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Query: UMLS:C0001175 (AIDS)
 120,706 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human immunodeficiency virus (HIV)-infected cells induce acid-labile interferon-alpha (al-IFN-alpha) in cultures of mononuclear cells from peripheral human blood. We have investigated the physiochemical properties of such preparations to elucidate the reasons for acid-lability of this IFN. Al-IFN-alpha is a mixture of both glycosylated and unglycosylated molecules as shown by separation on Concanavalin-A Sepharose. Acid-lability is associated only with glycosylated molecules. Upon chromatography of the glycosylated fraction on Sepharose coupled to IFN-alpha-specific antibody, the portion of the IFN that is retained and eluted with guanidine-HCl is acid-stable, whereas the excluded antiviral activity is acid-labile, and is partially neutralized by antibodies to either IFN-alpha or IFN-gamma. Also, upon further purification of the unglycosylated fraction on the same antibody column, all antiviral activity remains indistinguishable from conventional IFN-alpha. Reconstitution experiments showed that glycosylated material excluded from the anti-IFN-alpha column potentiates antiviral activity of the IFN that is specifically retained by the column. This potentiation is abolished by acid treatment. Similar results are obtained with al-IFN-alpha from the serum of acquired immunodeficiency syndrome (AIDS) patients, indicating that its acid-lability is also the consequence of an acid-labile component that is capable of enhancing the antiviral activity. The potentiation of antiviral activity obtained by combining recombinant preparations of IFN-alpha and IFN-gamma suggests that the cooperating molecule is IFN-gamma.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Acid lability is not an intrinsic property of interferon-alpha induced by HIV-infected cells. 128 11

Human interferon-gamma (IFN-gamma) is an important immunomodulatory protein produced predominantly by T cells and large granular lymphocytes (LGLs). Whereas large amounts of data have been accumulated regarding IFN gamma gene expression in these two cell types, little information about IFN gamma expression in other cell types exists. In this study, we have analyzed the production of IFN gamma by the Epstein-Barr virus (EBV)-positive B-cell line, JLP(c), derived from a patient with Burkitt's lymphoma, and another human B-cell line, PA682BM-1, which was derived from an acquired immunodeficiency syndrome patient. Southern blot analysis indicates the presence of an Ig heavy chain gene rearrangement, but no rearrangement of the T-cell receptor beta chain gene or IFN gamma gene in these B-cell lines. Both cell lines were found to express surface IgD and other B-cell surface markers, thus confirming their B-cell lineage. Analysis for surface Ig, cytoplasmic Ig, and secreted Ig indicates that the two cell lines are in relatively early stages of the B-cell differentiation pathway. We now report that PA682BM-1 can be triggered by the protein kinase C (PKC) activators, phorbol 12-myristate 13-acetate (PMA) and (-)Indolactam-v, to secrete IFN gamma, whereas JLP(c) cells spontaneously produce low levels of IFN gamma that can be enhanced by PKC activators and interleukin-2 (IL-2). After activation of the cell lines with IL-2, (-)Indolactam-v, and PMA, increases in cytoplasmic messenger RNAs (mRNAs) of IFN gamma and the IL-2 receptor chains were also observed. The induction of IFN gamma mRNA and protein by IL-2 was completely blocked by a monoclonal antibody to IL-2 receptor p75 (beta chain), but not by the monoclonal antibody to p55 (alpha chain). Analysis of IFN gamma genomic DNA indicates that the gene is not amplified, but that hypomethylation in the 5' noncoding region of the IFN gamma gene has occurred in the B-cell line from the Burkitt's lymphoma patient that spontaneously produces IFN gamma. This finding suggests that the methylation state of the promoter region may play an important role in the control of IFN gamma gene expression in B cells.
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PMID:Interferon-gamma gene expression in human B-cell lines: induction by interleukin-2, protein kinase C activators, and possible effect of hypomethylation on gene regulation. 132 3

