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)

We have provided evidence that tumor necrosis factor alpha (TNF-alpha) enhances the proliferation and the state of activation of human thymocytes cultured with concanavalin A or interleukin 2 (IL-2), as evidenced by an increase in the expression of the c-myc gene and the gene of the IL-2 receptor (alpha-chain, Tac antigen) and by the expression of Tac antigen on the cell surface. Our observations suggest that TNF-alpha interacts with IL-2 and with another factor(s) which is induced in the course of activation by concanavalin A, since the immunosuppressant drug cyclosporin A-, which inhibits thymocyte activation, prevents the effect of TNF-alpha on thymocytes activated with concanavalin A, whereas anti-Tac, which prevents the binding of IL-2 to its receptor without affecting the production of IL-2 or the expression of IL-2-specific mRNA, inhibits proliferation only partially. By contrast, anti-Tac inhibits the response to TNF-alpha of thymocytes induced with IL-2 completely. These observations show that TNF-alpha exerts a potentially important immunoregulatory effect in synergy with IL-2 on thymocytes, which could contribute to tumor rejection. In addition, we show that activated human thymocytes express the TNF-alpha gene and that the expression of this gene is inhibited by cyclosporin A and dexamethasone.
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PMID:Immunoregulation and production of tumor necrosis factor alpha by human thymocytes. 265 63

The role of interleukin 2 (IL-2) for growth and differentiation of normal and malignant B cells still remains controversial. We assessed normal peripheral blood B cells and cell lines derived from patients with B non-Hodgkin's lymphomas (NHLs) with respect to their responsiveness to recombinant human IL-2 (rIL-2). The NHL cell lines used in our experiments expressed the Tac antigen (CD25)--a compound of the IL-2 receptor (IL-2R)--in a percentage ranging from 28 to 57%. As measured in a [3H]thymidine uptake assay, the normal peripheral blood B cells demonstrated a dose-dependent proliferative response to rIL-2, whereas the NHL cells did not show any responsiveness to rIL-2. In a clonogenic culture assay we evaluated the colony formation of the NHL cells and found a decrease of 28 to 41% on average in the presence of rIL-2 (10-50 U/ml). This moderate inhibitory effect on the clonal growth of the NHL cells was not due to a differentiation inducing effect of rIL-2, as studied by measuring the Ig production under increasing doses of rIL-2 (1 to 100 U/ml). Thus, malignant NHL B cells may express the CD25 compound of the IL-2 receptor on their surface, demonstrating a different functional responsiveness to rIL-2 compared to normal peripheral blood B cells.
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PMID:Effect of recombinant human interleukin 2 (rIL-2) on normal peripheral blood B cells and B lymphoblastoid cell lines. 268 Sep 16

The production and targeting of a major T cell derived lymphokine, Interleukin 2 (IL-2), were studied in 23 uremic patients undergoing regular hemodialysis treatment and 20 uremic patients prior to the onset of renal replacement therapy. In hemodialyzed patients, abnormally increased proportions of circulating T cells spontaneously expressing high affinity IL-2 receptors (IL-2 Rec) were detected: they bound a monoclonal antibody specifically directed to the IL-2 Rec 55 kDa chain (Tac antigen) (mean +/- SEM: 7.12 +/- 0.81% in patients vs. 2.15 +/- 0.39% in normal controls, P less than 0.0001) and significantly proliferated in presence of human recombinant IL-2 alone (mean +/- SEM: 5438 +/- 729 cpm in patients vs. 1647 +/- 244 cpm in normal controls). Hemodialyzed patients also exhibited significantly increased serum levels of soluble IL-2 receptor (mean +/- SEM: 4036 +/- 947 U/ml in patients vs. 253 +/- 29 U/ml in normal controls. P less than 0.001). Moreover, a significantly decreased IL-2 activity was detected in the supernatants of stimulated T cells from hemodialyzed patients (mean +/- SEM: 0.93 +/- 0.12 U/ml in patients vs. 2.49 +/- 0.22 U/ml in normal controls, P less than 0.0001). In nine hemodialyzed patients who were analyzed before and immediately after the hemodialysis session no acute modifications of the various parameters analyzed were detected. Although less profound, a similar pattern of T cell abnormalities was observed in the uremic non-hemodialyzed patients studied.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:In vivo T cell preactivation in chronic uremic hemodialyzed and non-hemodialyzed patients. 268 33

