Positive and Negative Regulation of Cellular Immune Responses in Physiologic Conditions and Diseases

Figure 1

Regulatory molecules and their ligands. Schematic overview of the different costimulatory and coinhibitory molecules expressed by T cells (right panel) and association with their respective ligands expressed by antigen-presenting cells (APCs) or target cells (left panel). Coinhibitory molecules are color coded according to their relevant families. The four families of regulatory molecules include (1) B7-CD28 family including CD28, cytotoxic T-lymphocyte antigen-4 (CTLA-4; CD152), programmed death-1 (PD-1; CD279), inducible costimulatory molecule (ICOS; CD278), and B- and T-lymphocyte attenuator (BTLA; CD272); (2) CD2/signaling lymphocyte activation molecule (SLAM) family including SLAM (CD150), 2B4 (CD244), and CD48; (3) Ig family including T-cell immunoglobulin mucin-3 (TIM-3), CD160, and Lymphocyte-activation gene 3 (Lag-3); and (4) TNF-receptor superfamily including CD27.