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)

IL-2 is one of the principal growth factors regulating the proliferation of T lymphocytes. Although two independent IL-2-binding molecules have been molecularly cloned and shown to participate in the formation of a high affinity receptor complex, their primary structures do not suggest a specific mechanism for IL-2 growth signal transduction across the cell membrane. Neither IL-2 receptor subunit contains an intrinsic kinase domain; nevertheless, tyrosine phosphorylation of various intracellular substrates is one of the first biochemical changes observed following activation of the IL-2 receptor (IL-2R). Both serine/threonine and tyrosine kinases can be co-precipitated as part of the IL-2R complex suggesting that the IL-2 signalling may involve the activation of non-covalently associated intracellular kinases. However, controversy exists as to which kinases are involved in IL-2 signal transduction; in particular, which kinase(s) mediates the first or proximal event(s) in the signalling process. Activation of the IL-2R leads to serine and threonine phosphorylation of the SRC tyrosine kinase family member, LCK, and an increase in LCK tyrosine kinase activity. Furthermore, LCK can be co-immunoprecipitated with the beta chain of the IL-2R indicating its association with the receptor complex. IL-2 has also been reported to increase FYN kinase activity and to alter its association with the 85 kDa subunit of phosphatidylinositol-3 kinase thus suggesting a role for FYN in IL-2 signal transduction. However, in this report, we now demonstrate that neither LCK nor FYN are obligatory for IL-2-induced growth of HTLV-I-infected human T cells. Lack of expression of LCK or FYN in the HTLV-I-infected T cell lines was demonstrated by a combination of Northern blotting, polymerase chain reaction, Western blotting, and in vitro kinase activity. Despite the absence of LCK or FYN, IL-2 induced similar patterns of rapid tyrosine phosphorylation. Similar results were observed in cell lines lacking expression of the LYN, FGR, HCK, and LTK tyrosine kinases. Thus, none of these tyrosine kinases alone appears to be required for growth signalling through the IL-2R in the HTLV-I-infected T cell lines analyzed. The findings raise the possibility that an, as yet, unidentified tyrosine kinase is involved. Alternatively, this biological signalling system may exhibit remarkable redundancy whereby several different tyrosine kinases may be capable of associating with the IL-2R complex and mediating intracellular signalling.
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PMID:Neither the LCK nor the FYN kinases are obligatory for IL-2-mediated signal transduction in HTLV-I-infected human T cells. 147 76

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

The majority of non-Hodgkin's lymphomas (NHLs) are of B-cell lineage, with less than 20% of cases being of T-cell lineage. The B-cell NHLs phenotypically correspond to normal cells in the mid stages of normal differentiation. More specifically, by their expression of B-cell activation antigens, these tumors are the neoplastic counterparts of normal activated B cells. The follicular lymphomas--including the small cleaved, mixed small and large cell, and large cell types, as well as the small noncleaved cell (Burkitt's) lymphomas--represent malignant expansions of normal germinal center B cells by their expression of pan-B cell antigens, B-cell activation antigens, and CD10 (CALLA). The diffuse lymphomas also correspond to normal activated B cells. The small lymphocytic lymphomas express the low-affinity IL-2 receptor and CD5, both of which are induced on normal B cells following mitogen stimulation. The other diffuse B-cell NHLs similarly express activation antigens and resemble "transformed" B cells. The T-cell NHLs generally correspond to normal activated CD4+ T cells. These tumors--which include most peripheral T-cell lymphomas, cutaneous T-cell lymphomas, and HTLV-I-associated adult T-cell leukemias/lymphomas--express antigens induced on activated T cells, including IL-2 and transferrin receptors (CD25 and CD71, respectively), as well as HLA-DR. The lymphoblastic lymphomas, which are generally of T-cell lineage, phenotypically correspond to stages of intrathymic differentiation, often by their coexpression of CD4 and CD8, as well as expression of CD1. It remains controversial whether the immunophenotype of lymphoblastic lymphoma differs significantly from T-cell acute lymphoblastic leukemia. Since immunologic heterogeneity of NHL was first observed, attempts have been made to employ the data as a prognostic variable. Early studies suggested that lineage derivation or expression of markers of proliferating cells affected outcome in NHL. However, these reports were often retrospective, included various histologies, and did not treat patients uniformly. More recent prospective studies with relatively uniformly treated patients, predominantly involving DLCL, suggest that certain immunologically defined subgroups may have significantly different clinical outcomes. However, additional clinical studies will be necessary before treatment options are based upon immunologic markers.
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PMID:Immunologic markers in non-Hodgkin's lymphoma. 193 59

Ten patients with human T lymphotropic virus type I-associated myelopathy (HAM), 5 asymptomatic HTLV-I carriers and 11 healthy normal volunteers were studied to determine if peripheral blood lymphocytes spontaneously release IL-2 and soluble IL-2 receptors. Peripheral blood lymphocytes obtained from HAM patients proliferated spontaneously when cultured for 5 days in vitro. Proliferating cells were CD3+ lymphocytes and both CD4+ cells and CD8+ cells as shown by morphologic and immunohistochemical observations. These T cell responses were also found in asymptomatic carriers, but the responses were not as marked as those of HAM patients. IL-2 activity in the culture supernatants was much higher in HAM patients than in asymptomatic carriers; IL-2 activity correlated well with the intensity of spontaneous proliferation of lymphocytes. Furthermore, soluble IL-2 receptors in the cell-free supernatants from HAM patients were markedly increased compared to those from asymptomatic carriers. These results indicate that spontaneous proliferation of T cells is intimately related to HTLV-I infection and is probably due to autocrine or paracrine pathways which involve IL-2 and IL-2 receptor system.
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PMID:Immunological abnormalities in HTLV-I-associated myelopathy: spontaneous release of interleukin-2 and interleukin-2 receptor by peripheral blood lymphocytes. 198 52

