title: Analysis of the activation profile of dendritic cells derived from the bone marrow of interleukin-12/interleukin-23-deficient mice.
abstract: We have previously shown that macrophages from interleukin (IL)-12p40 gene knockout (IL-12/IL-23-/-) mice have a bias towards the M2 activation profile, spontaneously secreting large quantities of transforming growth factor-beta1 (TGF-beta1) and producing low levels of nitric oxide (NO) in response to lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). To verify whether the activation profile of dendritic cells (DCs) is also influenced by the absence of IL-12/IL-23, bone marrow-derived DCs from IL-12/IL-23-/- and C57BL/6 mice were evaluated. At first we noticed that approximately 50% of the C57BL/6 DCs were dead after LPS-induced maturation, whereas the mortality of IL-12/IL-23-/- DCs was < 10%, a protective effect that diminished when recombinant IL-12 (rIL-12) was added during maturation. Similarly to macrophages, mature IL-12/IL-23-/- DCs (mDCs) produced higher levels of TGF-beta1 and lower levels of NO than C57BL/6 mDCs. NO release was IFN-gamma-dependent, as evidenced by the poor response of IFN-gamma-/- and IL-12/IL-23-/-IFN-gamma-/- mDCs. Nevertheless, IFN-gamma deficiency was not the sole reason for the weak NO response observed in the absence of IL-12/IL-23. The high level of TGF-beta1 secretion by IL-12/IL-23-/- mDCs could explain why exogenous IFN-gamma partially restored the NO production of IFN-gamma-/- mDCs, while IL-12/IL-23-/- IFN-gamma-/- mDCs remained unresponsive. We also showed that CD4+ T-cell proliferation was inhibited by C57BL/6 mDCs, but not by IL-12/IL-23-/- mDCs. IFN-gamma and NO appear to mediate this antiproliferative effect because this effect was not observed in the presence of mDCs from IFN-gamma-/- or IL-12/IL-23-/- IFN-gamma-/- mice and it was attenuated by aminoguanidine. We conclude that the presence of IL-12/IL-23 during LPS-induced maturation influences the activation profile of DCs by a mechanism that is, only in part, IFN-gamma dependent.
authors.affiliation: Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil. krbastos@usp.br
authors.forename: Karina R B
authors.initials: KR
authors.lastname: Bastos
authors.forename: Luciana
authors.initials: L
authors.lastname: de Deus Vieira de Moraes
authors.forename: Cláudia A
authors.initials: CA
authors.lastname: Zago
authors.forename: Cláudio R F
authors.initials: CR
authors.lastname: Marinho
authors.forename: Momtchilo
authors.initials: M
authors.lastname: Russo
authors.forename: José M M
authors.initials: JM
authors.lastname: Alvarez
authors.forename: Maria R
authors.initials: MR
authors.lastname: D'Império Lima
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology*; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000172:deficiency / Q000276:immunology; D018664:Interleukin-12 / Q000172:deficiency* / Q000276:immunology; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D007378:Interleukins / Q000172:deficiency / Q000276:immunology; D008213:Lymphocyte Activation / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009569:Nitric Oxide / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: C508841:Il23a protein, mouse; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D007378:Interleukins; D016212:Transforming Growth Factor beta; D018664:Interleukin-12; D009569:Nitric Oxide; D007371:Interferon-gamma