Lipoteichoic Acid Is Important in Innate Immune Responses to Gram-Positive Bacteria

ABSTRACTTo define the role of lipoteichoic acid (LTA) in innate immunity to gram-positive bacteria, we investigated the production of tumor necrosis factor alpha (TNF-α) by macrophages stimulated with gram-positive bacterial culture supernatants (GPCSs) after their LTA was removed or inactivated. GPCSs were obtained from three gram-positive species (pneumococci, staphylococci, and group B streptococci) during the exponential growth phase (designated early GPCSs) or at the senescent stage (designated late GPCSs). LTA was removed using an anti-LTA antibody or was inactivated by alkaline hydrolysis or platelet-activating factor acetylhydrolase (PAF-AH) treatment. Both early and late GPCSs from the three gram-positive bacteria stimulated macrophages to produce TNF-α primarily via Toll-like receptor 2 (TLR2), although late pneumococcal supernatant could stimulate macrophages via TLR4 as well. Following LTA inactivation by both methods, early GPCS lost about 85 to 100% of its activity and late GPCS lost about 50 to 90%. Both early and late culture supernatants fromEscherichia colicould be inactivated by alkali hydrolysis but not by PAF-AH. In addition, removal of LTA from an early staphylococcal culture supernatant with a monoclonal antibody reduced about 70 to 85% of its potency. Reconstitution of inactivated early GPCS with a highly purified LTA restored its inflammatory activity, but the restored GPCS had higher activity than the pure LTA alone. These findings indicate that LTA is the primary TLR2 ligand in the early phase of gram-positive bacterial infection and remains a major ligand in the late phase when another TLR2 and TLR4 ligand(s) appears. In addition, our findings suggest that another gram-positive bacterial factor(s) synergizes with LTA in inducing inflammatory responses.

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Lipopolysaccharide- and gram-positive bacteria-induced cellular inflammatory responses: role of heterotrimeric Gαi proteins

AJP Cell Physiology ◽

10.1152/ajpcell.00394.2004 ◽

2005 ◽

Vol 289 (2) ◽

pp. C293-C301 ◽

Cited By ~ 32

Author(s):

Hongkuan Fan ◽

Basilia Zingarelli ◽

Octavia M. Peck ◽

Giuseppe Teti ◽

George E. Tempel ◽

...

Keyword(s):

Inflammatory Responses ◽

Neutrophil Infiltration ◽

In Vivo Studies ◽

Myeloperoxidase Activity ◽

Group B Streptococci ◽

Gram Positive ◽

Lps Challenge ◽

Tnf Α ◽

Genetic Deletion

Heterotrimeric Gi proteins may play a role in lipopolysaccharide (LPS)-activated signaling through Toll-like receptor 4 (TLR4), leading to inflammatory mediator production. Although LPS is a TLR4 ligand, the gram-positive bacterium Staphylococcus aureus (SA) is a TLR2 ligand, and group B streptococci (GBS) are neither TLR2 nor TLR4 ligands but are MyD88 dependent. We hypothesized that genetic deletion of Gi proteins would alter mediator production induced by LPS and gram-positive bacterial stimulation. We examined genetic deletion of Gαi2 or Gαi1/3 protein in Gαi2-knockout (Gαi2−/−) or Gαi1/3-knockout (Gαi1/3−/−) mice. LPS-, heat-killed SA-, or GBS-induced mediator production in splenocytes or peritoneal macrophages (MΦ) was investigated. There were significant increases in LPS-, SA-, and GBS-induced production of TNF-α and IFN-γ in splenocytes from Gαi2−/− mice compared with wild-type (WT) mice. Also, LPS-induced TNF-α was increased in splenocytes from Gαi1/3−/− mice. In contrast to splenocytes, LPS-, SA-, and GBS-induced TNF-α, IL-10, and thromboxane B2 (TxB2) production was decreased in MΦ harvested from Gαi2−/− mice. Also, LPS-induced production of IL-10 and TxB2 was decreased in MΦ from Gαi1/3−/− mice. In subsequent in vivo studies, TNF-α levels after LPS challenge were significantly greater in Gαi2−/− mice than in WT mice. Also, myeloperoxidase activity, a marker of tissue neutrophil infiltration, was significantly increased in the gut and lung of LPS-treated Gαi2−/− mice compared with WT mice. These data suggest that Gi proteins differentially regulate murine TLR-mediated inflammatory cytokine production in a cell-specific manner in response to both LPS and gram-positive microbial stimuli.

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Gram-positive bacteria cell wall-derived lipoteichoic acid induces inflammatory alveolar bone loss through prostaglandin E production in osteoblasts

Scientific Reports ◽

10.1038/s41598-021-92744-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tsukasa Tominari ◽

Ayumi Sanada ◽

Ryota Ichimaru ◽

Chiho Matsumoto ◽

Michiko Hirata ◽

...

