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)

A monoclonal antibody is described which recognises an epitope associated with a receptor for interleukin-2 (IL-2) on pig lymphocytes. The monoclonal antibody inhibits high affinity binding of radiolabelled recombinant human IL-2 (rhIL-2) by pig lymphoblasts and also non-competitively inhibits both pig-TCGF and rhIL-2 maintained proliferation. By flow cytometry the antigen is apparently not present on freshly isolated blood lymphocytes but is detectable on small cells between 6 and 12 h after activation and on large cells by 24-h. These findings are comparable with those obtained using monoclonal antibodies recognising the 55 kDa alpha chain of the human and mouse IL-2 receptor (p55, TAC) expressed on activated cells in vivo and in vitro. However, the molecular weight of the porcine antigen is between 65 and 70 kDa.
 ...
PMID:A monoclonal antibody recognising an epitope associated with pig interleukin-2 receptors. 138 6

We have defined a population of CD3-, CD56+ small lymphocytes (SLs) that exhibit the same phenotype and lytic capacity as natural killer (NK) cells. NK cells characteristically express the surface markers CD16 and CD56, mediate non-major histocompatibility complex (MHC)-restricted lysis, and have been equated with CD3- large granular lymphocytes (LGLs). In the present study we extended the observation that CD3-, CD56+ SLs can mediate NK- and antibody-dependent cellular cytotoxicity activity by studying the activation signals and lytic mechanisms that might be utilized by CD3-, CD56+ SLs in comparison to CD3- CD56+ LGLs. Our results show that CD3- SLs, similar to CD3- LGLs, exhibited activated killing in response to interleukin-2 (IL-2). In addition, after IL-2 activation, the CD3- SLs exhibited morphologic changes, including increases in size and granularity, and both morphologically and phenotypically became virtually indistinguishable from CD3- LGLs. Similar to CD3- LGLs, CD3- SLs could be directly activated by IL-2 alone to secrete significant quantities of interferon-gamma (IFN-gamma) and to express IL-2 receptor (IL-2R) p55. Examination of serine esterases and pore-forming protein (PFP) demonstrated that these cells exhibited a cytoplasmic distribution of perforin, which, unlike that of CD3- LGLs, was not associated with dense cytoplasmic azurophilic granules. Serine esterase levels were similar. However, after IL-2 activation PFP was concentrated in dense cytoplasmic granules, similar or identical to the situation in CD3-, CD56+ LGLs. These CD3-, CD56+ subsets appear to represent a continuum of activated cells that might represent various states of maturation of NK cells.
 ...
PMID:Relationship of large and small CD3- CD56+ lymphocytes mediating NK-associated activities. 138 42

We analyzed cellular interactions between T lymphocytes and a recently established immortal glial line, L3 that retains several properties of immature oligodendrocytes (Aloisi et al., J Neurosci Res 27:16-24, 1990). L3 oligodendrocytes (L3-OL) cannot be induced to express class II antigens, nor do they specifically present antigen to syngeneic specific T lymphocyte. However, L3-OL strongly enhance the proliferation of freshly activated, interleukin-2(IL-2)-dependent T-line lymphocytes and concanavalin A (ConA)-activated lymphoblasts, irrespective of their antigen specificity or surface phenotype (CD4+ or CD8+). Resting and some activated T cells were susceptible to the mitogenic effect of L3-OL only in the presence of exogenous IL-2, not of other cytokines. The mitogenic effect of L3-OL did not depend on cell viability. It was observed in paraformaldehyde-fixed L3-OL cells and in membrane preparations, but not in culture supernatant. Neither intact L3-OL cells nor membrane preparations had direct IL-2 activity. The conclusion that the mitogenic effect of L3-OL cells is exerted by membrane structures acting as a costimulatory factor(s) of IL-2 is supported by the finding that it is largely blocked by a monoclonal anti-IL-2 receptor antibody. The effect is distinct from membrane-bound IL-1, membrane-bound tumor necrosis factor-alpha (TNF-alpha), IL-3, or IL-6 and cannot be reconstituted by these cytokines.
 ...
PMID:Interaction between oligodendroglia and immune cells: mitogenic effect of an oligodendrocyte precursor cell line on syngeneic T lymphocytes. 138 59

