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)

Toll-like receptor 2 (TLR2) and TLR4 play important roles in the early innate immune response to microbial challenge. To clarify the functional roles of TLRs 2 and 4 in mast cells, we examined bone marrow-derived mast cells (BMMCs) from TLR2 or TLR4 gene-targeted mice. Peptidoglycan (PGN) from Staphylococcus aureus stimulated mast cells in a TLR2-dependent manner to produce TNF-alpha, IL-4, IL-5, IL-6, and IL-13, but not IL-1beta. In contrast, LPS from Escherichia coli stimulated mast cells in a TLR4-dependent manner to produce TNF-alpha, IL-1beta, IL-6, and IL-13, but not IL-4 nor IL-5. Furthermore, TLR2- but not TLR4-dependent mast cell stimulation resulted in mast cell degranulation and Ca2+ mobilization. In a mast cell-dependent model of acute sepsis, TLR4 deficiency of BMMCs in mice resulted in significantly higher mortality because of defective neutrophil recruitment and production of proinflammatory cytokines in the peritoneal cavity. Intradermal injection of PGN led to increased vasodilatation and inflammation through TLR2-dependent activation of mast cells in the skin. Taken together, these results suggest that direct activation of mast cells via TLR2 or TLR4 by respective microligands contributes to innate and allergic immune responses.
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PMID:Differential responses of mast cell Toll-like receptors 2 and 4 in allergy and innate immunity. 1202 Dec 51

D40 is a cell surface protein belonging to the tumor necrosis factor (TNF) receptor family. Ligation of monocyte CD40 by the T cell-derived CD40 ligand can trigger the production of various mediators, the transcription and activation of enzymes, and the upregulation of costimulatory molecules involved in the pathogenesis of sepsis. To test the hypothesis that CD40 is expressed on the surface of monocytes during sepsis, we measured CD40 expression by flow cytometry on freshly sampled monocytes from 40 patients with severe sepsis, including 15 patients with bacteremia, and from eight healthy volunteers. Plasma concentrations of interleukin (IL) 6, IL-10, and IL-13 were also measured. We detected CD40 only on monocytes from patients with sepsis (mean 6.5 +/- 0.4 median channel fluorescence). There was an inverse correlation between peak CD40 expression and survival (P = 0.05), particularly in the patients with bacteremia (P = 0.019). In the bacteremic group, there was an inverse correlation between CD40 expression and bilirubin levels (r2 = 0.52, P = 0.004) and plasma IL-6 concentrations (r2 = 0.30, P = 0.04). Our results showed that upregulation of CD40 expression on peripheral blood monocytes is a protective phenomenon during severe sepsis. Monocyte deactivation reflected by low CD40 expression may represent impairment of immune function associated with severity of illness and poor outcome. Further studies on monocyte phenotype and function may help to assess the immune status of patients with sepsis and perhaps be useful to guide immunomodulatory strategy in the future.
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PMID:Monocyte CD40 expression in severe sepsis. 1255 39

Sepsis in experimental animals and humans has been associated with perturbed immune response. A major event contributing to the decrease in immune functions in septic disorders seems to be the inadequate balance of cytokines mediating the interactions between the innate and adaptive immune systems. We previously observed that a cyclic peptide derived from the Limulus anti-LPS factor (LALF), which partially protect mice from endotoxic shock lethality, has the ability to modulate cytokine secretion in vitro. We herein examined the effects of the LALF(31-52) peptide in an experimental model of Gram-negative peritoneal sepsis and analyzed the cytokine gene expression in the spleen and liver of peptide-treated mice. The prophylactic administration of LALF(31-52) abrogated the systemic TNF-alpha response, reduced organ damage and increased the survival of infected mice. Histological examination of spleen and liver in peptide-treated mice showed prevention of tissue damage induced by the high dose of Pseudomonas aeruginosa. This treatment modulates the cytokine gene expression in these tissues, stimulating IL-2, IL-12 and IL-13 mRNA synthesis, while IL-4 and IL-10 mRNA expression was not modified. This cytokine profile induced by the LALF-derived peptide seems to be favorable for host resistance against Gram-negative bacteria acute infection. In addition, peptide treatment was effective after the initiation of the systemic inflammatory response, promoting a significant increase in mice survival. These results further demonstrate the immunomodulatory potential of LALF(31-52) and are relevant for the design of prophylactic and therapeutic strategies for acute bacteria infection and sepsis, especially for preventing or ameliorating host immunity defects in these disorders.
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PMID:A Limulus anti-LPS factor-derived peptide modulates cytokine gene expression and promotes resolution of bacterial acute infection in mice. 1258 5

