CXCR5. also known as CD185 or Burkitt lymphoma receptor 1 (BCR1), is a chemokine receptor belonging to the G protein-coupled receptor (GPCR) family. It is primarily expressed on B lymphocytes, follicular helper T (Tfh) cells, and certain dendritic cell subsets. CXCR5 interacts with its specific ligand, CXCL13 (a chemokine), to mediate immune cell migration and positioning within lymphoid tissues. This receptor-ligand axis is critical for the formation of germinal centers in secondary lymphoid organs, facilitating B cell maturation, antibody affinity maturation, and adaptive immune responses.
CXCR5 antibodies are immunological tools designed to detect or modulate CXCR5 activity. In research, these antibodies are widely used to identify CXCR5-expressing cells via flow cytometry, immunofluorescence, or immunohistochemistry. They also aid in studying immune cell trafficking, lymphoid tissue organization, and interactions between Tfh cells and B cells. Clinically, CXCR5 antibodies have potential therapeutic relevance. Aberrant CXCR5 signaling is implicated in autoimmune diseases (e.g., rheumatoid arthritis, lupus), B-cell malignancies (e.g., non-Hodgkin lymphoma), and chronic inflammatory conditions. Therapeutic antibodies targeting CXCR5 or its pathway may help regulate dysregulated immune responses.
Moreover, CXCR5 is explored in vaccine development due to its role in germinal center formation, which is essential for generating long-lasting immunity. Research continues to uncover its involvement in HIV/SIV infection, as some studies suggest CXCR5+ Tfh cells serve as viral reservoirs. Overall, CXCR5 antibodies serve as vital reagents for both basic immunology research and translational investigations into immune-related diseases.