High resistance of immunocompetent spleen cells to repeated exposure of γ-radiation and its abolition by syngeneic lymphocytes

Abstract

Spleen cells from mice, subjected to γ-radiation at dose 500 R and taken 14 days later, possessed an increased radioresistance by their capacity to accumulate antibody-producing cells in culture in vivo. The addition of syngeneic lymphocytes to radioresistant spleen cells abolished the effect of radioresistance. It is suggested that high radioresistance of immunocompetent cell population may be a consequence of interference with normal cell-to-cell cooperation processes under conditions of decreased level of lymphocytes and of relatively elevated content of stem elements in postirradiated spleens. It seems likely that the change of lymphocyte: stem cell ratio on Day 14 after irradiation of mice decreases the occurrence of transmission of immunological information from lymphocyte to stem cell, and this situation may be estimated phenomenologically as high radioresistance of antibody-producing cells.