Megakaryocytic cell line-specific hyperploidy by cytotoxic necrotizing factor bacterial toxins

Cytotoxic necrotizing factor (CNF) toxins, isolated from certain Escherichia coli strains known to cause intestinal and extra intestinal infections, induce reorganization of the actin cytoskeleton and generate hyperploidy in adherent cell lines. We have examined the effect of CNF toxin on one of the few cell types that naturally increase nuclear DNA content, megakaryocytes. Our studies show that only hematopoietic cells capable of differentiating along the megakaryocyte lineage responded to the CNF2 toxin by becoming polyploid and by reorganizing actin. The K562, HEL, and CHRF-288–11 cell lines can be induced with phorbol ester to differentiate along the megakaryocyte lineage, and these cel…