Effect of human leukocyte and other tissue dialysates on Listeria resistance and phagocytosis in mice.

The effect of dialyzable transfer factor (TFd) on Listeria resistance was measured by survival studies and by assessing phagocytic capacity of peritoneal macrophages. Unfractionated dialysates from human leukocytes (DLE), bovine liver, porcine spleen and kidney as well as saline were injected i.p. into NMRI mice 72 h before the i.p. injection of 1-3 x 10(6) Listeria organisms. The results show that DLE, porcine spleen and bovine liver dialysate increased the LD50 5-20 times. Porcine kidney dialysate had no effect on the survival of the mice. After the fractionation of porcine spleen dialysate on Sephadex G-10 column, a significant activity was found in two fractions, II and IX. When active fractions were given together (II + IX) i.p. three days prior to the infection with listeria organisms, the survival of mice increased significantly, whereas no effect was seen when the fractions were given i.v. and the bacteria i.p. Also the treatment with active fractions increased significantly the phagocytic capacity of peritoneal macrophages. Taken together, our results suggest that the Listeria protective substances seem to operate via monocyte activation.