PLoS Medicine (Jan 2008)

IFN-gamma mediates the rejection of haematopoietic stem cells in IFN-gammaR1-deficient hosts.

  • Martin Rottman,
  • Claire Soudais,
  • Guillaume Vogt,
  • Laurent Renia,
  • Jean-François Emile,
  • Hélène Decaluwe,
  • Jean-Louis Gaillard,
  • Jean-Laurent Casanova

DOI
https://doi.org/10.1371/journal.pmed.0050026
Journal volume & issue
Vol. 5, no. 1
p. e26

Abstract

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BACKGROUND: Interferon-gamma receptor 1 (IFN-gammaR1) deficiency is a life-threatening inherited disorder, conferring predisposition to mycobacterial diseases. Haematopoietic stem cell transplantation (HSCT) is the only curative treatment available, but is hampered by a very high rate of graft rejection, even with intra-familial HLA-identical transplants. This high rejection rate is not seen in any other congenital disorders and remains unexplained. We studied the underlying mechanism in a mouse model of HSCT for IFN-gammaR1 deficiency. METHODS AND FINDINGS: We demonstrated that HSCT with cells from a syngenic C57BL/6 Ifngr1+/+ donor engrafted well and restored anti-mycobacterial immunity in naive, non-infected C57BL/6 Ifngr1-/- recipients. However, Ifngr1-/- mice previously infected with Mycobacterium bovis bacillus Calmette-Guérin (BCG) rejected HSCT. Like infected IFN-gammaR1-deficient humans, infected Ifngr1-/- mice displayed very high serum IFN-gamma levels before HSCT. The administration of a recombinant IFN-gamma-expressing AAV vector to Ifngr1-/- naive recipients also resulted in HSCT graft rejection. Transplantation was successful in Ifngr1-/- x Ifng-/- double-mutant mice, even after BCG infection. Finally, efficient antibody-mediated IFN-gamma depletion in infected Ifngr1-/- mice in vivo allowed subsequent engraftment. CONCLUSIONS: High serum IFN-gamma concentration is both necessary and sufficient for graft rejection in IFN-gammaR1-deficient mice, inhibiting the development of heterologous, IFN-gammaR1-expressing, haematopoietic cell lineages. These results confirm that IFN-gamma is an anti-haematopoietic cytokine in vivo. They also pave the way for HSCT management in IFN-gammaR1-deficient patients through IFN-gamma depletion from the blood. They further raise the possibility that depleting IFN-gamma may improve engraftment in other settings, such as HSCT from a haplo-identical or unrelated donor.