Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P14784 (IL-2 receptor)
 3,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Staphylococcal Enterotoxin A (SEA) at picogram amounts induces high levels of interleukin 2 (IL-2) and interferon in human mononuclear cells. SEA is a stronger inducer of IL-2 than phytohemagglutinin, leukoagglutinin, and concanavalin A. The IL-2 induction is very rapid with maximal levels being reached after 18 to 24 hr. The IL-2 concentration decreases rapidly and almost no IL-2 activity can be detected in supernatants of cells cultured for 3 days or more. Maximal DNA synthesis is recorded 3 days after maximal IL-2 levels have been reached in the culture medium. The DNA synthesis shows a 24 hr delay as compared to the expression of the IL-2 receptor during the initiation phase. An increase in the level of IL-2 receptor expression is apparent as early as 12 hr after stimulation with SEA and maximal expression is reached 48 to 72 hr after stimulation. The percentage of cells expressing the IL-2 receptor is maximal at 96 hr after onset of culture but the surface concentration of the receptor is lower than at 72 hr. The decline in expression of the IL-2 receptor is accompanied by a decline in mean cell size and in DNA-synthesis. The concentration of the T-cell marker T11 increases in parallel with the growing expression of the IL-2 receptor. It remains increased over a longer period than the IL-2 receptor and is still significantly augmented after 10 days' exposure to SEA.
 ...
PMID:Kinetics of IL-2 and interferon-gamma production, expression of IL-2 receptors, and cell proliferation in human mononuclear cells exposed to staphylococcal enterotoxin A. 393 9

The mitogenic activity of human T-cell leukemia virus type I (HTLV-I) is triggering the proliferation of human resting T lymphocytes through the induction of the interleukin-2 (IL-2)/IL-2 receptor autocrine loop. This HTLV-I-induced proliferation was found to be mainly mediated by the CD2 T-cell antigen, which is first expressed on double-negative lymphoid precursors after colonization of the thymus. Thus, immature thymocytes express the CD2 antigen before that of the CD3-TCR complex. We therefore investigated the responsiveness of these CD2+CD3- immature thymocytes and compared it with that of unseparated thymocytes, containing a majority of the CD2+CD3+ mature thymocytes, and that of the CD2-CD3- prothymocytes. Both immature and unseparated thymocytes were incorporating [3H]thymidine in response to the virus, provided that they were cultivated in the presence of submitogenic doses of phytohemagglutinin. In contrast, the prothymocytes did not proliferate. Downmodulation of the CD2 molecule by incubating unseparated and immature thymocytes with a single anti-CD2 monoclonal antibody inhibited the proliferative response to HTLV-I. These results clearly underline that the expression of the CD2 molecule is exclusively required in mediating the proliferative response to the synergistic effect of phytohemagglutinin and HTLV-I. Immature thymocytes treated with a pair of anti-CD2 monoclonal antibodies were shown to proliferate in response to HTLV-I, even in the absence of exogenous IL-2. We further verified that the proliferation of human thymocytes is consecutive to the expression of IL-2 receptors and the synthesis of IL-2. These observations provide evidence that the mitogenic stimulus delivered by HTLV-I is more efficient than that provided by other conventional mitogenic stimuli, which are unable to trigger the synthesis of endogenous IL-2. Collectively, these results show that the mitogenic activity of HTLV-I is able to trigger the proliferation of cells which are at an early stage of T-cell development. They might therefore represent target cells in which HTLV-I infection could favor the initiation of the multistep lymphoproliferative process leading to adult T-cell leukemia.
 ...
PMID:Human T-cell leukemia virus type I-induced proliferation of human immature CD2+CD3- thymocytes. 810 12

CD30 has been extensively studied as a cell surface marker expressed by Reed-Sternberg cells of Hodgkin's disease and other hematologic malignancies, although little is known about its expression by normal lymphoid cells. We therefore characterized the requirements for the induction of CD30 expression and identified the subsets of T cells that express CD30. CD30 is inducible on approximately 15% of normal PBMC stimulated with any of a variety of nonspecific T cell activators, including PHA, Con A, anti-T11(2) + T11(3), and anti-CD3; ionomycin alone induced lower percentages of CD30+ T cells (3 +/- 2%) compared to other stimuli. Maximal numbers of CD30+ cells were observed at 48 to 72 h of activation and the addition of rIL-2 did not affect these kinetics. However, CD30 expression was enhanced by the addition of exogenous rIL-2 to any of the stimuli tested, although rIL-2 alone did not lead to CD30 expression. The induction of CD30 during anti-CD3 mitogenesis was completely inhibitable by anti-IL-2 antibodies and partially inhibitable by rIL-4, indicating a requirement for both TCR triggering and IL-2 for its expression. Dual immunofluorescence analysis revealed that CD30+ cells were confined to CD3+ T cells that coexpressed higher levels of the p55 IL-2 receptor (CD25) than the CD30- population. Furthermore, CD30 expression was restricted to a subset of cells derived from CD45RO+ T cell precursors. Cell cycle analysis showed that CD30+ expression was not cell cycle dependent. Cross-linking of membrane CD30 induced Ca2+ in TCR+, but not TCR- Jurkat T cells. These results demonstrate that CD30 can serve as a T cell signal-transducing molecule and expressed by a unique subset of activated CD45RO+ T cells.
 ...
PMID:CD30 is a signal-transducing molecule that defines a subset of human activated CD45RO+ T cells. 810 64

