Murine orthotopic corneal transplantation in high-risk eyes. Rejection is dictated primarily by weak rather than strong alloantigens.

Abstract

These findings indicate that for orthotopic corneal allografts placed in high-risk graft beds, minor H antigens offer a more formidable barrier to graft acceptance than do MHC-encoded antigens. The authors speculate that this unexpected outcome may reflect a reduced level of MHC expression on corneal tissue. Moreover, because the cornea as a graft lacks bone marrow-derived dendritic cells, allorecognition by recipient T cells must occur by way of the indirect pathway of alloantigen processing, and in this situation, minor H antigens may compete favorably with MHC antigens for presentation by recipient antigen-presenting cells that infiltrate the graft.