Human T lymphocytes and myeloid colony forming cells share common antigen

Human peripheral blood T lymphocyte antigen has been detected by goat antisera raised to thymocytes of Rhesus monkey. An absorbed antiserum reacted in complement-mediated cytotoxicity reactions and absorption experiments with isolated human peripheral blood T lymphocytes, thymocytes, cells of T lymphocyte line, but not with B lymphocytes or cells of B lymphocyte line. Anti-T lymphocyte antibodies blocked the T lymphocyte rosette formation with sheep erythrocytes. By cytotoxicity test an average of 85% cells of unfractionated lymphocyte preparations and 98% cells of isolated T lymphocyte preparations were positive for the antigen. Peripheral blood granulocytes and monocytes were shown to lack the antigen by cytotoxicity and absorption tests. Lysis of bone marrow cells by the antiserum abolished granulocyte-macrophage colony formation in vitro. Absorption studies showed that myeloid colony forming cells express antigen common to T lymphocytes. The common antigen may be the membrane structure located close to the lymphocyte receptors for spontaneous binding of sheep erythrocytes. This common antigen probably represents an antigen characteristic of the T lymphocyte line which is shared with and thus may be inherited from the pluripotent stem cells.