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Periodontal Disease and Osteomyelitis
Published in Wilson Harvey, Alan Bennett, Prostaglandins in Bone Resorption, 2020
Although LPS has received more attention than other bacterial components, these should not be overlooked. Lipoteichoic acids, which are polymers containing carbohydrates and fatty acids, are found in the cell wall of Gram-positive organisms which include some plaque-forming bacteria.56 Hausmann et al.33 showed that they were capable of stimulating bone resorption in culture, but were independent of endogenous PG synthesis. When the lipids were removed by hydrolysis, the remaining teichoic acid did not stimulate resorption. Similar properties were reported57 for an amphipathic antigen (αcA) from Actinomyces viscosus, a Gram-positive bacteria also found in dental plaque. It caused bone resorption dependent on the presence of its lipid moiety, but independent of PG synthesis in the bone.
Lipids of Candida Albicans
Published in Rajendra Prasad, Mahmoud A. Ghannoum, Lipids of Pathogenic Fungi, 2017
R. Prasad, A. Koul, P. K. Mukherjee, M. A. Ghannoum
Involvement of lipids in the form of lipoteichoic acids (LTA) and glycosphingolipids in the adherence of bacteria to host cells has been reported.103-105 The fatty acid moieties of LTA are believed to bind spontaneously to the molecules of the animal cells.105 It is known that acylated LTA are present mainly in association with the plasma membrane and such compounds become exposed to the surfaces of intact bacteria.106 Hakomori104 reported that glycosphingolipids are present in small amounts in the plasma membranes of animal cells, to which the fimbriae of Gram-negative bacteria adhere.
CD14, An Innate Immune Receptor for Various Bacterial Cell Wall Components
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
Artur J. Ulmer, Volker T. El-Samalouti, Ernst T. Rietschel, Hans-Dieter Flad, Roman Dziarski
Lipoteichoic acids (LTA) are glycolipids that are present in the cell wall of gram-positive but not gram-neg ative bacteria. They constitute, like LPS, negatively charged amphiphilic structures, which are hydrophobically anchored to the cell wall (55,56). Like other cell wall components, such as LPS and PG, LTA are also released from bacteria, in particular during treatment with cell wall-active antibiotics (56). It has, therefore, been discussed whether LTA may contribute to the inflammatory reactions observed in an infected host. Indeed, it has been shown by various groups that LTA preparations are able to induce the production of inflammatory cytokines (TNF, IL-18, IL-6, IL-8, and IL-12) as well as inducible nitric oxide synthase (iNOS) (57–60), both in vitro and in vivo. The activation of phosphatidylcholine-phospholipase C (PCPLC), phosphorylation of tyrosine kinases, as well as the transcription factor NF-κB was also demonstrated to be involved in the bioactivity of LTA (61). Despite the release of inflammatory cytokines, involved in the septic shock reaction, lethality or organ failure was not observed at relevant concentrations of LTA (62,63). More recently it was shown that LTA are able to act in synergy with PG (64). The synergistic action of these two gram-positive cell wall components was demonstrated in vitro after stimulation of murine J774.2 macrophages as well as in vivo after treatment of rats, which reacted with the production of TNF and IFN-γ. Furthermore, a synergism of LTA and PG during induction of iNOS as well as multiple organ dysfunction syndrome (MODS) was described. These findings provide strong evidence that LTA as well as PG may be involved in the fatal response after severe bacterial infections.
Photodynamic and peptide-based strategy to inhibit Gram-positive bacterial biofilm formation
Published in Biofouling, 2019
Laura Marise de Freitas, Esteban Nicolás Lorenzón, Eduardo Maffud Cilli, Kleber Thiago de Oliveira, Carla Raquel Fontana, Thomas S. Mang
Lipoteichoic acid is composed of a polymer of glycerol phosphate or ribitol phosphate attached to a diacylglycerol residue, responsible for the insertion of the polymer into the plasma membrane (Percy and Gründling 2014). Gram-positive bacteria incorporate teichoic acid polymers of varying lengths (15–50 residues, varying according to species) in their envelope, which directly influence the density of negative charges of the bacterial surface by the amount of phosphate groups present (Malanovic and Lohner 2015). Antimicrobial peptides with their overall positive charge are attracted by the negative charges of LTA and their binding to that molecule in the cell wall does not affect their bactericidal activity. This led to the postulation that the binding of the AMP to the LTA is the starting point for action on the membrane: AMPs anchor to the LTA and use it as a “ladder”, which leads them to the plasma membrane (Malanovic and Lohner 2015).
(3R)-5,6,7-trihydroxy-3-isopropyl-3-methylisochroman-1-one alleviates lipoteichoic acid-induced photoreceptor cell damage
Published in Cutaneous and Ocular Toxicology, 2018
As a major component of cell membrane in Gram-positive bacteria, lipoteichoic acid (LTA) is well-characterized for its induction of inflammatory responses7. LTA activates retinal microglia to result in an increased secretion of pro-inflammatory cytokines through the nuclear factor-κB (NF-κB)8. Over-production of pro-inflammatory cytokines can stimulate oxidants production with subsequent peroxidative damage to biological macromolecules such as proteins, lipids, and nucleic acids, resulting in the activation of intracellular toxic events by increasing the permeability of mitochondrial membrane, releasing cytochrome-c, activating caspase-related apoptotic proteins, and finally causing DNA damage and cell death9,10.
Communication between the gut microbiota and peripheral nervous system in health and chronic disease
Published in Gut Microbes, 2022
Tyler M. Cook, Virginie Mansuy-Aubert
Lipopolysaccharide and lipoteichoic acid are surface proteins found on gram-negative and gram-positive bacteria, respectively. LPS and LTA are considered pathogen-associated molecular patterns (PAMPs) because they can trigger innate immune responses through toll-like receptors (TLRs). Circulating LPS levels are altered based on diet,62 with increased levels in high fat diet (HFD) rodent models,63,64 and in people with a subset of IBS (diarrhea-predominant).65 LPS levels also correlate with weight gain,62 and chronic LPS injections can induce adipose macrophage infiltration66 and weight gain.63