LYMPHOID CELLULAR RESPONSES IN THE BLOOD AFTER IMMUNIZATION IN MAN

Abstract

A combined morphological and metabolic study has been made of the lymphoid cells in the blood during the immune response in man. Similar changes were observed in both primary and secondary responses to a number of different microbial antigens. The cellular response involved an increase in numbers of three types of cell; hyperbasophilic medium lymphocytes, plasma cells, and large lymphoid cells. The large lymphoid cells were about 20 µ in diameter with large nuclei, prominent nucleoli, and an intensely basophilic cytoplasm with numerous polyribosomes. About 30% of these cells were in the DNA synthetic phase of cell growth. Electron microscopy has shown that many of the basophilic medium-sized cells have sufficient well-organized endoplasmic reticulum to be included in the plasma cell series. The hyperbasophilic cells labeled more heavily with tritiated uridine and tritiated leucine than the normal small and medium lymphocytes from the peripheral blood of patients not under antigenic stimulation.