Adoptive immunotherapy of intracerebral murine lymphomas: role of different lymphoid populations.

In an attempt to elucidate the cellular mechanisms responsible for the therapeutic activity of systemic immunotherapy in an adoptive transfer system, lymphoma cells were implanted i.c. It was found that, upon peripheral injection of cytotoxic T-lymphocytes with specificity for the tumor, the cells reached and infiltrated the diseased brain but did not accumulate selectively in the malignant graft. In order to accomplish significant tumor inhibition, the infused lymphocytes, largely expressing the Lyt-1+2+ phenotype, apparently cooperated with radioresistant phagocytic cells present in histocompatible hosts and athymic mice.