A novel CXC chemokine PBSF/SDF-1 and its receptor CXCR4: their functions in development, hematopoiesis and HIV infection.

PBSF/SDF-1 is a CXC chemokine which has unique functions among chemokines. It is essential for viability of the embryo, B lymphopoiesis, bone marrow hematopoiesis and cardiogenesis. A receptor for PBSF/SDF-1 was shown to be CXCR4 that is an entry co-receptor for T cell line-tropic HIV-1. Although murine cells had been thought to have no functional co-receptors, murine CXCR4 allowed entry of HIV-1 into target cells with human CD4. In addition, a small molecule CXCR4 inhibitor that blocks HIV-1 entry was identified.