Growth kinetics of leukocyte cell lines cultured with hydatid fluid of Echinococcus granulosus equinus.

Oxidation of 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and tritiated thymidine uptake were used to measure, respectively, the viable cell count and the S-phase activity of D10, B9, A20 and p388d leukocytic cell lines cultured in the presence of varying concentrations of fluid from fertile and infertile hydatid cysts of Echinococcus granulosus equinus. Exposure to hydatid fluid raised or lowered the entry of D10 cells into S-phase depending on the concentration of the fluid and of the supporting cytokines. Enlargement of the S-phase population was unaccompanied by increase in viable count indicating that the mitotic cycles induced by hydatid products were not completed. A similar conclusion was reached in respect of the p388d monocytic line, and both changes appear consistent with those occurring in histopathology in vivo. By contrast, the main effect on B9 and A20 B cells was inhibition of entry into S-phase.