THE LIFE SPAN OF IgA PLASMA CELLS FROM THE MOUSE INTESTINE

Tritiated thymidine was injected during the neonatal period into conventional CBA mice. The disappearance rate of tritium-labeled IgA plasma cells was followed by a technique combining immunofluorescence with autoradiography which permitted the identification of the immunoglobulin class of plasma cells with labeled nuclei. In this way, it was possible to calculate that the major population of intestinal IgA plasma cells have a half-life of 4.7 days under physiological conditions of stimulation. It was also found that the maximum life span of both intestinal IgA plasma cells and the IgA, IgG, and IgM plasma cells from the spleen is of the order of 7–8 wk.