title: A unique role for IL-23 in promoting cellular immunity.
abstract: 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.
authors.affiliation: Laboratory of Cell Biology, Division of Monoclonal Antibodies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
authors.forename: Carla S R
authors.initials: CS
authors.lastname: Lankford
authors.forename: David M
authors.initials: DM
authors.lastname: Frucht
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D018664:Interleukin-12 / Q000276:immunology; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D007378:Interleukins / Q000276:immunology* / Q000502:physiology; D051379:Mice; D015398:Signal Transduction / Q000276:immunology
chemical_list: C508840:IL23A protein, human; C508841:Il23a protein, mouse; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D007378:Interleukins; D018664:Interleukin-12