CELL INTERACTIONS BETWEEN HISTOINCOMPATIBLE T AND B LYMPHOCYTES : I. ALLOGENEIC EFFECT BY IRRADIATED HOST T CELLS ON ADOPTIVELY TRANSFERRED HISTOINCOMPATIBLE B LYMPHOCYTES

The adoptive transfer of 2,4-dinitrophenyl(DNP)-keyhole limpet hemocyanin(KLH)-primed lymphocytes into a heavily irradiated allogeneic recipient permits the development of a secondary anti-DNP antibody response to DNP-bovine gamma globulin(BGG) whether or not the irradiated allogeneic host possesses BGG-specific helper T cells. This "allogeneic effect" has been demonstrated to result from the capacity of residual, apparently radioresistant, T cells in the irradiated host to exert an active effect on the transferred histoincompatible B lymphocytes. This conclusion derives from two corroborative experiments. In the first, an allogeneic effect was shown to occur on DNP-primed F₁ spleen cells that had been adoptively transferred to irradiated parental recipients; the second experiment demonstrated the development of an allogeneic effect on anti-θ-treated, DNP-specific donor cells transferred to irradiated allogeneic hosts. These results emphasize the extreme caution required in designing and interpreting experiments that may involve adoptive cell transfers into histoincompatible hosts, and illustrate why such models are unsuitable for investigation of the question of physiologic cooperative interactions between T and B lymphocytes. Suitable approaches are described in the accompanying paper.