Interleukin-2 (IL-2) potently stimulates natural killer (NK) cell proliferation and cytotoxic function. However, the molecular mechanisms by which IL-2 delivers activation signals from the IL-2 receptor to the NK cell interior are incompletely understood. Previous studies demonstrated that IL-2 stimulation induced the tyrosine phosphorylation of multiple proteins in NK cells, together with a prominent reduction in the electrophoretic mobility of p56lck. The present studies indicate that IL-2 induces a rapid (< or = 1 min) increase in the catalytic activity of p56lck, as measured by increases in protein tyrosine kinase activity in vitro. Furthermore, in response to IL-2, p56lck itself undergoes complex alterations in serine and tyrosine phosphorylation. Cyanogen bromide cleavage maps indicate that IL-2 stimulates a pronounced increase in the phosphorylation of the NH2-terminal region of p56lck containing multiple known sites of serine phosphorylation. In addition, IL-2 induced a marked increase in the phosphorylation of a COOH-terminal peptide containing the regulatory Tyr-505 residue of p56lck. These results suggest that p56lck serves as a substrate for both protein serine and tyrosine kinases activated during stimulation of this cell type with IL-2. Furthermore, these results indicate that the pleiotropic effects of IL-2 on NK cell physiology are initiated and regulated by a complex and multitiered interaction of different protein kinases including p56lck.
 ...
PMID:Interleukin-2 signal transduction in human NK cells: multisite phosphorylation and activation of the tyrosine kinase p56lck. 138 59

The immunosuppressive activity of culture supernatants from human T cell leukemia virus type I (HTLV-I)-infected cell lines was examined in vitro. Culture supernatants of both a HTLV-I-infected B cell line, IWS, established from an adult T cell leukemia (ATL) patient and a T cell line, MT-2, suppressed lymphocyte proliferative responses to stimulation with the mitogens phytohemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM). The immunosuppressive factor was not cytotoxic for lymphocytes and did not inhibit the spontaneous growth of ATL cells. It inhibited interleukin-2 (IL-2) production by PHA-stimulated T cells and it arrested PHA-stimulated T cells at the G0/G1 phase of the cell cycle and inhibited entry into the S phase. Furthermore, the factor significantly inhibited the expression of CD3, CD4, and IL-2 receptor (IL-2R) alpha-chain (CD25) on PHA-stimulated T cells. These results suggest that the immunosuppressive factors produced by HTLV-I-infected cell lines might function in the regulation of normal lymphocyte proliferative responses, and that they could play some role in the induction of the immunodeficient condition observed in ATL patients.
 ...
PMID:Immunosuppressive factor produced by a B cell line derived from an adult T cell leukemia patient. 139 4

Mouse interleukin-2 (mIL-2) proteins with substitutions at two residues (D34 and Q141) that interact specifically with different signalling subunits (respectively, beta and gamma) of the IL-2 receptor (IL-2R) were examined using several in vitro cellular assays. Proteins with specific substitutions at both residues were partial agonists and their maximal responses varied widely in different IL-2-responsive cell types. Two of these cell types had comparable numbers of IL-2R and similar affinities for wild-type mIL-2 and mutant mIL-2 proteins. However, the more responsive cell type had 'spare' IL-2R. Various mIL-2 proteins with substitutions at Q141 had modest defects in IL-2R-binding and were potent antagonists of native mIL-2 action. Proteins with bulky or basic substitutions at residue D34 were weak antagonists due to severely reduced IL-2 binding and their reduced binding paralleled their defects in IL-2R activation. Our results suggest that interaction of mIL-2 with IL-2R beta is more important for binding than activation and that the converse holds for mIL-2 interaction with IL-2R gamma. Also genetic manipulation of the interaction of IL-2 with IL-2R beta and IL-2R gamma has led to the discovery of potentially useful IL-2 antagonists and selective agonists.
 ...
PMID:Receptor antagonist and selective agonist derivatives of mouse interleukin-2. 139 84

The Fc gamma RIII receptor (CD16) has been described on natural killer cells and a small subset of T lymphocytes. CD16+bright lymphocytes represent the typical population of peripheral blood CD3- NK cells. In these studies in addition to CD16+bright NK cells Fc gamma RIII expressing cytotoxic T lymphocytes in peripheral blood from one healthy individual are characterized as CD16+dim non-MHC-restricted CTLs either expressing the alpha/beta (80%) or the gamma/delta T cell receptor (20%). Both CD16+ subsets are clearly distinct in their functional capacity performing NK and ADCC activity. Freshly isolated CD16+dim T cells exert higher ADCC, CD16+bright NK cells higher NK activity. They are also differentially activated by interleukin-2 since CD16+bright NK cells reveal a bright expression of the p75 IL-2 receptor beta-chain in contrast to the very low p75 expression on CD16+dim T cells. This activation leads to a gradual increase of ADCC by NK cells. Finally the CD16 expression pattern with low and bright intensity represents a stable phenotype expressed by clones generated from these different subpopulations. On a clonal level CD16+dim non-MHC-restricted T cells can be distinguished from CD16+bright NK cells by their lower capacity in NK killing, but they are equally potent in ADCC. Finally these CD3+CD16+dim clones provide the basis for studies of Fc gamma RIII and TcR interaction.
 ...
PMID:Analysis of CD16+dim and CD16+bright lymphocytes--comparison of peripheral and clonal non-MHC-restricted T cells and NK cells. 139 40

