Kinetics of intraepithelial lymphocytes in the small intestine of thymus-deprived mice and antigen-deprived mice.

The kinetics of lymphoid cells within the epithelium of the small gut has been studied in various thymus-deprived mice and in antigen-deprived mice by the use of 3H-thymidine injections and radioautography. In thymus-deprived mice--including adult thymectomized, thymectomized and irradiated, neonatally thymectomized, and nude mice - and in germ-free mice decreased numbers of intraepithelial lymphocytes (IL) were found. On the other hand, the radioautographic results indicated that the remaining IL populations included both newly formed and long-lived lymphoid cells in the same percentages as found in sham-operated controls and normal mice. It is concluded that although the presence of the thymus and the antigen content of the gut is of importance to the maintenance of the numbers of cells in the lymphoid populations of the intestinal wall, the basic kinetics of these cell populations are preserved in deprived mice.