IL-2 and IL-7 induce heterodimerization of STAT5 isoforms in human peripheral blood T lymphoblasts

Cell Immunol. 1997 Nov 1;181(2):172-81. doi: 10.1006/cimm.1997.1208.


Despite differences in T cell responses induced by interleukin (IL)-2 and IL-7, both cytokines modulate T cell functions by activation of signal transducers and activators of transcription (STAT) proteins. We examined the contribution of the two isoforms of STAT5, STAT5A and STAT5B, to IL-2- and IL-7-induced activation of human peripheral blood T lymphoblasts. Both cytokines induced assembly of STAT5A and STAT5B containing complexes capable of binding to the interferon-gamma activation sequence (GAS), and these complexes rapidly translocated (within 1 min) into the nucleus of IL-2- or IL-7-treated cells. The kinetics of this translocation were delayed in IL-7-treated as compared to IL-2-treated cells. IL-2 and IL-7 were equivalent in their ability to induce tyrosine phosphorylation of STAT5A and STAT5B and to facilitate binding of these STATs to an immobilized GAS element. Both IL-2 and IL-7 induced substantial amounts of STAT5A/STAT5B heterodimerization. Moreover, we observed constitutive association of STAT3 with each STAT5 isomer. These data suggest that IL-2 and IL-7 induce assembly of STAT heterodimers in a similar manner and that subsequent cellular responses may be driven by induction of similar sets of genes.

Publication types

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

MeSH terms

  • Animals
  • Cell Nucleus / metabolism
  • Cells, Cultured
  • DNA / metabolism
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism*
  • Dimerization
  • Electrophoresis, Polyacrylamide Gel
  • Gene Expression Regulation / drug effects
  • Humans
  • Interleukin-2 / pharmacology*
  • Interleukin-7 / pharmacology*
  • Isoenzymes / chemistry
  • Isoenzymes / metabolism*
  • Mice
  • Milk Proteins*
  • Promoter Regions, Genetic / genetics
  • Protein Multimerization / drug effects
  • Recombinant Proteins / metabolism
  • Regulatory Sequences, Nucleic Acid
  • STAT5 Transcription Factor
  • Signal Transduction / drug effects
  • T-Lymphocytes / drug effects*
  • T-Lymphocytes / metabolism
  • Trans-Activators / chemistry
  • Trans-Activators / metabolism*
  • Tumor Suppressor Proteins


  • DNA-Binding Proteins
  • Interleukin-2
  • Interleukin-7
  • Isoenzymes
  • Milk Proteins
  • Recombinant Proteins
  • STAT5 Transcription Factor
  • STAT5A protein, human
  • STAT5B protein, human
  • Stat5a protein, mouse
  • Stat5b protein, mouse
  • Trans-Activators
  • Tumor Suppressor Proteins
  • DNA