Direct cytotoxicity against chicken erythrocytes in mice. II. Nature of immunoglobulin on cytotoxic T lymphocytes.

Direct cytotoxicity raised at an early interval after immunization with chicken erythrocytes (CRBC) has been ascribed to O-positive, immunoglobulin (Ig)-bearing lymphocytes. Cytotoxicity of such effector cells was not affected by trypsinization. Cytotoxity was reduced by the treatment of effector cells with anti-IgG serum and complement or by the addition of anti-IgG serum to culture medium for cytotoxicity test. When the effector cells were treated with trypsin before cytotoxicity test, such procedures with anti-IgG serum did not affect their cytotoxicity. Ig molecules on cytotoxic T lympohcytes may not be an essential element for antigen recognition. This explanation may be supported by the fact that cytotoxicity against CRBC could be raised in 600 rad irradiation, thymus-cell transferred mice in the absence of antibody production.