Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vesnarinone, a synthetic oral cardiotonic agent that has been used for treatment of patients with congestive heart failure, was found to inhibit replication of HIV-1 in a peripheral blood lymphocytes model and in chronically infected macrophages at clinically achieved concentrations. Vesnarinone has no direct inhibitory activity against the reverse transcriptase of HIV-1, syncytium formation in short term assays, or retroviral protease. In addition, vesnarinone inhibits production of TNF-alpha and IL-6 by human peripheral blood mononucleated cells stimulated with LPS. These observations suggest that vesnarinone may be therapeutically useful in patients infected with HIV-1.
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PMID:Vesnarinone inhibits production of HIV-1 in cultured cells. 821 57

Based on our finding that HIV-1 gp41 independently of CD4 can bind to several proteins (gp41 binding protein: GBP) on the human T-cell line H9, B-cell line Raji and monocyte-cell line U937, we examined the effect of mitogens and cytokines on binding of gp41 to H9, Raji and U937 cells. Flow cytometry (FACS) analysis demonstrated that PWM and LPS, IFN-gamma and IL-6, but not Con A, IFN-alpha, -beta, -omega and IL-2, could increase gp41 binding to Raji cells. In controls, none of the regulators (IFN-alpha, -beta, -gamma, -omega, IL-2, IL-6, Con A, PWM, LPS) could modify the binding potential of H9 and U937 cells. Our data suggest that the expression of HIV-1 binding proteins is subject to regulation by PWM, LPS, IFN-gamma and IL-6 in the case of B-cells, while on T-cells and macrophages, the binding proteins may be constitutively expressed.
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PMID:Enhancement of HIV-1 gp41 binding to Raji cells by PWM, LPS, interferon-gamma and interleukin-6. 824 28

The effects of a concurrent HIV-1 and Mycobacterium avium infection in vitro were assessed in human peripheral blood-derived macrophages (M phi). M phi were infected with HIV-1Ba-L strain for 14 days then infected with M. avium (HIV/M. avium) or treated with LPS (HIV/LPS). At various times after M. avium or LPS treatment, Mo phi cultures were harvested for quantitation of HIV and M. avium replication, as well as M phi cellular viability. In addition, mRNA and supernatants were collected for assessment of induction of the cytokines TNF-alpha, IL-1 beta and IL-6. M. avium multiplication was greater in HIV-infected M phi, whereas no difference in virus production, based on p24 and RT values, was observed between HIV-infected cells and HIV/M. avium or HIV/LPS M phi. M. avium infection of HIV-1-infected M phi also caused a decrease in viability of the M phi. HIV-1/M. avium-infected M phi had a 24 h delay in induction of TNF-alpha steady state mRNA when compared with HIV/LPS or M. avium only or LPS-only treated M phi. HIV infection also increased the amount and the length of induction of IL-1 beta and IL-6 steady state mRNA stimulated by either M. avium or LPS. In addition, prolonged and increased protein production of TNF-alpha, IL-6, and IL-1 beta was observed in HIV/M. avium-infected cells when compared with the other treatments. In direct contrast to M. avium infection, no significant differences in LPS-induced protein production of the three cytokines was observed between HIV-1-infected and -noninfected M phi. Treatment of HIV/M. avium-infected cells with human rGM-CSF did not increase either the time or quantity of induction of TNF-alpha mRNA or protein production in HIV/M. avium-infected M phi. The increase in M. avium numbers, dysregulation of cytokine production, and subsequent cell death seen in vitro in HIV/M. avium-infected human M phi may reflect part of the underlying cause of the highly disseminated M. avium disease pattern observed in AIDS patients.
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PMID:Concurrent infection of human macrophages with HIV-1 and Mycobacterium avium results in decreased cell viability, increased M. avium multiplication and altered cytokine production. 834 8

