Interleukin-2 (IL-2) receptor gamma chain mutations in X-linked severe combined immunodeficiency disease result in the loss of high-affinity IL-2 receptor binding

Eur J Immunol. 1994 Feb;24(2):475-9. doi: 10.1002/eji.1830240232.


Interactions of interleukin-2 (IL-2) with its high-affinity, heterotrimeric receptor (IL-2R alpha beta gamma) play a pivotal role in the autocrine pathway of T lymphocyte expansion required in an immune response. Mutations in the IL-2R gamma chain-encoding gene have been found in SCIDX1, a primary immunodeficiency characterized by the absence of T cell and NK cell development. We have investigated six unrelated SCIDX1 patients for molecular abnormalities of the IL-2R gamma gene. A variety of defects were identified, including the absence of transcripts, frame-shift deletions and point mutations within canonical cytokine receptor motifs (conserved cysteines and the "WS" box). The ability of these mutated IL-2R gamma chains to participate in the function of a high-affinity IL-2R complex was examined by radiolabeled IL-2 binding studies using Epstein-Barr virus-transformed B lymphoblastoid cell lines (B-LCL) derived from SCIDX1 patients. Although normal control B-LCL express high-affinity IL-2 binding sites (Kd = 60 pM, 150 sites/cell), B-LCL derived from SCIDX1 patients failed to bind IL-2 under high-affinity conditions. These SCIDX1 mutations confirm the critical role of the IL-2R gamma chain in T cell and NK cell development. In addition, these data provide insight into the structure/function relationship of the IL-2R gamma chain by identifying residues required for the formation of a high-affinity IL-2R complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • DNA Primers / chemistry
  • Humans
  • Molecular Sequence Data
  • Point Mutation
  • RNA, Messenger / genetics
  • Receptors, Interleukin-2 / genetics*
  • Receptors, Interleukin-2 / metabolism
  • Severe Combined Immunodeficiency / genetics
  • Severe Combined Immunodeficiency / immunology*
  • X Chromosome


  • DNA Primers
  • RNA, Messenger
  • Receptors, Interleukin-2