Study of human T and B lymphocytes with heterologous antisera. II. Partial characterization of a human T lymphocyte antigen.

Using a horse anti-human thymocyte serum made specific for T lymphocytes by absorption (anti-HTLA serum), a material reacting with it has been extracted from detergent-lysed peripheral blood lymphocytes. Acid elution and gel-filtration analysis allowed recovery of two peaks containing HTLA activity: one of 30,000-40,000 Daltons, the other being excluded by Sephadex G-200 and likely to be more than 300,000 Daltons. HTLA appeared to be released by lymphocytes incubated at 37 degrees, but not at 4 degrees, and significantly detectable after 10-24-h incubation. Finally co-capping experiments with anti-beta2m antibodies and absence of inhibition of cytolysis by anti-HTLA serum of celld beta2m.