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)

Although studies indicate that a shift from a Th1 to a Th2 response contributes to a marked suppression of cell-mediated immunity during sepsis, the mechanism by which this occurs remains unknown. Given that the mitogen-activated protein kinase (MAPK) p38 plays a critical role in the activation and function of immune cells, the aim of this study was to determine the contribution of MAPK p38 activation to the immune dysfunction seen in polymicrobial sepsis. To study this, polymicrobial sepsis was induced in C3H/HeN male mice by cecal ligation and puncture (CLP). Splenic lymphocytes and purified T cells were harvested 24 h post-CLP, pretreated with the specific MAPK p38 inhibitor SB-203580, and then stimulated with a monoclonal antibody against the T cell marker CD3. The results indicate that interleukin (IL)-2 release is markedly depressed while the release of the immunosuppressive mediator, IL-10, as well as mRNA levels of IL-10 and IL-4, are augmented after CLP. Inhibition of MAPK p38 suppressed in vitro IL-10 levels as well as IL-10 and IL-4 gene expression while restoring the release of IL-2. To determine whether these in vitro findings could be translated to an in vivo setting, mice were given 100 mg of SB-203580/kg body wt or saline vehicle (intraperitoneal) at 12 h post-CLP. Examination of ex vivo lymphocyte responsiveness indicated that, as with the in vitro finding, septic mouse Th1 responsiveness was restored. In light of our recent finding that delayed in vivo SB-203580 treatment also improved survival after CLP, we believe that these results not only illustrate the role of MAPK p38 in the induction of immunosuppressive agents in sepsis but demonstrate that SB-203580 administration after the initial proinflammatory state of sepsis significantly prevents the morbidity from sepsis.
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PMID:MAPK p38 antagonism as a novel method of inhibiting lymphoid immune suppression in polymicrobial sepsis. 1144 65

Trauma causes the release of anti-inflammatory factors thought to cause infections by inhibiting T cells. We have found that hypertonic saline (HS) enhances functions of normal T cells. Here we studied if HS can rescue T cells from suppression by costimulating interleukin (IL)-2 production. Human peripheral blood mononuclear cells were treated with the immunosuppressive factors IL-4, IL-10, transforming growth factor (TGF)-beta(1), and PGE(2) and with serum of trauma patients and stimulated with phytohemagglutinin, and IL-2 production was measured. Costimulation with HS tripled IL-2 production of normal cells. IL-4, IL-10, TGF-beta(1), and PGE(2) suppressed IL-2 production with IC(50) of 500, 1, 36,000, and 0.01 pg/ml, respectively. Costimulation of suppressed cells with HS restored IL-2 production and increased IC(50) values >70-fold. Serum from trauma patients could completely suppress normal cells; however, costimulation with HS restored IL-2 production by up to 80% of the control response. These findings show that HS can restore the function of suppressed T cells, suggesting that HS resuscitation of trauma patients could reduce posttraumatic sepsis.
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PMID:Hypertonicity rescues T cells from suppression by trauma-induced anti-inflammatory mediators. 1150 61

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

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

In sepsis, both necrotic and apoptotic cell death can occur. Apoptotic cells induce anergy that could impair the host response, whereas necrotic cells cause immune activation that might result in enhanced antimicrobial defenses. We determined whether adoptive transfer of apoptotic or necrotic cells impacted survival in a clinically relevant sepsis model. We also evaluated the effects of adoptive transfer of apoptotic or necrotic cells on the prototypical TH1 and TH2 cytokines IFN-gamma and IL-4, respectively. C57BL6/J mice had adoptive transfer of apoptotic (irradiated) or necrotic (freeze thaw) splenocytes. Controls received saline. Apoptotic cells greatly increased mortality, whereas necrotic splenocytes markedly improved survival, P < or = 0.05. The contrasting effects that apoptotic or necrotic cells exerted on survival were mirrored by opposite effects on splenocyte IFN-gamma production with greatly decreased and increased production, respectively. Importantly, either administration of anti-IFN-gamma antibodies or use of IFN-gamma knockout mice prevented the survival benefit occurring with necrotic cells. This study demonstrates that the type of cell death impacts survival in a clinically relevant model and identifies a mechanism for the immune suppression that is a hallmark of sepsis. Necrotic cells (and likely apoptotic cells) exert their effects via modulation of IFN-gamma
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PMID:Adoptive transfer of apoptotic splenocytes worsens survival, whereas adoptive transfer of necrotic splenocytes improves survival in sepsis. 1273 77

It has been suggested that excessive activation of the anti-inflammatory pathways in sepsis may lead to poor outcome of patients with sepsis. The aim of this study was to test the value of histocompatibility leukocyte antigen (HLA)-DR-expression on blood monocytes and plasma levels of interleukin (IL)-4 and -10 in prediction of hospital mortality in patients with sepsis. Sixty-one critically ill patients with sepsis were prospectively enrolled to this study in two university hospital intensive care units. Survivors (n = 41) and nonsurvivors (n = 20) differed significantly in HLA-DR expression at admission: survivors' median 84% (interquartile range 64%-98%) versus nonsurvivors' median 62% (interquartile range 47%-83%, P = 0.025 by Mann-Whitney test). Similarly, the analysis revealed statistically significant differences between survivors and nonsurvivors in admission plasma IL-10 levels and in admission Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores, but not in IL-4 levels. The areas under receiver operating curves (AUC) showed that both monocyte HLA-DR expression and plasma IL-4 level showed poor discriminative power in prediction of hospital mortality (AUC < 0.70). Only IL-10 levels on days 1 and 2 showed reasonable predictive power (AUCs 0.706 and 0.725, respectively). The highest AUC values were those of APACHE-II (0.786) and admission SOFA score (0.763). In conclusion, APACHE II and SOFA scores on admission showed better discriminatory power than HLA-DR expression and IL-10 and IL-4 levels in prediction of hospital mortality in critically ill patients with sepsis.
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PMID:Predictive value of monocyte histocompatibility leukocyte antigen-DR expression and plasma interleukin-4 and -10 levels in critically ill patients with sepsis. 1281 60

