Mutation in the signal-transducing chain of the interferon-gamma receptor and susceptibility to mycobacterial infection

J Clin Invest. 1998 Jun 1;101(11):2364-9. doi: 10.1172/JCI2901.

Abstract

IFN-gamma is critical in the immune response to mycobacterial infections, and deficits in IFN-gamma production and response have been associated with disseminated nontuberculous mycobacterial infections. Mutations in the IFN-gamma receptor ligand-binding chain (IFNgammaR1) have been shown to confer susceptibility to severe infection with nontuberculous mycobacteria. However, mutations in the IFN-gamma receptor signal-transducing chain (IFNgammaR2) have not been described. We describe a child with disseminated Mycobacterium fortuitum and M. avium complex infections and absent IFN-gamma signaling due to a mutation in the extracellular domain of IFNgammaR2. In vitro cytokine production by patient PBMCs showed 75% less PHA-induced IFN-gamma production than in normal cells, while patient PHA-induced TNF-alpha production was normal. The normal augmentation of TNF-alpha production when IFN-gamma was added to endotoxin was absent from patient cells. Expression of IFNgammaR1 was normal, but there was no phosphorylation of Stat1 in response to IFN-gamma stimulation. DNA sequence analysis of the gene for IFNgammaR2 showed a homozygous dinucleotide deletion at nucleotides 278 and 279, resulting in a premature stop codon in the protein extracellular domain. This novel gene defect associated with disseminated nontuberculous mycobacterial infection emphasizes the critical role that IFN-gamma plays in host defense against mycobacteria.

Publication types

  • Case Reports

MeSH terms

  • Disease Susceptibility
  • Female
  • Humans
  • Infant, Newborn
  • Interferon-gamma / biosynthesis
  • Male
  • Mutation*
  • Mycobacterium Infections / immunology*
  • Pregnancy
  • Receptors, Interferon / genetics*
  • Signal Transduction*

Substances

  • Receptors, Interferon
  • interferon gamma receptor
  • Interferon-gamma