Application note: Tools for cell therapy and immunoregulation

Multiple co-signalling molecules regulate T cell activation.

T cell activation requires two signals: 1) recognition of the antigenic peptide/ major histocompatibility complex (MHC) by the T cell receptor (TCR) and 2) antigen-independent co-stimulation induced by interactions between co-signalling molecules expressed on target cells, such as antigen-presenting cells (APCs), and their T cell-expressed receptors. Engagement of the TCR in the absence of this second co-stimulatory signal typically results in T cell anergy or apoptosis.