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 expression of a range of surface molecules/receptors that are important in the host response to infection and foreign antigens was examined using peritoneal macrophages isolated from patients on continuous ambulatory peritoneal dialysis (CAPD) with peritonitis. The macrophage phenotypic profile was compared with that of normal peripheral blood monocytes. Consistently there was increased expression by macrophages of CD14, ICAM-1 (CD54), Fc gamma RI (CD64), Fc gamma RII (CDw32), Fc gamma RIII (CD16), transferrin receptors (CD71) and tissue factor. Increased expression of MHC class II was marginally significant. There was no detectable expression of either the p55 (CD25) or p70 chains of the IL-2 receptor. The expression of the complement receptors, CR1 (CD35) and CR3 (CD11b, CD18), was reduced. The activity of well-known inflammatory cytokines, rather than uraemic molecules, can account for the phenotypic profile of these extravasated peritoneal macrophages. The results of this study indicate that peritoneal macrophages from CAPD patients with peritonitis display a phenotype consistent with them being in vivo-derived inflammatory macrophages, and that they are appropriate for use in studies of anti-inflammatory agents.
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PMID:Peritoneal macrophages during peritonitis. Phenotypic studies. 160 34

Interleukin-2 (IL-2) plays a central role in the immune system by regulating the proliferation and differentiation of T lymphocytes. However, the molecular mechanism of the signal transduction through the IL-2 receptor is poorly understood. We have studied the role of phosphatidic acid (PA) on IL-2 signal transduction using cloned T lymphocytes. IL-2 stimulated a transient increase in the PA concentration in resting CTLL-2 cells prelabeled with [3H]palmitic acid. This effect was detected as early as 1 min after IL-2 addition and peaked at 5 min. IL-2 similarly increased phospholipase D activity in intact CTLL-2 cells, as inferred by phosphatidylethanol production. By contrast, IL-2 did not affect [3H]palmitic acid-labeled diacylglycerol levels. Furthermore, exogenous addition of several natural or synthetic PA to T cells mimicked IL-2 activity. Thus, PA were able to induce DNA synthesis on CTLL-2 cells, although this effect was only 10%-20% of that observed with IL-2. PA showed a synergistic effect with low doses of IL-2. In addition, PA was able to induce c-myc RNA transcription in CTLL-2 cells as well as IL-2 receptor (CD25) expression on the cell membrane with equal potency as saturating doses of IL-2. It is likely that IL-2-induced PA accumulation is a consequence of phospholipase D activation. This hypothesis is further supported by the fact that the addition of exogenous phospholipase D but not phosphatidylinositol-specific phospholipase C also reproduced the IL-2 or PA effects mentioned above. In summary, our results suggest a role of phospholipase D activation and PA formation as second messengers of IL-2 activity.
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PMID:Regulation of interleukin-2 responses by phosphatidic acid. 162 28

Interleukin-2 (IL-2) stimulates the proliferation of activated antigen-specific T cells through its interaction with high affinity receptors. This event is largely regulated by the inducible expression of the alpha-chain (CD25) which, in combination with the beta-chain and possibly additional chains, forms the high affinity IL-2 receptor (IL-2R) complex. From a concanavalin A (Con A)-activated ovine T-cell complementary DNA (cDNA) library we have isolated two cDNA clones which together constitute a 2650 base pair (bp) messenger RNA (mRNA) species encoding the ovine IL-2R alpha chain. The nucleotide sequence has high homology with analogous cDNA from other species and predicts a mature protein of 254 amino acids. In addition to the predominate 2.6 kilobase (kb) ovine IL-2R alpha chain mRNA species. Northern blot analysis of activated T-cell RNA revealed two larger mRNA species. The ovine IL-2R alpha chain cDNA was transfected into CHO cells and low affinity binding of human recombinant IL-2 demonstrated. Polyclonal antisera generated against the transfected cells cross-reacted with Con A-activated ovine lymphocytes. In addition these antisera were used to immunoprecipitate a unique 50,000 MW protein from the transfected cells. It is likely that this protein represents the expressed ovine IL-2R alpha chain cDNA which is heavily glycosylated as distinct from the 30,869 MW primary translation product. Southern blot analysis of ovine genomic DNA suggests that the ovine IL-2R alpha chain is encoded by a single copy gene.
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PMID:Molecular cloning, expression and characterization of the ovine IL-2R alpha chain. 162 87

