  Myeloid hypoxia-inducible factor 1alpha prevents airway allergy in mice through macrophage-mediated immunoregulationToussaint, Marie  ; Fievez, Laurence ; Drion, Pierre et alin Mucosal Immunology (2012) Hypoxia-inducible factor (HIF) has important roles in promoting pro-inflammatory and bactericidal functions in myeloid cells. Conditional genetic ablation of its major subunit Hif1alpha in the myeloid ... [more ▼] Hypoxia-inducible factor (HIF) has important roles in promoting pro-inflammatory and bactericidal functions in myeloid cells. Conditional genetic ablation of its major subunit Hif1alpha in the myeloid lineage consequently results in decreased inflammatory responses in classical models of acute inflammation in mice. By contrast, we report here that mice conditionally deficient for Hif1alpha in myeloid cells display enhanced sensitivity to the development of airway allergy to experimental allergens and house-dust mite antigens. We support that upon allergen exposure, MyD88-dependent upregulation of Hif1alpha boosts the expression of the immunosuppressive cytokine interleukin (IL)-10 by lung interstitial macrophages (IMs). Hif1alpha-dependent IL-10 secretion is required for IMs to block allergen-induced dendritic cell activation and consequently for preventing the development of allergen-specific T-helper cell responses upon allergen exposure. Thus, this study supports that, in addition to its known pro-inflammatory activities, myeloid Hif1alpha possesses immunoregulatory functions implicated in the prevention of airway allergy. [less ▲] Detailed reference viewed: 9 (2 ULg)IL-4Ralpha-responsive smooth muscle cells contribute to initiation of T(H)2 immunity and pulmonary pathology in Nippostrongylus brasiliensis infections.; ; et al in Mucosal immunology (2010), 4(1), 83-92 Nippostrongylus brasiliensis infections generate pulmonary pathologies that can be associated with strong T(H)2 polarization of the host's immune response. We present data demonstrating N. brasiliensis ... [more ▼] Nippostrongylus brasiliensis infections generate pulmonary pathologies that can be associated with strong T(H)2 polarization of the host's immune response. We present data demonstrating N. brasiliensis-driven airway mucus production to be dependent on smooth muscle cell interleukin 4 receptor-alpha (IL-4Ralpha) responsiveness. At days 7 and 10 post infection (PI), significant airway mucus production was found in IL-4Ralpha(-/lox) control mice, whereas global knockout (IL-4Ralpha(-/-)) and smooth muscle-specific IL-4Ralpha-deficient mice (SM-MHC(Cre) IL-4Ralpha(-/lox)) showed reduced airway mucus responses. Furthermore, interleukin (IL)-13 and IL-5 cytokine production in SM-MHC(Cre) IL-4Ralpha(-/lox) mice was impaired along with a transient reduction in T-cell numbers in the lung. In vitro treatment of smooth muscle cells with secreted N. brasiliensis excretory-secretory antigen (NES) induced IL-6 production. Decreased protein kinase C (PKC)-dependent smooth muscle cell proliferation associated with cell cycle arrest was found in cells stimulated with NES. Together, these data demonstrate that both IL-4Ralpha and NES-driven responses by smooth muscle cells make important contributions in initiating T(H)2 responses against N. brasiliensis infections.Mucosal Immunology advance online publication 25 August 2010. doi:10.1038/mi.2010.46. [less ▲] Detailed reference viewed: 17 (3 ULg) |
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