Detection and partial characterization of a new murine T-lineage antigen: evidence for its enzymatic modulation.

A molecule with an apparent molecular weight of 21,000 daltons was found to be a predominating differentiation antigen of peripheral rat T lymphocytes. This antigen is also expressed on the cell surface of thymus lymphocytes though partially in masked form. The observation that these determinants could be unmasked by neuraminidase treatment in vitro suggests that enzymatic processes may play an important role in antigenic transformation along the differentiation pathway of T axis lymphocytes. Since this structure was found to be displayed also by peritoneal exudate macrophages, it is referred to as T lymphocyte-macrophage antigen. The finding that an identical antigen could be identified in the mouse suggests its more common biological significance.