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)

The human high-affinity receptor for interleukin 2 (IL-2) has been proposed as being a membrane complex composed of at least two distinct polypeptide chains: p55 (alpha chain), recognized by the anti-Tac monoclonal antibody (mAb), and p75 (beta chain), both of which are capable of binding IL-2. Whereas the alpha chain itself has been shown to be nonfunctional, the beta chain appears to be pivotal in the IL-2 signal transduction, although the beta chain is otherwise poorly characterized. Three beta chain-specific mAbs, designated Mik-beta 1, -beta 2, and -beta 3, were developed. Mik-beta 1 and -beta 2 completely inhibited the IL-2 binding to the beta chain, whereas Mik-beta 3 immunoprecipitated the beta chain crosslinked with 125I-labeled IL-2. The beta chain immunoprecipitated by these mAbs was revealed to have a Mr of 68,000-72,000. High-affinity IL-2 binding was completely abolished by Mik-beta 1. Although IL-2-dependent T-cell growth at high IL-2 concentrations was not inhibited by the anti-Tac, it was almost completely inhibited by Mik-beta 1 in the presence of the anti-Tac. These results clearly indicate that the beta chain is an indispensable component to the high-affinity IL-2 receptor and is responsible for the IL-2 signal transduction. The beta chain was found to be constitutively expressed without the alpha chain on the surface of peripheral blood Leu-19+ natural killer cells.
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PMID:Characterization of the interleukin 2 receptor beta chain using three distinct monoclonal antibodies. 246 93

The monoclonal antibody (mAb) AHT-107 recognized a determinant distal to the interleukin 2 (IL-2) binding site on the p55 subunit of the IL-2 receptor (IL-2R) (the Tac antigen, CD25) of human T lymphoblasts, while the mAb AHT-54 recognized a determinant close to the IL-2 binding site as did the anti-Tac. The AHT-107 inhibited IL-2 dependent proliferation of human T lymphoblasts equally as well as did the AHT-54. Both mAbs inhibited the high-affinity binding and crosslinking of IL-2 to the p55 + p75 heterodimeric complex on forskolin-treated YT cells. Remarkably, the AHT-107 did not inhibit the low-affinity binding and cross-linking of IL-2 to the p55 molecule on human p55 cDNA-transfected cells, while the AHT-54 as well as anti-Tac did so. In contrast, the mAb PC61, that was previously reported to recognize a determinant distal to the IL-2 binding site on the mouse p55 subunit of IL-2R and to dissociate IL-2 from the high-affinity IL-2R complex by altering the conformation of the p55 molecule itself, inhibited the low-affinity binding and cross-linking of IL-2 to the p55 molecule on mouse p55 cDNA-transfected cells. Further, we showed that the AHT-107 did not dissociate IL-2 from the high-affinity IL-2R complex once formed on human T lymphoblasts.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies on the formation of high-affinity IL-2 binding sites of an IL-2 receptor p55 + p75 heterodimeric complex: functional importance of a determinant on the p55 subunit defined by a monoclonal antibody AHT-107. 246 50

The high-affinity receptor for interleukin-2 (IL-2) is composed of two distinct subunits with molecular weights of 55,000 and 75,000 (p55 and p75). While the presence of the high-affinity receptor requires the simultaneous expression of p55 and p75, these subunits can also be expressed independently, resulting in IL-2 receptors with low and intermediate affinities, respectively. IL-2 can induce proliferation in cells expressing either the intermediate affinity p75 receptor or the p55.p75 high-affinity complex, suggesting that p75 is responsible for signal transduction. We have previously shown that signal transduction by the high-affinity IL-2 receptor involves the activation of a tyrosine protein kinase. In order to evaluate the role of p75 in the activation of this kinase we assessed the ability of IL-2 to induce the activation of a tyrosine protein kinase in the human leukemic cell lines Hut 78 and YT. These cells express p75 as the predominant IL-2 receptor. IL-2-dependent tyrosine phosphorylation was observed in both cell lines and the concentrations of IL-2 needed to stimulate this phosphorylation were similar to that required for binding to the p75 receptor. Antibodies that inhibit binding of IL-2 to p55 had no effect on the IL-2-induced tyrosine phosphorylations in YT cells, while antibodies that block the binding of IL-2 to p75 completely inhibited the phosphorylations. These results demonstrate that the signaling capacity for the IL-2-induced tyrosine phosphorylation resides in the p75 receptor.
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PMID:The 75,000-dalton interleukin-2 receptor transmits a signal for the activation of a tyrosine protein kinase. 251 Nov 97

