CXCR3

1. 본문

CXCR3, also known as C-X-C motif chemokine receptor 3, G protein-coupled receptor 9 (GPR9), or CD183, is a chemokine receptor. Chemokines are signaling proteins that are secreted by cells, and they cause directional chemotaxis, which is the directed movement of cells, in nearby cells that are responsive.
Key features of CXCR3:

• Structure: CXCR3 is a G protein-coupled receptor (GPCR) with seven transmembrane domains.
• Isoforms: In humans, there are three isoforms of CXCR3: CXCR3-A, CXCR3-B, and CXCR3-alt.
• Ligands:
• CXCR3-A binds to the CXC chemokines CXCL9 (MIG), CXCL10 (IP-10), and CXCL11 (I-TAC).
• CXCR3-B can bind to CXCL4, in addition to CXCL9, CXCL10, and CXCL11.
• CXCL11 binds to the receptor with higher affinity than the other ligands, which leads to receptor internalization.
• Expression:
• It's primarily expressed on activated T lymphocytes, natural killer (NK) cells, and some epithelial cells.
• Th1 cells preferentially express CXCR3 and CCR5, whereas Th2 cells favor CCR3 and CCR4 expression.
• Function:
• CXCR3 plays a crucial role in the targeted migration of effector T cells, such as Th1-type CD4+ T lymphocytes and cytotoxic CD8+ T lymphocytes, and NK cells, to sites of inflammation and tumors.
• It is involved in immune responses, infection, autoimmune diseases, and tumor immunity.
• CXCR3 and its ligands influence cellular functions like survival, adhesion, invasion, and proliferation.
• It mediates the proliferation, survival, and angiogenic activity of human mesangial cells (HMC).
• Role in Disease: CXCR3 is associated with various diseases. It plays a role in autoimmune diseases, infections and tumors.
• Dual Role in Cancer: CXCR3 has both anti-tumor and pro-tumor effects, that are dependent on different variants of the receptor (CXCR3-A, CXCR3-B, and CXCR3-alt).