Role of the Heterotrimeric G Proteins in Stromal-Derived Factor-1α-Induced Natural Killer Cell Chemotaxis and Calcium Mobilization

The CXC chemokine stromal derived factor-1α (SDF-1α) induces both the chemotaxis and calcium mobilization in IL-2-activated NK (IANK) cells. The ability of SDF-1α to induce IANK cell chemotaxis is inhibited upon incorporating antibodies to the α subunit of Goand Gqbut not Gi, Gs, or Gz, whereas (Ca++)imobilization is inhibited with anti-Gi, anti-Gqand anti-Gs, but not with any other anti-G proteins examined. Further analysis showed that antibody to phospholipase C (PLC)β but not PLCγ inhibited SDF-1α-induced (Ca++)imobilization, suggesting that this signal is mediated by G protein coupled receptor and not by tyrosine kinase receptors. Our results are the first to show that SDF-1α is chemoattractant for NK cells, and that this effect is coupled to G proteins.