Innate and Adaptive Interferons Suppress IL-1α and IL-1β Production by Distinct Pulmonary Myeloid Subsets during Mycobacterium tuberculosis Infection

SummaryInterleukin-1 (IL-1) receptor signaling is necessary for control of Mycobacterium tuberculosis (Mtb) infection, yet the role of its two ligands, IL-1α and IL-1β, and their regulation in vivo are poorly understood. Here, we showed that both IL-1α and IL-1β are critically required for host resistance and identified two multifunctional inflammatory monocyte-macrophage and DC populations that coexpressed both IL-1 species at the single-cell level in lungs of Mtb-infected mice. Moreover, we demonstrated that interferons (IFNs) played important roles in regulating IL-1 production by these cells in vivo. Type I interferons inhibited IL-1 production by both subsets whereas CD4+ T cell-derived IFN-γ selectively suppressed monocyte-macrophages. These data provide a cellular basis for both the anti-inflammatory effects of IFNs and probacterial functions of type I IFNs during Mtb infection and reveal differential regulation of IL-1 production by distinct cell populations as an additional layer of complexity in the activity of IL-1 in vivo.

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► Besides IL-1β, IL-1α is also required for IL-1R1-mediated host resistance to Mtb
► Both IL-1 species are coproduced by two subsets of inflammatory myeloid cells
► Type I IFN suppresses IL-1α and IL-1β production by inflammatory monocytes and DCs
► CD4 T cell-derived IFN-γ inhibits IL-1α and IL-1β production by inflammatory monocytes