Pertussis toxin selectively interferes with the responses of the HL-60 human promyelocytic cell line to dimethylsulfoxide

Abstract

The effects of pertussis toxin (PT) on the growth and dimethylsulfoxide (Me2SO4)-induced differentiation of the HL-60 human promyelocytic leukemia cell line were tested. Cell growth was quantified by direct cell counts. Cell differentiation was estimated by measuring the expression of myeloid-specific cell-surface antigens (Mo-1 and fMet-Leu- Phe [fMLP] receptors), the ability of the cells to produce superoxide anions on stimulation with fMLP, the calcium ionophore A23187 and phorbol 12-myristate 13-acetate (PMA), and by monitoring the level of expression of messenger RNA (mRNA) for tumor necrosis factor alpha (TNF alpha). By itself, PT did not affect the proliferation of HL-60 cells in serum-containing medium. In contrast, PT (but not its B-oligomer) dose-dependently inhibited the Me2SO4-induced expression of Mo-1, fMLP receptors, and the oxidative responses to the chemotactic factor and to A23187, but not to PMA. The addition of Me2SO4 induced a significant increase in the steady-state levels of TNF alpha mRNA, and this effect was strongly inhibited by PT. Finally, the bacterial toxin did not reverse the block of cell division that follows the addition of Me2SO4. These results provide evidence for the involvement of a PT substrate (presumably a guanine nucleotide-binding protein) in the regulation of the maturation of the excitation-response coupling sequence in human myeloid cell precursors and show that the regulation of cell division and maturation of HL-60 cells are under distinct sets of control mechanisms.