Accommodation of vascularized xenografts: expression of "protective genes" by donor endothelial cells in a host Th2 cytokine environment

Nat Med. 1997 Feb;3(2):196-204. doi: 10.1038/nm0297-196.


Organ xenografts under certain circumstances survive in the presence of anti-graft antibodies and complement, a situation referred to as "accommodation." We find that the endothelial cells (ECs) in hamster hearts that accommodate themselves in rats express genes, such as A20 and bcl-2, that in vitro protect ECs from apoptosis and prevent upregulation in those cells of proinflammatory genes such as cytokines, procoagulant and adhesion molecules. Hearts that are rejected do not express these genes. In addition, vessels of rejected hearts show florid transplant arteriosclerosis whereas those of accommodated hearts do not. Accommodated xenografts have an ongoing T helper cell type 2 (Th2) cytokine immune response, whereas the rejected grafts have a Th1 response. We propose a model for factors that contribute to the survival of xenografts and the avoidance of transplant arteriosclerosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology
  • Antibody Formation
  • Cricetinae
  • Endothelium, Vascular / immunology
  • Graft Rejection / genetics
  • Graft Rejection / immunology*
  • Graft Rejection / prevention & control
  • Heart Transplantation / immunology*
  • Male
  • Mesocricetus
  • Rats
  • Rats, Inbred Lew
  • Th1 Cells / immunology
  • Th2 Cells / immunology*
  • Transfection
  • Transplantation, Heterologous


  • Antibodies, Monoclonal