Sepsis and septic shock account for substantial morbidity and mortality in the intensive care units. NF-kappaB activation, and elevated concentrations of macrophage migration inhibitory factor (MIF), tumor necrosis factor-a (TNF-alpha), interleukin-1 (IL-1), IL-6, free radicals, inducible nitric oxide (iNO), and stress hyperglycemia are some of the factors that induce systemic inflammatory response and myocardial depression seen in sepsis. Conversely, adenosine, activated protein C, oxidized phospholipids, w-3 fatty acids, and insulin have beneficial effects in sepsis and septic shock. These molecules and in particular insulin have the ability to suppress synthesis of MIF, TNF-alpha, IL-1, IL-6, and free radicals, enhance endothelial NO production, and enhance the production of anti-inflammatory cytokines IL-10, and IL-4. In addition, insulin corrects stress hyperglycemia and improves myocardial function. Thus insulin, adenosine, activated protein C, oxidized phospholipids, and w-fatty acids show anti-inflammatory actions and explain why and how they are useful in sepsis and septic shock and possibly, other inflammatory conditions. Hence, their combined use may be of significant benefit in sepsis and septic shock.
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PMID:Current advances in sepsis and septic shock with particular emphasis on the role of insulin. 1294 44

Streptococcus pneumoniae infection may result in asymptomatic carriage, mucosal or invasive disease. We hypothesize that self-limiting or fatal disease outcome follows infection with S. pneumoniae differential activation of the host immune response. BALB/c and C57BL/6 mice were inoculated intranasally with S. pneumoniae serotype 3 strain WU2 and serotype 14 strain DW14 and mortality, bacterial load, pathological changes in the lungs and cytokines mRNA levels in the spleen were analysed. No differences between the C57BL/6 and the BALB/c inbred mice were observed except for the severity of their lung pathology and IL-4 expression. Infection of the two mouse strains with S. pneumoniae WU2 resulted in sepsis and death that occurred within 4 days post-inoculation. This death was preceded, in both mouse strains, in an increase over time of the lung bacterial load and bacteraemia. The lung pathology was characterized by diffuse pneumonia with marked congestion of the lungs. Analysis of mRNA expression of cytokines in the spleen revealed no alterations in tumour necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, interleukin (IL)-12 and interferon (IFN)-gamma and induction of IL-10 and IL-4. The two strains of mice survived infection with S. pneumoniae DW14. This was accompanied by a reduction over time of lung bacterial load and bacteraemia. The lung pathology was characterized by focal lymphocyte infiltration and preserved architecture of the organ. Analysis of mRNA expression of cytokines in the spleen revealed a significant decrease in the levels of TNF-alpha, TGF-beta, IL-12 and IFN-gamma mRNA expression, which usually precedes cytokine protein expression. Interestingly, a significant increase in the levels of IL-4 mRNA expression was found in BALB/c mice only. This study suggests that differential activation or evasion of cytokine expression by S. pneumoniae virulent strains determines disease outcome regardless of the host's immunogenetic background.
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PMID:Differential activation of the immune system by virulent Streptococcus pneumoniae strains determines recovery or death of the host. 1297 50

During the last 2 decades, the incidence of sepsis due to gram-positive bacteria has increased dramatically. Nevertheless, effects of the cell-wall components that do not contain endotoxin, on immunity, are still largely unknown. Here, we demonstrate, for the first time, that the gram-positive bacterial cell-wall component peptidoglycan (PGN) severely inhibits the production of interleukin (IL)-2 by cultured human peripheral blood mononuclear cells stimulated with anti-CD3 and anti-CD28 antibodies. Furthermore, we provide evidence that the inhibitory effect is mediated predominantly by a soluble mediator produced by T cells and that the production of the inhibitory mediator is induced by direct cell-to-cell contact of T cells with PGN-stimulated monocytes. The T cell-derived inhibitory mediator is distinct from known immunosuppressive lymphokines, such as IL-10 and IL-4. In light of the key role of IL-2 in cell-mediated immunity, it can be suggested that PGN induces the dysfunction of cell-mediated immunity.
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PMID:Staphylococcal peptidoglycan suppresses production of interleukin-2 by T cells through a T cell-derived factor induced by direct contact between T cells and monocytes. 1459 85

NF-kappaB activation, and elevated concentrations of macrophage migration inhibitory factor (MIF), tumor necrosis factor-alpha (TNF-alpha), interleukin-1(IL-1), IL-6, free radicals, inducible nitric oxide (iNO), and stress hyperglycemia occurs in sepsis and this leads to systemic inflammatory response and myocardial depression seen in sepsis and septic shock. Conversely, insulin suppresses production of MIF, TNF-alpha, IL-1, IL-6, and free radicals, enhances endothelial NO generation, and enhances the production of anti-inflammatory cytokines IL-4, and IL-10, corrects stress hyperglycemia and improves myocardial function. This supports my earlier proposal that insulin (with or without glucose and potassium) therapy to maintain euglycemia suppresses the inflammatory response, improves myocardial function, and thus, is of benefit in acute myocardial infarction, sepsis andseptic shock.
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PMID:Insulin in sepsis and septic shock. 1462 Oct 41


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