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Query: UNIPROT:P14784 (IL-2 receptor)
 3,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The interleukin-2 receptor (IL-2R) consists of three distinct chains (alpha, beta, gamma) which bind IL-2 and generate a proliferative signal in T cells. To define the mechanism of receptor activation, chimaeric receptors were constructed from the intracellular region of either IL-2R beta or IL-2R gamma and the extracellular region of c-kit, a receptor tyrosine kinase that homodimerizes on binding stem cell factor (SCF). We report here that binding of SCF to the beta-chain chimaera induced proliferation of the pro-B-cell line BA/F3, but not T cells. But in T cells expressing both the beta- and gamma-chain chimaeras, SCF induced proliferation and tyrosine phosphorylation characteristic of the native IL-2R signal. Chimaeric IL-2 receptor beta and gamma chains constructed with the heterodimeric extracellular regions of the granulocyte-macrophage colony stimulating factor receptor (GM-CSFR) also provided the IL-2R signal. Thus, heterodimerization of the cytoplasmic domains of IL-2R beta and -gamma appears necessary and sufficient for signalling in T cells.
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PMID:Cytoplasmic domains of the interleukin-2 receptor beta and gamma chains mediate the signal for T-cell proliferation. 751 77

The interferons (IFNs) are a family of secretory glycoproteins possessing potent antiviral, antiproliferative, antimicrobial, and immunomodulatory activities. It has been shown that the IFNs and superantigens have an important effect on the course of certain autoimmune disorders, and thus we have examined the effect of the type I and type II IFNs on superantigen-induced stimulation. The type I IFNs, alpha, beta, and tau, inhibited induction of T cell proliferation by several staphylococcal enterotoxin superantigens; the type II IFN, gamma, was without effect. The type I IFNs inhibited T cell proliferation to the same extent, approximately 50% at 10(3) units of IFN/ml, and in a dose-dependent manner. Consistent with inhibition of proliferation, the type I IFNs also inhibited IL-2 production as well as levels of IL-2 receptor expression. Inhibition was not increased by using the IFNs in combination, suggesting that they inhibited proliferation by the same mechanism. IFNs alpha and beta, but not IFN-tau, were toxic to cells at high concentrations (> or = 10(4) units/ml). Thus, the mechanism by which type I IFNs inhibit cell proliferation differs from that associated with their toxic effects. A partial reduction of V beta-specific superantigen-induced T cell expansion by type I IFNs was also demonstrated using flow cytometry. We recently showed that superantigens play an important role in the reactivation of experimental allergic encephalomyelitis. The potent antiproliferative activities of the type I IFNs strongly suggest the further study of their use as therapies for superantigen-associated diseases, such as multiple sclerosis and other autoimmune disorders, as well as toxic shock syndrome.
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PMID:Type I interferon inhibition of superantigen stimulation: implications for treatment of superantigen-associated disease. 764 33

The high affinity interleukin-2 (IL-2) receptor is composed of at least three cell surface proteins (alpha, beta and gamma subunits), each of which is independently capable of ligand binding. Physiologically, these subunits cooperate to form dimeric and trimeric complexes that efficiently capture IL-2 and transmit the signal across the membrane. The knowledge of how each subunit functions with respect to ligand capture, signal transmission and internalization is essential for the development of ligand-based IL-2 agonists and antagonists, as well as receptor-related therapeutic and diagnostic reagents. Only one of the subunits (p55 or alpha chain) is capable of interacting with ligand in solution in a manner that resembles cell surface binding. To generate soluble multimeric complexes of the IL-2 receptor subunits that may bind ligand in solution in a fashion that mimics the same receptor complexes on the cell surface, we have added recognition sequences (coiled-coil heptad repeats) to the ectodomains of the individual receptors. Here we describe the expression and characterization of a prototype IL-2 beta receptor ectodomain-coiled-coil fusion protein and demonstrate that this is a feasible approach to the preparation of cytokine receptor solution complexes.
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PMID:Coiled-coil molecular recognition: directed solution assembly of receptor ectodomains. 783 Dec 85

