The allogeneic effect in inbred mice. II. Establishment of the cellular interactions required for enhancement of antibody production by the graft-versus-host reaction.

Experimental conditions have been established for the elicitation of an allogeneic effect on the adoptive transfer secondary anti-2,4-dinitrophenyl (DNP) antibody response in mice. Thus, spleen cells from DNP-keyhole limpet hemocyanin (KLH)-primed mice manifest good secondary anti-DNP responses to a challenge with DNP-KLH, but not with DNP-bovine gamma globulin (BGG), after adoptive transfer to irradiated syngeneic recipients. However, a good adoptive transfer secondary anti-DNP response of such cells can be elicited with DNP-BGG when a second transfer of allogeneic lymphoid cells, in appropriate numbers, is carried out 24 hr before secondary challenge. The advantage to this system is that the DNP-primed cell population as well as the population of allogeneic lymphoid cells are accessible to experimental manipulation such that the T lymphocytes of one or the other can be removed. Utilizing this model, we have established that the allogeneic effect on antibody production can operate on a population of primed B lymphocytes which have been depleted of their isologous T lymphocytes by in vitro incubation with anti-theta serum plus complement. The potential cellular interactions involved in the mechanism of this phenomenon are considered and discussed in detail.