scholarly journals Predominant phosphorylation patterns in Neisseria meningitidis lipid A determined by top-down MS/MS

2020 ◽  
Vol 61 (11) ◽  
pp. 1437-1449
Author(s):  
Constance M. John ◽  
Nancy J. Phillips ◽  
Gary A. Jarvis
Keyword(s):  
Inflammatory Cytokines ◽  
Ion Mobility ◽  
Posttranslational Modifications ◽  
Lipid A ◽  
Molecular Ions ◽  
Innate Immune ◽  
Toll Like Receptor 4 ◽  
Adaptive Immune ◽  
Phosphoryl Groups ◽  
Pro Inflammatory Cytokines

Among the virulence factors in Neisseria infections, a major inducer of inflammatory cytokines is the lipooligosaccharide (LOS). The activation of NF-κB via extracellular binding of LOS or lipopolysaccharide (LPS) to the toll-like receptor 4 and its coreceptor, MD-2, results in production of pro-inflammatory cytokines that initiate adaptive immune responses. LOS can also be absorbed by cells and activate intracellular inflammasomes, causing the release of inflammatory cytokines and pyroptosis. Studies of LOS and LPS have shown that their inflammatory potential is highly dependent on lipid A phosphorylation and acylation, but little is known on the location and pattern of these posttranslational modifications. Herein, we report on the localization of phosphoryl groups on phosphorylated meningococcal lipid A, which has two to three phosphate and zero to two phosphoethanolamine substituents. Intact LOS with symmetrical hexa-acylated and asymmetrical penta-acylated lipid A moieties was subjected to high-resolution ion mobility spectrometry MALDI-TOF MS. LOS molecular ions readily underwent in-source decay to give fragments of the oligosaccharide and lipid A formed by cleavage of the ketosidic linkage, which enabled performing MS/MS (pseudo-MS3). The resulting spectra revealed several patterns of phosphoryl substitution on lipid A, with certain species predominating. The extent of phosphoryl substitution, particularly phosphoethanolaminylation, on the 4′-hydroxyl was greater than that on the 1-hydroxyl. The heretofore unrecognized phosphorylation patterns of lipid A of meningococcal LOS that we detected are likely determinants of both pathogenicity and the ability of the bacteria to evade the innate immune system.

Toll‐like receptor 4 polymorphisms were associated with low serum pro‐inflammatory cytokines in BCG osteitis survivors

2019 ◽  
Vol 109 (7) ◽  
pp. 1417-1422 ◽  
Author(s):  
Matti Korppi ◽  
Johanna Teräsjärvi ◽  
Eero Lauhkonen ◽  
Heini Huhtala ◽  
Kirsi Nuolivirta ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Low Serum ◽  
Pro Inflammatory Cytokines

scholarly journals Peptidoglycan derived from Lactobacillus rhamnosus MLGA up-regulates the expression of chicken β-defensin 9 without triggering an inflammatory response

2020 ◽  
Vol 26 (8) ◽  
pp. 733-745
Author(s):  
Juan Huang ◽  
Junhui Li ◽  
Qiufen Li ◽  
Lin Li ◽  
Nianhua Zhu ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Immune Responses ◽  
Mrna Expression ◽  
Salmonella Enteritidis ◽  
Lactobacillus Rhamnosus ◽  
Innate Immune ◽  
Induction Effect ◽  
Adaptive Immune ◽  
Critical Components ◽  
Pro Inflammatory Cytokines

Defensins are critical components of the innate immune system and play an important role in the integration of innate and adaptive immune responses. Although information on the immunomodulatory properties of peptidoglycan from bacteria is abundant, little is known about the β-defensin induction effect of peptidoglycan from the probiotic Lactobacillus. This study investigated the effect of intact peptidoglycan from L. rhamnosus MLGA on the induction of avian β-defensin 9 in chicken immune cells and intestinal explants. Peptidoglycan from Lactobacillus rhamnosus MLGA dose dependently promoted avian β-defensin 9 mRNA expression in chicken PBMCs, splenocytes, thymocytes, hepatocytes, and chicken embryo jejunum, ileum, and cecum explants and increased the capacity of PBMC or splenocyte lysates to inhibit the growth of Salmonella Enteritidis. In contrast to the effect of L. rhamnosus MLGA-derived peptidoglycan, peptidoglycan derived from pathogenic Staphylococcus aureus reduced avian β-defensin 9 mRNA expression in chicken PBMCs and splenocytes. The inducible effect of peptidoglycan from L. rhamnosus MLGA on avian β-defensin 9 expression in PBMCs and splenocytes was observed without activation of the expression of associated pro-inflammatory cytokines IL-1β, IL-8, and IL-12p40, whereas these cytokine expressions were suppressed by peptidoglycan hydrolysate obtained by lysozyme digestion. The results of the present study show the capability of peptidoglycan derived from L. rhamnosus MLGA to induce the antimicrobial peptide defensin while simultaneously avoiding the deleterious risks of an inflammatory response.

