CCR7

CCR7 is a G protein-coupled receptor (GPCR) that plays a central role in the control of cell migration in the immune system. It belongs to the chemokine receptor family and preferentially binds the ligands CCL19 and CCL21, which are involved in homeostatic cell migration.

Structure of CCR7:

• CCR7 is a transmembrane protein with seven transmembrane domains. This structure is characteristic of a G-protein-coupled receptor.
• CCR7 has extracellular and intracellular loops that are crucial for ligand binding and signal transduction.
• The intracellular domain interacts with G-proteins to transduce signals into the cell.

Function of CCR7:

• Leukocyte migration: CCR7 mediates the migration of T cells and dendritic cells (DCs) into secondary lymphoid organs (e.g. lymph nodes, spleen).
• Adaptive immune response: CCR7 supports the interaction of antigen-presenting cells with T cells.
• T cell homing: Naive T cells express CCR7 to migrate into the T cell zones of the lymph nodes.
• Tumor biology: CCR7 is overexpressed in some tumors and may contribute to metastasis.

Importance of CCR7 in medicine:

• Autoimmune diseases: CCR7 dysregulation may contribute to diseases such as rheumatoid arthritis or multiple sclerosis.
• Oncology: CCR7 overexpression is associated with increased metastasis in breast cancer, melanoma and other carcinomas. CCR7 is expressed together with L-selectin and CD27 by Sézary cells, highlighting its role as a "lymph node homing molecule" (Sokolowska-Wojdylo M et al. 2005; Campbell JJ et al. 2010).
• Therapeutic target: CCR7-is a potential drug target for influencing immune cell migration or tumor spread.

1. Campbell JJ et al. (2010) Sezary syndrome and mycosis fungoides arise from distinct T-cell subsets: a biologic rationale for their distinct clinical behaviors. Blood116:767-771.
2. Sokolowska-Wojdylo M et al. (2005) Circulating clonal CLA(+) and CD4(+) T cells in Sezary syndrome express the skin-homing chemokine receptors CCR4 and CCR10 as well as the lymph node-homing chemokine receptor CCR7. Br J Dermatol 152:258-264.