The antigenicity of serum proteins and their role in xenograft rejection.

I T HAS been reported previously that following xenotransplantation. liver secretes proteins of donor origin into the serum of xenograft recipients. thus allowing them to retain their species-specificity. I The persistence and the function of hamster xenoproteins in long-surviving hamster --> rat liver transplant recipients has already been well established. ~ In the present study, we have extended this concept further by evaluating the possible immunogenicity o f donor (hamster) serum proteins . To this end. we have attempted to ( I) characterize the hamster serum proteins that elicit an antigenic response in the rat and (2) identify do nor proteins in th e recipient serum that share common epitopes with those on the cell surface of the vascular endothelium. which are the primary targets of antibodymediated rejection of vascularized xenografts.