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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The transcription of the human immunodeficiency virus type 1 (HIV-1) is under the control of cellular proteins that bind to the viral long terminal repeat (LTR). Among the protein-binding regions of the HIV-1 LTR is the transcription-enhancer region. We show that at least one inducible, C1, and one constitutive, C2, protein can bind to the HIV enhancer in Jurkat cells. The two proteins differ in their surface charge, since they are separable by anion-exchange chromatography. Bivalent cations such as Mg2+ and Zn2+ differentially affect their binding to oligonucleotides which contain the HIV-enhancer domain. Both C1 and C2 proteins also bind to a similar sequence found in the interleukin-2-receptor alpha-subunit enhancer. The inducible C1 protein was partially purified by three chromatographic steps and characterized by u.v. cross-linking as a 47 kDa protein.
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PMID:Characterization of the human immunodeficiency virus type 1 enhancer-binding proteins from the human T-cell line Jurkat. 230 85

To determine the degree of mononuclear blood cell activation in Crohn's disease (CD), 65 patients were prospectively investigated (22 with mild, 26 with moderate and 17 with severe disease). Serum levels of soluble receptors for interleukin-2 (SR-IL-2) were measured by ELISA. In CD patients SR-IL-2 levels were significantly higher (m = 707 +/- 326 U/ml) than in three other groups: 70 controls (m = 258 +/- 87 U/ml, p less than 0.0001); 8 patients with acute infectious colitis (m = 405 +/- 216 U/ml, p less than 0.0001); 101 HIV seropositive subjects (m = 564 +/- 216 U/ml, p less than 0.002). There was a positive correlation between SR-IL-2 level and the Van Hees activity index (r = 0.595, p less than 0.0001). On the other hand, the numbers of activated T cells (CD 3+, HLA DR+), CD 4+, CD 8+ and NK cells did not differ according to the CD activity groups. Furthermore, CD patients treated with steroids (n = 39) did not differ from those without any medication. As a marker of monocyte activation, serum neopterin level was determined by RIA. All CD patients considered as a group, serum neopterin level was 2.89 +/- 1.44 ng/l (n less than 2.5 ng/l). Neopterin level increased with disease activity (1.97 +/- 0.92 vs 3.10 +/- 1.46 vs 3.74 +/- 1.36, p less than 0.01), and was positively correlated with SR-IL-2 (r = 0.609, p less than 0.0001). These results suggest a monocyte-macrophage activation in CD, which parallels disease activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Mononuclear cell activation in Crohn's disease. Evaluation using serum assay of neopterin and interleukin-2 soluble receptors]. 231 49

We studied the prevalence of four serum factors in individuals at different stages of human immunodeficiency virus-1 (HIV-1) infection. Soluble interleukin-2 receptors (sIL-2R) were elevated in all antibody-positive groups compared with high-risk, antibody-negative controls. Paraproteins, usually of the IgG-kappa isotype, were found in the sera of a significant number of HIV-1-infected individuals as were antibodies to lymphocytes (ALAs). Serum factors that inhibit proliferation of peripheral blood mononuclear cells from healthy donors appear late in the course of infection and were associated with increasing clinical severity. Measurement of these factors may prove to be useful in defining the stages of infection and in predicting the appearance or exacerbation of symptoms. They may also play a role in the development of the HIV-1-induced immune defects that lead to the expression of clinical acquired immunodeficiency syndrome.
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PMID:Serum factors in the progression of human immunodeficiency virus type 1 infection to AIDS. 235 58

The production of tumor necrosis factor (TNF)-alpha and TNF-beta by various human hematopoietic cell lines was quantitatively examined using a highly sensitive radioimmunoassay specific to TNF-alpha, or a cytolytic assay performed with mouse L929 cells. It was found that the HTLV-1-infected T cell lines examined produced large amounts of both TNF-alpha and TNF-beta. In particular, interleukin-2 (IL-2)-dependent cell lines produced large amounts of TNF-alpha. In contrast, human cell lines not infected with HTLV-1 essentially did not produce either of the TNFs. It was also found that the high production of TNF-alpha by HTLV-1-infected cells partially correlated to their high sensitivity to human immunodeficiency virus (HIV) infection. Treatment of MT-4 cells, one of the most HIV-sensitive HTLV-1-infected cell lines, with antibody specific to TNF-alpha reduced their sensitivity to HIV infection.
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PMID:Production of tumor necrosis factors by human T cell lines infected with HTLV-1 may cause their high susceptibility to human immunodeficiency virus infection. 235 83