The electrophoretic mobility shift assays (EMSA) with the use of the synthetic HIV-1 NF-kappa B motif as a probe, showed that LPS-treatment of J774 cells (a mouse macrophage cell line) leads to the activation of the fast-moving (denoted as B1) and the slow-moving NF-kappa B (denoted as B2). The binding of both B1 and B2 to the NF-kappa B probe was inhibited specifically by either unlabelled NF-kappa B, or competitor probes, but not by unrelated probes. LPS-induced activation of NF-kappa B was inhibited by a protein kinase A (PKA) inhibitor (H-89), but not by a protein kinase C (PKC) inhibitor (H-7). PMA itself failed to activate NF-kappa B and the depletion of PKC did not prevent LPS-induced activation of NF-kappa B. The pre-treatment of J774 cells with dibutyric cAMP, forskolin, prostaglandin E2 or cholera toxin resulted in NF-kappa B activation. Thus, these data suggested a probable involvement of PKA in LPS-induced NF-kappa B activation in macrophages.
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PMID:Role of protein kinase A in LPS-induced activation of NF-kappa B proteins of a mouse macrophage-like cell line, J774. 839 97

Monocytes/macrophages play a critical role in the pathogenesis of HIV infection, both as targets for virus replication and as sources of production of multifunctional cytokines. Endothelins, peptides with potent vasoconstricting activities originally isolated from endothelial cells, are also produced and secreted by macrophages in a manner similar to that of other cytokines. In an attempt to explore the potential role of endothelins in HIV-infection, we investigated the effect of the HIV-1 envelope glycoprotein, glycoprotein 120, on monocytic endothelin-1 production. This glycoprotein has been identified as a potent stimulator of monokines such as TNF-alpha and IL-6, which have been implicated as potential mediators of HIV-encephalopathy. We found that glycoprotein 120, similar to LPS, stimulates the secretion of endothelin-1, as well as TNF-alpha, from macrophages in a concentration-dependent manner. Using reverse transcriptase polymerase chain reaction, we found that circulating monocytes in HIV-infected individuals show a distinct expression of the endothelin-1 gene that is not detectable in healthy controls, indicating chronic activation of this gene in HIV-infection. In addition, cerebral macrophages in patients with HIV-encephalopathy were strongly positive for endothelin. Thus, monocytic endothelins appear to be stimulated during HIV infection. Their potent vasoactive properties render them potential candidates for mediating alterations in the cerebral perfusion pattern associated with the AIDS dementia complex.
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PMID:Potent stimulation of monocytic endothelin-1 production by HIV-1 glycoprotein 120. 848 49

Ten years ago, the term "oxidative stress" (sigma -O2) was created to define oxidative damage inflicted to the organism. This definition brings together processes involving reactive oxygen species production and action such as free radical production during univalent reduction of oxygen within mitochondria, activation of NADPH-dependent oxidase system on the membrane surface of neutrophils, flavoprotein-catalyzed redox cycling of xenobiotics and exposure to chemical and physical agents in the environment. Since the discovery of the nitric oxide biosynthetic pathway, the deleterious effects of uncontrolled nitric oxide generation are generally classified as oxidative stress. Indeed, products of the reaction of NO and superoxide lead to oxidants such as peroxinitrite, nitrogen dioxide and hydroxyl radical, which are involved in mechanisms of cell-mediated immune reactions and defence of the intracellular environment against microbiol invasion. However NO can also regulate many biological reactions and signal transduction pathways that lead to a variety of physiological responses such as blood pressure, neurotransmission, platelet aggregation, endothelin generation or smooth muscle cell proliferation. Then the uncontrolled NO production can lead to a variety of physiological and pathophysiological responses similar to a Nitric Oxide Stress: activation of guanylate cyclase and production of cGMP: overstimulation of the inducible L-arginine to L-citrulline and NO pathway by bactericidal endotoxins and cytokines has been shown to promote undesired increases in vasodilatation, which may account for hypotension in septic shock and cytokine therapy. stimulation of auto-ADP-ribosylation and modification of SH-groups of glyceraldehyde-3-phosphate dehydrogenase in a cGMP-independent mechanism: by this way, NO in excess can strongly inhibits this important glycolytic enzyme and reduce the cellular energy production. inhibition of ribonucleotide reductase: extensive inhibition of this key enzyme in DNA synthesis in the presence of large amounts of NO could lead to important antiproliferative effects; inhibition of cytochrome P450-dependent metabolism: in Kupffer cells and hepatocytes, LPS-induced overproduction of NO has been shown to inhibit cytochrome P450-dependent metabolism and to mediate the suppression of hepatic metabolism. Moreover, NO synthetized in the peripheral nervous system is known to mediate nonadrenergic noncholinergic (NANC) neurotransmission. Overstimulation of NO synthases might therefore contribute to pathophysiological states such as: gastrointestinal motility, reflux oesophagitis, asthma, adult respiratory distress syndrome (ARDS) and chronic pulmonary artery hypertension. To these NO-mediated biological functions, one could add the biological effects of NO-derivatives such as N-nitrosocompounds, which act as carcinogenic agents, or C-nitrosocompound which were recently used as "zinc-ejecting" agents to inhibit HIV-1 infectivity of human T-lymphocytes.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Does nitric oxide stress exist?]. 852 Oct 87