Macrophage/neutrophil-specific IL-4 receptor alpha-deficient mice (LysM(Cre)IL-4Ralpha(-/flox)) were generated to understand the role of IL-4/IL-13 responsive myeloid cells during Type 2 immune responses. LysM(Cre)IL-4Ralpha(-/flox) mice developed protective immunity against Nippostrongylus brasiliensis accompanied by T(H)2 development and goblet cell hyperplasia. In contrast, LysM(Cre)IL-4Ralpha(-/flox) mice were extremely susceptible to Schistosoma mansoni infection with 100% mortality during acute infection. Mortality was not dependent on neutrophils and occurred in the presence of T(H)2/Type 2 responses, granuloma formation, and egg-induced fibrosis. Death was associated with increased T(H)1 cytokines, hepatic and intestinal histopathology, increased NOS-2 activity, impaired egg expulsion, and sepsis. IL-10 was not able to compensate for the absence of IL-4/IL-13-activated alternative macrophages. Together, this shows that alternative macrophages are essential during schistosomiasis for protection against organ injury through downregulation of egg-induced inflammation.
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PMID:Alternative macrophage activation is essential for survival during schistosomiasis and downmodulates T helper 1 responses and immunopathology. 1514 30

C57BL/6 and BALB/c mice are prototypical Th1- and Th2-type mouse strains, respectively. In the present study, we attempted to characterize the innate immune response of macrophages from these mouse strains. Macrophages from C57BL/6 mice produced higher levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-12 than those from BALB/c mice after stimulation with macrophage-activating lipopeptide-2 (MALP-2, a synthetic TLR-2 ligand) or lipopolysaccharide (LPS, a TLR-4 ligand). The augmented IL-12 production by C57BL/6 macrophages increased interferon-gamma and, in contrast, decreased IL-13 production by CD4+ T cells. On stimulation with MALP-2 or LPS, C57BL/6 macrophages produced lysosomal enzyme and nitric oxide, effector molecules for bacterial killing, whereas BALB/c macrophages did not. Bactericidal activity of BALB/c macrophages was impaired relative to C57BL/6 macrophages when cells were infected with live bacteria in vitro. In a murine model of septic peritonitis induced by cecal ligation and puncture (CLP), BALB/c mice failed to facilitate bacterial clearance relative to C57BL/6 mice despite an augmented peritoneal leukocyte infiltration that was associated with increased peritoneal levels of cytokines/chemokines. BALB/c mice exhibited increased plasma and hepatic levels of cytokines/chemokines, resulting in an exaggerated systemic inflammation as determined by acute-phase proteins. Finally, BALB/c mice were vulnerable to CLP-induced lethality relative to C57BL/6 mice. Altogether, innate immune response of macrophages is different between these mouse strains, which may affect the development of Th1 and Th2 adaptive immunity in these strains. Reduced systemic inflammatory response in C57BL/6 mice that may result from an eminent local response appears to be beneficial during sepsis.
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PMID:Innate immune response in Th1- and Th2-dominant mouse strains. 1548 39

The activation of a pro-inflammatory cascade after infection, major surgery, burn or trauma appears to be important in the development of subsequent immune dysfunction, susceptibility to sepsis and multiple organ failure. It is well known that T-cell plays a critical role in the systemic response to infection. Distinct patterns of cytokines are produced by two different types of T-helper cells (Th). Th1 lymphocytes produce IFN-gamma and IL-2, favoring cell mediated immunity; Th2 cells secrete IL-4, IL-5, IL-10, IL-13, favoring humoral immunity. Cytokines produced in systemic inflammatory response syndrome (SIRS) may effect Th subset predominance and subsequent immune responses. We measured Thl/Th2 balance in patients with severe sepsis, SIRS patients with non sepsis, and healthy subjects by flow cytometry. In patients with severe sepsis, Th2 antibody mediated (humoral) immune responses predominate. We believe that severe sepsis clearly induce polarization of T-helper lymphocyte activity with a clear shift in Th2 direction. This type of response may lead immunosuppression. Modulation of Th cell subset predominance may present a novel therapeutic option in the treatment of severe sepsis.
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PMID:[Th1/Th2 balance in systemic inflammatory response syndrome (SIRS)]. 1559 90

Bacterial factors stimulate the release of tissue factor as well as proinflammatory and antiinflammatory cytokines. TNF augments inflammation, TNF and IFN-gamma induce coagulation, and IL-1beta induces coagulation and fibrinolysis. IL-8 augments synergistic inflammation and coagulation. IL-6 augments coagulation and inhibits fibrinolysis. IL-10 inhibits inflammatory process and inhibits fibrinolysis. IL-4, IL-13, and TGF-beta act for anticoagulation. Administration of IL-2, G-CSF or IFN-gamma has been reported to have side effect of induction of coagulation. IL-12 induces coagulation first and fibrinolysis later. On the other, tissue factor induces proinflammatory (except TNF) and antiinflammatory cytokines, and thrombin enhances inflammation. Patients who died of SIRS/sepsis have been complicated with hypercoagulopathy and impaired fibrinolysis correlated with increased IL-10 production. Inhibition of IL-10 production or administration of fiblynolitic agents may be useful. Recently, activated protein C (APC) which has antiinflammatory effect has been paid attention in the treatment of SIRS/sepsis.
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PMID:[Correlation between intravascular coagulation/fibrinolysis system and cytokines]. 1559 92

