Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The bactericidal activities of human complement and human antibody directed against specific Haemophilus influenzae type b cell surface determinants were investigated. Strain Eagan, a laboratory isolate, and strain Kn, a clinical isolate, were used as the test organisms and gave qualitatively similar results. In the absence of antibody, both isolates were resistant to killing by 60% agammaglobulinemic serum (AGS) containing normal complement levels. The addition of affinity-purified immunoglobulin G anticapsular antibody was bactericidal with 15% AGS as the complement source. Bactericidal activity was also demonstrated with this antibody when the complement source was AGS-Mg-EGTA [ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid], C2-deficient human serum (alternative complement pathway), or AGS in which factor D and properdin had been selectively inactivated (classical pathway). Immunoglobulin G fractions from a human serum pool or from serum from an adult who had recovered from H. influenzae type b (Kn) sepsis were absorbed to remove anticapsular antibody. The absorbed fractions containing noncapsular antibodies also activated complement-dependent bactericidal activity. But, in contrast to the results with anticapsular antibody, noncapsular antibodies did not elicit alternative pathway bactericidal activity. Incubation of cells of H. influenzae type b in C2-deficient serum or AGS-Mg-EGTA did not cause complement consumption (total hemolytic complement and C3). The addition of immunoglobulin G anticapsular antibody (but not noncapsular antibody) increased consumption of total complement and C3, paralleling the results of the bactericidal assays. These studies demonstrated an absolute requirement for anticapsular antibody in alternative pathway activation and killing of H. influenzae type b.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antibody-dependent alternative pathway killing of Haemophilus influenzae type b. 660 28

Renal replacement therapy in acute renal failure (ARF) and chronic renal failure (end-stage renal disease; ESRD) has been based on the use of modifications of dialysis (continuous arteriovenous hemofiltration and hemodiafiltration) to remove middle-molecular-weight toxins, consisting of low-molecular-weight proteins and peptides (LMWP) and cytokines involved in inflammation. High-flux dialyzers are not efficient at removing LMWP, and for this reason, sorbents have been studied to augment or replace dialysis. Removal of LMWP such as beta2-microglobulin, leptin, complement factor D, angiogenin and cytokines such as interleukin (IL)-1, IL-6, IL-10, IL-18 and tumor necrosis factor-alpha has been established in animal models of sepsis and in ESRD patients using sorbents. Sorbent devices added to hemodialysis, or the use of such devices alone in inflammatory states, including sepsis, ARF, cardiopulmonary bypass, pre-explantation of donor organs and ESRD, are being studied.
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PMID:Sorbents in acute renal failure and end-stage renal disease: middle molecule and cytokine removal. 1473 14

Standard renal replacement therapy in acute renal failure (ARF) and end-stage renal disease (ESRD) is based on membrane technology. The transition from natural cellulosic membranes to synthetic membranes has not been associated with improvement in mortality rates. Modifications of dialysis with continuous arteriovenous hemofiltration and hemodiafiltration to remove middle molecular weight toxins, low molecular weight proteins and peptides (LMWP) and cytokines involved in inflammation appear to have reached their limits. High flux dialyzers are not efficient at removing LMWP and for this reason sorbents to augment or replace dialysis have been used in clinical trials. Removal of LMWP such as beta2-microglobulin, leptin, complement factor D, angiogenin, and cytokines such as IL-1, IL-6, IL-10, IL-18 and TNFalpha, have been established in animal models of sepsis, and in ESRD patients using sorbents in conjunction with high flux dialysis. Sorbent devices added to hemodialysis, or alone in inflammatory states, are being studied in diseases which possess a common pathway of systemic inflammatory response syndrome; these states are sepsis, ARF, cardio-pulmonary bypass, in brain dead subjects prior to explantation of donor organs and ESRD.
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PMID:Sorbents in the treatment of renal failure. 1546

Therapeutic complement inhibition is a promising strategy for treatment of a number of diseases as judged from rodent studies. The species distance from rodents to humans may limit the clinical relevance of these studies. The pig is an alternative animal for studies of human diseases like sepsis and ischemia/reperfusion injury. However, available complement inhibitors for use in pigs are scarce. The aim of the present study was to investigate and compare the efficacy of selected candidate inhibitors of porcine complement in vitro for possible future application in vivo. Sera from three different pigs were each incubated with three different activators of the complement system (zymosan, heat-aggregated immunoglobulin G (HAIGG) and Escherichia coli). Three groups of complement inhibitor candidates were tested: serine protease inhibitors (FUT-175 and C1-inhibitor), monoclonal antibodies (anti-factor B (fB) and anti-factor D (fD)) and a recombinant regulatory protein (vaccinia virus complement control protein (VCP)). Read-out was the terminal C5b-9 complement complex (TCC). The serine protease inhibitors FUT-175 and C1-inhibitor dose-dependently inhibited TCC formation in zymosan-, HAIGG- and E. coli-activated porcine sera, but with different efficacy. Complete inhibition of TCC was obtained using 0.2 mg/mL FUT-175, but required 16 mg/mL of C1-inhibitor. The monoclonal anti-fB and -fD antibodies both inhibited TCC formation dose-dependently, but in different ways. Anti-fB at high dose (1 mg/mL) completely inhibited TCC formation in sera activated with zymosan and virtually completely in sera activated with HAIGG, but not in sera activated with E. coli. Anti-fD inhibited all three activators at low dose (0.05 mg/mL), and approximately 50% TCC reduction was obtained. The recombinant complement regulatory protein VCP efficiently and dose-dependently inhibited TCC formation with a complete inhibition found at 0.05 mg/mL for all three activators. All candidates tested inhibited porcine complement activation, but in different ways and to different degrees. Of the complement-specific candidates, VCP inhibited all activators completely at low doses.
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PMID:Candidate inhibitors of porcine complement. 1710 63

