Abstract
The relative toxic effect of tuberculin (PPD) and of Escherichia coli filtrate on endotoxin for splenic cells of normal and tuberculin-sensitive animals was determined in tissue culture. The degree of toxicity was estimated by quantitative determinations of the relative effect on migration or growth of wandering cells and fibroblasts from explants of spleen maintained in a semisolid tissue culture medium. The concentration of PPD employed did not affect normal cells but definitely decreased the migration and growth of leukocytes, macrophages, and fibroblasts from tuberculin-sensitive animals. E. coli endotoxin in concentrations between 0.25 and 100 gamma per ml of culture medium had a variable effect on leukocytes, but a fairly regular and marked toxic effect on macrophages from man, rabbits, and guinea pigs. The relative sensitivity of the macrophage to endotoxin was similar in the 3 species. Although some variation existed in the cellular sensitivity of individual animals, splenic leukocytes and macrophages from tuberculin-sensitive rabbits and guinea pigs were not found to be more sensitive to coli filtrate or endotoxin than the corresponding cells from normal animals. The results confirm the specificity of the method for studying delayed allergy. The highest concentration of endotoxin used in comparative tests (l[gamma] per ml) did not decrease the growth of normal or tuberculin-sensitive fibroblasts.