Effects of local lipopolysaccharide administration on the expression of Toll-like receptor 4 and pro-inflammatory cytokines in uterus and oviduct of rabbit does

2018 ◽  
Vol 107 ◽  
pp. 162-174 ◽  
Author(s):  
Laura Menchetti ◽  
Olimpia Barbato ◽  
Iulia Elena Filipescu ◽  
Giovanna Traina ◽  
Leonardo Leonardi ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Pro Inflammatory Cytokines

scholarly journals Macrophages and Dendritic Cells Are Not the Major Source of Pro-Inflammatory Cytokines Upon SARS-CoV-2 Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Marc A. Niles ◽  
Patricia Gogesch ◽  
Stefanie Kronhart ◽  
Samira Ortega Iannazzo ◽  
Georg Kochs ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Inflammatory Cytokines ◽  
Immune Cells ◽  
Influenza A ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
M2 Macrophages ◽  
Myeloid Dendritic Cells ◽  
M1 And M2 Macrophages ◽  
Pro Inflammatory Cytokines

The exact role of innate immune cells upon infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and their contribution to the formation of the corona virus-induced disease (COVID)-19 associated cytokine storm is not yet fully understood. We show that human in vitro differentiated myeloid dendritic cells (mDC) as well as M1 and M2 macrophages are susceptible to infection with SARS-CoV-2 but are not productively infected. Furthermore, infected mDC, M1-, and M2 macrophages show only slight changes in their activation status. Surprisingly, none of the infected innate immune cells produced the pro-inflammatory cytokines interleukin (IL)−6, tumor necrosis factor (TNF)-α, or interferon (IFN)−α. Moreover, even in co-infection experiments using different stimuli, as well as non-influenza (non-flu) or influenza A (flu) viruses, only very minor IL-6 production was induced. In summary, we conclude that mDC and macrophages are unlikely the source of the first wave of cytokines upon infection with SARS-CoV-2.

scholarly journals Identification of PGN_1123 as the Gene Encoding Lipid A Deacylase, an Enzyme Required for Toll-Like Receptor 4 Evasion, inPorphyromonas gingivalis

2019 ◽  
Vol 201 (11) ◽  
Author(s):  
Sumita Jain ◽  
Ana M. Chang ◽  
Manjot Singh ◽  
Jeffrey S. McLean ◽  
Stephen R. Coats ◽  
...  
Keyword(s):  
Immune Response ◽  
Porphyromonas Gingivalis ◽  
Innate Immune Response ◽  
Lipid A ◽  
Innate Immune ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Gene Encoding ◽  
Content Type ◽  
Chronic Inflammatory Condition

ABSTRACTRemoval of one acyl chain from bacterial lipid A by deacylase activity is a mechanism used by many pathogenic bacteria to evade the host's Toll-like receptor 4 (TLR4)-mediated innate immune response. InPorphyromonas gingivalis, a periodontal pathogen, lipid A deacylase activity converts a majority of the initially synthesized penta-acylated lipid A, a TLR4 agonist, to tetra-acylated structures, which effectively evade TLR4 sensing by being either inert or antagonistic at TLR4. In this paper, we report successful identification of the gene that encodes theP. gingivalislipid A deacylase enzyme. This gene, PGN_1123 inP. gingivalis33277, is highly conserved withinP. gingivalis, and putative orthologs are phylogenetically restricted to theBacteroidetesphylum. Lipid A of ΔPGN_1123 mutants is penta-acylated and devoid of tetra-acylated structures, and the mutant strain provokes a strong TLR4-mediated proinflammatory response, in contrast to the negligible response elicited by wild-typeP. gingivalis. Heterologous expression of PGN_1123 inBacteroides thetaiotaomicronpromoted lipid A deacylation, confirming that PGN_1123 encodes the lipid A deacylase enzyme.IMPORTANCEPeriodontitis, commonly referred to as gum disease, is a chronic inflammatory condition that affects a large proportion of the population.Porphyromonas gingivalisis a bacterium closely associated with periodontitis, although how and if it is a cause for the disease are not known. It has a formidable capacity to dampen the host's innate immune response, enabling its persistence in diseased sites and triggering microbial dysbiosis in animal models of infection.P. gingivalisis particularly adept at evading the host's TLR4-mediated innate immune response by modifying the structure of lipid A, the TLR4 ligand. In this paper, we report identification of the gene encoding lipid A deacylase, a key enzyme that modifies lipid A to TLR4-evasive structures.