HIV-1 penetration of the brain is a pivotal event in the neuropathogenesis of AIDS-associated dementia. The establishment of productive viral replication or up-regulation of adhesion molecule expression on brain microvascular endothelial cells (BMVEC) could permit entry of HIV into the central nervous system. To investigate the contribution of both, we inoculated primary human BMVEC with high titer macrophage-tropic HIV-1 or cocultured them with virus-infected monocytes. In both instances, BMVEC failed to demonstrate productive viral replication. Cell to cell contact between monocytes and microvascular endothelium resulted in E-selectin expression on BMVEC. BMVEC. cocultured with LPS-activated HIV-infected monocytes expressed even higher levels of E-selectin and vascular cell adhesion molecule-1 (VCAM-1). Transwell assays supported a role of soluble factors, from virus-infected monocytes, for the induction of adhesion molecules on BMVEC. To verify the in vivo relevance of these findings, levels of adhesion molecules were compared with those of proinflammatory cytokines and HIV-1 gene products in brain tissue of AIDS patients with or without encephalitis and HIV-seronegative controls. E-Selectin, and to a lesser degree VCAM-1, paralleled the levels of HIV-1 gene products and proinflammatory cytokines in brain tissue of subjects with encephalitis. Most importantly, an association between macrophage infiltration and increased endothelial cell adhesion molecules was observed in encephalitic brains. Monocyte binding to encephalitic brain tissue was blocked with Abs to VCAM-1 and E-selectin. These data, taken together, suggest that HIV entry into brain is, in part, a consequence of the ability of virus-infected and immune-activated monocytes to induce adhesion molecules on brain endothelium.
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PMID:Mechanisms for the transendothelial migration of HIV-1-infected monocytes into brain. 855 9

A proportion of HIV-infected individuals experience episodes of localized or systemic bacterial infections caused by Gram-negative bacteria. Many of the clinical side effects of these infections are associated with the production of proinflammatory cytokines, which are induced primarily by LPS, a constituent of the bacterial cell wall of Gram-negative bacteria. The present study examines the mechanisms involved in LPS-mediated induction of HIV expression in U1 cells, a promonocytic cell line chronically infected with HIV. Stimulation of U1 cells by LPS alone induced minimal levels of HIV expression, which was significantly enhanced by granulocyte-macrophage colony-stimulating factor (GM-CSF). Costimulation of U1 cells with LPS plus GM-CSF resulted in the accumulation of steady-state levels of HIV RNA; however, only a weak induction of HIV long terminal repeat-driven transcription, which was not associated with the activation of the cellular transcription factor nuclear factor-kappa B, was noted. Costimulation of cells with LPS plus GM-CSF induced the production of proinflammatory cytokines, IL-8, IL-1 beta and IL-6, but not TNF-alpha. IL-1 receptor antagonist (ra) inhibited LPS enhancement of HIV expression in GM-CSF-stimulated cells, suggesting that endogenous IL-1 was involved in LPS-mediated viral production. In this regard, anti-inflammatory cytokines inhibited LPS plus GM-CSF-stimulated HIV expression, and this effect closely correlated with inhibition of IL-1 beta release and, in particular, with up-regulation of endogenous IL-1ra production. Thus, the balance between an endogenously produced viral inducer (IL-1 beta ) and an inhibitor (IL-1ra) may represent an important pathway leading to modulation of HIV expression from monocytic cells.
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PMID:Modulation of endogenous IL-1 beta and IL-1 receptor antagonist results in opposing effects on HIV expression in chronically infected monocytic cells. 861 79