Sequential gene expression of two type 1 cytokines (interleukin 2 [IL-2] and gamma interferon), one type 2 cytokine (IL-10), two monokines (IL-6 and tumor necrosis factor alpha), and one cytokine receptor (IL-2 receptor [IL-2R]) in normal human peripheral blood mononuclear cells (PBMC) following in vitro stimulation was investigated by reverse transcription-PCR methods. Two stimuli were utilized: phytohemagglutinin (PHA), which acts on the CD2 molecule and T-cell receptors, and anti-CD3 monoclonal antibody, which acts on the CD3 molecule and on T-cell receptors. Increased expression of all studied genes occurred between 1 and 4 hours after stimulation, except for that of the gene encoding IL-10, which was delayed. Expression of all but one of the genes was transient, with a maximal mRNA accumulation at about 8 h on average. IL-2R mRNA expression was an exception, showing a prolonged increase (72 h). The general profiles of expression of the five cytokine genes were similar but not identical, suggesting some shared regulatory mechanisms. When responses to four additional stimuli (pokeweed mitogen, Candida albicans, and IL-2 at high and low doses) were compared, similar profiles of cytokine gene expression were found. Thus, the various stimuli caused induction of all cytokines with quantitative, not qualitative, differences. Altogether, the present data are useful for defining the kinetics of gene expression for key cytokines in response to standard immune-cell stimuli.
 ...
PMID:Cytokine gene expression in normal human lymphocytes in response to stimulation. 960 88

We demonstrate that a mouse-human chimeric anti-ganglioside GD2-interleukin (IL)-2 fusion protein (ch14.18-IL2) substantially amplifies tumor-protective immunity against murine melanoma induced by an autologous oral DNA vaccine containing the murine ubiquitin gene fused to murine melanoma peptide epitopes gp100(25-35) and TRP-2(181-188). This combination therapy led to the complete rejection of a lethal challenge with B78D14 murine melanoma cells in six of eight mice and a marked suppression of s.c. tumor growth in the two remaining animals. The tumor-protective immunity was mediated by MHC class I antigen- restricted CD8(+) T cells together with CD4(+) T cell help, which was required only for tumor cell killing in the effector phase of the immune response. A single oral vaccination with the DNA vaccine, which was carried by attenuated Salmonella typhimurium, was equally as effective as three such vaccinations applied at 2-week intervals. The immunological mechanisms involved in this antitumor effect were suggested by a decisively increased secretion of tumor necrosis factor alpha TNFTnTNa and IFN-gamma from CD4(+) and CD8(+) T cells and a markedly up-regulated expression on CD8(+) T cells of high-affinity IL-2 receptor alpha chain (CD25), costimulatory molecule CD28, and adhesion molecule lymphocyte function-associated antigen-2 (LFA-2/CD2). Additionally, the combination therapy induced increased expression of costimulatory molecules B7.1 and CD48 on murine antigen-presenting cells. Taken together, our results suggest that IL-2 targeted to the tumor microenvironment by a specific antibody-IL-2 fusion protein is a potent enhancer of tumor-protective immunity induced by an oral DNA vaccine that may ultimately enhance the chances of success in its clinical application.
 ...
PMID:Targeted interleukin 2 therapy enhances protective immunity induced by an autologous oral DNA vaccine against murine melanoma. 1150 70

A high-affinity IL-2 receptor requires two Janus protein tyrosine kinases (JAKs) for IL-2 signal transduction: JAK1 and JAK3. Since transphosphorylation of the two kinases is presumed to occur after receptor engagement we examined the phosphorylation by recombinant JAK3 of a peptide substrate corresponding to the JAK1 activation loop (KAIETDKEYYTVKD), which has two adjacent tyrosines. Mass spectral analysis of the enzymatically phosphorylated peptide showed that the second tyrosine was phosphorylated at a 30-fold greater rate than the first tyrosine. Moreover, no doubly phosphorylated peptide was detected by this analysis. Kinetic analysis of the reactions of singly phosphorylated JAK1 activation loop peptides showed that phosphorylating the first or second tyrosine decreased the k(cat)/K(m) for the phosphorylation of the other 115- and 26-fold, respectively. Singly changing each side chain of the KEYYTV portion of the peptide to a methyl group (alanine) yielded substrates comparable to the wild-type sequences in all cases except that of the first or second tyrosine, which showed a 153- or 70-fold drop in k(cat)/K(m), respectively. Using libraries of immobilized peptides with all 20 naturally occurring amino acids substituted for Y9 or T11 showed that the JAK3 tolerated substitution at T11 but prefers large hydrophobic amino acids at Y9. These results show that JAK3 does not act processively on the JAK1 activation loop in vitro and illustrate the role of Y9 in the recognition of the preferred site of phosphorylation which is Y10.
 ...
PMID:Mechanism of Janus kinase 3-catalyzed phosphorylation of a Janus kinase 1 activation loop peptide. 1255 72


<< Previous 1 2 3