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)

Natural killer cell stimulatory factor (NKSF) is a 70-kD heterodimeric cytokine that was initially isolated from conditioned medium of human B lymphoblastoid cell lines. The effects of recombinant NKSF on the function of human peripheral blood NK cells were examined. NKSF directly augmented the cytolytic activity of freshly isolated NK cells. Both CD56dim and CD56bright NK cells demonstrated enhanced cytotoxicity after brief exposure to NKSF. In contrast, highly purified T lymphocytes did not exhibit major histocompatibility complex-unrestricted cytotoxicity after short-term culture with NKSF. Like interleukin 2 (IL-2), NKSF augmented the lysis of NK-sensitive, NK-resistant, and antibody-coated targets. Both NKSF and IL-2 induced marked upregulation of several NK cell adhesion molecules known to participate in cytolysis, including CD2, CD11a, and CD54. However, NKSF activates NK cells through a pathway distinct from that of IL-2, since the presence of anti-IL-2 receptor (anti-IL-2R) antibodies or IL-4 did not inhibit the effects of NKSF. NKSF by itself induced very little proliferation of resting NK cells. NK cells preactivated in vitro with IL-2 demonstrated enhanced proliferation to NKSF, but the degree of proliferation was always inferior to that induced by IL-2 alone. Moreover, NKSF strongly inhibited IL-2-induced proliferation of either resting or preactivated NK cells. This inhibition was not the result of decreased IL-2R expression, because NKSF-activated NK cells expressed higher levels of both IL-2Rs p75 and p55. Furthermore, NKSF did not inhibit the proliferation of mitogen-activated T cells, indicating a selective effect on NK cell proliferation. Human NK cells expanded in vivo by prolonged continuous infusions of IL-2 remained fully responsive to NKSF. Picomolar concentrations of NKSF were as effective as nanomolar concentrations of IL-2 in augmenting the cytolytic activity of NK cells expanded in vivo by IL-2. NKSF may play an important role in the regulation of human NK cell function, and its possible use as a therapeutic cytokine deserves further investigation.
 ...
PMID:Response of human natural killer (NK) cells to NK cell stimulatory factor (NKSF): cytolytic activity and proliferation of NK cells are differentially regulated by NKSF. 134 96

Cytokines are important mediators involved in the development of effector cells and in the regulation of immune responses. The gene expression of these mediators in T cell subset has yet to be fully elucidated. Using sensitive reverse transcription-polymerase chain reaction (RT-PCR), the kinetics of cytokine gene expression in human CD4+ and CD8+ T cells were examined. CD4+ T cells were more readily activated by phorbol myristate acetate (PMA) and phytohaemagglutinin (PHA) than CD8+ T cells in terms of the IL-2 receptor (IL-2R) mRNA expression. Quantitative differences in cytokine gene expression between CD4+ and CD8+ T cells were confirmed and higher levels of cytokine mRNAs were induced in CD4+ than in CD8+ T cells. Early induction of IL-2 mRNA was observed in both T cell subsets. The demonstration of different kinetics of cytokine gene expression illustrates one of the examples of the complexity of immunoregulation. The differential response of cytokine gene expression in different T cell subsets should be taken into consideration when clinical studies in cytokine production by peripheral blood mononuclear cells are interpreted.
 ...
PMID:Characterization of cytokine gene expression in CD4+ and CD8+ T cells after activation with phorbol myristate acetate and phytohaemagglutinin. 135 69

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

The aim of this study was to examine the cytokine production and cytokine responsiveness of the first T-cell receptor (TcR) positive cells that appear in the murine fetal thymus, namely TcR V gamma 3 cells. It is shown that IL-2-cultured fetal TcR V gamma 3 thymocytes were capable of producing IL-3, GM-CSF, TNF-alpha and IFN-gamma upon TcR triggering. IL-2, IL-4, IL-5 and IL-6 could not be detected. With regard to cytokine responsiveness, TcR V gamma 3 cells proliferated to a high extent when high concentrations of rIL-2 were added. rIL-4 or rIL-7 alone, but not rIL-1 alone, were capable of inducing a modest proliferation of TcR V gamma 3 thymocytes. When combined with low concentrations of IL-2, a synergistic effect could be observed with IL-1, IL-4 or IL-7. It is shown that the synergistic effect of IL-2 with IL-4 was mainly due to induction of IL-2 receptor expression. The synergistic effect of IL-2 and IL-7 on the proliferation of TcR V gamma 3 cells could only be partially inhibited by anti-IL-2 receptor MoAb, and this antibody had no effect on the IL-2 + IL-1 cultures. These observations can explain the extensive proliferation of TcR V gamma 3 thymocytes during fetal life and they indicate that TcR V gamma 3 thymocytes have the potential to play a functional role during fetal thymus development.
 ...
PMID:Cytokine production and responsiveness of fetal T-cell receptor V gamma 3 thymocytes. 146 22

