In vitro characterization of a murine recipient anti-donor effector cell responsible for the development of chronic graft-versus-host disease.

Injection of parental spleen cells into unirradiated F1 hybrid recipients is frequently used for the induction of murine graft-vs-host disease (GVHD). Injection of C57BL/6 spleen cells into B6D2F1 recipients results in the acute form of GVHD whereas injection of DBA/2J cells into the same recipients results in a chronic form of GVHD. In vivo studies have suggested that injection of DBA/2J cells into B6D2F1 recipients results in the chronic form of GVHD instead of acute GVHD because of recipient B6D2F1 effector cells that inhibit DBA/2J CD8+ T cell function. The present report describes the development of an in vitro assay that measures the activity of these B6D2F1 effector cells. The results obtained using this assay indicate that these B6D2F1 effector cells are found primarily in the LN, need to be activated in order to function, are inhibited by anti-CD8 antibodies, and mediate their function as a result of DBA/2J cells binding to Ag expressed on their cell surface.