title: Mycobacteria-infected dendritic cells attract neutrophils that produce IL-10 and specifically shut down Th17 CD4 T cells through their IL-10 receptor.
abstract: Neutrophils participate in the control of mycobacterial infection both by directly eliminating bacilli and by interacting with macrophages and dendritic cells (DCs). Despite host defenses, slow-growing mycobacteria can persist in the host for decades, mostly inside macrophages and DCs, and eventually destroy tissues after exacerbated inflammation. IL-17A-driven neutrophil recruitment may participate in this process. We report that mouse bone marrow-derived DCs infected with live Mycobacterium bovis Bacillus Calmette-Guérin (BCG) produced large amounts of CXCL1 and CXCL2, and attracted neutrophils. After physical contact with DCs infected with live BCG, the neutrophils produced large quantities of the immunosuppressive cytokine IL-10 via the MyD88 and spleen tyrosine kinase pathways. The CD11b integrin was involved in this neutrophil-DC interaction and allowed IL-10 production. TCR OVA transgenic mice immunized with a BCG strain producing OVA mounted an OVA-specific Th17 and Th1 CD4 response. Interestingly, IL-10-producing neutrophils specifically shut down IL-17A production by Th17 CD4 cells, but not IFN-γ production by Th1 cells. This was due to Th17 CD4 cell-restricted expression of the receptor for IL-10. After neutrophil depletion, total mouse lung cells produced less IL-10 but more IL-17A; IFN-γ production was not affected. Therefore, we suggest that during mycobacterial infection, regulatory neutrophils are instructed by infected reservoir DCs to produce IL-10 that specifically targets IL-10Rα-expressing Th17 CD4 T cells. This could be important to control the otherwise exuberant Th17 response.
authors.affiliation: Institut National de la Recherche Agronomique, Université de Tours, Unité Mixte de Recherches 1282, Infectiologie et Santé Publique, 37380 Nouzilly, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Doz
authors.forename: Robin
authors.initials: R
authors.lastname: Lombard
authors.forename: Florence
authors.initials: F
authors.lastname: Carreras
authors.forename: Dominique
authors.initials: D
authors.lastname: Buzoni-Gatel
authors.forename: Nathalie
authors.initials: N
authors.lastname: Winter
mesh_terms: D000818:Animals; D039481:CD11b Antigen / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism* / Q000382:microbiology; D005260:Female; D016753:Interleukin-10 / Q000096:biosynthesis*; D020381:Interleukin-17 / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D018448:Models, Immunological; D009163:Mycobacterium bovis / Q000276:immunology; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000378:metabolism; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D053701:Receptors, Interleukin-10 / Q000378:metabolism*; D000072377:Syk Kinase; D058504:Th17 Cells / Q000276:immunology* / Q000382:microbiology*; D014376:Tuberculosis / Q000662:veterinary
chemical_list: D039481:CD11b Antigen; D020381:Interleukin-17; D047908:Intracellular Signaling Peptides and Proteins; D053594:Myeloid Differentiation Factor 88; D053701:Receptors, Interleukin-10; D016753:Interleukin-10; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; C000606897:Syk protein, mouse