C-X-C chemokine receptor type 6 (CXCR6)

C-X-C chemokine receptor type 6 (CXCR6) is a G protein-coupled receptor expressed mainly on subsets of T cells—especially activated CD8+ and CD4+ T cells—as well as NK and NKT cells. Its sole known ligand is CXCL16, which can exist as a membrane-bound or soluble chemokine mainly produced by macrophages, monocytes, dendritic cells, B cells, and sinusoidal endothelial cells of the liver. CXCR6 mediates chemotactic and adhesion signals important for immune cell localization and retention, particularly in the liver and at sites of inflammation or tumor infiltration. CXCR6 is also notable as a minor entry co-receptor for HIV and SIV in conjunction with CD4, though its primary function is regulating immune cell trafficking. In cancer, high CXCR6 expression—especially in infiltrating T cells—correlates with improved prognosis and responsiveness to immune checkpoint inhibitor therapies, making it a relevant therapeutic biomarker and suggesting its potential as a future drug target in oncology and immunotherapy.

Other names

BONZOSTRL33TYMSTRCD186CXC-R6CXCR-6CDw186G-protein coupled receptor STRL33G-protein coupled receptor bonzochemokine (C-X-C motif) receptor 6

Modulation of T cell migration and retention in tissues (via CXCL16 binding) Co-receptor function for viral entry (HIV/SIV) Enhancing immune cell infiltration in tumors, promoting anti-tumor immunity