Radiation-induced surface IgG modulation: protein kinase C involvement

Although radiation-induced loss of surface IgG (s-IgG) expression on murine B cells is known to be dependent on intact energy metabolism and integrity of the cytoskeleton, the exact mechanism of this radiation effect is not known. Evidence reported here shows that inhibition of protein kinase C (PKC) by H-7 impairs the radiation-induced s-IgG modulation, whereas addition of HA-1004, which preferentially inhibits c-AMP-dependent protein kinase, shows only minor effects. On the other hand PMA, a PKC activator, mimics the radiation effect, and H-7 but not HA-1004 inhibits the PMA-induced loss of s-IgG expression. Therefore it is suggested that PKC is involved in the modulation of s-IgG induced by irradiation on B cells. The possibility of membrane participation in this event is discussed. (author)