Generation of diacylglycerol and ceramide during homologous complement activation.

摘要: Formation of sublytic terminal complement complexes (TCC) on nucleated cells produces transient increase in [Ca2+]i and activates protein kinase C. The present study is to evaluate whether TCC can generate endogenous signal messengers other than Ca2+ that regulate cell activities by measuring mass-levels sn-1,2-diacylglycerol (DAG) ceramide. As targets, lymphoblastoid human B lines JY25 its mutant JY5 were used. JY5, deficient glycosylphosphatidylinositol-anchored proteins with higher lytic susceptibility complement, are four times more efficient forming C5b-9. When sensitized limited anti-class II IgG exposed serum TCC, a sustained DAG ceramide was observed maximum 3.6-fold over basal level 2.8-fold 6.3-fold JY5. effect evaluated C7-deficient (C7D) +/- C7 also C5b6, C7, C8, C9 proteins. C7D + control 1.6- 1.8-fold, respectively, JY25, 2.3-, two-fold activation induced an increased hydrolysis sphyingomyelin phosphatidylcholine. In addition, primarily achieved C5b-7 preincubation pertussis toxininhibited increase, suggesting involvement toxin-sensitive GTP-binding protein. important transduction molecules, generated response assembly, could participate during inflammation repair.