Brucella abortus has been characterized as a T-independent type 1 antigen/carrier in human and murine antibody responses. In this report it is shown that BA can activate human CD3+ T cells to secrete interferon-gamma (IFN gamma). Unlike mitogens, such as phytohemagglutinin, this stimulation was associated with minimal T-cell proliferation or upregulation of interleukin-2 (IL-2) receptor. Monocytes inhibited BA-mediated IFN gamma secretion since their removal resulted in increased responses, whereas adding monocytes back to cultures caused inhibition. BA elicited IFN gamma from CD4+ and CD8+ T cells, although CD4+ T cells secrete significantly more (p less than 0.05) IFN gamma than CD8+ T cells. The ability of BA to elicit IFN gamma from human T cells was inhibited in the presence of anti-Tac, suggesting that BA also induces IL-2 secretion and that IL-2 is involved in BA-mediated IFN gamma secretion. Detectable IL-2 secretion was induced by BA in the presence of anti-Tac. Exogenous IL-2 acted synergistically with BA to enhance IFN gamma secretion, suggesting that the amount of IL-2 released by BA alone was insufficient for optimal IFN gamma release. Furthermore, addition of IL-2 to T cells from individuals with poor or absent responses to BA, including individuals infected with HIV-1, restored their ability to secrete IFN gamma in response to BA. These data indicate that BA is capable not only of activating human B cells but can also induce T cells, probably of the TH1 phenotype, to secrete IFN gamma.(ABSTRACT TRUNCATED AT 250 WORDS)
AIDS Res Hum Retroviruses 1992 Apr
PMID:Brucella abortus stimulates human T cells from uninfected and HIV-infected individuals to secrete IFN gamma: implications for use of Brucella abortus as a carrier in development of human vaccines. 135 Sep 16

To improve evaluation of new antiretroviral drugs in the acquired immunodeficiency syndrome (AIDS), sensitive biological markers that accurately predict response to treatment are needed. Two possible markers are endogenous interferon (E-IFN), which is a cytokine involved in the pathophysiology of AIDS, and serum triglycerides (TG), which are raised in patients with AIDS, possibly reflecting enhanced cytokine activity. E-IFN, TG, body-mass index, CD4 count, and HIV p24 were measured in 19 patients (15 with AIDS, 4 with AIDS-related complex), who were part of the phase II licensing trial of zidovudine (ZDV). 10 received ZDV and 9 received placebo. Rapid, significant, and sustained declines from initial values in E-IFN and TG concentrations were observed in ZDV patients but not in placebo patients. Baseline values of E-IFN and TG concentrations after 4 months on ZDV treatment were both important contributors to long-term survival. The findings suggest that these indicators of abnormal cytokine expression may be useful measures of not only disease severity but also efficacy of antiretroviral therapy in AIDS.
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PMID:Endogenous interferon and triglyceride concentrations to assess response to zidovudine in AIDS and advanced AIDS-related complex. 134 48

Infection causes disturbances in lipid metabolism that may be mediated by cytokines. Therefore we studied plasma lipids, lipoproteins, triglyceride (TG) metabolism, and serum cytokines in three groups: patients with the acquired immunodeficiency syndrome (AIDS) without active secondary infection, patients with evidence of human immunodeficiency virus infection but without clinical AIDS (HIV+), and controls. Plasma TGs and FFA were increased in AIDS, while plasma cholesterol, high density lipoprotein (HDL) cholesterol, apolipoprotein-A-1 (Apo-A-1), low density lipoprotein (LDL) cholesterol, and Apo-B-100 levels were decreased. Increased TG levels in AIDS were primarily due to increases in very low density lipoprotein of normal composition; in addition, LDL and HDL were TG enriched. In HIV+, TGs and FFA were not increased, but total cholesterol, HDL cholesterol, Apo-A-1, and Apo-B-100 were significantly decreased. Interferon-alpha (IFN alpha) and C-reactive protein levels were increased in AIDS, but tumor necrosis factor and haptoglobin levels were not. There was a significant correlation between plasma TGs and IFN alpha levels (r = 0.477; P less than 0.01), but not between TGs and tumor necrosis factor, C-reactive protein, haptoglobin, or P-24 antigen. In addition, there was no relationship between circulating IFN alpha levels and plasma cholesterol, HDL cholesterol, Apo-A-1, LDL cholesterol, Apo-B-100, or FFA. TG clearance time and postheparin lipase were significantly decreased in AIDS and HIV+. There was a strong correlation between serum IFN alpha levels and TG clearance time in AIDS and HIV+ (r = 0.783; P less than 0.001). In summary, decreases in cholesterol and cholesterol containing lipoproteins (including HDL) in both AIDS and HIV+ precede the appearance of hypertriglyceridemia and are not related to IFN alpha or TG levels. Our data raise the possibility that with development of AIDS, subsequent increases in IFN alpha may contribute to increases in plasma TG levels in part by decreasing the clearance of TG.
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PMID:Lipids, lipoproteins, triglyceride clearance, and cytokines in human immunodeficiency virus infection and the acquired immunodeficiency syndrome. 137 35

