CD8 and antigen-specific T cell adhesion cascades

Activation of T cells involves both the antigen-specific T cell receptor and a number of additional accessory receptors. For cytotoxic T lymphocytes these include CD8, LFA-1 and VLA receptors. Recent studies have demonstrated that these receptors become activated to mediate adhesion upon crosslinking of the T cell receptor, and can deliver co-stimulatory signals upon binding their ligands. Rather than being redundant adhesion/co-signalling systems, these various receptors participate in a cascade of adhesion and signalling events leading to full activation of cellular responses.