STIMULATION OF NEUTROPHIL RESPIRATORY BURST AND DEGRANULATION BY JAPANESE ENCEPHALITIS VIRUS-INDUCED MACROPHAGE-DERIVED FACTOR

The effects of Japanese encephalitis virus (JEV) and JEV-induced macro phage derived neutrophil chemotactic factor (MDF) on respiratory burst and granule exocytosis in neutrophils were studied and were compared with N-formyl-methionyl-leucyl-phenylalanine (FMLP). JEV-stimulated ne utrophils released reactive oxygen metabolites with maximum activity b etween days 7 and 9. The response in mice was sensitive to anti-JEV-an tisera treatment. Stimulation by MDF resulted in quick release of supe roxide and granule enzymes from neutrophils upon both in-vivo and in-v itro stimulation in a dose dependent manner. The effect was abrogated by the MDF-specific antisera treatment. These responses were similar i n kinetics and magnitude to those produced in response to FMLP. The re spiratory burst elicited by MDF was abrogated by staurosporine, indica ting that neutrophil activation and signal transduction by MDF and FML P are dependent on protein kinase C.