Immunol Lett
January 2007
T-cell immunoglobulin mucin-1 (TIM-1) is associated with the regulation of T helper type 2 (Th2) immune responses and has been associated with asthma susceptibility. Previous studies have shown that administration of TIM-1 results in T cell hyperproliferation and increased Th2 cytokine secretion. TIM-1 has also been shown to bind to macrophages, but the effects of TIM-1 administration on macrophage activity have not been assessed.
View Article and Find Full Text PDFThe B7 family member programmed death ligand 2 (PD-L2) has been implicated in both positive and negative regulation of T cell activity. In this study, we demonstrate that on human T cells, PD-L2 acts only as a negative regulator of T cell activity, inhibiting proliferation, IL-2 production, and IFN-gamma production via its interaction with programmed death-1 (PD-1). This study also shows a novel role for PD-1 in inhibiting beta1 and beta2 integrin-mediated adhesion.
View Article and Find Full Text PDFOne of the earliest functional responses of T lymphocytes to extracellular signals that activate the Ag-specific CD3/TCR complex is a rapid, but reversible, increase in the functional activity of integrin adhesion receptors. Previous studies have implicated the tyrosine kinase zeta-associated protein of 70 kDa (ZAP-70) and the lipid kinase phosphatidylinositol 3-kinase, in the activation of beta(1) integrins by the CD3/TCR complex. In this report, we use human ZAP-70-deficient Jurkat T cells to demonstrate that the kinase activity of ZAP-70 is required for CD3/TCR-mediated increases in beta(1) integrin-mediated adhesion and activation of phosphatidylinositol 3-kinase.
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