Separation of T and B lymphocytes and their role in the mixed lymphocyte reaction.

Electrophoretic separation was used to purify mouse spleen T and B lymphocytes for a study of the stimulating and proliferating cells in mixed lymphocyte reaction. In one-way mixed lymphocyte studies with mouse lymphocytes it is shown that mitomycin C-blocked T cells as well as 100% pure mytomycinblocked B lymphocytes can induce high and significant stimulation when cultured together with allogeneic T lymphocytes. Exclusively T lymphocytes have the ability to recognize allogeneic lymphocytes and, as a consequence to this event, to initiate proliferation in MLR. Mitomycin C-treated T cells can, after allogeneic recognition, stimulate lymphocytes which by themselves are not able to proliferate in response to an allogeneic stimulus. The implication of these findings in regard to experiments published elsewhere, in which non-T cells “responded” in mixed lymphocytes, is discussed.