UC Irvine

Peritoneal macrophages from Sarcoma 1 (SAl)-sensitized CS7B1/6 mice release a toxic factor (s), termed macrophage toxic factor (MTF), into the medium when exposed to allogeneic target L cells in vitro. Medium containing MTF is cytotoxic to cultures of allogeneic L cells, syngeneic C57B1/6 fetal fibroblasts and xenogenic HeLa cells. The cell toxin (s) is insensitive to the effects of nuclease, neuraminidase and trypsin, but is partially abrogated by treatment with pronase. Two fractions of toxic activity are eluted from Sephadex G-100, one associated with a 150,000 mol wt marker (IgG), and the other associated with a 47,000 mol wt marker (ovalbumin). Goat antiserum prepared against PHA-induced mouse lymphotoxin (MLT) is capable of neutralizing the toxicity of both MTF and MLT, indicating that the factors may be similar. © 1972.