Donor Treatment With Carbon Monoxide Can Yield Islet Allograft Survival and Tolerance

  1. Hongjun Wang1,
  2. Soo Sun Lee1,
  3. Wenda Gao2,
  4. Eva Czismadia1,
  5. James McDaid1,
  6. Robert Öllinger1,
  7. Miguel P. Soares1,
  8. Kenichiro Yamashita1 and
  9. Fritz H. Bach1
  1. 1Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
  2. 2Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
  1. Address correspondence and reprint requests to Hongjun Wang, Beth Israel Deaconess Medical Center, Harvard Medical School, 99 Brookline Ave., RN #361, Boston, MA 02215. E-mail: hwang3{at}


Treatment of animals or certain cells with carbon monoxide (CO), a product of heme degradation by heme oxygenase-1 (HO-1), has potent anti-inflammatory and antiapoptotic effects that contribute to the survival of transplanted organs. We report here that inducing HO-1 in, or administering CO to, only the donor can be used in a therapeutic manner to sustain the survival of transplanted allogeneic islets. Similar treatments of only the islets or only the recipient are also salutary. Administering CO only to the donor frequently leads to long-term survival of those islets in untreated allogeneic recipients, which are then antigen-specifically tolerant. Several proinflammatory and proapoptotic genes that are strongly induced in islets after transplantation in the untreated situation were significantly suppressed after administering CO to the donor without further treatment. These included tumor necrosis factor-α, inducible nitric oxide synthase, monocyte chemoattractant protein-1, granzyme B, and Fas/Fas ligand, all of which contribute to the pathogenesis of the rejection of transplanted islets. This correlated with a lesser infiltration of recipient macrophages into the transplanted islets. Our present findings show that induction of HO-1 in, or administration of CO to, only the donor, islets, or the recipient or combinations of such treatments improve allogeneic islet survival.


  • K.Y. and F.H.B. contributed equally to this work.

    M.P.S. is currently affiliated with the Gulbenkian Institute of Science, Oeiras, Portugal.

    • Accepted January 28, 2005.
    • Received June 18, 2004.
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