Cytolytic effect of macrophages and polymorphonuclear leukocytes treated with acidic fraction of bakers' yeast mannan against MM46 tumor cells in vitro.

Macrophages (M phi) and polymorphonuclear leukocytes (PMN) were obtained from C3H/He mice which had received intraperitoneal administration of an acidic fraction of bakers' yeast mannan (WAM025), 150 mg/kg/d, for 5d and the cells were investigated for their cell-injuring effect against MM46 tumor cells in vitro. The M phi displayed a marked cytolytic effect in the range of effector cells to target cells ratios of 100 to 200 with concomitant increase of lysosomal enzyme and active oxygen production. On the other hand, the PMN did not show the cytolytic effect, and the enhancing effect of the lysosomal enzyme activity was also very low, while these cells produced larger amounts of active oxygens and interleukin-1 (IL-1) than did the M phi.