Cells infected with human immunodeficiency virus (HIV) induce antiviral activity in peripheral blood mononuclear cells (PBMC) from healthy donors. This activity is neutralized by anti-interferon-alpha antibody and partially destroyed at pH 2. Previous studies with enriched cell populations and monoclonal antibodies suggest that B lymphocytes are the main IFN-producing cells, and that both CD4 and HLA class II antigens are essential for IFN induction. Since the initial event of HIV infection of CD4+ cells is the interaction of the virus coat glycoprotein gp120 with CD4 molecule, we investigated whether gp120 is responsible for IFN induction. Using PBMC and recombinant gp120 obtained from a baculovirus expression system, dose-dependent induction of antiviral activity was observed with titers approaching 10(3) IU/ml. This induction was blocked in the presence of antibody to gp120. The antiviral activity was characterized as IFN-alpha by neutralization with IFN alpha-specific antibody. Preincubation of PBMC with anti-CD4 or the presence of soluble CD4 during incubation inhibited IFN induction, indicating that interaction of gp120 with cell-associated CD4 is responsible for this induction. Neither lymphoproliferation nor interleukin-2 (IL-2) production was observed during IFN induction. However, class G immunoglobulin secretion was enhanced by gp120, indicating that B cells are direct or indirect targets of gp120 stimulation in this experimental system. Since gp120 is shed from HIV-infected cells and occurs in the serum of acquired immunodeficiency syndrome (AIDS) patients, our data suggest that this glycoprotein is responsible for the induction of endogenous IFN and the polyclonal activation of B cells both of which are observed in AIDS patients.
AIDS Res Hum Retroviruses 1992 May
PMID:Recombinant glycoprotein 120 of human immunodeficiency virus is a potent interferon inducer. 138 Dec 3

Adriamycin (ADR) is an anticancer drug commonly used in the treatment of HIV-related cancers. Due to its effect on DNA metabolism, ADR might be able to modulate HIV replication in monocyte-macrophages (M/M), resting cells potentially less sensitive to the toxic effect of this drug. Thus, we assessed the efficacy of ADR against HIV replication in both lymphocytes and M/M. We further investigated the mechanism(s) of action of ADR and its potential synergistic activity with zidovudine (AZT) or alpha-interferon (IFN alpha). ADR consistently inhibited viral replication in M/M: 50% viral inhibition was obtained with 0.005 micrograms/ml ADR, while greater 90% viral inhibition was obtained with 0.05 micrograms/ml ADR. No cell toxicity was seen in M/M at concentrations up to 0.5 micrograms/ml. No anti-HIV activity was shown by ADR in lymphocytes at concentrations up to 0.05 micrograms/ml, that is also the toxic dose 50% (TCID50 for these cells). ADR neither inactivates HIV virions nor affects HIV binding with CD4 receptors. No inhibition of HIV reverse transcriptase by ADR was found at concentrations at least 2,000-fold greater than the 50% HIV inhibitory concentration in M/M. Molecular analysis by polymerase chain reaction (PCR) suggests that ADR substantially affects virus DNA production at concentrations that inhibit viral replication. Finally, late stages of HIV replication were not affected by ADR. At least additive effects of the association ADR + AZT and ADR + IFN alpha were obtained against de novo HIV infection of M/M.(ABSTRACT TRUNCATED AT 250 WORDS)
AIDS Res Hum Retroviruses 1992 Jul
PMID:Selective inhibition of HIV replication by adriamycin in macrophages but not in lymphocytes. 138 99

