Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0021051 (immunodeficiency)
71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study demonstrates that the beta-chemokines macrophage inflammatory proteins 1 alpha and 1 beta (MIP-1 alpha and MIP-1 beta) and, RANTES (regulated on activation, normally T-cell expressed and secreted) inhibit human immunodeficiency virus (HIV) replication in anti-CD3 or recall antigen-stimulated peripheral blood mononuclear cells (PBMCs) of asymptomatic HIV-infected subjects. Significant levels of beta-chemokines were produced by both CD4+ and CD8+ PBMC subsets from HIV-infected individuals. Neutralization of endogenous MIP-1 alpha, MIP-1 beta, and RANTES did not rescue HIV replication in cultures to which greater than 10% CD8+ T cells had been added, indicating that the HIV suppressor activity of CD8+ T cells cannot be explained entirely by the beta-chemokines. However, significant enhancement of viral replication was observed upon neutralization of endogenous beta-chemokines in CD8-depleted or CD4+ PBMCs from most donors, particularly in cultures with low inducible levels of HIV production. In contrast, certain endogenous proinflammatory cytokines induced HIV replication in these same cells. These data suggest that the levels of HIV replication in CD4+ PBMC reflect the balance of the opposing effects of endogenous suppressive factors, such as the beta-chemokines, and HIV-inducing cytokines, such as tumor necrosis factor alpha and interleukin 1 beta.
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PMID:HIV replication in CD4+ T cells of HIV-infected individuals is regulated by a balance between the viral suppressive effects of endogenous beta-chemokines and the viral inductive effects of other endogenous cytokines. 894 63

Seven of 112 hemophiliacs infected with human immunodeficiency virus type-1 (HIV-1) before 1986 through contaminated plasma products are currently healthy, with CD4 T-cell counts above 500 cells/microL, and have never received antiretroviral therapy (long-term nonprogressors [LTNPs]). Seven age and sex-matched hemophiliacs infected in the same period but who have progressive HIV disease (progressors) and one additional slow-progressing individual were also studied. One hundred-fold, 20-fold, and 10-fold lower levels of full-length HIV RNA in plasma, peripheral blood mononuclear cells (PBMCs), and proviral DNA in PBMCs, respectively, were found in LTNPs compared with progressors. Plasma and cell-associated HIV RNA and proviral DNA were lower in LTNPs who tested negative for viral isolation from PBMCs or who were positive only after removal of CD8+ cells. No substantial differences were observed in the in vitro production of chemokines including RANTES, MIP-1 alpha, MIP-1 beta, MCP-1, and interleukin-8 (IL-8) in supernatants of activated PBMCs or CD8-depleted PBMCs of LTNPs, even when HIV isolation was simultaneously accomplished exclusively after removal of CD8+ cells. Low levels of HIV load and replication in peripheral blood are the strongest correlates of nonprogression in this small number of infected hemophiliacs.
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PMID:Hemophilia and nonprogressing human immunodeficiency virus type 1 infection. 932 56

Competitive PCR was used to evaluate the expression of cytokine, granzyme B, and chemokine genes in lymph nodes of macaques recently infected with the simian immunodeficiency virus (SIV) pathogenic molecular clone SIVmac239 (n = 16), the nonpathogenic vaccine strain SIVmac239 delta nef (n = 8), and the nonpathogenic molecular clone SIVmac1A11 (n = 8). For both SIVmac239 and its nef-deleted derivative, strong expression was observed as early as 7 days postinfection for interleukin 1beta (IL-1beta), IL-6, tumor necrosis factor alpha, gamma interferon, and IL-13. The levels of gene induction were equally intense for both viruses despite a lower viral load for SIVmac239 deltanef compared with that for SIVmac239. However, the nature of the cytokine network activation varied with the viral inocula. Primary infection with SIVmac239 was characterized by a higher level of IL-4, IL-10, MIP-1alpha, MIP-1beta, MCP-1, and RANTES gene expression and a lower level of IL-12 and granzyme B gene expression compared with infection with SIVmac239 delta nef. Thus, infection with nef-deleted SIV was associated with a preferential Th1 versus Th2 pattern of cytokine production. Infection with SIVmac1A11 was characterized by a delayed immune response for all markers tested. The unique patterns of cytokine and chemokine gene expression in lymph nodes correlated nicely with the pathogenic potential of the SIV strains used as well as with differences in their ability to serve as protective vaccines.
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PMID:Early cytokine and chemokine gene expression in lymph nodes of macaques infected with simian immunodeficiency virus is predictive of disease outcome and vaccine efficacy. 899 46