B-cells extracted from periodontal disease tissue were analyzed for the presence of activation markers using a range of monoclonal antibodies. In adult periodontitis (AP), 6% of B-cells expressed the IL-2 receptor (CD25) compared with 1-2% in peripheral blood and healthy or marginal gingivitis (H/MG) gingival B-cells. There was also an increase in the mean percentage of IgD-positive B-cells and a decrease in CD21 and CD22 expression. In both AP and H/MG lesions, 20-22% of the B-cells expressed CD23 compared with less than 5% in peripheral blood. As B-cells are activated by day 3 in culture and start differentiating into immunoglobulin-secreting cells by day 6, B-cell phenotypes were assayed at these times in this study. Following stimulation with the periodontopathic bacterium Porphyromonas gingivalis, the expression of CD23, CD21 and CD22 on B-cells extracted from AP lesions remained relatively constant over the 6-d culture period. However, with Fusobacterium nucleatum stimulation, there was a significant decrease in CD23, CD21 and CD22 expression after 3 d in culture, which corresponds to the activation time for B-cells. These results show that B-cells extracted from periodontal disease tissue display a range of activation markers and on stimulation, demonstrate differing responses to individual periodontopathic bacteria.
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PMID:Phenotypic analysis of B-cells extracted from human periodontal disease tissue. 166 49

Lymphocyte activation induces production of soluble IL-2 receptor (sIL-2R) which is a large portion of the CD25 membrane molecule and which is detectable in serum. Serum sIL-2R is reported here to increase as a direct effect of the HIV infection and not to be due to secondary opportunistic infections. sIL-2R increased promptly after HIV seroconversion in 83% of 50 initially seronegative homosexual men. The sIL-2R serum levels stabilized in the third year after seroconversion and were then predictive of later CD4 T cell levels and development of AIDS. In two studies of 59 and 395 seropositive men, beta-2 microglobulin (B2M) and neopterin levels in serum correlated closely with each other but not with sIL-2R levels. Thus, increased production of sIL-2R may reflect pathological processes distinct from those determining B2M and neopterin increases. Membrane CD25 expression on peripheral blood lymphocytes, unexpectedly, was found to be decreased in HIV infection. This contrasted with the increased sIL-2R in serum. Investigations with sensitive flow cytometry technics showed that CD25 was expressed at reduced levels and averaged only 12% of lymphocytes from HIV-infected individuals in contrast to 25% in noninfected individuals. All major lymphoid populations showed reductions in CD25 positive cells. This reduction in lymphoid membrane CD25, however, was not inversely correlated with the increased serum levels of sIL-2R or with other parameters of immune deficiency or activation. Thus, surface CD25 loss and serum sIL-2R increase are separate and independent consequences of HIV infection.
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PMID:Serum increases and lymphoid cell surface losses of IL-2 receptor CD25 in HIV infection: distinctive parameters of HIV-induced change. 168 May 89

Some recently defined lymphocyte immunophenotypes were determined in lesions of patients with American cutaneous leishmaniasis (ACL). New monoclonal antibodies have allowed the demonstration of cell surface antigens of T lymphocytes, such as CD45RA and CD45RO, which recognize different maturational stages of the same T CD4+ cell subgroup: 'virgin' (CD4+CD45RA+) and 'memory' (CD4+CD45RO+) T cells respectively. The CD4/CD8 cell ratios were higher in mucocutaneous leishmaniasis (MCL) than in localized cutaneous leishmaniasis (LCL) lesions. Diffuse cutaneous leishmaniasis (DCL) has the highest values of 'virgin' T cells; LCL and MCL patients have lower values, similar to each other. 'Memory' T cells were higher in MCL than in LCL or DCL. The ratio of 'memory'/'virgin' T cells was 7.9 for LCL, 9.6 for MCL and 2.5 for DCL. The highest value for IL-2 receptor positive cells (CD25) was observed in LCL, whereas single CD45RO-immunoreactive cells showed a peak value in DCL patients. HLA-DR+ cells were present in all three clinical forms of ACL. MCL patients showed a lack of epithelial Langerhans cell (CD1a+) in the nasal mucosa.
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PMID:Immunocytochemical characterization of immune cells in lesions of American cutaneous leishmaniasis using novel T cell markers. 168 61

Differential expression of various isoforms of leukocyte common antigen (CD45), which arises from alternate mRNA splicing, identifies naive and memory populations of human T cells. Some memory (CD45RO+ CD45RA-) populations of CD4+ T cells from adult individuals express IL-2 receptor (IL-2R) alpha-chain (CD25), but naive (CD45RO- CD45RA+) CD4+ T cells only do so to a small degree. We found that a small but significant fraction of CD4+ T cells in neonatal blood expressed CD25, although most generally exhibited the phenotype of naive cells. It was demonstrated that purified neonatal CD25+ CD4+ T cells expressed mRNA for the IL-2R alpha-chain. Two-color immunofluorescence analysis disclosed that a CD25+ population of neonatal CD4+ T cells had the naive (CD45RA+ CD45RO-) phenotypes. These CD25+ CD4+ T cells from newborns could express mRNA for some specified lymphokines such as IL-4, IL-5, and interferon-gamma on activation in a similar manner to CD45RO+ (memory) CD4+ T cells from adults. Notably, polymerase chain reaction analysis demonstrated that neonatal CD45RA+ CD4+ T cells expressing CD25 contained spliced mRNA transcripts possibly encoding CD45RO in addition to CD45RA-associated transcripts, seemingly indicating that this population might be in the recently antigen-primed states. Such a small population of CD45RA+ CD4+ T cells expressing CD25 appeared to be present in the blood throughout human life. The results suggest that CD4+ T cells with the naive (CD45RA+) phenotype expressing IL-2R alpha-chain (CD25) represent the novel transitional population in the maturation process of naive into memory CD4+ T cells.
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PMID:A novel subpopulation of CD45RA+ CD4+ T cells expressing IL-2 receptor alpha-chain (CD25) and having a functionally transitional nature into memory cells. 168 71

