Effects of Radiation on Direct and Developed Spleen Hemolysin Plaque-Forming Cells of Mice

Abstract

Summary The effects of 500 r whole body γ radiation on direct and developed hemolysin plaque-forming cells in spleen tissue and on serum hemolysin levels of LAF1 mice were investigated. The major findings were: Fourteen-day assay involving a single antigen injection: When radiation was administered 2 days before or 3 days after antigen, spleen hemolysin plaque-forming cell production was markedly lowered when compared with spleen hemolysin plaque-forming cells of non-radiated animals. With this injection scheme, the principal cell type was the developed hemolysin plaque-forming cell. Spleen cellularity of radiated animals was significantly below that of non-radiated control animals.Fourteen-day assay involving two antigen injections: A second antigen injection 6 days after radiation stimulated antibody-forming cell production so that the total spleen hemolysin plaque-forming cells of the once-radiated animals were comparable to non-radiated control animals. Radiation, administered after the second antigen, markedly inhibited hemolysin plaque-forming cell production as well as spleen cellularity.Twenty-eight-day observation period involving multiple antigen injections: The effects of a single dose of 500 r administered to LAF1 mice 3 days after an initial antigen injection and given a total of two, three and four antigen injections at weekly intervals and analyzed at 14, 21 and 28 days, respectively, showed no difference from non-radiated animals in their ability to respond to antigenic stimulation. In these animals, spleen cellularity was consistently lower than in non-radiated animals.