Evidence suggests that CD8+ lymphocytes are involved in the control of Human Immunodeficiency virus type 1 (HIV-1) infection by the release of HIV-suppressive factors. The human chemokines RANTES and the macrophage inflammatory protein 1 alpha (MIP-1 alpha) have been identified to be potent inhibitors of HIV in vitro. The aim of this study was to determine whether high levels of these chemokines are associated with a delayed progression of HIV disease. We have therefore analysed the in vitro production of RANTES and MIP-1 alpha from purified stimulated CD8+ cells from HIV+ long term survivors (LTS) and, as a comparison, from HIV+ patients with progressive disease. RANTES production was similar in LTS and progressors (14.06 +/- 3, 13.36 +/- 4.1 ng/ml, not statistically significant); the same cells from healthy controls show a RANTES production of 20 +/- 3.5 ng/ml (P = 0.034 versus LTS and P = 0.038 versus progressors). MIP-1 alpha production was slightly reduced in LTS (96.8 +/- 12 ng/ml) and progressors (91.6 + 17, not statistically significant between the two groups) when compared to healthy controls (109 +/- 7 ng/ml, P = 0.03). Our study suggests that resistance to HIV-1 progression in LTS may not be associated with high levels of RANTES and MIP-1 alpha production.
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PMID:CD8+ cells in HIV infection produce macrophage inflammatory protein-1 alpha and RANTES: a comparative study in long-term survivors and progressor patients. 902 86

The recent discovery of a chemokine receptor, fusin (fusin/CXCR-4), as the long-sought human immunodeficiency virus type 1 (HIV-1) coreceptor opened an entirely new field of aquired immunodeficiency syndrome (AIDS) research on mechanisms of viral entry, tropism and pathogenesis. It was soon followed by the identification of the chemokine receptor CCR-5 as the major macrophage-tropic (M-tropic) HIV-1 coreceptor and the demonstration that other chemokine receptors, CCR-3 and CCR-2b, also may serve as coreceptors, albeit at somewhat lower efficiency. Very recently it was demonstrated that the mechanism of the coreceptor function involves the formation of a complex on the cell surface between the HIV-1 envelope, the primary receptor CD4 and the coreceptor. Thus the prevention of the HIV-1 envelope glycoprotein-mediated fusion by the chemokines RANTES, macrophage inflammatory protein-1 alpha (MIP-1 alpha) and MIP-1 beta, as well as by the recently identified fusin/CXCR-4 ligand, stromal cell-derived factor-1 (SDF-1) could be explained by disruption of that complex. Interestingly, the identification of the HIV-1 coreceptor CCR-5 not only provided new insights into the mechanisms of viral entry and tropism, but also may help in explaining why some people with genetic alterations in CCR-5 are protected from HIV-1 infection.
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PMID:HIV and the 7-transmembrane domain receptors. 903 25

Entry of human immunodeficiency virus type 1 (HIV-1) requires CD4 and one of a family of related seven-transmembrane-domain coreceptors. Macrophage-tropic HIV-1 isolates are generally specific for CCR5, a receptor for the CC chemokines RANTES, MIP-1alpha, and MIP-1beta, while T-cell line-tropic viruses tend to use CXCR4 (also known as fusin, LESTR, or HUMSTR). Like HIV-1, simian immunodeficiency virus (SIV) requires CD4 on the target cell surface; however, whether it also requires a coreceptor is not known. We report here that several genetically divergent SIV isolates, including SIVmac, SIVsmSL92a, SIVsmLib-1, and SIVcpzGAB, can use human and rhesus CCR5 for entry. CXCR4 did not facilitate entry of any of the simian viruses tested, nor did any of the other known chemokine receptors. Moreover, SIVmac251 that had been extensively passaged in a human transformed T-cell line retained its use of CCR5. Rhesus and human CCR5 differed at only eight amino acid residues, four of which were in regions of the receptor that could be exposed, two in the amino-terminal extracellular region and two in the second extracellular loop. The human coreceptor was as active as the simian for SIV entry. In addition, HIV-1 was able to use the rhesus homologs of the human coreceptors, CCR5 and CXCR4. The SIV strains tested were specific for CCR5 regardless of whether they were able to replicate in transformed T-cell lines or macrophages and whether they were phenotypically syncytium inducing or noninducing in MT-2 cells. However, SIV replication was not restricted to cells expressing CCR5. SIV strains replicated efficiently in the human transformed lymphoid cell line CEMx174, which does not express detectable amounts of transcripts of CCR5. SIV also replicated in human peripheral blood mononuclear cells that were genetically deficient in CCR5. These findings indicated that, in addition to CCR5, SIV can use one or more unknown coreceptors that are expressed on human PBMCs and CEMx174 cells.
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PMID:Genetically divergent strains of simian immunodeficiency virus use CCR5 as a coreceptor for entry. 906 Jun 23

