ANTI-IGM AND ANTI-IGG MODULATE C-FOS RNA LEVELS DIFFERENTLY IN HUMAN B-LYMPHOCYTES

One component of the B cell activation cascade is the induction of the protooncogene c-fos. Data presented here demonstrate that stimulation of mIgM-bearing cells with either anti-IgM or the combination of PDB plus ionomycin generated comparable levels of c-Sos RNA. Furthermore, a synergistic response was observed when the cells were treated with s elected concentrations of anti-IgM plus either PDB or ionomycin. In co ntrast, stimulation of mIgG-bearing B cells with anti-IgG did not indu ce the c-fos RNA levels that were seen when these cells were treated w ith the combination of PDB plus ionomycin. Treatment of mIgG-bearing c ells with only the combination of anti-IgG plus ionomycin yielded a sy nergistic response and anti-IgG plus PDB did not. Thus, induction of c -fos RNA appears to be different in mIgM- and mIgG-bearing B cells aft er stimulation through mig. (C) 1994 Academic Press, Inc.