Activation of Rev-erbα attenuates lipopolysaccharide-induced inflammatory reactions in human endometrial stroma cells via suppressing TLR4-regulated NF-κB activation

2019 ◽  
Vol 51 (9) ◽  
pp. 908-914 ◽  
Author(s):  
Weijie Zhao ◽  
Liyuan Cui ◽  
Xixi Huang ◽  
Songcun Wang ◽  
Dajin Li ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Inflammatory Cytokines ◽  
Mrna Level ◽  
Biological Behavior ◽  
Mrna Levels ◽  
Toll Like Receptor 4 ◽  
Inflammatory Reactions ◽  
Endometrial Stroma ◽  
Behavior Function ◽  
Pro Inflammatory Cytokines

Abstract Perturbation of the circadian rhythm damages the biological characteristics of cells and leads to their dysfunction. Rev-erbα, an important gene in the transcription-translation loop of circadian rhythm, is involved in regulating the balance between pro-inflammation and anti-inflammation. The disruption of this balance in human endometrial stroma cells (hESCs) destroys their biological behavior function in maintaining the menstrual cycle and embryonic implantation. Whether pharmacological modulation of Rev-erbα affects the inflammation of hESCs remains unclear. In this study, we treated hESCs with lipopolysaccharide (LPS) and found that LPS treatment increased the mRNA levels of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, IL-8, IL-18, and TNFα, and the secretion of IL-6. SR9009, a Rev-erbα agonist, significantly alleviated the LPS-induced production of pro-inflammatory cytokines in hESCs. Meanwhile, knockdown of Rev-erbα increased the expressions of IL-1β, IL-6, and IL-8, accompanied by an increased mRNA level of the core clock gene Bmal1. Western blot analysis showed that SR9009 inhibited the expression of toll-like receptor 4 (TLR4) and the activation of NF-κB induced by LPS. All these findings suggested that pharmacological activation of Rev-erbα attenuated the LPS-induced inflammatory response of hESCs by suppressing TLR4-regulated NF-κB activation. This study may provide a strategy for preventing inflammation-related endometrial dysfunction and infertility or recurrent implantation failure.

Synergism between TLRs and NOD1/2 in Oral Epithelial Cells

2008 ◽  
Vol 87 (7) ◽  
pp. 682-686 ◽  
Author(s):  
A. Uehara ◽  
H. Takada
Keyword(s):  
Epithelial Cells ◽  
Immune Responses ◽  
Inflammatory Cytokines ◽  
Oral Bacteria ◽  
Innate Immune ◽  
Oral Epithelium ◽  
Innate Immune Responses ◽  
Oral Epithelial Cells ◽  
Oral Epithelial ◽  
Pro Inflammatory Cytokines

Oral epithelium is the first barrier against oral bacteria in periodontal tissue. Oral epithelial cells constitutively express Toll-like receptors (TLRs) and NOD1/2, functional receptors which induce the production of antibacterial factors such as peptidoglycan recognition proteins (PGRPs) and β-defensin 2, but not pro-inflammatory cytokines such as interleukin (IL)-8. In this study, we hypothesized that innate immune responses in the oral epithelium are enhanced in inflamed tissue. We found that NOD1 and NOD2 agonists, in combination with TLR agonists, synergistically induced production of PGRPs and of β-defensin 2 in human oral epithelial cells via NF-κB. In contrast, co-stimulation with NOD1/2 and TLR ligands had no effect on the production of pro-inflammatory cytokines (IL-6, IL-8, and monocyte chemoattractant protein-1). These findings indicate that, in innate immune responses to invading microbes, a combination of signaling through TLRs and NODs leads to the synergistic activation of antibacterial responses in the oral epithelium.

scholarly journals Effects of Adipose-Derived Biogenic Nanoparticle-Associated microRNA-451a on Toll-like Receptor 4-Induced Cytokines

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 16
Author(s):  
Xinghua Wang ◽  
Anthony Pham ◽  
Lu Kang ◽  
Sierra A. Walker ◽  
Irina Davidovich ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Signaling Pathways ◽  
Extracellular Vesicles ◽  
Inflammatory Cytokines ◽  
Stromal Cells ◽  
Toll Like Receptor ◽  
Immunomodulatory Effects ◽  
Toll Like Receptor 4 ◽  
Biogenic Nanoparticles ◽  
Pro Inflammatory Cytokines

Extracellular vesicles (EVs) are cell-released nanoparticles that transfer biomolecular content between cells. Among EV-associated biomolecules, microRNAs (miRNAs/miRs) represent one of the most important modulators of signaling pathways in recipient cells. Previous studies have shown that EVs from adipose-derived mesenchymal stromal cells (MSCs) and adipose tissue modulate inflammatory pathways in macrophages. In this study, the effects of miRNAs that are abundant in adipose tissue EVs and other biogenic nanoparticles (BiNPs) were assessed in terms of altering Toll-like receptor 4 (TLR4)-induced cytokines. TLR-4 signaling in macrophages is often triggered by pathogen or damage-induced inflammation and is associated with several diseases. This study demonstrates that miR-451a, which is abundant in adipose tissue BiNPs, suppresses pro-inflammatory cytokines and increases anti-inflammatory cytokines associated with the TLR4 pathway. Therefore, miR-451a may be partially responsible for immunomodulatory effects of adipose tissue-derived BiNPs.

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