In this study we analyzed the ability of peripheral blood mononuclear cells (PBMC) from hemophilic patients (He) with negative or positive serology for the human immunodeficiency virus (HIV), to increase natural killer (NK) cytotoxicity upon stimulation with physiological and non physiological agents. Purified interleukin-2 (IL-2), the interferon (IFN)-inducer polyinosinic polycytidylic acid (PIC), recombinant alpha- and gamma-IFN and the protein kinase activator phorbol myristate acetate (PMA) were used as stimulatory agents. The NK functional response was correlated with the presence of PBMC bearing phenotypic markers of activated cells (IL-2 receptor, IL-2R) and of different NK cell maturation stages. Our results demonstrate that NK effector cells with slight lytic activity (Leu 7+ CD16-) predominated in HIV+ He patients. On the other hand the occurrence of IL-2R positive cells was similarly high in both HIV+ and HIV- individuals and was probably more related to chronic replacement treatment with Factor VIII or Factor IX concentrates than to HIV infection. The ability to respond to physiological NK regulators such as IL-2 and IFNs, or to the IFN-inducer PIC was impaired in HIV+ He, especially in HIV+ LAS individuals, suggesting that the inability of these cells to increase NK cell activity after appropriate induction was due to an intrinsic defect. Since phosphoinositide turnover and subsequent protein kinase C activation are thought to be part of the physiological mechanism of NK cytotoxicity, we studied the effect of PMA on PBMC from each group of patients. The ability to respond to PMA was lost only in PBMC from HIV+ LAS patients, indicating that impairment of the NK lytic mechanism progresses as the disease gets worse.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:HIV infection and natural killer cytotoxicity in hemophilic patients. 238 63

An overview of the immune system is presented, and the pathogenesis, transmission, diagnostic tests, diagnosis, immunotherapy, and vaccine development for human immunodeficiency virus (HIV) are reviewed. More than 42,000 cases of acquired immunodeficiency syndrome (AIDS) have now been reported in the United States, and an additional 250,000 cases are expected by 1991. The immunopathogenesis of HIV infection involves both cellular and humoral components of the immune system, with a characteristic depletion of helper T lymphocytes, impaired delayed hypersensitivity, and polyclonal B-cell activation. Monocytes and macrophages are also infected, and these cells provide a transport mechanism into the central nervous system. HIV is transmitted primarily by sexual, blood, and perinatal mechanisms. Enzyme-linked immunosorbent and Western blot assays are used in diagnostic tests, and diagnosis of AIDS is based on the presence of secondary infection or tumor at least moderately indicative of cellular immune deficiency in the absence of predisposing factors. Three approaches are being tested for treating HIV infection: immunomodulators, vaccines, and antiviral agents. Immunomodulators--including interferons, interleukin-2, immune reconstitution with bone-marrow transplantation and lymphocyte transfusions, transfer factor, granulocyte-macrophage colony-stimulating factor, inosine pranobex (isoprinosine), and naltrexone--are being tested with no great successes. Various approaches to vaccine development, including genetically engineered subunit proteins, synthetic peptides, and infectious recombinant viruses, are being considered. Primary immune responses do result from at least one vaccine. Future studies will evaluate combination approaches to therapy. HIV infections confront the health-care system with a serious challenge. It is too early to assess the effectiveness of the various therapeutic strategies for immune deficiencies caused by HIV.
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PMID:Current concepts in clinical therapeutics: immunologic treatment of human immunodeficiency virus infections. 244 17