Keyword(s):

Cell Wall ◽

Bone Loss ◽

Alveolar Bone ◽

Osteoclast Differentiation ◽

Lipoteichoic Acid ◽

Alveolar Bone Loss ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

AbstractPeriodontitis is an inflammatory disease associated with severe alveolar bone loss and is dominantly induced by lipopolysaccharide from Gram-negative bacteria; however, the role of Gram-positive bacteria in periodontal bone resorption remains unclear. In this study, we examined the effects of lipoteichoic acid (LTA), a major cell-wall factor of Gram-positive bacteria, on the progression of inflammatory alveolar bone loss in a model of periodontitis. In coculture of mouse primary osteoblasts and bone marrow cells, LTA induced osteoclast differentiation in a dose-dependent manner. LTA enhanced the production of PGE2 accompanying the upregulation of the mRNA expression of mPGES-1, COX-2 and RANKL in osteoblasts. The addition of indomethacin effectively blocked the LTA-induced osteoclast differentiation by suppressing the production of PGE2. Using ex vivo organ cultures of mouse alveolar bone, we found that LTA induced alveolar bone resorption and that this was suppressed by indomethacin. In an experimental model of periodontitis, LTA was locally injected into the mouse lower gingiva, and we clearly detected alveolar bone destruction using 3D-μCT. We herein demonstrate a new concept indicating that Gram-positive bacteria in addition to Gram-negative bacteria are associated with the progression of periodontal bone loss.

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Mixed liposomes containing gram-positive bacteria lipids: Lipoteichoic acid (LTA) induced structural changes

Colloids and Surfaces B Biointerfaces ◽

10.1016/j.colsurfb.2020.111551 ◽

2021 ◽

Vol 199 ◽

pp. 111551

Author(s):

Bhavesh Bharatiya ◽

Gang Wang ◽

Sarah E. Rogers ◽

Jan Skov Pedersen ◽

Stephen Mann ◽

...

Keyword(s):

Structural Changes ◽

Lipoteichoic Acid ◽

Gram Positive ◽

Gram Positive Bacteria

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Gram-positive bacteria secrete RNA aptamers to activate human STING for IL-1β release.

10.1101/2021.07.21.453173 ◽

2021 ◽

Author(s):

Shivalee N Duduskar ◽

Mohamed Ghait ◽

Martin Westermann ◽

Huijuan Guo ◽

Anuradha Ramoji ◽

...

Keyword(s):

Molecular Mechanisms ◽

Rna Aptamers ◽

Inflammasome Activation ◽

Accessory Gene ◽

Group B Streptococci ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Accessory Gene Regulator ◽

New Perspective ◽

Group B

Molecular mechanisms through which Gram-positive bacteria induce the canonical inflammasome are poorly understood. Here, we studied the effects of Group B streptococci (GBS) and Staphylococcus aureus (SA) on inflammasome activation in human macrophages. Dinucleotide binding small RNA aptamers released by SA and GBS were shown to trigger increased IL-1β generation by inflammasomes. The stimulator of interferon genes-STING as a central mediator of innate immune responses has been identified as the key target of pathogenic RNA. Multi-lamellar lipid bodies (MLBs) produced by SA function as vehicles for the RNA aptamers. Notably, expression of RNA aptamers is controlled by an accessory gene regulator quorum sensing system of the bacteria. These findings have been translated to patients with Gram-positive sepsis showing hallmarks of MLB-RNA-mediated inflammasome activation. Together our findings may provide a new perspective for the pathogenicity of Gram-positive bacterial infection in man.

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Defect in neutrophil killing and increased susceptibility to infection with nonpathogenic gram-positive bacteria in peptidoglycan recognition protein-S (PGRP-S)–deficient mice

Blood ◽

10.1182/blood-2002-12-3853 ◽

2003 ◽

Vol 102 (2) ◽

pp. 689-697 ◽

Cited By ~ 128

Author(s):

Roman Dziarski ◽

Kenneth A. Platt ◽

Eva Gelius ◽

Håkan Steiner ◽

Dipika Gupta

Keyword(s):

Inflammatory Responses ◽

Protein S ◽

Intracellular Killing ◽

Gram Positive ◽

Peptidoglycan Recognition Protein ◽

Susceptibility To Infection ◽

Gram Positive Bacteria ◽

Recognition Protein ◽

Factor Α ◽

Increased Susceptibility

AbstractInsect peptidoglycan recognition protein-S (PGRP-S), a member of a family of innate immunity pattern recognition molecules conserved from insects to mammals, recognizes bacterial cell wall peptidoglycan and activates 2 antimicrobial defense systems, prophenoloxidase cascade and antimicrobial peptides through Toll receptor. We show that mouse PGRP-S is present in neutrophil tertiary granules and that PGRP-S–deficient (PGRP-S-/-) mice have increased susceptibility to intraperitoneal infection with gram-positive bacteria of low pathogenicity but not with more pathogenic gram-positive or gram-negative bacteria. PGRP-S-/- mice have normal inflammatory responses and production of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6). Neutrophils from PGRP-S-/- mice have normal phagocytic uptake of bacteria but are defective in intracellular killing and digestion of relatively nonpathogenic gram-positive bacteria. Therefore, mammalian PGRP-S functions in intracellular killing of bacteria. Thus, only bacterial recognition by PGRP-S, but not its effector function, is conserved from insects to mammals.