An IgM monoclonal antibody, UC-2C2 was produced using splenocytes from mice immunized with cultures of interleukin-2 (IL-2)-dependent bovine peripheral blood lymphocytes. UC-2C2 was found to recognize a cell surface antigen of apparent molecular weight 52,000-54,000 present on activated bovine peripheral blood mononuclear leucocytes (PBML) but not on resting PBML or cells of the bovine lymphoblastoid cell line BL3. The 52,000-54,000 MW antigen was expressed early following activation of PBML by mitogens or alloantigens, with the majority of cells positive by 48 h of culture. UC-2C2 was unable to block binding of phycoerythrin (PE)-conjugated human recombinant IL-2 to PHA-stimulated bovine PBML as determined by flow cytometric analysis. However, two-colour analyses indicated that the antigen recognized by UC-2C2 was present on the same cell population that expressed IL-2 receptors. All activated T lymphocytes of BoCD4, BoCD8 and gamma delta receptor positive phenotypes expressed the target antigen of UC-2C2 and IL-2 receptors. Monocytes and B lymphocytes expressed the target antigen of UC-2C2 and IL-2 receptors at a lower density. This differential expression by the various PBML subpopulations parallels that described for expression of the low-affinity IL-2 receptor (CD25) on human leucocyte subpopulations. Based upon the relative molecular weight, time-course of expression and cellular distribution of the antigen identified by UC-2C2, it is inferred that UC-2C2 recognizes an epitope on the bovine homologue of CD25 which is not involved in binding IL-2.
 ...
PMID:Development and characterization of a monoclonal antibody specific for the bovine low-affinity interleukin-2 receptor, BoCD25. 139 63

A U937 suppressor factor (U937SF) was purified from crude supernatant by sequential chromatography using fast protein liquid chromatography. The molecular weight and isoelectric point of U937SF were 69 kDa and 4.5, respectively. The U937SF preparation inhibited the proliferative response in human PBMC stimulated with an antigen tuberculin purified protein derivative, tetanus toxoid) or a mitogen (phytohaemagglutinin concanavalin-A). U937SF depressed both interleukin-2 (IL-2) production and IL-2 receptor (CD25) expression in peripheral blood mononuclear cells (PBMC) stimulated with an antigen but not with a mitogen. Anti-CD3 monoclonal antibody-induced responses including a proliferative response, IL-2 production and CD25 expression were suppressed by U937SF. In contrast, U937SF did not affect monocyte functions such as antigen processing and IL-1 production. Neither did it modulate the expression of T cell receptor (TCR) or CD3 molecules on the surface of lymphocytes. Moreover it did not inhibit CD25 expression in PBMC stimulated with phorbol myristate acetate plus A23187. These results suggest that U937SF prevents both IL-2 production and CD25 expression in lymphocytes activated through the TCR/CD3, but not through the other receptors or molecules. In addition, U937SF does not block the early activation events following TCR-mediated stimulation, nor affect the pre-TCR activation steps.
 ...
PMID:Pattern of the action of a suppressor factor produced by a human macrophage-like cell line, U937. 139 77

The growth, differentiation, and functional activities of antigen-stimulated T lymphocytes are regulated by the interaction of the T-cell-derived cytokine, interleukin-2 (IL-2), with the high-affinity IL-2 receptor (IL-2R). IL-2R occupancy initiates a rapid increase in intracellular protein tyrosine phosphorylation, suggesting that a receptor-coupled protein tyrosine kinase (PTK) serves as a proximal signaling element for the IL-2R. Previous studies implicated the src-family kinase, p56lck, as a potential IL-2R-linked signal transducer. In this study, we have characterized a spontaneous variant of the IL-2-dependent cytotoxic T-cell line, CTLL-2, which contains no detectable lck-derived mRNA transcripts, protein, or PTK activity. The p56lck-deficient CTLL-2 cells retained strict dependence on IL-2 for both viability and growth, indicating that p56lck activity was not required for the transduction of IL-2-mediated mitogenic signals. However, the p56lck-deficient cells exhibited a moderate decrease in their rate of IL-2-dependent proliferation. In contrast to this relatively modest proliferative defect, the p56lck-deficient cell line displayed a profound reduction in T-cell antigen receptor-dependent cytolytic effector functions. Both the proliferative and the cytolytic defects observed in the p56lck-deficient cells were completely reversed by transfection of these cells with a wild-type lck expression vector. These results indicate that p56lck expression is not obligatory for IL-2-mediated T-cell growth stimulation; however, this PTK plays a central role in the generation T-cell-mediated cytotoxic responses.
 ...
PMID:Effects of p56lck deficiency on the growth and cytolytic effector function of an interleukin-2-dependent cytotoxic T-cell line. 140 41


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>