To determine a role of protein kinase C (PKC) isozymes in lymphocyte activation, human peripheral blood mononuclear cells were activated with 12-deoxyphorbol-13-O-phenylacetate (dPP; an agonist of both calcium-dependent and calcium-independent PKC isozymes), thymeleatoxin (TX; an activator of calcium-dependent PKC alpha, beta, and gamma), and 12-deoxyphorbol-13-O-phenylacetate 20 acetate (dPPA; an activator of PKC beta 1 isozyme) and examined for DNA synthesis, lymphocyte proliferation, interleukin-2 (IL-2) production, expression of IL-2 receptor alpha and beta chains on CD3+, CD4+, and CD8+ T lymphocytes and CD20+ B lymphocytes, and translocation of PKC beta isozyme from cytosol to membrane fraction. The results show that dPPA activates lymphocytes by inducing the above changes in a manner analogous to that of dPP, TX, and phorbol myristate acetate. These data suggest that PKC beta 1 is involved in the activation of human peripheral blood T and B lymphocytes.
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PMID:12-Deoxyphorbol-13-O-phenylacetate 20 acetate [an agonist of protein kinase C beta 1 (PKC beta 1)] induces DNA synthesis, interleukin-2 (IL-2) production, IL-2 receptor alpha-chain (CD25) and beta-chain (CD122) expression, and translocation of PKC beta isozyme in human peripheral blood lymphocytes: evidence for a role of PKC beta 1 in human T cell activation. 792 99

IL-2 regulates growth and differentiation of various types of cells in the immune system via its interaction with IL-2 receptor (IL-2R). The high and intermediate-affinity IL-2Rs, which consist of the alpha beta gamma heterotrimer complex and the beta gamma heterodimer complex, respectively, harbor the function of the intracellular signal transduction, indicating that the beta and gamma chains are indispensable for the signal transduction but not the alpha chain. The reconstitution studies of IL-2Rs with alpha, beta and gamma chain genes demonstrated that each subunit has potential for altering the affinity of the receptor, and the cytoplasmic domains of the beta and gamma chains participate in signal transduction in terms of cell growth, activation of alpha tyrosine kinase and enhancement of c-myc, c-fos and c-jun transcription. The region containing the SH2 homologous sequence of the gamma chain should have a critical function for signal transduction. On the other hand, common subunits are known to be shared among receptors for IL-3, IL-5 and GM-CSF, and receptors for IL-6, LIF, OSM and LIF. We have demonstrated that the monoclonal antibody specific for the IL-2R gamma chain completely inhibited not only IL-2-dependent cell growth but also IL-4-dependent, IL-7-dependent, and IL-9-dependent cell growth, suggesting that the gamma chain is possibly shared among receptors for IL-2, IL-4, IL-7 and IL-9. Impairment of the gamma chain function is considered to be closely related to human XSCID characterized by profound T cell defect.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Structure and function of IL-2 receptor subunits]. 802 15

To gain an insight into roles of the interleukin-2 (IL-2) receptor gamma chain in IL-2 binding mechanisms, we examined association and dissociation rate constants for IL-2 binding with a series of fibroblastoid L929 cell lines expressing IL-2 receptor complexes reconstituted by transfection with the alpha, beta and gamma genes. The association rate constant (k) with the alpha beta gamma complex on L cells was fourfold larger than that with the alpha beta complex on L cells, and the dissociation rate constant (k') was one fifth of that with the alpha beta complex. These results indicate that the gamma chain is involved in both mechanisms by which IL-2 associates with and dissociates from receptors, resulting in the generation of the high-affinity IL-2 receptor along with the alpha and beta chains. During the course of this study, we found that the IL-2 dissociation from alpha beta gamma complex on lymphoid cells was a lot slower than that from the alpha beta gamma complex on fibroblast cells. A similar difference was observed with the beta gamma complex. These observations may indicate functional and constitutional differences of the high- and intermediate-affinity IL-2 receptor complexes between lymphoid and fibroblastoid cells.
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PMID:Kinetic study of interleukin-2 binding on the reconstituted interleukin-2 receptor complexes including the human gamma chain. 840 47

Activation of protein kinase C (PKC) in T cells leads to a variety of responses including IL-2 production and IL-2 receptor expression. PKC consists of several isoforms that exhibit some different in vitro properties. We have set up a Western blotting system to explore the regulation of PKC isoforms during T cell activation. In Jurkat T lymphoma cells, PKC alpha, beta, delta, epsilon, and zeta were detected. PKC alpha and beta existed primarily in the cytosol, translocated to the membrane fraction after 10 minutes of treatment with PMA, and almost completely disappeared within 16 h. A larger fraction of PKC delta and epsilon existed in the membrane fraction compared to PKC alpha or beta, and PKC epsilon translocated to the membrane fraction rapidly. Translocation of PKC delta was not apparent after 1 h treatment with PMA, but total PKC delta protein was reduced within 4 to 6 h of treatment. Consistent with this, overnight treatment with PMA caused down-regulation of both PKC delta and epsilon, but to a lesser degree than was observed with PKC beta. Anti-PKC zeta antibody detected two bands at 82 and 75 kDa. The 75-kDa band existed mostly in the cytosol fraction and showed no translocation or down regulation after PMA. We present evidence that this 75-kDa band represents PKC zeta. Similar PMA-induced translocation responses were observed in murine thymocytes showing that the responses are not unique to PKC isoforms in Jurkat. These results demonstrate that it is possible for the PKC isoforms to be differentially regulated during T cell activation.
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PMID:Regulation of protein kinase C isoform proteins in phorbol ester-stimulated Jurkat T lymphoma cells. 843 13

