ICOS ligand (ICOSLG)

ICOS ligand is a glycosylated transmembrane protein belonging to the B7 family, acting as a critical costimulatory molecule during immune responses[1][3]. It binds to ICOS (inducible T-cell co-stimulator receptor) on T cells, modulating activation, proliferation, cytokine production, and antibody secretion during secondary immune responses. ICOSLG is expressed in lymphoid and non-lymphoid tissues, particularly on B cells, dendritic cells, and endothelial cells. Its role is vital for T cell–dependent B cell activation, immune homeostasis, and migration of neutrophils; altered or deficient ICOSLG leads to impaired immune responses and immunodeficiency[1][3]. ICOSLG is a therapeutic target for autoimmune diseases and cancer immunotherapy, with both stimulatory and inhibitory monoclonal antibodies under clinical investigation[1].

Other names

ICOS ligandICOSLGCD275B7-H2B7RP-1hLICOSLOC102723996

Blocking ICOS–ICOSLG interaction to inhibit T cell activation (immunosuppression, autoimmunity) Stimulating ICOSLG to enhance antitumor T cell response (immuno-oncology)