Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P14784 (IL-2 receptor)
 3,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transcriptional activation of the human interleukin-2 (IL-2) gene, like induction of the IL-2 receptor alpha (IL-2R alpha) gene and the type 1 human immunodeficiency virus (HIV-1), is shown to be modulated by a kappa B-like enhancer element. Mutation of a kappa B core sequence identified in the IL-2 promoter (-206 to -195) partially inhibits both mitogen- and HTLV-I Tax-mediated activation of this transcription unit and blocks the specific binding of two inducible cellular factors. These kappa B-specific proteins (80 to 90 and 50 to 55 kilodaltons) similarly interact with the functional kappa B enhancer present in the IL-2R alpha promoter. These data suggest that these kappa B-specific proteins have a role in the coordinate regulation of this growth factor-growth factor receptor gene system that controls T cell proliferation.
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PMID:Kappa B-specific DNA binding proteins: role in the regulation of human interleukin-2 gene expression. 249 18

Serum and cerebrospinal fluid (CSF) levels of interleukin-2 (IL-2), soluble IL-2 receptor (sIL-2R), and gamma-interferon (gamma-IFN) were measured in multiple sclerosis (MS) patients, human immunodeficiency virus type 1 (HIV-1)-infected patients and normal controls (NC). Increased levels of both IL-2 and sIL-2R were found in MS serum. Moreover, 11 of 50 MS patients showed detectable levels of IL-2 in the CSF. HIV-1-infected patients had increased levels of sIL-2R in serum and, less frequently, in the CSF. gamma-IFN was never detected in serum and CSF of all the patients studied. These findings confirm preliminary reports, further stress a systemic T-cell activation in MS, and support the hypothesis that an immunologic disorder exists in such patients.
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PMID:Immune activation in multiple sclerosis: study of IL-2, sIL-2R, and gamma-IFN levels in serum and cerebrospinal fluid. 250 88

Interleukin-2 (IL-2) plays an essential role in the clonal expansion of antigen-activated T lymphocytes (T cells). In fact, the expression of both IL-2 and IL-2 receptor (IL-2R, p55, CD25) genes is transiently induced upon T cell activation through the interaction of antigen/major histocompatibility complex (MHC) and T cell receptor complex. To elucidate the mechanism(s) of the induced gene expression for IL-2 and IL-2R, we have investigated for the presence of potential transcription factors that specifically interact with regulatory cis-elements. Here, we demonstrate that one such factor mediates the induced expression of both genes. Interestingly, the recognition sequences by this factor are significantly diverse in these two genes and are related to those of immunoglobulin (Ig) kappa chain and MHC class I genes. We provide evidence that this factor indeed binds to the IL-2, IL-2R, and Ig sequence elements with different affinities, thereby affecting the magnitude of gene expression. Interestingly, this factor also binds to other cytokine genes, such as interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and HIV-1 and HTLV-1 LTR sequences.
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PMID:Involvement of a common transcription factor in the regulated expression of IL-2 and IL-2 receptor genes. 251 55

HIV infection is known to induce a progressive T helper/inducer (CD4) lymphopenia and to impair the functional activities of residual cells. The present studies examined the relationship between the CD4 cell count and three functional assays: T cell colony formation in semisolid media, the capacity of PHA-stimulated cells to express IL-2 receptors, and their ability to synthesize and secrete IL-2. Cells from antibody-positive homosexuals with normal numbers of CD4 cells (greater than 700/microliters) showed defective reactivity in two assays, colony growth, and IL-2 receptor expression. These defects became progressively more pronounced in homosexuals with moderate (400-700 cells/microliters) and severe (less than 400/microliters) reductions in assays for IL-2 production by PHA-stimulated lymphocytes. Mixing experiments suggest that cells from HIV-infected men nonspecifically inhibit the colony growth of normal cells; this abnormality could be reversed by addition of exogenous IL-2. These data suggest that defective colony growth and reduced IL-2 expression are functional abnormalities directly resulting from HIV infection. Furthermore, these changes can precede the CD4 lymphopenia induced by this viral infection.
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PMID:Defective T cell colony formation and IL-2 receptor expression in HIV-infected homosexuals: relationship between functional abnormalities and CD4 cell numbers. 252 69

