Cell-mediated cytotoxicity against hamster cells transformed by avian sarcoma viruses. 1. Description of the reaction.

The presence of new antigens on hamster cells transformed by avian sarcoma viruses was investigated by in vitro cellular microcytotoxicity assays using spleen cells obtained from immunized hamsters as effector cells and monolayers of transformed cells as targets. The effect of a number of variables was studied especially the concentration of effector cells and of target cells. Probit analysis has been used to statistical interpretation of data. Spleen cells obtained from hamsters immunized with RSV transformed rat cells have allowed the demonstration of new antigens on transformed hamster cells. These antigens have been also detected, in certain conditions, using effector cells obtained from hamsters immunized with RSV transformed hamster cells.