C-kinase activity in normal B cells treated with Staphylococcus aureus, Cowan strain I, and phorbol ester: response differences in a patient with prolymphocytic leukaemia.

Ca+2/phospholipid-dependent kinase (C-kinase) activity is intimately involved with the B-cell response after ligation of its mIg receptor. Here, we extend previous findings with anti-mIg by showing that polyclonal stimulation with Staphylococcus aureus, Cowan strain I (SAC), could also translocate C-kinase from the cytosol of intact, normal human B lymphocytes. This stimulus could not, however, induce redistribution of enzyme in a prolymphocytic leukaemia (PLL) B-cell population. Despite a normal density of mIg receptors on the latter cell type, PPL cells could not be stimulated to proliferate, express interleukin-2 (IL-2) receptors, and differentiate under the influence of SAC, even in the presence of exogenous IL-2. Normal B cells could respond appropriately to the same stimuli. PLL cells had a normal content of C-kinase activity and the enzyme could be translocated under the influence of the specific agonist, 12-0-tetradecanoyl phorbol-13-acetate (TPA). The same agent could induce cellular proliferation and differentiation in PLL cells, showing that its terminal C-kinase dependent pathways were intact. We conclude that the mIg receptor mechanism of this PLL population could not activate C-kinase appropriately.