title: Intracellular pathway of interleukin 2 following receptor-mediated endocytosis.
abstract: Electron microscope autoradiography was used to examine the intracellular pathway of radioiodinated interleukin 2 [( 125I]IL2) following its receptor-mediated endocytosis in CTLL cells. Direct measurement of the kinetics of endocytosis showed that 60-70% of surface-bound [125I]IL2 was internalized after 1 h at 37 degrees C. [125I]IL2 was observed to enter cells through invagination of coated pits at the cell surface and to concentrate into lysosomal multivesicular bodies as early as 5-10 min after endocytosis. These results provide ultrastructural information on the intracellular pathway of IL2 and on its probable site of degradation within the cell.
mesh_terms: D001692:Biological Transport; D002460:Cell Line; D003034:Coated Pits, Cell-Membrane / Q000378:metabolism / Q000648:ultrastructure; D004705:Endocytosis; D007376:Interleukin-2 / Q000378:metabolism*; D007700:Kinetics; D008247:Lysosomes / Q000378:metabolism / Q000648:ultrastructure; D008854:Microscopy, Electron; D011971:Receptors, Immunologic / Q000378:metabolism*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2