TCR Complex-Activated CD8 Adhesion Function by Human T Cells

TCR complex-activated CD8 adhesion function by human T cells.

The CD8 receptor plays a central role in the recognition and elimination of virally infected and malignant cells by cytolytic CD8(+) T cells. In conjunction with the TCR, the CD8 coreceptor binds Ag-specific class I MHC (MHC-I) molecules expressed by target cells, initiating signaling events that result in T cell activation. Whether CD8 can further function as an adhesion molecule for non-Ag MH...

TCR-complex signaling and Galectin-9 in human T cells

Galectin-9 (gal-9) is a multifunctional βgalactoside-binding lectin, frequently released in the extra-cellular medium, where it acts as a pleiotropic immune modulator. Despite its overall immunosuppressive effects, a recent study has reported a bimodal action of gal-9 on human resting blood T cells with apoptosis occurring in a majority of them, followed by a wave of activation and expansion of...

Generation of Human CD8 T Regulatory Cells by CD40 Ligand–activated Plasmacytoid Dendritic Cells

Although CD8 T cell-mediated immunosuppression has been a well-known phenomenon during the last three decades, the nature of primary CD8 T suppressor cells and the mechanism underlying their generation remain enigmatic. We demonstrated that naive CD8 T cells primed with allogeneic CD40 ligand-activated plasmacytoid dendritic cells (DC)2 differentiated into CD8 T cells that displayed poor second...

Activated Primary and Memory CD8 T Cells

TCR signal transduction in antigen-specific memory CD8 T cells.

Memory T cells are more responsive to Ag than naive cells. To determine whether memory T cells also have more efficient TCR signaling, we compared naive, effector, and memory CD8 T cells of the same antigenic specificity. Surprisingly, initial CD3 signaling events are indistinguishable. However, memory T cells have more extensive lipid rafts with higher phosphoprotein content before TCR engagem...