The cell-surface receptor for interleukin-2 (IL-2) consists of two unlinked polypeptides of 55 and 75 kDa (p55, p75). The monoclonal antibody antiTac binds to p55 alone. We show here that the binding of either IL-2 or antiTac to the surface of T lymphocytes triggered the generation of cAMP. Reagents which activate adenyl cyclase by stimulation of its guanine nucleotide-binding protein (Gs) also stimulated increases in cAMP. All of the above reagents, and cAMP itself, stimulated the turnover of phosphate residues bound to serine and threonine residues of an 85 kDa protein. The data provide evidence that the binding of ligands to the p55 component of the IL-2 receptor generates a biochemical signal by the stimulation of adenyl cyclase via Gs, and that the consequent generation of cAMP and activation of cAMP-dependent protein kinase modulates the turnover of p85-bound phosphate groups.
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PMID:The binding of ligands to the 55 kDa component of the interleukin-2 receptor triggers increased turnover of phosphate bound to an 85 kDa protein. Evidence for the role of cyclic AMP. 253 32

Antigen-induced activation of resting T cells induces the synthesis of interleukin-2 (IL-2) as well as the expression of specific cell surface high-affinity receptors for this lymphokine. There are at least two forms of the cellular receptors for IL-2, one with a very high affinity and the other with a lower affinity. Two IL-2 binding peptides, a 55-kd peptide reactive with the anti-Tac monoclonal antibody and a 75-kd, non-Tac IL-2-binding peptide, were identified. A multichain model for the high-affinity receptor in which an independently existing p55 or p75 peptide would represent low-or intermediate-affinity receptors, respectively, and high-affinity receptors would be expressed when both of these receptors are expressed and associated in a receptor complex, is proposed. An additional 95 - to 105-kd peptide may also participate in the multisubunit, high-affinity form of the IL-2 receptor. The p75 peptide is receptor for IL-2 on large granular lymphocytes and is sufficient for the IL-2 activation of these cells. In contrast to resting T cells, the T cells of patients with certain neoplasias of mononuclear cells and of patients with select autoimmune disorders, as well as T cells participating in organ allograft rejections, express the Tac antigen. To exploit the fact that IL-2 receptors are present on abnormally activated T cells but no on normal resting T cells, clinical trials have been initiated involving patients with neoplastic or autoimmune disorders as well as those receiving organ allografts. These patients are being treated with unmodified anti-Tac, with isotopic (212 Bi and 90Y) chelates of anti-Tac, with truncated Pseudomonas toxin conjugates of anti-Tac or IL-2, and with recombinant chimeric "humanized" anti-Tac.
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PMID:The multichain interleukin-2 receptor: a target for immunotherapy of patients receiving allografts. 268 57

The growth of mature T lymphocytes is regulated by interaction between interleukin-2 (IL-2) and its receptor. Three distinct binding sites for IL-2, namely low- (Kd 10 nM), intermediate- (Kd 100 pM) and high- (Kd 10 pM) affinity sites, have been found on human and primate T lymphocytes. Chemical crosslinking of labelled IL-2 to human T cells shows that two polypeptide chains, p55 (L chain) and p75 (H chain), bind IL-2 with low and intermediate affinities respectively. The high-affinity binding was shown to arise from ternary complex formation of IL-2, L and H chains. Construction of mutants of the L-chain complementary DNA indicated that the L chain is not directly involved in growth signal transduction. Nevertheless, expression of the IL-2 receptor L chain is tightly regulated by antigen or mitogen stimulation. To investigate the L chain function, we have produced transgenic mice using human L-chain cDNA of the IL-2 receptor under the control of a constitutive promoter. Studies on the L-chain transgenic mice showed that functionally active IL-2 receptors with high affinity were expressed on unstimulated spleen and thymus cells. The results indicate that the H chain of the IL-2 receptor is constitutively expressed in T cells.
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PMID:Expression of functional interleukin-2 receptors in human light chain/Tac transgenic mice. 282 38

The expression of interleukin 2 receptor (IL-2R) on leukemic cells of natural killer (NK) and T cell lineages in two patients with large granular lymphocytic (LGL) leukemia was examined. The p55 Tac IL-2R was not detected by the indirect immunofluorescence method and it did not participate in the IL-2 binding to the surface of these cells. However, these leukemic cells proliferated in a IL-2 dose-dependent manner and expressed p55. A p75 IL-2 receptor (IL-2-R) subunit was detected on the LGL leukemic cells of both NK and T lineages in a crosslink assay. Thus, it is suggested that the primary signal of IL-2 is mediated by the p75 alone. A study of the inhibitions of the proliferative response of LGL leukemia cells by anti-Tac revealed that both p75 and secondarily induced p55 are required for the cell proliferation.
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PMID:The expression of the p75 subunit of interleukin 2 receptor in Tac negative leukemic cells of two patients with large granular lymphocytic leukemia. 283 27

