Publisher Summary Studies of cytotoxicity by human lymphocytes revealed not only that
both allogeneic and syngeneic tumor cells were lysed in a non-MHC-restricted fashion, but
also that lymphocytes from normal donors were often cytotoxic. Lymphocytes from any
healthy donor, as well as peripheral blood and spleen lymphocytes from several
experimental animals, in the absence of known or deliberate sensitization, were found to be
spontaneously cytotoxic in vitro for some normal fresh cells, most cultured cell lines …