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Activation of T and natural killer (NK) cells leads to the tyrosine phosphorylation of pp36 and to its association with several signaling molecules, including phospholipase Cgamma-1 and Grb2. Microsequencing of peptides derived from purified rat pp36 protein led to the cloning, in rat and man, of cDNA encoding a T- and NK cell-specific protein with several(More)
Antibodies against the T3-antigen receptor complex can activate the human T cell line, Jurkat, to produce interleukin 2 (2-5). This activation is initiated by a receptor-mediated increase in the concentration of free cytoplasmic calcium ions [Ca2+]i (3, 4). In this communication, we investigate the mechanism by which the receptor complex increases [Ca2+ )i(More)
The MRC OX-44 molecule, which is expressed on all peripheral leukocytes, identifies the subset of thymocytes capable of proliferating in response to alloantigens and lectins (Paterson, D.J., J.R. Green, W.A. Jefferies, M. Puklavec, and A.F. Williams. 1987. J. Exp. Med. 165:1). When we isolated monoclonal antibodies (mAbs) on the basis of their ability to(More)
CD2, a cell surface glycoprotein expressed on T cells and natural killer cells, can couple to signaling pathways that result in T cell proliferation. An Src-like protein tyrosine kinase, p56lck, coprecipitates with CD2, and perturbation of CD2 by monoclonal antibodies results in an increase in the activity of p56lck, suggesting that an interaction with(More)
We conducted a study to determine the prevalence of extraarticular manifestations (ExRA) in a cohort of predominantly Hispanic and Asian patients with rheumatoid arthritis (RA), to identify factors associated with the development of ExRA, and to compare the prevalence of ExRA between Hispanic and Asian patients. Patients with RA followed in the outpatient(More)
The T cell surface molecule CD28 can provide costimulatory signals that permit the full activation of T cells. Here we demonstrate that stimulation of CD28, either by B7, its natural ligand, or by the anti-CD28 monoclonal antibody 9.3, induces an association between CD28 and phosphatidylinositol 3-kinase (PI3-K) in Jurkat T cells, raising the possibility(More)
Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is an essential negative regulator of T cell activation. Recent evidence suggests that CTLA-4 association with the immunological synapse during contact with antigen-presenting cells is important for its inhibitory function. In the present study, we observed a direct interaction of CTLA-4 with the(More)
OBJECTIVE C-reactive protein (CRP) levels>3 mg/L and>10 mg/L are associated with high and very high cardiovascular risk, respectively, in the general population. Because rheumatoid arthritis (RA) confers excess cardiovascular mortality, we determined the prevalence of these CRP levels among RA patients stratified on the basis of their RA disease activity.(More)
Exposure to levamisole-adulterated cocaine can induce a distinct clinical syndrome characterized by retiform purpura and/or agranulocytosis accompanied by an unusual constellation of serologic abnormalities including antiphospholipid antibodies, lupus anticoagulants, and very high titers of antineutrophil cytoplasmic antibodies. Two recent case reports(More)
Stimulation of the T cell antigen receptor (TCR) activates a protein tyrosine kinase and leads to the tyrosine phosphorylation of phosphoinositide-specific phospholipase C-gamma 1 (PLC gamma 1). The molecular interactions involved in this phosphorylation are not known. After stimulation of the TCR on Jurkat T cells, tyrosine-phosphorylated proteins of 36,(More)