Isolation and characterization of a molecular complex containing thy‐1 antigen from the surface of murine thymocytes and t cells

A complex containing the Thy‐1 (θ) antigen has been isolated from the surface of murine thymocytes and T cells by cell surface radioiodination, lysis by freezing and thawing, and immunoprecipitation. The specificity of the immunoprecipitation was firmly established using both congenic and noncongenic anti‐Thy‐1 sera and thymocytes from congenic and noncongenic mice. Unlike cell surface Ig and the TL and H‐2 alloantigens, the antigenicity of Thy‐1 was abolished by treatment with nonionic detergent. Thy‐1 was localized exclusively in a complex of cell surface molecules which has a density lower than that of protein. Moreover, Thy‐1 could be readily labeled by incubating thymocytes with [³H]galactose, but not ³H‐labeled amino acids. These observations suggest that the antigenicity of Thy‐1 may reside in a glycolipid.