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)

The mechanism for the gradual loss of CD4+ T lymphocytes and the development of the slowly progressive inflammatory/degenerative lesions that accompany human immunodeficiency virus infection are poorly understood. Using the Simian immunodeficiency virus (SIVmac) macaque model of AIDS, we found that persistently infected primary macrophages fuse with primary activated CD4+ lymphocytes and that this interaction results in production of tumour necrosis factor-alpha (TNF alpha) and interleukin 6 (IL-6). An earlier report had shown that SIV-infected macaque macrophages fuse with CEM174 cells (a human CD4+ cell line) and cause their lysis. In the present report, we have shown that TNF-alpha and IL-6 are also produced during the early stages of this interaction. Data from cocultivation of infected macrophages with several CD4+ T cell lines, including CEM174, suggested that the cytokines are produced by the T cells, and that cytokine production is restricted to those cells which not only express CD4, but are also capable of fusing with the infected macrophages. These data suggest that infected macrophages in vivo could fuse with and eliminate activated CD4+ lymphocytes and, during this interaction, release cytokines, which would contribute to the degenerative and inflammatory lesions characteristic of this disease.
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PMID:Tumour necrosis factor and interleukin 6 production during interaction between activated CD4+ lymphocytes and simian immunodeficiency virus-infected macrophages. 135 Mar 3

Retinoic acid (RA) exerts potent suppressive and upregulatory effects on human immunodeficiency virus (HIV) expression in mononuclear phagocytes, strikingly similar to the effects of the cytokine transforming growth factor beta (TGF-beta). RA significantly inhibited phorbol ester-mediated, but not tumor necrosis factor alpha-mediated, induction of HIV transcription in the chronically infected promonocytic U1 cell line. RA and TGF-beta also completely suppressed the induction of virus production in U1 cells by interleukin 6 alone or in combination with glucocorticoids, which predominantly upregulate virus expression at the posttranscriptional level. Despite the close parallel to TGF-beta-induced effects, no evidence was obtained that RA mediated its effect by inducing secretion of active TGF-beta 1, -beta 2, or -beta 3. As with chronically infected U1 cells, similar inhibitory effects were also observed in primary monocyte-derived macrophages previously infected with HIV and then exposed to either RA or TGF-beta. In contrast, stimulation of monocyte-derived macrophages or U937 cells (the parental cell line of U1) with either RA or TGF-beta prior to in vitro infection resulted in the enhancement of virus production. Given the already successful use of retinoids in the treatment of several malignancies and the present demonstration of their capability of blocking the induction of HIV expression in infected mononuclear phagocytes, it would be of interest to pursue the potential role of this class of compounds in the development of strategies aimed at the pharmacologic regulation of HIV expression.
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PMID:Retinoic acid mimics transforming growth factor beta in the regulation of human immunodeficiency virus expression in monocytic cells. 137 88

The involvement of feline interleukin 6 (IL-6)-like activity in polyclonal B-cell activation in feline immunodeficiency virus (FIV) infection was investigated by using the proliferative response of hybridoma cell clone B3B1. Cats spontaneously infected with FIV had hyperimmunoglobulinemia, as shown by increases in the percentage of gamma-globulin and the plasma IgG concentration and decrease in the albumin/globulin (A/G) ratio. Because IL-6 plays an essential role in the differentiation of activated B cells into Ig-secreting cells, we examined the effect of FIV infection on the plasma IL-6 level. Plasma IL-6-like activity was found to be significantly higher in FIV-infected cats than in healthy controls. Peripheral blood mononuclear cells (PBMC) isolated from FIV-infected cats and cultured without any exogenous activators of IL-6 production released more feline IL-6-like activity than cells from healthy controls. This phenomenon was mainly due to the increase in the production of IL-6 by adherent cells such as monocytes/macrophages, but also partly by nonadherent cells. These results indicate that elevation of feline IL-6-like activity is associated with FIV infection and that overproduction of IL-6 may contribute to the polyclonal B-cell activation seen in FIV infection.
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PMID:Elevation of feline interleukin 6-like activity in feline immunodeficiency virus infection. 145 26

