Pig Chemokine C-X-C-Motif Receptor 4 (CXCR4) Protein

Background

CXCR4 is a widely expressed G protein-coupled receptor that binds stromal cell-derived factor-1 (SDF-1/CXCL12), playing a key role in hematopoiesis, organ development, and immune cell trafficking. It is highly expressed on hematopoietic stem cells, lymphocytes, and endothelial cells. CXCR4 activation triggers pathways such as PI3K/Akt, MAPK, and JAK/STAT, promoting cell survival, migration, and proliferation. In the immune system, CXCR4 guides leukocyte migration to lymphoid tissues and inflammatory sites, facilitating immune surveillance. It is critical for embryonic development, particularly in the nervous, cardiovascular, and hematopoietic systems. In cancer, CXCR4 is overexpressed in many malignancies, including breast, lung, and pancreatic cancers, where it promotes tumor progression, metastasis, and angiogenesis by interacting with the CXCL12 gradient. CXCR4 also enhances the homing of cancer cells to distant organs, such as the bone marrow, contributing to metastasis and therapy resistance. In HIV infection, CXCR4 acts as a co-receptor for viral entry into T cells, playing a role in disease progression to AIDS. Targeting CXCR4 with antagonists like plerixafor is a therapeutic strategy for stem cell mobilization, HIV treatment, and anti-cancer therapy. Dysregulation of CXCR4 signaling is linked to inflammatory diseases, immune deficiencies, and metastatic cancer, highlighting its importance in immune regulation and disease pathogenesis.