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

Interleukin 2 (IL-2) receptor expression was examined on recombinant IL-2 (rIL-2)-propagated tumor-infiltrating lymphocytes (TIL) from eight metastatic melanoma and three sarcoma samples. All 11 TIL expanded with similar growth rates. rIL-2 propagated TIL from five of eight metastatic melanoma specimens contained no Tac antigen-positive lymphocytes as determined by immunofluorescence and flow cytometry performed multiple times during the 4 to 8 week culture period. However, "Tac-negative" TIL did express the non-Tac IL-2-binding peptide, p70-75 as determined by [125I]IL-2 cross-linking and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. IL-2-binding assays revealed that these "Tac-negative" TIL expressed only an intermediate affinity IL-2 receptor. In contrast, TIL from the other three of eight melanoma and all three sarcoma contained one-third Tac-positive cells as assessed by flow cytometry analysis, and expressed surface non-Tac (p70-75) and Tac (p55) peptides by [125I]IL-2 cross-linking. These "Tac-positive" TIL displayed both the high and intermediate affinity IL-2 receptors. However, rIL-2-dependent growth of both "Tac-negative" and "Tac-positive" TIL was significantly inhibited by anti-Tac mAb, suggesting a transient Tac expression on the "Tac-negative" TIL. Additionally, due to the limits of our methodology, we cannot rule out the possibility of a constitutive expression of a low level of Tac, with an indicible expression of higher levels. Addition of culture supernatants from phytohemagglutinin- and phorbol myristate acetate-stimulated peripheral blood mononuclear cells to the "Tac-negative" TIL-induced detectable Tac expression within 48 h. These results indicate that both non-Tac and Tac IL-2 receptors play important roles during IL-2-dependent proliferation of TIL.
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PMID:Involvement of both Tac and non-Tac interleukin 2-binding peptides in the interleukin 2-dependent proliferation of human tumor-infiltrating lymphocytes. 278 85

We have earlier shown that first trimester human decidual cells and decidual macrophages suppress T lymphocyte alloreactivity in an MHC-unrestricted manner by secreting PGE2, which blocks the generation of IL-2 receptors (IL-2R) and production of IL-2 by lymphocytes but does not interfere with the interaction between IL-2 and IL-2R or the lytic function of CTL, once generated. The present study examined whether these events constituted a physiological, immunoprotective mechanism in situ against the activation of maternal decidua-infiltrating leukocytes with potential anti-trophoblast cytocidal function. We examined (1) whether there was IL-2R expression, IL-2 production, or anti-trophoblast killer activity in short-term (0-3 day) cultures of collagenase-dispersed first trimester human decidua inclusive of leukocytes; (2) if not, whether any of these parameters could be stimulated in these cultures by blocking PGE2 synthesis with indomethacin, or neutralizing PGE2 with anti-PGE2 antibody; (3) whether exogenously added recombinant IL-2 in the presence or absence of indomethacin stimulated IL-2R expression or anti-trophoblast killer function in these cultures. IL-2R (as defined by Tac antigen) was measured in the whole cell population by a radioimmunoassay and further examined at the cellular level with radioautography. IL-2 production in culture supernatants was measured from the proliferative response (3HTdR uptake) of an IL-2-dependent (CTLL) cell line. Killer activity in fresh or cultured decidua-associated cells as well as PBL of normal or pregnant subjects was measured against 51Cr-labeled targets inclusive of autologous cytotrophoblast cells or long-term human trophoblast cell lines, K562 and Daudi cells. Results revealed a complete absence of IL-2R expression, IL-2 production, or anti-trophoblast killer activity in the untreated cultures of the decidua, but all these parameters were significantly stimulated in the presence of indomethacin or anti-PGE2 antibody. The indomethacin-stimulated killer cells had NK-like activity. Presence of high dose exogenous IL-2 alone in these cultures strongly stimulated IL-2R expression and anti-trophoblast killer function, which were augmented further in the additional presence of indomethacin. The resultant killer cells had LAK cell-like activity. These findings suggest that PGE2 secretion by first trimester human decidual cells blocks activation of maternal leukocytes in the decidua with potential anti-trophoblast killer function, by inhibiting IL-2 receptor generation and IL-2 production in situ.
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PMID:PGE2-mediated immunosuppression by first trimester human decidual cells blocks activation of maternal leukocytes in the decidua with potential anti-trophoblast activity. 278 22

The effect of in vitro administration of Cyclosporin A (CsA) during mitogen, antigen and alloantigen activation of human T-lymphocytes on high affinity interleukin-2 (IL-2) receptor expression and -turnover and IL-2 production was investigated. The presence of CsA reduced 3H-thymidine incorporation and binding of radiolabelled human recombinant (ala125) IL-2 to high-affinity receptors in a dose-dependent fashion, although a pronounced inter- and intra-individual variation in sensitivity to CsA mediated immunosuppression was observed. Maximum inhibition was obtained when antigen and CsA were added to culture medium simultaneously. Preincubation with CsA did not influence the response. Although the number of IL-2 receptors was reduced, the turnover of the remaining high affinity IL-2 receptors on CsA treated cells was unaffected. Thus, binding, internalization and degradation were qualitatively unaltered by CsA administration. Finally, T cell activation in the presence of CsA reduced radioimmuno detectable IL-2 in cell culture supernatants to about 20%. CsA, added during antigen activation, reduced the number of Tac antigen presenting cells, but anti-Tac was unable to detect variations in the expression of high affinity IL-2 receptors. The present data indicate that CsA mediates immunosuppression by affecting early events during T-cell activation, and that variations in high affinity IL-2 receptor expression and IL-2 production are secondary to this affection.
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PMID:Cyclosporin A mediated immunosuppression in vitro: effect on high affinity interleukin-2 receptor expression and -turnover. 278 98

