A unique role for IL-23 in promoting cellular immunity

J Leukoc Biol. 2003 Jan;73(1):49-56. doi: 10.1189/jlb.0602326.


Recent discoveries of interleukin (IL)-23, its receptor, and its signal-transduction pathway add to our understanding of cellular immunity. IL-23 is a heterodimer, comprising IL-12 p40 and the recently cloned IL-23-specific p19 subunit. IL-23 uses many of the same signal-transduction components as IL-12, including IL-12Rbeta1, Janus kinase 2, Tyk2, signal transducer and activator of transcription (Stat)1, Stat3, Stat4, and Stat5. This may explain the similar actions of IL-12 and IL-23 in promoting cellular immunity by inducing interferon-gamma production and proliferative responses in target cells. Additionally, both cytokines promote the T helper cell type 1 costimulatory function of antigen-presenting cells. IL-23 does differ from IL-12 in the T cell subsets that it targets. Whereas IL-12 acts on naïve CD4+ T cells, IL-23 preferentially acts on memory CD4+ T cells. This review summarizes recent advances regarding IL-23, providing a functional and mechanistic basis for the unique niche that IL-23 occupies in cellular immunity.

Publication types

  • Review

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / immunology
  • Humans
  • Immunity, Cellular
  • Interleukin-12 / immunology
  • Interleukin-23
  • Interleukin-23 Subunit p19
  • Interleukins / immunology*
  • Interleukins / physiology
  • Mice
  • Signal Transduction / immunology


  • IL23A protein, human
  • Il23a protein, mouse
  • Interleukin-23
  • Interleukin-23 Subunit p19
  • Interleukins
  • Interleukin-12