The Fairfield Hospital experience with isolation of HIV from peripheral blood leucocytes, cerebrospinal fluid and semen is described. To date HIV has been isolated from single specimens of blood from 45% of patients with AIDS, 35% of patients with lymphadenopathy syndrome AIDS-related complex or ARC and 14% of asymptomatic antibody positive individuals. HIV was recovered from peripheral blood leucocytes in the presence of phytohemagglutinin and interleukin-2. The presence of virus in the supernatant fluid was detected using reverse transcriptase and immunofluorescence assays. Supernatants with borderline activity were confirmed by infection of a continuous cell line.
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PMID:Isolation of HIV from Australian patients with AIDS, AIDS related conditions and healthy antibody positive individuals. 245 95

We describe here several African isolates of HIV, compare them to U.S.-European prototype isolates and to each other, correlate the number of isolates with serological results, and provide insights into the disease spectrum associated with HIV infection in Africa. Three of 25 healthy Zairian donors and 54 of 87 Zairian patients selected for specific pathology and hospitalized in the internal medicine department of the University Clinic of Kinshasa, Zaire, were HIV positive over a six month period in 1985 either by serum antibody (42 cases) or virus isolation (40 cases). The virus positive cases showed a decrease in number of T4 cells and interleukin-2 (IL2) production by mononuclear cells. Restriction endonuclease analysis of HIV sequences from these isolates showed that genomic diversity is also observed in the Zairian isolates but closely related viruses could also be found, similar to the spectrum of diversity among isolates obtained from the U.S. and Europe. A number of isolates (12 of 40) were obtained from serum antibody negative adults. These results are difficult to explain by viral antigenic diversity alone since hybridization with a HTLV-III-B (clone BH10) probe under stringent conditions indicated an overall high degree of relatedness. Rather, these results indicate that some African HIV infected patients fail to make detectable antibodies to HIV or the antibodies were bound in immune complexes not detectable by current techniques.
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PMID:Genomic diversity of Zairian HIV isolates: biological characteristics and clinical manifestation of HIV infection. 245 28

Recent investigations have identified a homologous sequence between the lymphokine interleukin 2 (IL-2) and the envelope protein of HIV. This homology is one of six amino acids corresponding to interleukin-2 (IL-2) residues 14-19 (Leu-Glu-His-Leu-Leu-Leu) and to the carboxy terminal six amino acids of HIV envelope protein gp41 (Leu-Glu-Arg-Ile-Leu-Leu). Thus, it is conceivable that an anti-HIV antibody response would generate antibodies which would crossreact with IL-2. We show here that the two peptides are recognized by the immune system as being almost identical. More importantly, antibodies against the HIV envelope peptide bind IL-2. Thus, these studies are the first step in investigating what could be characterized as an HIV-induced autoimmune response, that is, the induction of antibodies to the HIV envelope protein which also crossreact with IL-2.
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PMID:Antibodies against a peptide sequence within the HIV envelope protein crossreacts with human interleukin-2. 246 83

The only animal that can be reproducibly infected with HIV, and that thus provides an experimental system for testing the effectiveness of prototype vaccines, is the chimpanzee. We compared proliferative responses to HIV and to vaccinia virus (VV) antigens of lymphocytes taken at various times from chimpanzees vaccinated with recombinant VV expressing different HIV genes. Animals were immunized with the original VV strain, as control, or with constructs expressing gp160 (VV160) given exclusively or in combination with one or two other constructs producing p25 (VV25), F/3'-orf (VVF), or the human interleukin-2 (IL-2) gene, which was included in an attempt to amplify immune responses. Irrespective of the HIV gene utilized, lymphocyte proliferation to HIV was usually weak and rapidly decreased after each inoculation, contrasting with strong and sustained responses to VV. Lack of adequate recall reactivity after challenge with fixed autologous lymphocytes expressing VV-produced HIV antigens indicated that vaccination resulted only in low levels of HIV-specific memory cell priming. The use of IL-2-producing VV did not lead to increased responsiveness. Reactivity to soluble purified gp160, but not to p25, could be detected in PBL from animals that had received both VV160 and VV25, while immunization with VVF resulted in a significant response to this protein in one of two animals. The transient nature of T cell reactivity to HIV might explain why, in similar studies, chimpanzees were not protected from infection with live HIV.
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PMID:Cell-mediated immune proliferative responses to HIV-1 of chimpanzees vaccinated with different vaccinia recombinant viruses. 247 Mar 98


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