COMPARISON OF THE STRUCTURE OF THE MURINE INTERLEUKIN 2 (IL 2) RECEPTOR ON CYTOTOXIC AND HELPER T CELL LINES BY CHEMICAL CROSS-LINKING OF 125I-LABELED IL 2

摘要: The structure of the murine interleukin 2 receptor (IL 2R), on a cytotoxic (CTLL) and helper (HT2) cell line, has been studied by combination chemical cross-linking with 125I-labeled IL immunoprecipitation an anti-receptor monoclonal antibody (7D4). In CTLL cells both methods detected major 57-kDa 2-binding protein in addition studies revealed presence 70-75-kDa associated high-affinity receptor. HT2 however, three additional proteins 18, 22 37 kDa to expected 50-kDa protein. Again demonstrated protein, which was not immunoprecipitable 7D4 antibody. low molecular polypeptides were low-affinity represented most likely breakdown products Whereas 18- 22-kDa involved ligand binding, 37-kDa fragment carried epitope recognized Comparative two 2R antibodies, PC61 7D4, that only inhibited formation alpha/beta chain complex, although antibodies reportedly prevent biological response 2. It is speculated fragment, reacts antibody, might be signal transduction. Finally there no evidence for existence high weight component 2R, previously described as gamma chain. summary, two-chain confirmed lines some heterogeneity alpha possibility raised plays role