Cell lines derived from Kaposi sarcoma lesions of patients with AIDS (AIDS-KS cells) produce several cytokines, including an endothelial cell growth factor, interleukin 1 beta, and basic fibroblast growth factor. Since exposure to human immunodeficiency virus increases interleukin 6 (IL-6) production in monocytes and endothelial cells produce IL-6, we examined IL-6 expression and response in AIDS-KS cell lines and IL-6 expression in AIDS Kaposi sarcoma tissue. The AIDS-KS cell lines (N521J and EKS3) secreted large amounts of immunoreactive and biologically active IL-6. We found both IL-6 and IL-6 receptor (IL-6-R) RNA by slot blot hybridization analysis of AIDS-KS cells. The IL-6-R was functional, as [3H]thymidine incorporation by AIDS-KS cells increased significantly after exposure to human recombinant IL-6 (hrIL-6) at greater than 10 units/ml. When AIDS-KS cells (EKS3) were exposed to IL-6 antisense oligonucleotide, cellular proliferation decreased by nearly two-thirds, with a corresponding decrease in the production of IL-6. The decrease from IL-6 antisense in AIDS-KS cell proliferation was reversed by the addition of hrIL-6. We confirmed that AIDS-KS cells produced IL-6 in vivo by preparing RNA and tissue sections from involved and uninvolved skin from a patient with AIDS Kaposi sarcoma. We detected immunoreactive IL-6 in the involved tumor areas and to a lesser extent in the surrounding normal epidermis. Slot blot hybridization showed a great excess of IL-6 and IL-6-R RNA in involved skin compared to uninvolved skin. These results show that both IL-6 and IL-6-R are produced by AIDS-KS cells and that IL-6 is required for optimal AIDS-KS cell proliferation, and they suggest that IL-6 is an autocrine growth factor for AIDS-KS cells.
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PMID:AIDS Kaposi sarcoma-derived cells produce and respond to interleukin 6. 169 29

The effects of glutathione (GSH), glutathione ester (GSE), and N-acetyl-L-cysteine (NAC) on the induction of human immunodeficiency virus (HIV) expression were investigated in the chronically infected monocytic U1 cell line, a previously described cellular model for HIV latency. U1 cells constitutively express low levels of virus, which can be increased by phorbol 12-myristate 13-acetate (PMA), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and other inducers. GSH, GSE, and NAC suppressed in a dose-dependent fashion the induction of HIV expression mediated by PMA, TNF-alpha, and IL-6, in the absence of cytotoxic or cytostatic effects. Reverse transcriptase activity, inducible by PMA, TNF-alpha, or IL-6, was decreased by 80-90% after pretreatment with GSH, GSE, or NAC. The induction of total HIV protein synthesis was also decreased appreciably after pretreatment with GSH, GSE, or NAC. The accumulation of HIV mRNA was substantially suppressed after pretreatment with NAC but to a lesser extent after pretreatment with GSH or GSE. Although PMA induces the expression of TNF-alpha in U1 cells, the suppressive effect of GSH, GSE, and NAC on PMA-induced HIV expression in U1 cells was not associated with the inhibition of TNF-alpha expression. The present findings, which elucidate relationships between cellular GSH and HIV expression, suggest that therapy with thiols may be of value in the treatment of HIV infection.
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PMID:Suppression of human immunodeficiency virus expression in chronically infected monocytic cells by glutathione, glutathione ester, and N-acetylcysteine. 170 37

The pleiotropic immunoregulatory cytokine transforming growth factor beta (TGF-beta) potently suppresses production of the human immunodeficiency virus (HIV), the causative agent of the acquired immunodeficiency syndrome, in the chronically infected promonocytic cell line U1. TGF-beta significantly (50-90%) inhibited HIV reverse transcriptase production and synthesis of viral proteins in U1 cells stimulated with phorbol myristate acetate (PMA) or interleukin 6 (IL-6). Furthermore, TGF-beta suppressed PMA induction of HIV transcription in U1 cells. In contrast, TGF-beta did not significantly affect the expression of HIV induced by tumor necrosis factor alpha (TNF-alpha). These suppressive effects were not mediated via the induction of interferon alpha (IFN-alpha). TGF-beta also suppressed HIV replication in primary monocyte-derived macrophages infected in vitro, both in the absence of exogenous cytokines and in IL-6-stimulated cultures. In contrast, no significant effects of TGF-beta were observed in either a chronically infected T cell line (ACH-2) or in primary T cell blasts infected in vitro. Therefore, TGF-beta may play a potentially important role as a negative regulator of HIV expression in infected monocytes or tissue macrophages in infected individuals.
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PMID:Transforming growth factor beta suppresses human immunodeficiency virus expression and replication in infected cells of the monocyte/macrophage lineage. 170 78

