Induction of F1 hybrid antiparent cytotoxic effector cells: an in vitro model for hemopoietic histoincompatibility.

An in vitro system has been developed in which F1 spleen cells can generate cytotoxic activity directed specifically against parental cells. The antigenic differences detected are controlled by the H-2D-Hh-1 region of the murine major histocompatibility complex. The parent-F1 combinations demonstrating F1 antiparent activity in vitro are the same as those demonstrating F1 rejection of parental hemopoietic grafts in vivo. Hence, the F1 antiparent cytotoxicity test serves as an in vitro model for the recognition and effector phases of hybrid resistance to parental hemopoietic grafts and may be of value in clinical transplantation.