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

HTLV-I infection of peripheral mature T cells appears to induce the expression of cellular genes including those of some cytokines and their receptors. We examined the expression of interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-2, IL-3, IL-4 and granulocyte/macrophage colony-stimulating factor (GM-CSF) at the mRNA level in fresh leukemic cells from 20 adult T cell leukemia patients to see whether there is any association between cytokine expression and HTLV-I expression and between their expression and clinical manifestations such as hypercalcemia or neutrophilia. IL-1 alpha, IL-1 beta and IL-3 expression was observed in 3, 7 and 1 of 20 cases examined, respectively. However, there seemed to be no association between IL-1 expression and clinical manifestations. IL-2, IL-4 and GM-CSF mRNA expression was not detected. HTLV-I viral RNA expression was detected only in one case in which IL-3 mRNA was expressed in both peripheral blood and lymph node cells and a relatively high proportion of leukemic cells expressed IL-2 receptor (p55, Tac). Thus, in the present study we could not find any correlation between cytokine expression and HTLV-I expression in peripheral blood fresh leukemic cells except in one unusual case.
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PMID:Expression of cytokine mRNA in leukemic cells from adult T cell leukemia patients. 250 74

Activation of resting T cells induces synthesis of IL-2 and expression of its specific high-affinity receptor. We have proposed a multichain model for the high-affinity IL-2 receptor in which both a 55 kDa IL-2-binding peptide identified by the anti-Tac monoclonal antibody and a 70/75 kDa IL-2-binding peptide are associated in a receptor complex. The IL-2 receptor is proving to be an extraordinarily versatile therapeutic target, since it is expressed by the abnormal T cells in patients with certain lymphoid malignancies or autoimmune disorders and in individuals rejecting allografts, whereas it is not expressed by normal resting cells. Specifically, HTLV-I-associated adult T-cell leukaemia cells constitutively express large numbers of IL-2 Tac receptors. A 42 kDa tax protein encoded predominantly by the pX region of HTLV-I may play a part in directly or indirectly increasing the transcription of the 55 kDa Tac IL-2 receptor gene. To exploit the fact that IL-2 receptors are present on abnormally activated T cells but not on normal resting cells, clinical trials have been initiated involving patients with Tac-expressing haematologic malignancies. These patients are being treated with unmodified anti-Tac, with anti-Tac conjugated to truncated PE toxin, with isotopic (212Bi and 90Y) chelates of anti-Tac and with recombinant 'humanized' anti-Tac. Thus, the clinical application IL-2 receptor-directed therapy represents a new perspective for the treatment of certain neoplastic diseases.
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PMID:IL-2 receptor expression in the haematologic malignancies: a target for immunotherapy. 270 34

The effects of 1,25(OH)2D3 and dexamethasone on cellular proliferation and gene expression of the HTLV-I-infected T-cell line, KH-2, established from a patient with adult T-cell leukemia, endemic in the south-west Japanese islands and the Caribbean, were examined. KH-2 cells are integrated by HTLV-I proviral DNA and expressed mRNA for c-myc, IL-2 receptor alpha-chain (IL-2R alpha), and T-cell receptor beta-chain (TCR beta) while it did not express IL-2 mRNA. 1,25(OH)2D3 and dexamethasone did not suppress the mRNA levels of HTLV-I, IL-2R alpha or TCR beta but reduced the c-myc mRNA level. The reduction of c-myc mRNA level was marked in 1,25(OH)2D3-treated cells but relatively weak in dexamethasone-treated cells. This inhibitory effect of the steroid hormones correlated with the inhibition of KH-2 cell proliferation.
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PMID:Suppression of c-myc mRNA expression by steroid hormones in HTLV-I-infected T-cell line, KH-2. 279 41

We report a rare case of adult T cell leukemia/lymphoma (ATLL) in which cardiac invasion was clinically demonstrated and treated effectively. A 45-year-old female was admitted because of exertional dyspnea and cervical tumors. The leukocyte count was 19,100/microliters with 20% of flower cells. HTLV-I antibody was positive. She was diagnosed as ATLL and treated with VEPA. She got remission for a short duration which was followed by relapse. OPEC was started as salvage therapy. In the course, extensive pericardial effusion was found in chest X-P. Pericardial puncture demonstrated ATLL cells and high titer of free IL-2 receptor (57,400U/ml) in the effusion. It was diagnosed as pericardial invasion of ATLL cells. Chemotherapy was started with new combination of drugs (cisplatin, mitoxantrone, ifosfamide, and prednisolone). Concomitantly pericardial drainage was performed and the drugs were administered directly into the pericardial cavity. The clinical improvement was obtained and pericardial effusion did not appear thereafter. She died 4 months after the diagnosis of cardiac invasion. On autopsy myocardial invasion was identified. The pericardium widely adhered and effusion measured 42 ml.
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PMID:[Cardiac invasion of ATLL cells and therapeutic effects of local along with systemic treatments]. 281 Jul 92


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