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)

ADP ribosylation in the presence of cholera or pertussis toxin indicated the presence of G-proteins in Nb2 cell membranes. Two protein bands, with mol wt of 43.5K and 46.5K, were radiolabeled by cholera toxin, while a single protein (41.5K mol wt) was ADP ribosylated by pertussis toxin. Northern hybridization of total RNA from Nb2 cells with specific cDNA probes indicated the presence of mRNA transcripts encoding Gs, Gi2, Go, and, to a lesser extent, Gi3. A characteristic of receptors coupled to G-proteins is that their binding properties are regulated by guanine nucleotides. The binding of [125I]human GH to the lactogen receptor as well as the binding of [125I]IL-2 to the IL-2 receptor were decreased in a dose-dependent manner by GTP, GDP, and the analog guanosine 5'-O-(3-thiotriphosphate). GMP, however, had no effect. The addition of pyruvate kinase and phosphoenolpyruvate to regenerate GTP from GDP greatly increased the apparent potency of GTP. Cholera toxin inhibited PRL- and interleukin-2-stimulated DNA synthesis and cell proliferation in the Nb2 cells. In contrast, pertussis toxin had a differential effect on PRL- and IL-2-stimulated cells. Pertussis toxin, at an optimal concentration of 0.01 ng/ml, significantly enhanced the stimulatory effects of PRL on DNA synthesis (P less than or equal to 0.01; n = 9) and cell proliferation (P less than or equal to 0.05; n = 9) compared with the effect of PRL alone. However, at higher concentrations the toxin inhibited PRL-stimulated DNA synthesis and cell proliferation. Complete inhibition was achieved with 1000 ng/ml toxin. In contrast to the biphasic effect on PRL-stimulated cells, pertussis toxin was only weakly inhibitory to cells treated with IL-2. At the highest concentration tested, pertussis toxin (1000 ng/ml) inhibited IL-2-stimulated DNA synthesis and cell growth by only 30-35%. (Bu)2cAMP (IC50 = 0.019 mM) or methylxanthine (MIX; IC50 = 0.25 mM) also inhibited PRL-stimulated DNA synthesis. In the absence of mitogen, neither agent, from 0.0001-1 mM, had any effect on DNA synthesis. Similarly, IL-2-stimulated DNA synthesis in Nb2 cells was inhibited by (Bu)2cAMP (IC50 = 0.019 mM) or MIX (IC50 = 0.072 mM). However, MIX was approximately 3 times as potent in inhibiting the cell response to IL-2 as that to PRL. The susceptibility of Nb2 cells to both bacterial toxins suggests a role for G-proteins in regulating PRL- or IL-2-stimulated mitogenesis in these cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:G-proteins modulate prolactin- and interleukin-2-stimulated mitogenesis in rat Nb2 lymphoma cells. 246 72

In addition to the mobilization of neutrophils and monocytes, granulocyte-macrophage colony-stimulating factor (GM-CSF) also mobilizes lymphocytes into peripheral blood. We examined the ability of GM-CSF to induce the proliferation of purified human T cells (CD3+ CD4+ CD56- CD16- B1- MO2-) in two major aspects: (1) the mechanisms of GM-CSF interaction with interleukin-2 (IL-2) causing T-cell proliferation, and (2) the intracellular signals transmitted by GM-CSF in T lymphocytes. We observed that concentrations of GM-CSF between 0.01 ng/mL and 10 ng/mL had a synergistic effect with concentrations of IL-2 between 1 U/mL and 10 U/mL in stimulating T-cell proliferation. This effect of GM-CSF was maximal when it was added at the start of the culture. In situ hybridization showed the presence of mRNA for GM-CSF receptors in T cells. Further analysis showed that GM-CSF induced the expression of IL-2 receptor (IL-2R) on the surface of T lymphocytes. These events coincide with the ability of GM-CSF to increase the intracellular levels of both cyclic 3',5'-adenosine monophosphate (cAMP) and cyclic 3',5'-guanosine monophosphate (cGMP) in T cells, to increase the binding of (gamma-35S) GTP to T-cell membranes, and to enhance GTPase activity as determined by increased hydrolysis of 32P-GTP. IL-2 also induced IL-2R expression, cyclic nucleotide secretion, and G-protein activation. However, the presence of IL-2 reduced GM-CSF induction of these activities. Addition of antibodies to the alpha and beta subunits of IL-2R permitted the activation of G protein by GM-CSF even when IL-2 was present. Furthermore, GTP binding and GTPase activity induced by GM-CSF or IL-2 were inhibited by the addition of cholera toxin (CT), but not pertussis toxin (PT). Cumulatively, these results suggest that in T lymphocytes, receptors for GM-CSF or IL-2 may be coupled to the same CT-sensitive G protein, although other possibilities may exist. The role that G proteins play in mediating the intracellular signaling pathways induced by GM-CSF or IL-2 in human T cells is supported by adenosine diphosphate-ribosylation of a 44-kD or a 39-kD G protein in T-cell membranes by CT and PT, respectively.
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PMID:Priming effects of granulocyte-macrophage colony-stimulating factor are coupled to cholera toxin-sensitive guanine nucleotide binding protein in human T lymphocytes. 811 33

