Influence of splenectomy on first set rejection reactions of C57BL/6 females to male skin isografts

The tempo with which C57BL/6 females reject male skin isografts is determined in part by the immunogenicity of the H-Y antigen and in part by the capacity of the host to respond immunologically. Our studies indicate that the spleen plays an important role in determining the briskness of the rejection process in that splenectomy 7-30 days before grafting with male skin significantly shortens the survival time. The results of reconstitution experiments suggests that a population of cells is present in spleens of normal, but not specifically sensitized, females which can restore the conventional first set reaction in splenectomized females. It is inferred that this resident population normally operates in spleen-intact females to delay the development of specific effector responses. Lymphoid cells from H-Y antigen- sensitized, splenectomized females failed to evoke graft-vs.-host responses in males whereas similar cells from females with spleens intact did possess graft-vs.-host potential.