We isolated a cDNA clone for the gamma chain of the mouse interleukin 2 receptor. Introduction of the mouse gamma chain cDNA clone into a mouse fibroblast cell line, L929, expressing the mouse alpha beta heterodimer IL-2 receptor converted pseudo-high affinity of the IL-2 receptor into functional high, resulting in internalization of IL-2 and induction of the c-myc, c-fos and c-jun genes. The mouse beta gamma heterodimer, however, failed to bind IL-2 unlike the human beta gamma heterodimer intermediate-affinity receptor. These results indicate that the mouse functional IL-2 receptor is a complex comprising three distinct subunits, alpha, beta and gamma chains, but the beta gamma heterodimer is not functional and different from the human heterodimer.
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PMID:Cloning of the mouse interleukin 2 receptor gamma chain: demonstration of functional differences between the mouse and human receptors. 850 26

The interleukin-2 (IL-2) receptor gamma chain is an essential component of high and intermediate affinity IL-2 receptors (IL-2Rs), playing critical roles for ligand binding and internalization. We report here the isolation and characterization of the genomic locus for human IL-2R gamma, which, like IL-2R beta, is a member of the cytokine receptor superfamily. The IL-2R gamma gene is composed of eight exons and seven introns and spans approximately 4.2 kilobases. Analogous to the IL-2R beta gene, the two pairs of conserved cysteines typical of cytokine receptor superfamily proteins are located in adjacent exons, and the conserved WSXWS motif is located in the exon preceding the one that encodes the transmembrane domain and a small part of the cytoplasmic domain. In each gene, the remainder of the cytoplasmic domain is encoded by the final two exons. Southern blot analysis suggests that IL-2R gamma is encoded by a single copy gene. Cross-hybridizing sequences were detected in DNA derived from a number of other mammalian species but not from yeast. Primer extension analysis and ribonuclease protection assays revealed that there are three principal transcription initiation sites located 32-38 nucleotides 5' to the translation initiation AUG codon. These sites are upstream of the 5' end of the published IL-2R gamma cDNA sequence. The region 5' to the transcription initiation sites exhibited promoter activity when cloned upstream of the luciferase reporter gene. With this study, the organization of the genes encoding all three chains (alpha, beta, and gamma) of the IL-2 receptor has been determined and promoters for each identified.
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PMID:Characterization of the human interleukin-2 receptor gamma chain gene. 851 92

Although tumor necrosis factor-alpha (TNF) is constitutively expressed in human and mouse thymus, the effects of TNF on thymocyte proliferation, differentiation and survival suggest that its influence in the thymus is complex. To determine if this complexity results from changes in the expression of the two TNF receptors during thymocyte differentiation, we examined the expression of the 55 kDa TNF receptor (TNF-R1) and the 75 kDa TNF receptor (TNF-R2) on postnatal human thymocytes. Both TNF-R1 and TNF-R2 mRNA were found in resting human thymocytes by reverse transcriptase-polymerase chain reaction (RT-PCR). Using mAb which specifically react with the respective TNF receptors and a highly sensitive, three-step method of immunofluorescence, cell surface TNF-R1 was detected on the vast majority of thymocytes. In contrast, detectable cell surface TNF-R2 was present on a mean of only 12.9% of thymocytes. TNF conjugated to phycoerythrin (TNF-PE) also reacted with a small population of thymocytes and was found to specifically block binding of the TNF-R2 mAb and not the TNF-R1 mAb, implicating preferential binding of TNF-PE to TNF-R2. Using dual-color immunofluorescence with TNF-PE we found that the population of cells which express TNF-R2 also express high levels of the TCR alpha, beta-CD3 complex, CD4 or CD8, and IL-2 receptor alpha chain. Thus, immature (TCRneg/low) thymocytes express TNF-R1 while mature (TCRhigh) thymocytes can also express TNF-R2. This differential expression of TNF receptors provides a mechanism for distinct effects of TNF on immature vs. mature thymocytes.
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PMID:Characterization of TNF receptors on human thymocytes. 852 4


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