T cell co-stimulation modulator

A T cell co-stimulation modulator refers to any molecule, typically a receptor or ligand, that influences the secondary signaling required for full T cell activation. These modulators can either enhance (co-stimulatory) or inhibit (co-inhibitory) the primary signal delivered through the T cell receptor (TCR), thereby determining the fate and function of T cells in immune responses. Key examples include CD28 and CD80/CD86 (co-stimulatory) and CTLA-4 and PD-1 (co-inhibitory). Modulation of these pathways has significant therapeutic implications in cancer immunotherapy, autoimmunity, and transplantation.

Modulates T cell activation by influencing the secondary signaling pathways initiated upon T cell receptor (TCR) engagement with peptide-MHC complexes. Can either enhance (co-stimulatory) or inhibit (co-inhibitory) T cell activation.