Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bacillus anthracis exotoxins mediate most of the symptomatology of severe anthrax. In addition to a clinical syndrome reminiscent of septic shock, which may be mediated by cytokines produced by macrophages stimulated with lethal toxin, infected patients show profound edema at sites of infection. Edema is mediated by edema toxin (ET), which comprises of a binding molecule, protective antigen, and an active moiety, edema factor, which possesses intrinsic adenylyl cyclase activity. Intracellular cyclic AMP (cAMP) regulates the production of several cytokines that modulate edema formation and play important roles in host defense against invading bacteria. To determine whether ET enhanced the accumulation of cAMP in monocytes and thereby influenced cytokine production, we cultured human monocytes with endotoxin (lipopolysaccharide [LPS]) and dilutions of ET and determined the levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) in culture supernatant fluids. We further estimated cytokine-specific mRNA accumulation in monocytes by reverse transcription PCR and examined intracellular cAMP concentrations following treatment with ET. ET and LPS each induced monocytes to secrete comparable amounts of IL-6. ET did not inhibit and in most experiments modestly enhanced LPS-induced IL-6 production. In contrast to this stimulatory effect on IL-6 production, ET induced little or no TNF-alpha production. Moreover, ET profoundly inhibited LPS-induced TNF-alpha synthesis. These regulatory phenomena were also observed at the mRNA level in association with dose-related enhancement of intracellular cAMP in ET-treated monocytes. Monocytes treated with dibutyryl cAMP, an active analog of cAMP, produced cytokines in a pattern identical to that of cells treated with ET. The disruption of cytokine networks as a consequence of unregulated, ET-induced cAMP accumulation in human monocytes may impair cellular antimicrobial responses and contribute to clinical signs and symptoms.
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PMID:Anthrax edema toxin differentially regulates lipopolysaccharide-induced monocyte production of tumor necrosis factor alpha and interleukin-6 by increasing intracellular cyclic AMP. 792 6

Bacillus anthracis, the etiological agent of anthrax, is a gram-positive, spore-forming bacterium. The inhalational form of anthrax is the most severe and is associated with rapid progression of the disease and the outcome is frequently fatal. Transfer from the respiratory epithelium to regional lymph nodes appears to be an essential early step in the establishment of infection. This transfer is believed to occur by means of carriage within alveolar macrophages following phagocytosis. Therefore, the ability of B. anthracis to transit through the host macrophage or dendritic cell appears to be an early and critical step in B. anthracis pathogenesis. In this work, we examined the cytokine responses to spore infection in mouse primary peritoneal macrophages, in primary human dendritic cells, and during a spore aerosol infection model utilizing the susceptible A/J mouse strain. We demonstrated that both mouse peritoneal macrophages and human dendritic cells exhibited significant intracellular bactericidal activity during the first hours following uptake, providing the necessary time to mount a cytokine response prior to cell lysis. Strong tumor necrosis factor (TNF-alpha) and interleukin-6 (IL-6) responses were seen in mouse peritoneal macrophages. In addition to TNF-alpha and IL-6, human dendritic cells produced the cytokines IL-1beta, IL-8, and IL-12. A mixture of Th1 and Th2 cytokines were detected in sera obtained from infected animals. In this study, we provide further evidence of an acute cytokine response when cells in culture and mice are infected with B. anthracis spores.
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PMID:Cytokine response to infection with Bacillus anthracis spores. 1550 68

Bacillus anthracis edema toxin (ET), an adenylyl cyclase, is an important virulence factor that contributes to anthrax disease. The role of ET in anthrax pathogenesis is, however, poorly understood. Previous studies using crude toxin preparations associated ET with subcutaneous edema, and ET-deficient strains of B. anthracis showed a reduction in virulence. We report the first comprehensive study of ET-induced pathology in an animal model. Highly purified ET caused death in BALB/cJ mice at lower doses and more rapidly than previously seen with the other major B. anthracis virulence factor, lethal toxin. Observations of gross pathology showed intestinal intralumenal fluid accumulation followed by focal hemorrhaging of the ileum and adrenal glands. Histopathological analyses of timed tissue harvests revealed lesions in several tissues including adrenal glands, lymphoid organs, bone, bone marrow, gastrointestinal mucosa, heart, and kidneys. Concomitant blood chemistry analyses supported the induction of tissue damage. Several cytokines increased after ET administration, including granulocyte colony-stimulating factor, eotaxin, keratinocyte-derived cytokine, MCP-1/JE, interleukin-6, interleukin-10, and interleukin-1beta. Physiological measurements also revealed a concurrent hypotension and bradycardia. These studies detail the extensive pathological lesions caused by ET and suggest that it causes death due to multiorgan failure.
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PMID:Bacillus anthracis edema toxin causes extensive tissue lesions and rapid lethality in mice. 1625 15

Bacillus anthracis, the causative agent of inhalational anthrax, enters a host through the pulmonary system before dissemination. We have previously shown that human alveolar macrophages participate in the initial innate immune response to B. anthracis spores through cell signal-mediated cytokine release. We proposed that the lung epithelia also participate in the innate immune response to this pathogen, and we have developed a human lung slice model to study this process. Exposure of our model to B. anthracis (Sterne) spores rapidly activated the mitogen-activated protein kinase signaling pathways ERK, p38, and JNK. In addition, an RNase protection assay showed induction of mRNA of several cytokines and chemokines. This finding was reflected at the translational level by protein peak increases of 3-, 25-, 9-, 34-, and 5-fold for interleukin-6 (IL-6), tumor necrosis factor alpha, IL-8, macrophage inflammatory protein 1alpha/beta, and monocyte chemoattractant protein 1, respectively, as determined by an enzyme-linked immunosorbent assay. Inhibition of individual pathways by UO126, SP600125, and SB0203580 decreased induction of chemokines and cytokines by spores, but this depended on the pathways inhibited and the cytokines and chemokines induced. Combining all three inhibitors reduced induction of all cytokines and chemokines tested to background levels. An immunohistochemistry analysis of IL-6 and IL-8 revealed that alveolar epithelial cells and macrophages and a few interstitial cells are the source of the cytokines and chemokines. Taken together, these data showed the activation of the pulmonary epithelium in response to B. anthracis spore exposure. Thus, the lung epithelia actively participate in the innate immune response to B. anthracis infection through cell signal-mediated elaboration of cytokines and chemokines.
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PMID:Human lung innate immune response to Bacillus anthracis spore infection. 1751 78