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

A unique feature of both human T-cell leukemia virus type I (HTLV-I) carriers and subjects with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a chronic inflammatory disease of the nervous system, is the presence of large numbers of activated T cells that spontaneously proliferate in vitro. We have investigated the mechanisms of T-cell activation by HTLV-I in freshly isolated blood T cells and in naturally infected T-cell clones obtained by direct single-cell cloning from patients with HAM/TSP. Both CD4+ and CD8+ HTLV-I-infected T-cell clones showed the unusual ability to proliferate in the absence of exogenous interleukin 2 (IL-2). Nevertheless, HTLV-I-infected clones were not transformed, as they required periodic restimulation with phytohemagglutinin and feeder cells for long-term growth. Irradiated or fixed HTLV-I-infected clones were found to induce the proliferation of blood T cells when cocultured, which we refer to as THTLV-1-T cell activation. This THTLV-1-T cell-mediated activation was blocked by monoclonal antibodies (mAbs) against CD2/lymphocyte function-associated molecule 3 (LFA-3), LFA-1/intercellular cell-adhesion molecule (ICAM), and the IL-2 receptor but not by mAbs against class I or class II major histocompatibility complex molecules, HTLV-I gp46, or a high-titer HAM/TSP serum. Spontaneous proliferation of blood T cells from HAM/TSP patients could also be inhibited by mAbs to CD2/LFA-3, LFA-1/ICAM and to the IL-2 receptor (CD25). These results show at the clonal level that HTLV-I infection induces T-cell activation and that such activated T cells can in turn stimulate noninfected T cells by cognate THTLV-1-T cell interactions involving the CD2 pathway.
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PMID:T-cell activation by autologous human T-cell leukemia virus type I-infected T-cell clones. 154 69

Pulmonary involvement has been demonstrated in patients with spastic myelopathy associated with HTLV-I infection (HAM/TSP). Pulmonary lesions in these patients are characterized by T-lymphocytosis and increased level of soluble IL-2 receptor in bronchoalveolar lavage fluid. T-lymphocytes from peripheral blood and bronchoalveolar lavage fluid proliferated spontaneously and released IL-2 and IL-2 receptor when cultured in vitro. Spontaneous proliferation of T-lymphocytes was also found in HTLV-I carriers without myelopathy, but less intensely than in HAM/TSP patients. Interestingly, HTLV-I-infected cells were markedly increased in bronchoalveolar lavage fluid from HAM/TSP patients compared to HTLV-I carriers without myelopathy. These results suggest that T-lymphocyte activation and increased HTLV-I-infected cells play an important role in the pathogenesis of pulmonary involvement in patients with HAM/TSP.
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PMID:[Pathogenesis of T-lymphocyte alveolitis associated with HTLV-I infection]. 163 41

A state of T-cell activation, reflected by a marked degree of spontaneous proliferation in vitro, exists among patients with human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) but not in those with retroviral-induced adult T-cell leukemia (ATL). We wished to define the mechanism by which the immune activation of circulating cells from HAM/TSP is driven, thus gaining insight into the pathogenesis of this HTLV-I-associated disease. By using a modification of the polymerase chain reaction, we compared the levels of interleukin 2 (IL-2) and IL-2 receptor alpha chain (IL-2R alpha) mRNA expression to the transcription of the HTLV-I transactivator gene, pX, in peripheral blood mononuclear cells of HAM/TSP and ATL patients as well as seropositive carriers. Up-regulation of IL-2 and IL-2R alpha transcripts was detected in HAM/TSP and seropositive carriers that paralleled the coordinate mRNA expression of the pX transactivator. In addition, IL-2 and soluble IL-2R alpha serum levels in HAM/TSP and seropositive carriers were elevated. Despite markedly elevated levels of soluble IL-2R alpha in ATL, transcripts for IL-2 and pX were not demonstrable in the circulating cells. Finally, the marked degree of in vitro spontaneous proliferation present in HAM/TSP was profoundly inhibited by specific anti-IL-2R or anti-IL-2 blocking antibodies. Collectively, these results suggest that immune activation in HAM/TSP, in contrast to ATL, is virally driven by the transactivation and coordinate expression of IL-2 and IL-2R alpha. This deregulated autocrine process may contribute to the evolution of inflammatory nervous system damage in HAM/TSP.
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PMID:Transactivation of interleukin 2 and its receptor induces immune activation in human T-cell lymphotropic virus type I-associated myelopathy: pathogenic implications and a rationale for immunotherapy. 236 34

