures and chorion cell cultures were established by standard techniques. With confluence, monolayers of each culture were incubated with purified bacterial products, including various concentrations of lipopolysaccharide (LPS), lipid A, and lipoteichoic acid (LTA) for 16 hr in quadruplicate. Culture supernatants were collected and assayed for immunodetectable IL-10 by enzyme-linked immunoadsorbent assay (ELISA).. Both decidual cell cultures and chorion cell cultures produced significant quantities of IL-10 after stimulation with LPS, lipid A, and LTA. Cultures of decidual cells produced more IL-10 than did chorion cell cultures.. Our data indicate that both maternal decidual cells and fetally derived chorion cells can produce IL-10 after incubation with bacterial virulence factors. This finding contrasts with our previous findings in which chorion cells did not produce IL-10 after stimulation with IL-1 beta, suggesting that chorion cell production after incubation with bacterial products is independent of IL-1 beta. We speculate that the contribution of anti-inflammatory IL-10 production by human gestational tissues to the inflammatory process in these tissues may be overcome or abrogated by the pro-inflammatory process.

Topics: Bacterial Infections; Cells, Cultured; Chorion; Decidua; Female; Humans; Interleukin-10; Lipid A; Lipopolysaccharides; Obstetric Labor, Premature; Pregnancy; Pregnancy Complications, Infectious; Teichoic Acids

Topics: Adult; Antibodies, Antiphospholipid; Antibodies, Bacterial; Female; Humans; Lipid A; Lipopolysaccharides; Lupus Erythematosus, Systemic; Male; Middle Aged; Teichoic Acids

The aim of this study was to develop an in vitro test system for pyrogenic substances. Three clones derived from human monocytoid cell lines, which were selected by their high sensitivity to lipopolysaccharide (LPS), were assessed for tumor necrosis factor (TNF) production. Their response to pyrogen-containing samples was compared with that in a Limulus amoebocyte lysate assay and the rabbit pyrogen test. We show here that the induction of TNF in these clones is a valid in vitro alternative to determine endotoxin in commercial preparations requiring pyrogenicity testing. Cell clones derived from Mono Mac 6 (MM6 2H8 and MM6 4B5) responded to sub-ng/ml concentrations of complete rough-strain and smooth-strain LPS, to ng/ml concentrations of diphosphoryl-lipid A, and to microgram/ml concentrations of monophosphoryl-lipid A and to detoxified LPS. Cells reacted to > or = 1 microgram/ml lipoteichoic acid by TNF production, and were relatively insensitive to toxic shock syndrome toxin-1 (TSST-1) and to muramyl dipeptide adjuvant peptide. The reaction pattern of a clone derived from THP-1 (THP-1 1G3) was in general, similar to that of the MM6 clones, except that THP-1 1G3 failed to react to diphosphoryl-lipid A. When tested on commercial samples destined for parenteral use, there was a close correlation between a sensitive Limulus amoebocyte lysate (LAL) test and the cell culture test on the one hand, and between the pyrogen test and the cell culture test on the other hand. The data suggest that this cell-based test is able to recognize pyrogens derived from gram-negative organisms in test samples with appropriate sensitivity and specificity. This test appears to be able to eliminate some of the false-positive data obtained in the LAL test.

Topics: Acetylmuramyl-Alanyl-Isoglutamine; Animals; Bacterial Toxins; Bacterial Vaccines; Biological Assay; Clone Cells; Endotoxins; Enterotoxins; False Positive Reactions; Humans; Limulus Test; Lipid A; Lipopolysaccharides; Monocytes; Pyrogens; Rabbits; Sensitivity and Specificity; Superantigens; Teichoic Acids; Tumor Necrosis Factor-alpha

It still remains unclear how anti-phospholipid antibody develops in a specific patient group, however, it is possible that certain microorganism(s) may cause anti-cardiolipin antibody (aCL) development since aCL is frequently detected in patients with Treponema pallidum (TP) and/or other infectious diseases. Accordingly, we conducted an investigation to clarify whether or not anticardiolipin antibody (aCL) and/or lupus anticoagulant (LA) can be induced in rabbits by immunization with Gram-positive or -negative microorganism derivatives, such as lipoteichoic acid, lipopolysaccharide and lipid A. We detected the induction of SLE type-aCL (beta 2GPI-dependent) and LA in some rabbits immunized with lipid A and lipoteichoic acid, thereby suggesting that some microorganisms may contribute to even the production of pathogenic (SLE-type) antiphospholipid antibody.

Topics: Animals; Antibodies, Anticardiolipin; Antibody Formation; Immunization; Lipid A; Lipopolysaccharides; Lupus Coagulation Inhibitor; Rabbits; Teichoic Acids

Lipid A (LA), ketodeoxyoctonate (KDO) and lipoteichoic acids (LTA) were used to produce homologous polyclonal antibodies. These haptens were administered to rabbits in differing immunogenic forms, using multiple intradermal and intraperitoneal injections with complete Freund adjuvant. Booster injections were either made intradermally with incomplete Freund adjuvant or intravenously in saline. The immune-response was monitored regularly with an enzyme-immunoassay. Lipid A and KDO covalently linked to bovine serum albumin (BSA), with hapten densities per BSA molecule of 17 and 9, respectively, produced nondetectable immune-response. Acid-hydrolysed and intact cells of Salmonella minnesota Re 595 used as LA and KDO immunogens, respectively, produced significant immune-response when administered intradermally or intraperitoneally. Good immune-response was obtained with LTA covalently linked to BAS. However, a better result was obtained with crude LTA, containing 21.5% proteins. Generally, the lengthy immunization schedules used produced IgG antibodies to the antigens and the highest reciprocal titres attained were 75,000, 55,000 and 150,000 for LA, KDO and LTA, respectively. Meaningful expression of antisera titres by enzyme-immunoassay is discussed. We defined titre as the reciprocal antiserum dilution of the intercept of the mid-point on the linear section ending at 0.2 absorbance on the antiserum dilution curve.

Topics: Animals; Antibodies, Bacterial; Antigens, Bacterial; Cell Membrane; Female; Immunization; Immunization, Secondary; Immunoenzyme Techniques; Injections, Intradermal; Injections, Intraperitoneal; Lacticaseibacillus casei; Lipid A; Lipopolysaccharides; Rabbits; Salmonella; Sugar Acids; Teichoic Acids