Murine Fetal Liver Augments Proliferation in an Allogenic Mixed Lymphocyte Culture: Benzo(A)Pyrene Reduces Augmentation

Abstract

The effect of cells from the liver of C3H fetuses syngeneic to splenic responder cells on an allogeneic mixed lymphocyte response (MLR) was studied. After fractionation on ficoll-hypaque, interface cells from corn oil (vehicle for BP) or normal fetal liver (FL) controls (CO), obtained from 17–19 days gestation, enhanced proliferation in the mixed lymphocyte culture (>2-fold), while cells from FLs transplacentally exposed to benzo(a)pyrene (BP) showed a decreased capacity for augmentation (>2-fold less than CO). Unfractionated CO-FL cells at 0.5×10⁶ did not augment proliferation, but at 0.10×25⁶ enhancement with control FL cells was significantly higher than with BP-FL cells. Pelleted cells from BP- and CO-FLs were severely suppressive at the higher dose, while at 0.25×10⁶ proliferation was augmented with CO-FL cells, but not affected with BP-FL cells. At doses of 0.1×10⁶ or less, no effect was observed for either control or BP-FL cells. These data indicate that: a) FL cells syngeneic to responder cells of an allogenic mixed lymphocyte culture (MLC) have an augmenting but not suppressive capacity on cell proliferation; b) in utero insult with BP modifies the capacity of FL cells to augment proliferation in the MLC.