Zidovudine (ZDV), an anti-human immunodeficiency virus (HIV) therapy, has been associated with reduction in mortality and improvement of patients with acquired immunodeficiency syndrome (AIDS). The ZDV recipients, however, experience a multitude of side effects of which bone marrow suppression is the most noteworthy, especially among patients with low CD4 cell counts. The effect of ZDV and interleukin-2 (IL-2) on phytohemagglutinin (PHA)-induced proliferative response of peripheral blood mononuclear cells (PBMs) from patients with HIV infection was investigated. ZDV 0.5 micrograms inhibited 40% of PHA-induced thymidine uptake in PBMs from healthy donors or patients with HIV, irrespective of their CD4 cell counts. However, IL-2 (10 U/ml) had differential effect on PHA-induced thymidine uptake that appeared to be dependent on absolute CD4 cell counts. While PBMs from patients with CD4 cell counts of 400/mm3 or more did not respond to IL-2 (low responders), IL-2 enhanced the PHA-induced thymidine uptake in PBMs from patients with CD4 cell counts less than 400/mm3 at an average of 60% (high responders). Moreover, IL-2 restored the ZDV-induced inhibition by almost 100% in the high responder group while it did not affect counts in the low responder group. The production of IL-2 in vitro, in response to PHA or recall antigens, was equivalently inhibited in both groups. These data suggest that ZDV and IL-2 could have an additive effect on immune parameters in certain groups of patients infected with HIV. The differential effect of IL-2 was independent of IL-2 receptor expression.
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PMID:Differential reconstitution of zidovudine-induced inhibition of mitogenic responses by interleukin-2 in peripheral blood mononuclear cells from patients with human immunodeficiency virus infection. 254 65

CD4 (T4) is a 60 kD glycoprotein expressed on a subset of T lymphocytes. CD4 augments T cell responses to suboptimal Ag stimulation. In addition, the CD4 molecule is the receptor for HIV-1. CD4 is phosphorylated on serine residues within the cytoplasmic domain and its cell surface expression is decreased in response to PMA, APC bearing the appropriate Ag or HIV infection. The kinetics of CD4 phosphorylation and modulation are similar, suggesting that the two events may be related. L3T4, the murine CD4 equivalent, is not modulated from the surface of mature, peripheral T cells in response to PMA. The difference in the ability to modulate L3T4 and CD4 in response to PMA may be due to differences between the two molecules or to differences between the cells in which they are expressed. To further define the requirements for CD4 modulation, we used retroviral vectors to transfer the cDNA for CD4 and various mutants of CD4 into two murine T cell hybridomas that express L3T4. One of these hybridomas, By155.16, does not modulate L3T4 in response to PMA and the other, 5D5.63, does modulate L3T4 in response to PMA. When expressed by these hybridomas CD4 is not modulated from the surface of By155.16 and is modulated from the surface of 5D5.63 in response to PMA. In both of these hybridomas, CD4 is phosphorylated on serine residues in response to PMA. A mutant form of CD4, CD4 delta, was constructed in which the majority of the cytoplasmic domain was deleted. When expressed in 5D5.63, CD4 delta was not modulated in response to PMA. Replacing the cytoplasmic domain of CD4 with that of the human IL-2 receptor did not reconstitute the ability of CD4 to be modulated. These results suggest that the inability to modulate L3T4 from the surface of murine peripheral T cells is due to features of the cell and not the molecule. Furthermore, the cytoplasmic domain of CD4 is required for its modulation from the cell surface in response to PMA.
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PMID:Requirements for modulation of the CD4 molecule in response to phorbol myristate acetate. Role of the cytoplasmic domain. 278 43

We have assessed the ability of HIV to infect cultures of peripheral blood lymphocytes derived from different healthy donors, varying in age between 20 and 76. The results indicate that cells from all of these people can be infected, although the percentage of infected cells varied from case to case. A similar variation was observed when attempts were made to infect cells from the same donor on more than one occasion. In most cases, infection by HIV led to persistence of an activated cell state, as indicated by the presence of Tac Ag or IL-2 receptor, at the cell surface. Co-incubation of HIV-infected lymphocytes with uninfected cells did not affect the ability of the latter either to respond to phytohaemagglutinin (PHA) or to express Tac Ag.
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PMID:Differential susceptibility of human lymphocyte cultures to infection by HIV. 282 57