A severe burn leads to hypermetabolism and catabolism resulting in compromised function and structure of essential organs. The massive release of cytokines is implicated in this hypermetabolic response. The aim of the present study was to compare cytokine expression profiles from severely burned children without signs of infections or inhalation injury (n = 19) to the cytokine profiles from normal, noninfected, nonburned children (n = 14). The Bio-Plex suspension array system was used to measure the concentration of 17 cytokines. The expression of proinflammatory and anti-inflammatory cytokines was maximal during the first week after thermal injury. Significant increases were measured for 15 mediators during the first week after thermal injury: interleukin (IL) 1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 p70, IL-13, IL-17, interferon gamma, monocyte chemoattractant protein 1, macrophage inflammatory protein 1beta, and granulocyte colony-stimulating factor (P < 0.05). Granulocyte-macrophage colony-stimulating factor was significantly increased during the second week after burn (P < 0.05). Within 5 weeks, the serum concentrations of most cytokines decreased, approaching normal levels. When compared with the cytokine levels measured in normal children, a total of 16 cytokines were significantly altered (P < 0.05). After severe burn, a specific cytokine expression profile is observed in patients without complications such as inhalation injury or sepsis. The cytokine concentrations decrease during 5 weeks after burn but remain elevated over nonburned values. Furthermore, the elevation in most serum cytokine levels during the first week after burn may indicate a potential window of opportunity for therapeutic intervention.
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PMID:Cytokine expression profile over time in severely burned pediatric patients. 1678 92

We investigated the efficacy of amino acids 55-76 of the synthetic shrimp anti-lipopolysaccharide factor peptide (SALF(55-76) cyclic peptide), the C-terminal part of the shrimp anti-lipopolysaccharide factor. This study was conducted to elucidate the effects of the antiseptic action of this peptide. The SALF(55-76) cyclic peptide was tested against bacterial clinical isolates and showed broad-spectrum antimicrobial activity. Transmission electron microscopic (TEM) examination of SALF(55-76) cyclic peptide-treated Pseudomonas aeruginosa showed that severe swelling preceded cell death and breakage of the outer membrane; the intracellular inclusion was found to have effluxed extracellularly. When mice were treated with the SALF(55-76) cyclic peptide before bacterial challenge with P. aeruginosa, the peptide highly protected mice against death by sepsis. The P. aeruginosa recovered from SALF(55-76) cyclic peptide-treated mice after 4 h exhibited reduced bacterial growth similar to that recovered from vancomycin-treated mice. In addition, the syntheses of inflammatory cytokines, such as interleukin (IL)-2, IL-4, IL-10, IL-12, IL-13, interferon-gamma, and tumor necrosis factor [TNF]-alpha, were significantly upregulated 4 h after SALF(55-76) cyclic peptide treatment except for IL-4 in the liver. The expressions of Toll-like receptor 4 (Tlr4), Irf3, myd88, and Tram, were considerably elevated, but only Tlr4 existed in the spleen 4 h after SALF(55-76) cyclic peptide treatment. The prophylactic administration of SALF(55-76) cyclic peptide was begun the TNF-alpha response in comparison to untreated mice by an ELISA analysis. Due to its multifunctional properties, the SALF(55-76) cyclic peptide may become an important prophylaxis against and therapy for bacterial infectious diseases, as well as for septic shock.
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PMID:Shrimp (Penaeus monodon) anti-lipopolysaccharide factor reduces the lethality of Pseudomonas aeruginosa sepsis in mice. 1738 16

The innate immune system provides immediate defense against infection and serves as the first line of host defense during infection. In innate immunity, leukocytes such as neutrophils and macrophages recognize and respond to pathogens in a non-specific manner. Therefore, the recruitment and activation of leukocytes are essential in innate immunity, and are governed by a variety of chemical mediators including cytokines. Cytokines are generally divided into 2 types, termed type-1 and type-2 cytokines. Type-1 cytokines are important in local host defense, while type-2 cytokines play a protective role when inflammatory response spreads to the body. These cytokines exert their biological functions through the janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. STAT1/3/4/6 are transcription factors that mediate IFNgamma/IL-10/IL-12/IL-13 cytokine signaling, respectively. Evidence indicates that STAT proteins have a significant impact on innate immunity during sepsis. This review focuses on recent understandings in the regulation of innate immunity by STAT proteins during sepsis and septic shock. The suppressor of cytokine signaling (SOCS) proteins are a family of SH2 domain-containing cytoplasmic proteins that complete a negative feedback loop to attenuate signal transduction from cytokines that act through the JAK/STAT pathway. The participation of SOCS proteins in sepsis is also discussed.
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PMID:STAT proteins in innate immunity during sepsis: lessons from gene knockout mice. 1797 40


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