Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0341503 (bacterial peritonitis)
 1,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bacterial infection triggers host inflammation through the activation of immune cells, leading to the elimination of bacteria. However, the regulatory mechanisms of the host inflammatory response remain unknown. Here we report that a subset of potent tolerogenic dendritic cells (DCs), regulatory DCs (DC(regs)), control the systemic inflammatory response. Unlike normal DCs, which produced proinflammatory cytokines in response to bacterial lipopolysaccharide (LPS), DC(regs) produced fewer proinflammatory cytokines and instead preferentially produced interleukin-10 (IL-10), and these events involved the expression of IkappaBNS and Bcl-3 as well as cyclic AMP (cAMP)-mediated activation of protein kinase A (PKA). In addition, DC(regs) not only suppressed LPS-induced production of proinflammatory cytokines in macrophages, but also reduced their serum levels in mice. Furthermore, DC(regs) protected mice against the lethality induced by experimental endotoxemia and bacterial peritonitis. The inhibitory effect of DC(regs) against inflammatory responses involved the production of IL-10. On the other hand, naturally existing tolerogenic DC subsets producing IL-10, CD11c(low)CD45RB(high) DCs, also suppressed LPS-induced host inflammatory responses. Thus, a subset of tolerogenic DCs act as potential regulators of the host inflammatory response, and they might have preventive and therapeutic potential for the treatment of systemic as well as local inflammatory diseases.
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PMID:Regulatory dendritic cells act as regulators of acute lethal systemic inflammatory response. 1641 Apr 44

Clearance of invading pathogens is essential to preventing overwhelming inflammation and sepsis that are symptomatic of bacterial peritonitis. Macrophages participate in this innate immune response by engulfing and digesting pathogens, a process called phagocytosis. Oxidized phospholipids (OxPL) are danger-associated molecular patterns (DAMPs) generated in response to infection that can prevent the phagocytic clearance of bacteria. We investigated the mechanism underlying OxPL action in macrophages. Exposure to OxPL induced alterations in actin polymerization, resulting in spreading of peritoneal macrophages and diminished uptake of E. coli. Pharmacological and cell-based studies showed that an anchored pool of PKA mediates the effects of OxPL. Gene silencing approaches identified the A-kinase anchoring protein (AKAP) WAVE1 as an effector of OxPL action in vitro. Chimeric Wave1(-/-) mice survived significantly longer after infection with E. coli and OxPL treatment in vivo. Moreover, we found that endogenously generated OxPL in human peritoneal dialysis fluid from end-stage renal failure patients inhibited phagocytosis via WAVE1. Collectively, these data uncover an unanticipated role for WAVE1 as a critical modulator of the innate immune response to severe bacterial infections.
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PMID:WAVE1 mediates suppression of phagocytosis by phospholipid-derived DAMPs. 2393 28