Antigen-induced activation of resting T-cells induces the synthesis of interleukin-2 (IL-2), as well as the expression of specific cell surface receptors for this lymphokine. There are at least two forms of the cellular receptors for IL-2, one with a very high affinity and the other with a lower affinity. We have identified two IL-2 binding peptides, a 55-kd peptide reactive with the anti-Tac monoclonal antibody, and a novel 75-kd non-Tac IL-2 binding peptide. Cell lines bearing either the p55, Tac, or the p75 peptide alone manifested low-affinity IL-2 binding, whereas cell lines bearing both peptides manifested both high- and low-affinity receptors. Fusion of cell membranes from low-affinity IL-2 binding cells bearing the Tac peptide alone with membranes from a cell line bearing the p75 peptide alone generates hybrid membranes bearing high-affinity receptors. We propose a multichain model for the high-affinity IL-2 receptor in which both the Tac and the p75 IL-2 binding peptides are associated in a receptor complex. In contrast to resting T-cells, human T-cell lymphotropic virus I-associated adult T-cell leukemia cells constitutively express large numbers of IL-2 receptors. Because IL-2 receptors are present on the malignant T-cells but not on normal resting cells, clinical trials have been initiated in which patients with adult T-cell leukemia are being treated with either unmodified or toxin-conjugated forms of anti-Tac monoclonal antibody directed toward this growth factor receptor.
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PMID:The role of the multichain IL-2 receptor complex in the control of normal and malignant T-cell proliferation. 289 1

Antigen-induced activation of resting T cells induces the synthesis of interleukin-2 (IL-2), as well as the expression of specific cell surface receptors for this lymphokine. There are at least two forms of the cellular receptors for IL-2, one with a very high affinity and the other with a lower affinity. We have identified two IL-2 binding peptides, a 55-kd peptide reactive with the anti-Tac monoclonal antibody and a 75-kd non-Tac IL-2 binding peptide. Cell lines bearing either the p55, Tac, or the p75 peptide alone manifested low-affinity IL-2 binding, whereas cell lines bearing both peptides manifested both high- and low-affinity receptors. Fusion of cell membranes from low-affinity IL-2 binding cells bearing the Tac peptide alone with membranes from a cell line bearing the p75 peptide alone generated hybrid membranes bearing high-affinity receptors. We propose a multichain model for the high-affinity IL-2 receptor in which both the p55 Tac and the p75 IL-2 binding peptides are associated in a receptor complex. The p75 peptide is the receptor for IL-2 on large granular lymphocytes and is sufficient for the IL-2 activation of these cells. In contrast to resting T cells, human T-cell lymphotropic virus I-associated adult T-cell leukemia cells constitutively express large numbers of IL-2 receptors. Because IL-2 receptors are present on the malignant T cells but not on normal resting cells, clinical trials have been initiated in which patients with adult T-cell leukemia are being treated with either unmodified or toxin-conjugated forms of anti-Tac monoclonal antibody directed toward this growth factor receptor.
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PMID:The role of the multichain IL-2 receptor complex in the control of normal and malignant T-cell proliferation. 289 96

There are at least two forms of cellular receptors for interleukin 2 (IL-2); one with a very high affinity and the other with a lower affinity. We identified a non-Tac IL-2 binding peptide with a relative molecular weight of 75,000 (p75). Cell lines bearing either the p55 Tac or the p75 peptide alone manifested low-affinity IL-2 binding, whereas a cell line bearing both peptides manifested both high- and low-affinity receptors. After the internalization of labeled IL-2 through high-affinity receptors, the p75 peptide could not be detected by cross-linking studies. Furthermore, fusion of cell membranes from low-affinity IL-2 binding cell lines bearing the Tac peptide alone with membranes from a cell line bearing the p75 peptide alone generated hybrid membranes bearing high-affinity receptors. These results suggest a multichain model for the high-affinity IL-2 receptor in which high-affinity receptors would be expressed when both Tac and p75 IL-2 binding peptides are present and associated in a receptor complex.
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PMID:Contribution of a p75 interleukin 2 binding peptide to a high-affinity interleukin 2 receptor complex. 310 87


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