Graft-versus-host reactivity of lymphoid cells from mice genetically selected for high (Hi/PHA) or low (Lo/PHA) responsiveness to phytohemagglutinin

Abstract Lymphocytes from mice genetically selected for high or low responsiveness of their lymphocytes to phytohemagglutinin (Hi/PHA or Lo/PHA) were measured for their proliferative responses to stimulation by alloantigens in a graft-versus-host reaction (GVHR) induced in irradiated allogeneic or semiallogeneic recipients. The high and low responder status of Hi/PHA and Lo/PHA lymphocytes to stimulation by PHA was also observed in GVHR, whatever the haplotype of the host. In contrast, Hi/PHA or Lo/PHA alloantigens produced an almost equivalent GVHR in semiallogeneic recipients. These experiments support the hypothesis that some of the alleles regulating PHA responsiveness intervene in the quantitative regulation of the GVHR.