We have developed an experimental mouse model to study the effect of daily cocaine administration on the immune system during an acquired immune deficiency syndrome (AIDS). Mice were infected with LP-BM5 murine leukemia virus, a retrovirus which causes immunosuppression with the development of functional murine AIDS. Increasing doses of cocaine given by daily intraperitoneal injection for 11 weeks reduced body weight. A daily cocaine injection in some mice as well as a saline injection in others showed a decrease in the percentage of Thy 1.2+, CD4+ and CD8+ cells, while both treatments increased the percentage and absolute numbers of B-cells per spleen. Saline and cocaine treatment induced an increase in gamma-IFN and TNF-alpha production by splenocytes. Cocaine treatment favored a decrease in sIL-2R secretion. Saline and cocaine treatment had slightly different effects on the splenocytes of protein-malnourished mice. Cocaine treatment induced an increase in the percentage of CD8+ cells. Saline and cocaine treatments decreased the number of Mac 1+ cells in the spleen. Moreover, saline- and cocaine-treated protein-malnourished mice splenocytes did not present the increase in gamma-IFN production as well-nourished mice splenocytes showed. Retrovirus-infected mice showed a decrease in the percentage of Thy 1.2+ and CD8+ cells and an increase in the percentage and absolute numbers of CD4+, IL-2R+, Mac 1+ and B-cells. Cocaine partially prevented the enlargement of lymphoid organs due to lymphoid cell proliferation induced by murine retrovirus infection, but had little effect on the elevated percentage of CD4+ cells or B-cells or the depressed numbers of CD8+ cells associated with virus infection. However, cocaine did reduce the number of activated IL-2R+ cells and macrophages (Mac 1+) in addition to reducing the total number of cells per spleen in all subsets in retrovirus-infected mice, but not in uninfected controls. Cocaine treatment and retrovirus infection alone or in combination suppressed the release of sIL-2R into supernatant fluid during in vitro culture of splenocytes. These data illustrate that cocaine treatment modulates cell proliferation in retrovirus-infected mice and thus modifies the absolute number of cells in those subsets already altered by retrovirus infection. Retrovirus-infected and retrovirus-infected cocaine-treated protein-malnourished mice showed similar results.
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PMID:Modification of spleen cell subsets by chronic cocaine administration and murine retrovirus infection in normal and protein-malnourished mice. 145

The marriage of two scourges, one old (mycobacterial disease) and one new (HIV), has presented an enormous challenge to the medical and public health communities, and has stirred renewed interest in mechanisms for immune control of mycobacterial infection. Virulence of both M. avium and M. tuberculosis appears to be inversely related to the capacity of the microorganisms to induce production of protective cytokines in infected hosts. TNF alpha and IFN gamma are central to this process, and mycobacterial polysaccharides may be their main determinant. Despite these similarities, M. tuberculosis and M. avium cause illnesses at the polar extremes of HIV disease. Tuberculosis, occurring early in the course of HIV disease, may promote HIV replication in otherwise latently infected cells via induction of cytokines. As such, the potential exists for accelerated progression to AIDS due to the mutual synergy of these pathogens.
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PMID:Macrophages, mycobacteria and HIV: the role of cytokines in determining mycobacterial virulence and regulating viral replication. 145 67

Both saponin and muramyl dipeptide (MDP) formulated with a squalane-in-water emulsion of large particle size prepared with a vortex mixer were superior to Al(OH)3 as adjuvants for HIV gp120 in mice. All the adjuvants induced IgG1 antibody, but saponin elicited the highest titers of IgG2a. The secretion of interleukin-5 (IL-5) and interferon gamma (IFN gamma) by lymph node cells cultured in vitro with gp120 was studied. All the cultures secreted IL-5, but only those from saponin-immunized mice produced IFN gamma, suggesting that saponin is capable of activating both the Th1 and TH2 T-cell subsets. The titers of neutralizing antibodies were low with both MDP and saponin, and they occurred in mice which were also positive for antibodies against a V3 loop peptide. Glucosaminylmuramyl dipeptide (GMDP) which is less pyrogenic than MDP and a nonpyrogenic analog GMDPA, displayed equivalent adjuvant activity to MDP. The level and isotype composition of antibodies induced by GMDP in combination with squalane emulsions depended on the dimension of the emulsion particles. With a large (2500 nm) particle size the response was confined to IgG1 in Balb/c mice, but when this was reduced to 150 nm by sonication the antibody response was increased and relatively high levels of IgG2a appeared in some mice.
AIDS Res Hum Retroviruses 1992 Oct
PMID:The control of the antibody isotype response to recombinant human immunodeficiency virus gp120 antigen by adjuvants. 145 90


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