HUMAN HEART ENDOTHELIAL-CELL-RESTRICTED ALLORECOGNITION

We studied the reactivity of cardiac graft-infiltrating cells, culture d from endomyocardial biopsy specimens, toward heart endothelial cells (Hec). In two cases, Hec derived from the specific donor heart or Hec compatible with the donor were lysed, but not the syngeneic B cell li ne. A vessel-derived endothelial cell Line was not lysed. Panel studie s suggest that the epitopes recognized are, in one case, a Hec-specifi c peptide presented in the context of HLA-Bw41 and, in the other case, a Hec-specific peptide presented by a subtype of HLA-B44. In conclusi on, we showed that cardiac graft-infiltrating cells cultured from endo myocardial biopsy specimens can exhibit cytotoxic reactivity specifica lly directed against HLA-peptide complexes on Hec.