Human polymorphonuclear neutrophils (PMN) and cytokines play a critical role in host defences against invading microorganisms. In response to a variety of stimuli, PMN are a major source of reactive oxygen species (ROS) which are essential for bacterial killing and may induce oxidative stress in tissue environment. A precise regulation of the oxidase activity is therefore necessary. Cytokines such as TNF alpha, GM-CSF, IL-8, IL-6, IL-1 alpha and IL-1 beta produced during the immune and inflammatory responses to pathogens have been reported to interact with PMN activities. However, contradictory results have been reported on their direct and priming effects on the PMN release of ROS (oxidative burst). We have used a flow cytometry method to study the effects of these cytokines on the oxidative burst of PMN in whole blood, in order to avoid PMN activation related to isolation procedures. None of the cytokines tested directly activated the PMN oxidative burst, but they did have differential priming effects on the oxidative burst in response to N-formyl peptides. TNF, GM-CSF and IL-8 strongly primed a subpopulation of PMN to produce H2O2 in response to fMLP, while IL-1 alpha, IL-1 beta and IL-6 failed to do so. Furthermore, the addition of TNF, GM-CSF or IL-8 to whole blood increased the capacity of a subpopulation of PMN to bind N-formyl peptides, a phenomenon that could account for the strong H2O2 production in response to fMLP following priming by the cytokines. These results show that, among the various cytokines tested, TNF, GM-CSF and IL-8 strongly prime the PMN oxidative burst in response to bacterial peptides in whole blood and suggest that these cytokines may play a critical role in bacterial killing in vivo and also in the surrounding tissue injury secondary to pathological inflammatory reactions. In particular, TNF and IL-8 plasma levels as well as LPS-induced monocytic production of these cytokines ex vivo have been correlated with the production of ROS by stimulated PMN and with the lung injury score in patients with Adult Respiratory Distress Syndrom (ARDS). However, desensitization phenomena have also been described. In particular, in HIV infected patients we demonstrated a decrease of H2O2 production by PMN in whole blood after ex vivo priming by IL-8 and TNF followed by fMLP stimulation. This decrease increased with the progression of the disease and was inversely correlated with IL-8 plasma level. Different mechanisms could explain such desensitization phenomena at the receptor and post receptor level. In addition cytokines are involved in a complex network of regulation and anti inflammatory cytokines, such as IL-10, could act as a negative signal on the proinflammatory cytokines induced-priming of oxidative burst.
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PMID:[Modulation of the oxidative burst of human neutrophils by pro- and anti-inflammatory cytokines]. 873 98

Production of cytokines by immunocompetent cells in vitro may be assessed after stimulation with polyclonal activators. Because it mimics the natural environment, diluted whole blood (WB) culture may be the most appropriate milieu in which to study cytokine production in vitro. We tested TNF alpha production by small volume of whole blood (25 microliters) from HIV-1 positive patients by using a one-step procedure that combines WB stimulation with LPS and PHA and cytokine measurement. We studied 30 patients without secondary infection or at distance of secondary infection staged according to the classification proposed by the CDC and 12 healthy seronegative subjects. The mean values of TNF alpha from patients were not statistically different from those from normal controls however in certain patients at different stages of the disease higher values than the mean +2 SD of controls and lower values than the mean -2 SD of controls were obtained. Heparinized blood from 5 control subjects had been collected sequentially during a period of 5 months. The individual variation of TNF alpha production were limited for all these individuals. For each of 6 HIV-1 patients, whole blood samples were collected sequentially during a period of 5 months and in most of patients large variations of levels of TNF alpha were observed from one sample to another one. Our method can detect abnormal cytokine production in HIV-1 positive individuals and can become a useful tool to investigate the role of cytokines in the outcome of HIV-1 infection.
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PMID:TNF alpha production by whole blood from HIV-1 infected patients. 875 83


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