The addition of both live and ultraviolet-inactivated preparations of human T lymphotropic virus type I (HTLV-I) and HIV to cultures of human peripheral lymphocytes impeded the ability of these cells to respond to phytohaemagglutinin (PHA). This inhibition depended on the concentration of the virus and seemed due, in part at least, to interference with the generation of interleukin-2 (IL-2) activity in the PHA-stimulated cultures. However, the addition of exogenous IL-2 did not effectively restore the lymphocyte proliferative responsiveness of cells which had been co-incubated with these human retroviruses. Exposure to the viruses did not affect expression on co-incubated cells of the Tac antigen, an epitope of the IL-2 receptor, as determined by an indirect immunofluorescence assay. These results suggest that one mechanism through which human retroviruses may be able to impede cellular proliferative responsiveness is interference with the ability of target cells to respond to IL-2, even though IL-2 receptors continue to be expressed under the conditions tested.
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PMID:Inhibition of human lymphocyte mitogenesis by human and other retroviruses. Differential effect of interleukin-2 in restoration of responsiveness. 283 64

HIV infection induces both immune deficiency and immune stimulation. Central to the pathology of HIV infection is reduction in the numbers and function of CD4 T cells. Impaired functions include decreased proliferation, IL-2 receptor expression and production of lymphokines (IL-2 and gamma interferon (IFN]. HIV infection stimulates B cells and CD8 T cells. This is seen relatively soon after HIV infection. Increased activation and immaturity are seen in both these cell groups. In vitro studies confirm HIV stimulation of these cells. Studies have been conducted on patients with AIDS and opportunistic infection (OI) or Kaposi's sarcoma (KS), with AIDS-related complex (ARC) or with persistent generalized lymphadenopathy (PGL), as well as on asymptomatic HIV-seropositive and -seronegative homosexually active men. The latter group has been followed at 6-month intervals for the past 2-3 years. Those who seroconverted (became HIV-infected) were studied to investigate early changes following HIV infection. To delineate the immunopathology of infection with HIV, serial testing of seropositive individuals was carried out to determine the rate of CD4-T-cell reduction. Lowered CD4-T-cell number and percentage and CD4/CD8 ratio correlate with the occurrence of AIDS and with survival after AIDS-KS diagnosis. Seropositive individuals, however, differed markedly in the rate of CD4-T-cell reduction; in some, no reduction in CD4 cells occurred over a two-year period of observation. We propose that, in individuals in which CD4 levels have reached a plateau, effective host resistance to further CD4 cytoreduction has occurred.
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PMID:Immune pathogenesis of AIDS and related syndromes. 295 95

The lung is continuously exposed to infectious and non-infectious agents causing cell activation. Activated cells in the lung such as antigen-presenting cells which harbour HIV may favour this organ as a site for virus production. To test this hypothesis, cells from blood and bronchoalveolar lavage (BAL) of HIV-infected patients and healthy controls were obtained and the activation of the cells were analysed by measuring the expression of IL-2 receptor, HLA-DR and VLA-1. The HIV-infected individuals were subdivided into 'lung symptomatic' or 'lung asymptomatic' patients, depending on the presence or absence of secondary lung diseases besides HIV. All HIV-infected individuals demonstrated a decreased number of CD4+ lymphocytes in blood; however, normal numbers of these cells were found in BAL. The activation state of CD4+ and CD8+ T lymphocytes in blood and BAL was higher in lymphocytes from HIV-infected patients compared with controls. The activation state was highest in the lung symptomatic group. Lung symptomatic patients and lung asymptomatic patients with extrapulmonary infections had increased levels of free virus in plasma. Four out of four individuals without or with only low amounts of cell-free HIV in plasma belonged to the symptom-free subgroup. These results suggest that microorganisms other than HIV may promote viral replication via antigen-driven accumulation and activation of CD4+ cells in the lung or other organs, and thus may be responsible for the loss of helper T cells and the progression of the disease.
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PMID:Accumulation of activated CD4+ lymphocytes in the lung of individuals infected with HIV accompanied by increased virus production in patients with secondary infections. 758 71


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