Cross-linking the T-cell receptor-associated CD3 complex using the immobilized monoclonal antibody OKT3 can induce low levels of proliferation of purified resting T cells. The effect of coimmobilizing a monoclonal antibody 19H8 specific for the alpha-chain of the integrin VLA-4 on T-cell activation was evaluated. The level of proliferation induced by coimmobilization of the anti-VLA-4 with OKT3 was about 2- to 3-fold over proliferation induced by maximal OKT3 stimulation. The costimulatory activity of 19H8 was dependent on CD3 stimulation since immobilized 19H8 by itself did not induce proliferation. IL-2 secretion was found to be increased over 2-fold with 19H8 costimulation. Addition of exogenous IL-2 resulted in enhanced proliferation of both OKT3 and OKT3 plus 19H8-stimulated cells, but T cells coactivated with 19H8 exhibited a greater capacity to proliferate in response to exogenously supplied IL-2. Analysis of IL-2 receptor expression by flow cytometry revealed that the percentage of CD25-positive cells activated with either OKT3 or OKT3 plus 19H8 is comparable, but the mean fluorescence of cells coactivated with 19H8 is about 3-fold over cells stimulated with OKT3 alone. Dependency of the 19H8 enhanced proliferation on the IL-2/IL-2 receptor system was established by using IL-2-specific neutralizing antisera that reduced the proliferation of T cells activated with OKT3 alone or OKT3 plus 19H8 to comparable levels.2+hese results demonstrate that adhesion molecules may operate at the level of cytokine production and expression of its receptors to modulate the activation state of a cell.
 ...
PMID:A VLA-4 alpha-chain specific monoclonal antibody enhances CD3-induced IL-2/IL-2 receptor-dependent T-cell proliferation. 146 62

We recently demonstrated that IL-2 is produced by reactive T cells in CD25-positive malignant lymphomas (ML). Using in situ hybridization, we investigated IL-6 mRNA expression in these CD25-positive ML. The ML tested included 9 anaplastic large cell lymphomas and 3 B-diffuse large cell lymphomas. Five CD25-negative ML were studied as controls. We show that IL-6 producing cells are present in all these ML. The density of positive cells was heterogeneous from case to case. However 3 cases of CD25-positive ML showed a dramatically higher density of IL-6 producing cells (70, 50, 43 producing cells per 10,000 cells, respectively) as compared to the other 9 cases of CD25-positive ML (mean 6.03 +/- 2.1 per 10,000). Morphological and topographical data suggested that several types of cells including fibroblasts, lymphocytes, macrophages and endothelial cells may synthesize IL-6. A combination of immunohistochemistry and in situ hybridization showed that reactive T cells and endothelial cells express the IL-6 gene whereas CD30-positive ML cells do not express this gene. Previous studies showed that IL-6 was capable to induce IL-2 receptor expression as well as production of IL-2 and stimulation of lymphomatous cells growth. Our present results indicate that the paracrine production of this cytokine may play a role in the proliferation of malignant lymphomas.
 ...
PMID:IL-6 mRNA expression in CD25 positive malignant lymphomas. 149 62

Leukocyte activation is known to involve cell membrane potential changes. Phenobarbital, an anesthetic and anticonvulsant that can inhibit neuronal membrane depolarization, may also affect leukocyte activation. Measuring membrane potential, actin polymerization, chemotaxis, superoxide production, lymphocyte proliferation, intracellular calcium concentration, and cytokine production, we found that phenobarbital at a concentration of 15-30 micrograms/ml, which is considered a therapeutic serum level for controlling seizures, did not affect polymorphonuclear neutrophil (PMN) activation. At levels higher than 100 micrograms/ml, phenobarbital significantly suppressed formylmethionyl-leucyl-phenylalanine (fMLP)-induced chemotaxis. Concentrations greater than 300 micrograms/ml also inhibited phorbol myristate acetate-stimulated membrane potential change. In contrast, 30 micrograms/ml phenobarbital significantly inhibited lymphocyte proliferation stimulated by phytohemagglutinin (PHA) and pokeweed mitogen. This concentration of phenobarbital also suppressed the increase of intracellular free calcium induced by PHA. However, only a higher concentration of phenobarbital (300 micrograms/ml) was able to inhibit PHA-induced interleukin-2 (IL-2) production and suppress the proliferation of PHA-induced IL-2 receptor-bearing lymphocytes. These results suggest that concentrations of phenobarbital associated with anticonvulsive levels do not affect PMN activation but suppress lymphocyte activation, possibly by affecting intracellular signal transduction.
 ...
PMID:Effects of phenobarbital on leukocyte activation: membrane potential, actin polymerization, chemotaxis, respiratory burst, cytokine production, and lymphocyte proliferation. 150 69