Accumulating evidence has suggested the involvement of HTLV-1 in the inflammatory lesions of various organs, including the lung. However, the causal relationship between HTLV-1 and inflammatory responses in the organs remains to be elucidated. In order to evaluate the expression of HTLV-1 and its effects in the lung, we examined the expression of mRNA for the HTLV-1 tax/rex gene in fresh bronchoalveolar lavage cells (BALC) and peripheral blood mononuclear cells (PBMC) of 23 seropositive individuals, including six patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), by use of an improved method of reverse transcription-polymerase chain reaction (RT-PCR). The tax/rex mRNA was more frequently detected in BALC than in PBMC. All the HAM/TSP patients and eight of 17 carriers without neurological symptoms showed the expression of tax/rex mRNA in the BALC. IgM class antibodies to HTLV-1 were preferentially detected in sera of the tax/rex mRNA-positive individuals. The detection of tax/rex mRNA correlated closely with the presence of lymphocytosis accompanied by an elevated proportion of IL-2 receptor-bearing T cells in the BALC. Our findings indicate the crucial role of viral expression in the inflammatory response in the lung in HTLV-1-infected individuals.
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PMID:Expression of human T lymphotropic virus type 1 (HTLV-1) tax/rex gene in fresh bronchoalveolar lavage cells of HTLV-1-infected individuals. 791 May 32

Immunocytochemical staining of spinal cords from five autopsied patients with HAM/TSP was performed using a panel of monoclonal antibodies reactive with T cells. T cell subsets, B cells, macrophages, natural killer cells, IL-2 receptor-positive cells, and HLA-ABC and HLA-DR. In the spinal cords of patients with a shorter duration of illness, CD4+ cells, CD8+ cells and macrophages were evenly distributed in active-chronic inflammatory lesions. In striking contrast, we noted the predominance of CD8+ cells over CD4+ cells in the inactive-chronic inflammatory lesions of patients with longer duration of illness. Natural killer cells, IL-2 receptor-positive cells and B cells were only rarely present in both the active-chronic and inactive-chronic lesions. HLA-ABC was positive in endothelial cells and infiltrating mononuclear cells, and HLA-DR was positive in endothelial cells, microglia and infiltrating mononuclear cells. This study suggests that immune responses in the spinal cord lesions of HAM patients gradually change along with the duration of illness.
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PMID:Immunocytochemical analysis of the cellular infiltrate in the spinal cord lesions in HTLV-I-associated myelopathy. 835 31

Human T-cell lymphotrophic virus I (HTLV-I)-encoded tax plays a role in the early phases of HTLV-I-induced disease by deregulating the expression of the genes that encode interleukin-2 (IL-2) and the multisubunit (IL-2R alpha, IL-2R beta, and IL-2R gamma) IL-2 receptor (IL-2R). However, later in the course of the disease adult T-cell leukemia (ATL), cells no longer produce IL-2 yet continue to express the IL-2R. During studies to define the pathogenic mechanisms that underlie this IL-2-independent proliferation, we defined a cytokine designated IL-T/IL-15 that stimulates T-cell proliferation and requires the expression of IL-2R beta and IL-2R gamma for its action. To exploit the fact that IL-2Rs are present on abnormal T cells in patients with tropical parasitic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) and ATL but not on normal resting cells, different forms of IL-2R-directed therapy have been initiated. Unmodified humanized anti-Tac is being used to treat patient with TSP/HAM. To enhance its effector function for the treatment of ATL anti-Tac was armed with alpha- and beta-emitting radionuclides. In a clinical trial with 90Y-anti-Tac at the doses used (5, 10, and 15 mCi), 9 of the 18 patients with ATL underwent a partial or sustained complete remission. Thus the clinical application of IL-2R-directed therapy using a humanized monoclonal antibody or that antibody armed with radionuclides provides a new perspective for the treatment of autoimmune disorders such as TSP/HAM and certain neoplastic diseases including ATL.
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PMID:The promiscuous IL-2/IL-15 receptor: a target for immunotherapy of HTLV-I-associated disorders. 879 21

Twenty-five years ago, we reported the production of the monoclonal antibody, anti-Tac that identifies the IL-2 receptor alpha subunit and blocks the interaction of IL-2 with this growth factor receptor. In 1997, daclizumab (Zenapax), the humanized form of this antibody, was approved by the FDA for use in the prevention of renal allograft rejection. In addition, we demonstrated that daclizumab is of value in the treatment of patients with noninfectious uveitis, multiple sclerosis, and the neurological disease human T-cell lymphotropic virus I associated myelopathy/tropical spastic paraparesis (HAM/TSP). Others demonstrated therapeutic efficacy with daclizumab in patients with pure red cell aplasia, aplastic anemia, and psoriasis. Thus, translation of basic insights concerning the IL-2/IL-2 receptor system obtained using the monoclonal antibody daclizumab provided a useful strategy for the prevention of organ allograft rejection and the treatment of patients with select autoimmune diseases or T-cell leukemia/lymphoma.
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PMID:Anti-Tac (daclizumab, Zenapax) in the treatment of leukemia, autoimmune diseases, and in the prevention of allograft rejection: a 25-year personal odyssey. 1721 65