The relative role of complement and CD14 in E. coli-induced cytokine synthesis in an in vitro human whole blood model of sepsis was examined. Fresh lepirudin-anticoagulated whole blood was incubated with E. coli for 2h. Monoclonal antibodies or a C5a receptor antagonist were used to block complement. Inflammatory mediators (n=27) were measured by multiplex technology, selected cytokine mRNA by real time PCR, and CD11b, oxidative burst and phagocytosis by flow cytometry. E. coli significantly increased 18 of the 27 inflammatory mediators, including proinflammatory cytokines (TNF-alpha, IL-6, INF-gamma and IL-1beta), chemokines (IL-8, MCP-1, MIP-1alpha, MIP-1beta, eotaxin and IP-10), growth factors (VEGF, FGF-basic, G-CSF and GM-CSF) and other interleukins (IL-9, IL-15 and IL-17). Notably, the increases in all mediators were abolished by a combined inhibition of CD14 and complement using anti-C2 and anti-factor D in combination, whereas the relative effect of the inhibition of complement and CD14 varied. In comparison, a C5a receptor antagonist and anti-CD14 in combination reduced cytokine synthesis less efficiently. Real time PCR analysis confirmed that the cytokine synthesis was blocked at the mRNA level. Similarly, E. coli-induced CD11b up-regulation, oxidative burst and phagocytosis was totally inhibited by CD14, anti-C2 and anti-factor D in combination after 2h incubation. In conclusion, the combined inhibition of complement using anti-C2, anti-factor D and CD14 almost completely inhibits the E. coli-induced inflammatory response. The combined approach may therefore be a new treatment regimen in Gram-negative sepsis.
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PMID:Combined inhibition of complement and CD14 abolish E. coli-induced cytokine-, chemokine- and growth factor-synthesis in human whole blood. 1860 53

The cDNA encoding of a complement factor D/adipsin and kallikrein-like serine protease, designated PoDAK, was isolated from the olive flounder Paralichthys olivaceus. PoDAK cDNA encodes a polypeptide with 277 amino acids containing conserved catalytic triad residues of serine proteases. The amino acid sequence of PoDAK showed high similarity to the kallikrein-like protein of medaka, mammalian adipsin/complement factor D and tissue kallikrein homolog, KT-14 of trout, complement factor D of zebrafish, and shared 31.6-36.8% homology with complement factor D/adipsin known from other species, including mammals. Phylogenetic analysis revealed that PoDAK clustered with the kallikrein-like protein of medaka and mammalian adipsin/complement factor D and tissue kallikrein homolog KT-14 of trout. The expression of PoDAK mRNA was high in the gills and heart, moderate in muscle, liver, intestine, stomach, kidney, and spleen of healthy flounder, and increased in the kidney, liver, and spleen of flounder challenged by the viral hemorrhagic septicemia virus (VHSV) or Streptococcus iniae. In situ hybridization confirmed that PoDAK mRNA is localized in the kidney and heart of individuals infected with VHSV. Further investigations are needed to clarify the function of PoDAK in vivo and in vitro.
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PMID:An immune responsive complement factor D/adipsin and kallikrein-like serine protease (PoDAK) from the olive flounder Paralichthys olivaceus. 1959 42

Severe sepsis involves massive activation of the innate immune system and leads to high mortality. Previous studies have demonstrated that various types of TLRs mediate a systemic inflammatory response and contribute to organ injury and mortality in animal models of severe sepsis. However, the downstream mechanisms responsible for TLR-mediated septic injury are poorly understood. In this article, we show that activation of TLR2, TLR3, and TLR4 markedly enhanced complement factor B (cfB) synthesis and release by macrophages and cardiac cells. Polymicrobial sepsis, created by cecal ligation and puncture in a mouse model, augmented cfB levels in the serum, peritoneal cavity, and major organs including the kidney and heart. Cecal ligation and puncture also led to the alternative pathway activation, C3 fragment deposition in the kidney and heart, and cfB-dependent C3dg elevation. Bacteria isolated from septic mice activated the serum alternative pathway via a factor D-dependent manner. MyD88 deletion attenuated cfB/C3 upregulation as well as cleavage induced by polymicrobial infection. Importantly, during sepsis, absence of cfB conferred a protective effect with improved survival and cardiac function and markedly attenuated acute kidney injury. cfB deletion also led to increased neutrophil migratory function during the early phase of sepsis, decreased local and systemic bacterial load, attenuated cytokine production, and reduced neutrophil reactive oxygen species production. Together, our data indicate that cfB acts as a downstream effector of TLR signaling and plays a critical role in the pathogenesis of severe bacterial sepsis.
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PMID:Complement factor B is the downstream effector of TLRs and plays an important role in a mouse model of severe sepsis. 2415 27