Renewal rates of murine T-lymphocyte subsets

The proliferative dynamics of T-cell subsets in lymphoid organs of BALB/c mice have been evaluated by means of [3H]thymidine injections for up to 3 days, followed by FACS and autoradiography. In the thymus, cells positive for both CD4 and CD8 antigens were more rapidly renewed than single-positive cells. Cell populations showing strong expression of Thy-1 and weak expression of CD5 antigens were more rapidly renewed than populations with the opposite antigen expressions. The results obtained from the spleen and the lymph nodes indicated that the majority of T cells have life spans exceeding a few days, and comparable cell kinetics were found in the different T-cell subpopulations. Results obtained after injections of hydroxyurea, which causes elimination of cycling cells, paralleled the autoradiographic results.