Recent data suggest that basophils express receptors for a variety of lymphokines. In this study we present the biochemical characterization of the interleukin-2 (IL-2) receptor on the basophil surface membrane. Highly enriched populations (purity: 92% to 99%) of blood basophils were obtained from chronic granulocytic leukemia (CGL) patients (n = 3) by negative selection using monoclonal antibodies (MoAbs) and complement. CGL basophils were found to bind CD25 MoAbs (n = 4) directed against different epitopes of the 55- to 60-Kd subunit of the IL-2 receptor (= Tac peptide). Immunoprecipitation experiments with lysates of purified CGL basophils and CD25 MoAbs showed a protein with a molecular weight of 60 Kd, equivalent to the Tac peptide on human T blasts. Quantitative binding studies and Scatchard plot analysis using radiolabeled recombinant human (rh) IL-2 indicated the presence of 12,000 +/- 4,700 low affinity IL-2 binding sites (kd = 66 nmol/L) per purified CGL basophil. Northern blot analysis with enriched CGL basophils showed two messenger RNA bands of 3.5 and 1.5 kilobases hybridizing to radiolabeled Tac cDNA. Immunoprecipitation of the Tac peptide from enriched basophils metabolically labeled with 35S-methionine showed active synthesis of the IL-2 receptor. Our results show that human blood basophils synthesize and express receptors for IL-2.
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PMID:Human blood basophils synthesize interleukin-2 binding sites. 169 35

Using a high-sensitivity immunofluorescence procedure, a proportion of blood lymphocytes can be shown to express the p55 chain of the IL-2 receptor (CD25, TAC) without in vitro stimulation. In this study, we measured the proportion of peripheral blood lymphocytes expressing CD25 in patients with a diagnosis of HIV infection and compared the results with cells from controls. The mean value for HIV-positive samples was 15%, while controls gave a mean value of 31%. The difference between the groups was highly significant (P less than 0.001, Mann-Whitney U test). When expression of CD25 was examined separately in CD4-positive and CD8-positive T cells and in B cells, there was a wider spread of values in the HIV group compared with controls, but no systematic difference. In the patient group studied (110 samples from 53 patients) there was a weak correlation between CD25 and CD4 expression (correlation coefficient r = 0.21, P less than 0.02), but there were patients with low CD25 and high CD4 as well as patients with high CD25 and low CD4, suggesting that CD25 can vary independently of changes in CD4 lymphocytes. Although the majority of very low values of CD25 (less than 10%) were found in patients with stage IV disease, such low values were also common in Stage II disease.
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PMID:Patients with HIV infection have a reduced proportion of lymphocytes expressing the IL2 receptor p55 chain (TAC, CD25). 170 15

Staphylococcal protein A (Cowan strain; SpA), a biologically active molecule capable of inducing augmented natural killer (NK) cell cytotoxicity, was studied in regard to its effects on lymphokine-activated killer (LAK) cell development. SpA, when co-cultured with interleukin-2 (IL-2) for 4 days, significantly augmented both LAK activity against NK-resistant M14 (melanoma) target cells and DNA synthesis of peripheral blood mononuclear cells (PBMC). This enhancement occurred with SpA concentrations of 1-100 micrograms/ml in a dose-dependent fashion; concentrations above 100 micrograms/ml were no more effective. When SpA (10 micrograms/ml) was added to PBMC cultures with various IL-2 concentrations, cytotoxicity was increased over controls with IL-2 alone. The peak cytotoxic effect reached a plateau at 80 U/ml IL-2. SpA alone induced early (day 1) cytotoxicity, which rapidly declined. SpA alone did not induce PBMC proliferation but it did increase expression of CD25 (Tac), IL-2 receptor alpha chain, on CD56(Leu19)-positive and -negative cells. The potentiating effect of SpA was significantly enhanced in serum-free medium. If either human AB serum or human IgG was added to cultures SpA-enhanced LAK cytotoxicity was diminished. The addition of anti-interferon gamma (anti-IFN gamma) antibody, but not anti-IFN alpha, inhibited (SpA+IL-2)-induced cytotoxicity, indicating that IFN gamma is partially responsible for the additive cytotoxic effect.
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PMID:The effects of staphylococcal protein A on human lymphokine-activated killer cell induction. 170 23


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