Molecular identification of T cell‐specific antigens on human T lymphocytes and thymocytes

摘要

AbstractWe have identified membrane glycoproteins which carry T cell‐specific antigens on human T lymphocytes and thymocytes. Purified cells were surface‐labeled with NaB3H4after treatment with neuraminidase and galactose oxidase. Immunoprecipitations were performed with rabbit anti‐human T cell‐specific antibodies using co precipitation with protein A‐containing staphylococci strain Cowan I. The labeled membrane glycoproteins and the precipitates were subjected to polyacrylamide slab gel electrophoresis and visualized by fluorography.The antibodies specifically precipitated 4 proteins called GP200, GP180, GP165 and GP160 (mol. wts. = 200000, 180000, 165000 and 160000) from surface‐labeled T lymphocytes and low‐density (medullary) thymocytes. The GP200 and GP180 were not labeled on high‐density (cortical) thymocytes. A protein with a mol. wt. of 45000 was precipitated from thymocytes. Another glycoprotein on T lymphocytes and thymocytes with a mol. wt. similar to that of mouse and rat Thy‐1 or Θ antigen (mol. wt. 25000) reacted w