Autoradiographic Observations of Plasma Cell Formation

Abstract

The temporal pattern of DNA labeling in plasmocytic cells of the lymph nodes of mice which have been stimulated by multiple injections of antigen was followed autoradiographically after single injections of tritiated thymidine. From an analysis of this pattern and the changes in the mean grain count the enormous proliferative capacity of cells in the plasmocytic series has been demonstrated. A maximum generation time of 12 to 14 hr has been calculated for the early plasmoblast. The most mature plasma cells are apparently nondividing cells which have a meanlife in the lymph node of the order of 8 to 12 hr. More preliminary autoradiographic observations following the single injection of H³-cytidine and H³-leucine indicate that this nondividing mature plasma cell does not synthesize RNA and is capable of only minimal protein synthesis.