The inhibitory effect of a diphtheria toxin-related interleukin 2 fusion protein, IL-2-toxin, on protein synthesis in adult T-cell leukemia/lymphoma (ATL) cells was examined in vitro. Peripheral blood ATL cells from 12 patients (six acute type, four chronic type, and two smoldering type ATL) and the lymph node cells from three ATL patients (two acute type and one lymphoma type ATL) were examined. At a concentration of 10(-8) M, IL-2-toxin inhibited protein synthesis by 60 to 98% in lymph node ATL cells, whereas protein synthesis in peripheral blood ATL cells was inhibited from 20 to 57% in acute type, and from 3 to 13% in chronic type. In contrast, IL-2-toxin had no measurable effect on T-cells from either patients with smoldering type ATL or normal controls. The cytopathic effects of IL-2-toxin were blocked by the addition of anti-CD25 monoclonal antibody, suggesting that the inhibition of protein synthesis in target cells was mediated by the IL-2 receptor (IL-2R). The degree of inhibition of protein synthesis, however, was not closely correlated with expression of CD25 antigen (low-affinity Mr 55,000 glycoprotein, IL-2R, Tac antigen) on ATL cells. There was an apparent correlation between the degree of inhibition and the rate of protein synthesis in ATL cells. We demonstrate that ATL cells from patients with acute or lymphoma type disease were more sensitive to IL-2-toxin than cells from chronic or smoldering disease. These findings suggest that the high affinity IL-2R present on acute and lymphoma type ATL cells may serve as a target for therapy with this recombinant chimeric toxin.
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PMID:Cytotoxicity of interleukin 2-toxin toward lymphocytes from patients with adult T-cell leukemia. 278 49

Human recombinant interleukin-2 (IL-2) and a soluble recombinant form of the human p55 (Tac antigen) component of the IL-2 receptor (IL-2R) have been cocrystallized in 1.7-1.8 M ammonium sulfate, in the pH range 7.0-8.2. Variously glycosylated forms of both receptor and ligand can be cocrystallized under those conditions. The best crystals of the putative receptor-ligand complex involve the enzymatically desialylated receptor and unglycosylated IL-2. These crystals belong to the trigonal space group P3(1)2(1) or its enantiomorph, with unit cell dimensions a = b = 91 A and c = 119 A, and diffract to 3.5 A resolution. There is one receptor-ligand complex asymmetric unit, with a Matthews coefficient of 2.7, assuming the presence of one IL-2 molecule-receptor molecule. Interestingly, in addition to IL-2 (Mr = 14,000), the p55 IL-2 receptor (Mr = 44,000) and two fragments of the receptor, of apparent Mr = 35,000 and 25,000, respectively, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the crystals are enriched in a reducible dimeric form of the desialylated receptor (apparent Mr = 90,000), as compared with protein solution from which the crystals grow. The overall amino acid content in the crystals is consistent with a 1:1 ratio of receptor to ligand. A native data set has been collected on a multiwire area detector and the search for suitable heavy atom derivatives is in progress.
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PMID:Crystallization and preliminary X-ray diffraction studies of a complex between interleukin-2 and a soluble form of the p55 component of the high affinity interleukin-2 receptor. 278 21

We examined the expression of cell-surface interleukin-2 (IL-2) receptor (Tac antigen) on peripheral blood leukemic cells and measured soluble IL-2 receptor p55(alpha) chain (sIL-2R) levels in sera from chronic myelogenous leukemia (CML) patients with blastic crisis. Flow cytofluorometric analysis performed by dual immunofluorescence in three cases demonstrated coexpression of Tac antigen with myeloid (CD13, CD14, or CD33) or lymphoid (CD10) antigen on significant proportions of peripheral blood leukemic cells. Radiolabeled IL-2-binding assay demonstrated the specific IL-2 binding sites in three cases examined. The exogenous IL-2, however, failed to induce proliferative response. A myeloid cell line, Yut-K3, established from peripheral blood leukemic cells from a CML patient with blastic crisis, also expressed cell-surface Tac antigen and CD13 concurrently. SIL-2R assay showed that Yut-K3 released a detectable amount of sIL-2R in its culture supernatant. The serum sIL-2R levels were significantly elevated (range: 2,580 to 172,000 U/mL) in 12 CML patients with blastic crisis and were slightly elevated in ten patients in chronic phase (range: 250 to 820 U/mL) and in three in accelerated phase (range: 790 to 1,305 U/mL) compared with those in 24 normal controls (range: 70 to 695 U/mL, P less than .01). These results indicated that the leukemic cells from CML patients with blastic crisis expressed and released IL-2 receptor (Tac antigen). Longitudinal studies performed in three cases of CML with blastic crisis showed that the change of serum sIL-2R level was closely associated with that of the number of peripheral blood leukocytes and blasts, the percentage of blasts and serum LDH levels, also suggesting that the serum sIL-2R level is a useful clinical indicator of the leukemic cell burden in vivo.
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PMID:Elevated serum-soluble interleukin-2 receptor (Tac antigen) levels in chronic myelogenous leukemia patients with blastic crisis. 278 81


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