INHIBITION OF THE ALLOANTIBODY RESPONSE BY CD95 LIGAND

We investigated the effect of Fas/APO1-ligand (CD95L) gene transfer on allogeneic immune responses in vivo. A colon carcinoma cell line from BALB/c mice, CT26, was stably transfected with a vector encoding mous e CD95L and was inoculated into C57BL/6 mice. CD95L expression markedl y reduced allogeneic cytotoxic T lymphocyte and helper T lymphocyte ac tivity directed toward CT26. Strikingly, expression of CD95L on these allogeneic tumors completely inhibited the generation of alloantibodie s of both IgM and IgG subclasses. Thus, CD95L inhibited alloantibody p roduction and conferred localized immune suppression through this mech anism. These results provide insight into the role of CD95L in regulat ing the alloantibody response and the generation of local immune respo nses.