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Innate Immune Responses of Human Neonatal Cells to Bacteria from the Normal Gastrointestinal Flora

Infection and Immunity ◽

10.1128/iai.70.12.6688-6696.2002 ◽

2002 ◽

Vol 70 (12) ◽

pp. 6688-6696 ◽

Cited By ~ 145

Author(s):

Helen Karlsson ◽

Christina Hessle ◽

Anna Rudin

Keyword(s):

Immune System ◽

Mononuclear Cells ◽

Innate Immune ◽

Enzyme Linked Immunosorbent Assay ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Tnf Α ◽

Adult Cells

ABSTRACT The hygiene hypothesis postulates that the prevalence of allergy has increased due to decreased microbial stimulation early in life, leading to delayed maturation of the immune system. The aim of this study was to examine the cytokine pattern produced from cord blood mononuclear cells relative to adult cells after stimulation with bacterial strains from the normal flora. Mononuclear cells from cord and adult blood samples were stimulated with the following bacteria: Bifidobacterium adolescentis, Enterococcus faecalis, Lactobacillus plantarum, Streptococcus mitis, Corynebacterium minutissimum, Clostridium perfringens, Bacteroides vulgatus, Escherichia coli, Pseudomonas aeruginosa, Veillonella parvula, and Neisseria sicca. The levels of interleukin 12 (IL-12), tumor necrosis factor alpha (TNF-α), IL-10, and IL-6 were measured by enzyme-linked immunosorbent assay. The TNF-α production was also analyzed after blocking CD14, Toll-like receptor 2 (TLR-2), and TLR-4 prior to stimulation with bacteria. The levels of IL-12 and TNF-α were similar in cord and adult cells. Gram-positive bacteria induced considerably higher levels of IL-12 and TNF-α than gram-negative bacteria in both cord and adult cells. The levels of IL-6 were significantly higher in newborns than in adults, whereas the levels of IL-10 were similar in newborns and adults. Gram-negative and gram-positive bacteria induced similar levels of IL-6 and IL-10 in cord cells. L. plantarum bound or signaled through CD14, TLR-2, and TLR-4, whereas E. coli acted mainly through CD14 and TLR-4. These results indicate that the innate immune response in newborns to commensal bacteria is strong and also suggest that different bacterial strains may have differential effects on the maturation of the immune system of infants.

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L-Ficolin Specifically Binds to Lipoteichoic Acid, a Cell Wall Constituent of Gram-Positive Bacteria, and Activates the Lectin Pathway of Complement

The Journal of Immunology ◽

10.4049/jimmunol.172.2.1198 ◽

2004 ◽

Vol 172 (2) ◽

pp. 1198-1202 ◽

Cited By ~ 186

Author(s):

Nicholas J. Lynch ◽

Silke Roscher ◽

Thomas Hartung ◽

Siegfried Morath ◽

Misao Matsushita ◽

...

Keyword(s):

Cell Wall ◽

Lipoteichoic Acid ◽

Lectin Pathway ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Cell Wall Constituent ◽

A Cell

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Mechanism of Gram-positive Shock: Identification of Peptidoglycan and Lipoteichoic Acid Moieties Essential in the Induction of Nitric Oxide Synthase, Shock, and Multiple Organ Failure

Journal of Experimental Medicine ◽

10.1084/jem.188.2.305 ◽

1998 ◽

Vol 188 (2) ◽

pp. 305-315 ◽

Cited By ~ 164

Author(s):

Ken M. Kengatharan ◽

Sjef De Kimpe ◽

Caroline Robson ◽

Simon J. Foster ◽

Christoph Thiemermann

Keyword(s):

Nitric Oxide ◽

Multiple Organ Failure ◽

Organ Failure ◽

Lipoteichoic Acid ◽

Interferon Γ ◽

Multiple Organ ◽

Organ Injury ◽

Gram Positive ◽

Gram Positive Bacteria ◽

No Formation

The incidence of septic shock caused by gram-positive bacteria has risen markedly in the last few years. It is largely unclear how gram-positive bacteria (which do not contain endotoxin) cause shock and multiple organ failure. We have discovered recently that two cell wall fragments of the pathogenic gram-positive bacterium Staphylococcus aureus, lipoteichoic acid (LTA) and peptidoglycan (PepG), synergize to cause the induction of nitric oxide (NO) formation, shock, and organ injury in the rat. We report here that a specific fragment of PepG, N-acetylglucosamine-β-[1→ 4]-N-acetylmuramyl-l-alanine–d-isoglutamine, is the moiety within the PepG polymer responsible for the synergism with LTA (or the cytokine interferon γ) to induce NO formation in the murine macrophage cell line J774.2. However, this moiety is also present in the PepG of the nonpathogenic bacterium Bacillus subtilis. We have discovered subsequently that S. aureus LTA synergizes with PepG from either bacterium to cause enhanced NO formation, shock, and organ injury in the rat, whereas the LTA from B. subtilis does not synergize with PepG of either bacterium. Thus, we propose that the structure of LTA determines the ability of a particular bacterium to cause shock and multiple organ failure (pathogenicity), while PepG acts to amplify any response induced by LTA.

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