Interleukin-2 (IL-2) plays a vital role in the generation and regulation of the immune response, including important aspects of T cell survival. IL-2-mediated survival of T cells appears to be dependent on the activation of a pool of membrane-associated protein kinase C (PKC) that occurs in the absence of detectable translocation of the enzyme from the cytosol to membranes. In this report we investigate the mechanism(s) responsible for this PKC activation after IL-2 stimulation in the cytotoxic T cell line, CTLL-2. Tyrosine kinase activity, activated after IL-2 stimulation, was found not to be linked to the activation of PKC by the cytokine. On the other hand, a pertussis toxin (PTX)-sensitive G protein did appear coupled to PKC activation since PTX effectively blocked IL-2 stimulated PKC activity. Diacylglycerols (DAG), but not inositol 1,3,5-triphosphate (IP3) and intracellular Ca2+, increased after IL-2 stimulation suggesting that DAGs were generated via the phosphatidylcholine-phospholipase C (PC-PLC) or phosphatidylcholine-phospholipase D (PC-PLD) pathways. The increase in DAG by IL-2 was probably necessary for activation of membrane-resident PKC since exogenously applied DAG stimulated this PKC pool in both intact cells and in isolated membranes. IL-2 also increased arachidonic acid (AA) production in CTLL-2 cells, probably via phospholipase A2 (PLA2) since the PLA2 inhibitors oleoyloxyethyl phosphocholine and AACOCF3 (AACF) effectively blocked IL-2 stimulated PKC activation. Exogenous AA also increased PKC activity in intact cells and isolated membranes, suggesting that AA produced by IL-2 receptor stimulation was probably linked to PKC activation. These results suggest that the activation of membrane-resident PKC by IL-2 involves multiple second messengers, including G proteins, DAG and AA.
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PMID:Signalling events mediating the activation of protein kinase C by interleukin-2 in cytotoxic T cells. 1037 5

Experimental autoimmune encephalomyelitis (EAE) is an animal model of human multiple sclerosis that requires the activation of autoreactive T cells for the expression of pathology. EAE has been most frequently studied in the Lewis rat model as well as in several murine models of EAE including the PLJ and B10PL strains. In the present study we describe a novel model of EAE induced in the Wistar rat strain by immunization with guinea pig spinal cord antigens and pertussis toxin (PT). T cell responses were induced to myelin basic protein. Autoreactive T cells could be totally blocked by the in vitro treatment with CTLA4Ig, a protein that blocks the costimulation of autoreactive T cells. The addition of IL-2 could reverse the inhibition seen in vitro with CTLA4Ig. The effects of inhibition of B7 costimulation were also examined by an analysis of cytokine responses and IL-2 receptor on T cells. CTLA4Ig treatment in vitro reduced the expression of IL-2 receptor on T cells, enhanced T cell apoptosis and decreased the synthesis of IL-2, IFN-gamma and TNF-alpha. CTLA4Ig treatment had no effect on IL-10 synthesis by T cells, a cytokine implicated in the functions of regulatory T cell subsets. Overall, our studies support the rationale of B7 blocking therapies as a potential treatment for models of multiple sclerosis. The induction of EAE in the Wistar rat provides yet another novel model in which to examine the regulation of T cell autoimmunity.
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PMID:Experimental autoimmune encephalomyelitis in the Wistar rat: dependence of MBP-specific T cell responsiveness on B7 costimulation. 1238 44