Differential half-life of major histocompatibility complex encoded class I molecules in T and B lymphoblasts.
Major histocompatibility complex encoded class I molecules have been reported to be internalized in T lymphocytes but not in B lymphocytes. In order to better understand the physiology of these molecules, we investigated their kinetics of disappearance and the fate of antibody bound to them in T and B lymphoblasts. Metabolically labelled H-2K molecules were immunoprecipitated from the surface and from inside the cells after different periods of chase and analyzed by gel electrophoresis. In T lymphoblasts, there was a rapid disappearance of both surface and intracellular H-2K molecules with a half-life of about 5 hr. After a 20 hr chase, only lower mol. wt products were immunoprecipitated. In contrast, in B lymphoblasts, H-2K molecules were more stable with a half-life of greater than 20 hr. Bound anti-H-2K antibodies were degraded in T but not in B lymphoblasts. These results suggest that class I molecules and antibodies bound to them do not recycle back to the cell surface but are degraded after internalization in T lymphoblasts, whereas these molecules are less degraded in B lymphoblasts.
Machy
P
P
Department of Cell Biology, Smith Kline and French Laboratories, Philadelphia, PA 19101.
Truneh
A
A
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D006183:H-2 Antigens / Q000032:analysis / Q000276:immunology*; D006207:Half-Life; D007700:Kinetics; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
D000954:Antigens, Surface; D006183:H-2 Antigens