Cytokines, a class of soluble mediators involved in cell-to-cell communication, are generated in response to many stimuli by a variety of tissues. They include interferons (IFNs), Interleukins (ILs) and colony stimulation factors (CSFs), and have been most extensively studied in the context of hematopoiesis and immune responses, however their molecular nature remained totally elusive due to the scarcity of the cytokines produced, under optimized conditions for producer cells. With the advent of recombinant DNA technology, we have isolated in 1983 the gene encoding one of the first identified Interleukins, IL-2, and thus initiated our molecular analyses of the IL-2 system. In fact, IL-2 plays a major role in the clonal expansion of T lymphocytes (T cells) by interacting with specific cell surface receptor (IL-2 receptor). The functional, high-affinity form of IL-2 receptor (IL-2R) is composed of two receptor components, IL-2R alpha (p55) and IL-2R beta (p70-75) chains. We have cloned a human and murine IL-2R beta cDNAs. Unlike the IL-2R alpha chain, the IL-2R beta chain contains a large cytoplasmic domain which shows no obvious tyrosine kinase motif. We established a system in which the cDNA-directed human IL-2R beta allows growth signal transduction in murine IL-3-dependent cell lines. Utilizing this system, we have identified a cytoplasmic region of the receptor critical for the growth signal transduction. Furthermore, we have provided evidence for the physical association of IL-2R beta with protein tyrosine kinase, 56lck. The functional significance of such association may be profound in understanding the general mechanisms of cytokine-induced signal transduction.
 ...
PMID:Structure and function of IL-2 and IL-2 receptors. 152 74

The proliferation potential of highly purified human CD3-CD4-CD8- (triple negative) and CD3low(lo)CD4-CD8- thymocyte precursors in response to various cytokines was investigated. High in vitro growth ability was observed in response to recombinant human IL-2 (rIL-2) and human rIL-7, both in the absence of any co-mitogen and in combination with phorbol 12-myristate 13-acetate (PMA). Furthermore, the proliferation of these thymocyte precursors in the presence of rIL-7, although accompanied by a significant increase of IL-2 receptor (IL-2R) p55 expression, appeared independent of that mediated by the autocrine IL-2 pathway, since mAbs to IL-2 and IL-2R p55 did not eliminate responsiveness to rIL-7. Synergism of rIL-7 with rIL-2 was also observed, while no cooperation was detectable with rIL-4 or rIL-6. Analysis of surface phenotype and cell cycle status of cells cultured in the presence of rIL-7, both plus and minus PMA, showed that CD3- as well as CD3lo cells readily proliferated to rIL-7. Upregulation of the levels of expression of CD3 antigen was also observed in these cultures. These results, together with the previous characterization of IL-7 as a human pre-B cell and mature T cell growth factor, identify IL-7 as a cytokine with biologic activities on a variety of target cells. They also suggest that IL-7, in analogy with the mouse system, might play a role in human T cell ontogeny.
 ...
PMID:IL-7 induces proliferation of CD3-/low CD4- CD8- human thymocyte precursors by an IL-2 independent pathway. 153 63

Granulomas around Schistosoma mansoni eggs are a principal cause of morbidity in mice infected with this helminth. In vivo treatment of infected mice with anti-IL-2 antibodies, with or without anti-IL-2 receptor antibodies, significantly diminished the size of circumoval granulomas in the liver and decreased hepatic fibrosis to half that in untreated mice. Antibody-treated animals also displayed a marked reduction in both peripheral blood and tissue eosinophilia while IgE levels were unchanged or increased. Spleen cell cytokine production in response to Ag or mitogen stimulation was selectively altered by in vivo anti-IL-2 administration. IL-5 responses were dramatically reduced, whereas IL-4, IL-2, and IFN-gamma responses were not consistently changed. These findings confirm previous observations, suggesting a role for IL-2 in egg-induced pathology but indicate that the primary function of this cytokine in schistosome-infected mice may be in the generation of Th2- rather than Th1-associated responses.
 ...
PMID:Treatment with anti-IL-2 antibodies reduces hepatic pathology and eosinophilia in Schistosoma mansoni-infected mice while selectively inhibiting T cell IL-5 production. 153 55


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