Although CD8+ lymphocytes in human immunodeficiency virus type 1 (HIV-1)-infected individuals have been demonstrated to suppress viral replication, the mechanisms of inhibition have not been defined precisely. A large body of evidence indicates that these cells act via soluble inhibitory factors, but the potential role of HLA class I-restricted cytolysis has remained controversial. Here we demonstrate that HIV-1-specific cytotoxic T lymphocytes (CTL) mediate antiviral suppression by both cytolytic and noncytolytic mechanisms. The predominant mechanism requires direct contact of CTL with the infected cells, is HLA class I restricted, and can achieve complete elimination of detectable virus in infected cell cultures. Inhibition occurs even at high multiplicities of infection or at ratios of CTL to CD4 cells as low as 1:1,000. The other mechanism is mediated by soluble inhibitory factors which are triggered in an antigen-specific and HLA-restricted fashion but then act without HLA restriction. These include MIP-1alpha, MIP-1beta, and RANTES, as well as a distinct factor(s) capable of inhibiting HIV-1 strains insensitive to these chemokines. These data indicate that HIV-1-specific CTL are potent mediators of HIV-1 suppression at cell ratios existing in vivo and demonstrate an antigen-specific trigger for CD8+ cell-derived soluble inhibitory factors. These results suggest that CTL play an important role in the observed antiviral activity of CD8+ cells from infected individuals.
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PMID:Suppression of human immunodeficiency virus type 1 replication by CD8+ cells: evidence for HLA class I-restricted triggering of cytolytic and noncytolytic mechanisms. 906 Jun 75

The chemokine receptors CXCR4 and CCR5 have recently been shown to act as coreceptors, in concert with CD4, for human immunodeficiency virus-type 1 (HIV-1) infection. RANTES and other chemokines that interact with CCR5 and block infection of peripheral blood mononuclear cell cultures inhibit infection of primary macrophages inefficiently at best. If used to treat HIV-1-infected individuals, these chemokines could fail to influence HIV replication in nonlymphocyte compartments while promoting unwanted inflammatory side effects. A derivative of RANTES that was created by chemical modification of the amino terminus, aminooxypentane (AOP)-RANTES, did not induce chemotaxis and was a subnanomolar antagonist of CCR5 function in monocytes. It potently inhibited infection of diverse cell types (including macrophages and lymphocytes) by nonsyncytium-inducing, macrophage-tropic HIV-1 strains. Thus, activation of cells by chemokines is not a prerequisite for the inhibition of viral uptake and replication. Chemokine receptor antagonists like AOP-RANTES that achieve full receptor occupancy at nanomolar concentrations are strong candidates for the therapy of HIV-1-infected individuals.
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PMID:Potent inhibition of HIV-1 infectivity in macrophages and lymphocytes by a novel CCR5 antagonist. 909 81

Human immunodeficiency virus-1 (HIV-1) expression in monocyte-derived macrophages (MDM) infected in vitro is known to be inhibited by lipopolysaccharide (LPS). However, the mechanisms are incompletely understood. We show here that HIV-1 suppression is mediated by soluble factors released by MDM stimulated with physiologically significant concentrations of LPS. LPS-conditioned supernatants from MDM inhibited HIV-1 replication in both MDM and T cells. Depletion of C-C chemokines (RANTES, MIP-1 alpha, and MIP-1 beta) neutralized the ability of LPS-conditioned supernatants to inhibit HIV-1 replication in MDM. A combination of recombinant C-C chemokines blocked HIV-1 infection as effectively as LPS. Here, we report an inhibitory effect of C-C chemokines on HIV replication in primary macrophages. Our results raise the possibility that monocytes may play a dual role in HIV infection: while representing a reservoir for the virus, they may contribute to the containment of the infection by releasing factors that suppress HIV replication not only in monocytes but also in T lymphocytes.
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PMID:C-C chemokines released by lipopolysaccharide (LPS)-stimulated human macrophages suppress HIV-1 infection in both macrophages and T cells. 912 Mar 86

Chemokines are a family of related proteins that regulate leukocyte infiltration into inflamed tissue. Some chemokines such as MIP-1 alpha also inhibit hematopoietic progenitor cell proliferation. Recently, three chemokines, MIP-1 alpha, MIP-1 beta, and RANTES, have been found to significantly decrease human immunodeficiency virus production from infected T cells. We report here the cloning and characterization of a novel human chemokine termed Exodus for its chemotactic properties. This novel chemokine is distantly related to other chemokines (28% homology with MIP-1 alpha) and shares several biological activities. Exodus is expressed preferentially in lymphocytes and monocytes, and its expression is markedly upregulated by mediators of inflammation such as tumor necrosis factor or lipopolysaccharide. Purified synthetic Exodus was found to inhibit proliferation of myeloid progenitors in colony formation assays. Exodus also stimulated chemotaxis of peripheral blood mononuclear cells. The sequence homology, expression, and biological activity indicate that Exodus represents a novel divergent beta-chemokine.
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PMID:Cloning and characterization of exodus, a novel beta-chemokine. 912 37


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