Development of anti-tissue antibodies in the rat liver transplant model

Background. The aim of this study was to analyze the humoral immune response associated with orthotopic liver transplantation in the rat liver transplant model, and in particular to test the presence of antitissue antibodies. Methods. Rearterialized liver transplantations were performed in the Dark Agouti (DA)-to-Lewis (LEW) and the LEW-to-DA rat strain combinations. Sera of recipients were analyzed by immunofluorescence (on DA and LEW organ sections) and by western blotting (with DA and LEW liver proteins). Results. We have shown that liver (but not heart or skin) recipients develop a humoral response against non-MHC tissue antigens as evidenced (1) by a pattern of staining comparable to that described in human patients harboring anti-smooth muscle antibodies and (2) by the presence of donor liver peptides recognized in the sera of the recipient by Western blotting. bi]Conclusions. These experiments indicate that orthotopic transplantation of a nonacutely rejected liver allograft is associated with the development of a previously undescribed anti-tissue antibody response that seems to be neither organ nor MHC restricted.