MURINE ASTROCYTES EXPRESS A FUNCTIONAL CHEMOKINE RECEPTOR

Elevated levels of chemokines have been observed in various diseases o f the CNS. Little is known, however about how these chemokines affect parenchymal cells of the CNS. The current studies examine astrocyte ch emotaxis to the mouse chemokine macrophage inflammatory protein-1 alph a (MIP-1 alpha). Murine astrocytes demonstrate directed migration alon g a chemical gradient in response to 10(-10)-10(-8) an MIP-1 alpha. Pe ak chemotactic responses are noted at 10(-9) Ni. MIP-1 alpha-induced a strocyte migration is specifically inhibitable with pertussis toxin, s uggesting a role for G alpha(i) proteins in the signaling process. RT- PCR and in situ hybridization were used to identify expression of the murine CCR1 MIP-1 alpha receptor on astrocytes. Astrocytes contain mRN A for CCR1, but messages for CCR4 and the orphan chemokine receptor MI P-1 alpha R-like#1 were not detected. The combined results suggest tha t a functional chemokine receptor is expressed on resident cells of th e CNS. We speculate that the interactions of chemokines with astrocyte s are involved in inflammatory reactions of the CNS.