title: Early interleukin 12 production by macrophages in response to mycobacterial infection depends on interferon gamma and tumor necrosis factor alpha.
abstract: Interleukin 12 (IL-12) produced by macrophages immediately after infection is considered essential for activation of a protective immune response against intracellular pathogens. In the murine Mycobacterium bovis Bacillus Calmette-Guérin (BCG) model we assessed whether early IL-12 production by macrophages depends on other cytokines. In vitro, murine bone marrow-derived macrophages produced IL-12 after infection with viable M. bovis BCG or stimulation with LPS, however, priming with recombinant interferon gamma (rIFN-gamma) was necessary. In addition, IL-12 production by these macrophages was blocked by specific anti-tumor necrosis factor alpha (TNF-alpha) antiserum. Macrophages from gene deletion mutant mice lacking either the IFN-gamma receptor or the TNF receptor 1 (p55) failed to produce IL-12 in vitro after stimulation with rIFN-gamma and mycobacterial infection. In vivo, IL-12 production was induced in spleens of immunocompetent mice early during M. bovis BCG infection but not in those of mutant mice lacking the receptors for IFN-gamma or TNF. Our results show that IL-12 production by macrophages in response to mycobacterial infection depends on IFN-gamma and TNF. Hence, IL-12 is not the first cytokine produced in mycobacterial infections.
authors.affiliation: Department of Immunology, University of Ulm, Germany.
authors.forename: I E
authors.initials: IE
authors.lastname: Flesch
authors.forename: J H
authors.initials: JH
authors.lastname: Hess
authors.forename: S
authors.initials: S
authors.lastname: Huang
authors.forename: M
authors.initials: M
authors.lastname: Aguet
authors.forename: J
authors.initials: J
authors.lastname: Rothe
authors.forename: H
authors.initials: H
authors.lastname: Bluethmann
authors.forename: S H
authors.initials: SH
authors.lastname: Kaufmann
mesh_terms: D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D005260:Female; D007371:Interferon-gamma / Q000494:pharmacology / Q000502:physiology*; D018664:Interleukin-12 / Q000096:biosynthesis*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009164:Mycobacterium Infections / Q000276:immunology*; D009163:Mycobacterium bovis; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
chemical_list: D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D007371:Interferon-gamma