ROLES OF PHOSPHOLIPASE-C BETA-2 IN CHEMOATTRACTANT-ELICITED RESPONSES

The physiological roles of phospholipase C (PLC) beta 2 in hematopoies is, leukocyte function, and host defense against infection were invest igated using a mouse line that lacks PLC beta 2. PLC beta 2 deficiency did not affect hematopoiesis, but it blocked chemoattractant-induced Ca2+ release, superoxide production, and MAC-1 up-regulation in neutro phils. In view of these effects, it was surprising that the absence of PLC beta 2 enhanced chemotaxis of different leukocyte populations and sensitized the in vivo response of the PLC beta 2-deficient mice to b acteria, viruses, and immune complexes, These data raise questions abo ut the roles that PLC beta 2 may play in signal transduction induced b y chemoattractants in leukocytes.