To study the effect of persistent human immunodeficiency virus (HIV) infection on host metabolism, we performed indirect calorimetry in 11 asymptomatic HIV-infected patients (Centers for Disease Control group II or III) who were seropositive for greater than or equal to 1 y, but who still had normal numbers of circulating CD4+ T cells, and in 11 healthy control subjects of similar age and relative body composition. HIV-infected patients had 8% (P less than 0.05) higher rates of resting energy expenditure than did control subjects. Fat-oxidation rates were significantly higher in the patients (means +/- SE: 2.90 +/- 0.08 vs 2.19 +/- 0.17 g.kg FFM-1.d-1, patients vs control subjects, P less than 0.01) whereas no significant differences in carbohydrate-oxidation rates between patients and control subjects were found. These alterations in metabolism were not associated with increased concentrations of catecholamines, cortisol, or thyroid hormones. Mean concentrations of interleukin 6 in the patients were increased only twofold when compared with healthy control subjects. The results indicate that HIV infection affects host metabolism in the early asymptomatic stage, before CD4+ T cell numbers start to decline.
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PMID:Resting energy expenditure and substrate oxidation in human immunodeficiency virus (HIV)-infected asymptomatic men: HIV affects host metabolism in the early asymptomatic stage. 183 Apr 51

We have measured the production of interleukin 1 (IL 1), interleukin 6 (IL 6), and tumor necrosis factor alpha (TNF alpha) by unstimulated monocytes and monocytes stimulated with lipopolysaccharide (LPS) isolated from the peripheral blood of patients infected with human immunodeficiency virus 1 (HIV-1) and healthy controls. Spontaneous and LPS-induced cytokine production were not significantly different between patients and controls. Median lipopolysaccharide-stimulated cytokine secretion for patients and controls was 1.7 and 4.3 U/ml for IL 1, 475 and 625 U/ml for IL 6, and 468 and 580 pg/ml for TNF alpha. Cytokine levels were not related to stage of disease. We conclude that in vivo HIV infection itself does not alter peripheral blood monocyte cytokine secretion.
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PMID:Cytokine secretion by peripheral blood monocytes from human immunodeficiency virus-infected patients is normal. 193 24

Freshly isolated B lymphocytes from patients infected with human immunodeficiency virus (HIV), in contrast to B cells from normal controls, were shown to induce viral expression in two cell lines: ACH-2, a T cell line, and U1, a promonocytic cell line, which are chronically infected with HIV, as well as in autologous T cells. In 10 out of 10 HIV-infected individuals with hypergammaglobulinemia, spontaneous HIV-inductive capacity was found with highly purified peripheral blood B cells, whereas peripheral blood or tonsillar B cells from six healthy, HIV-negative donors did not induce HIV expression unless the cells were stimulated in vitro. The induction of HIV expression was observed in direct coculture experiments of B lymphocytes and HIV-infected cells, and could also be mediated by supernatants from cultures of B cells. Significantly higher amounts of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) were detected in the B cell culture supernatants from HIV-infected patients with hypergammaglobulinemia (IL-6: mean = 536 pg/ml; TNF-alpha: mean = 493 pg/ml), as compared with normal uninfected controls (IL-6: mean = 18 pg/ml; TNF-alpha: mean = 23 pg/ml). Antibodies against these cytokines abolished the HIV-inductive capacity of B cells. We conclude that in vivo activated B cells in HIV-infected individuals can upregulate the expression of virus in infected cells by secreting cytokines such as TNF-alpha and IL-6, and, therefore, may play a role in the progression of HIV infection.
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PMID:Activated B lymphocytes from human immunodeficiency virus-infected individuals induce virus expression in infected T cells and a promonocytic cell line, U1. 198 16

Macrophages, unlike CD4+ T cells, can be productively infected by human immunodeficiency virus (HIV) without prior cellular activation. Cytopathic infection ensues without the induction of tumor necrosis factor alpha (TNF alpha), interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), or tissue factor genes. In detailed studies on TNF alpha, HIV infection did not affect the regulation of TNF alpha in response to bacterial lipopolysaccharide. In an effort to examine the interferon responsiveness of HIV-infected macrophages, the cells were challenged with vesicular stomatitis virus (VSV) with or without interferon pretreatment. Surprisingly, HIV-infected macrophages were completely resistant to VSV-induced lysis even in the absence of interferon; however, no interferon was detected in the supernatants of these infected cells. The resistance of HIV-infected macrophages to superinfection with VSV indicates a previously undescribed effect of HIV upon macrophage cellular metabolism.
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PMID:Characterization of a macrophage-tropic HIV strain that does not alter macrophage cytokine production yet protects macrophages from superinfection by vesicular stomatitis virus. 217 98


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