title: IFNgamma enhances IL-23 production during Francisella infection of human monocytes.
abstract: We previously demonstrated that monocytes produce IL-23 during Francisella infection, and that IL-23 induces IFNgamma from NK cells. Here, we demonstrate that IFNgamma-priming of monocytes enhances IL-23 production during Francisella infection. This effect was seen on the IL12/23 p40 subunit. Induction of IL-12/23 p40 is reported to be enhanced by IRF-1 and IRF-8. Consistently, microarray analysis of IFNgamma-treated monocytes revealed a significant induction of the IRFs. Interestingly, IFNgamma-primed monocytes produced IL-12 p70, a more potent inducer of IFNgamma than IL-23. We propose that there exists an amplification loop between monocyte IL-23 and NK/T cell IFNgamma that leads to IL-12 p70 production.
authors.affiliation: Division of Pulmonary and Critical Care, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Butchar
authors.forename: Kishore V L
authors.initials: KV
authors.lastname: Parsa
authors.forename: Clay B
authors.initials: CB
authors.lastname: Marsh
authors.forename: Susheela
authors.initials: S
authors.lastname: Tridandapani
mesh_terms: D002460:Cell Line; D005604:Francisella tularensis; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D018664:Interleukin-12 / Q000096:biosynthesis; D053762:Interleukin-12 Subunit p40 / Q000096:biosynthesis; D053759:Interleukin-23 / Q000096:biosynthesis*; D009000:Monocytes / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology*
chemical_list: D053762:Interleukin-12 Subunit p40; D053759:Interleukin-23; D018664:Interleukin-12; D007371:Interferon-gamma