Type I Interferon Targets Alveolar Macrophages to Promote Bacterial Pneumonia after Viral Infection.

ABSTRACT: Exposure to influenza A virus, respiratory syncytial virus, and human metapneumovirus is well known to increase the risk of Streptococcus pneumoniae (SPn) pneumonia in humans. Type I IFN (IFN-I) is a hallmark response to acute viral infections, and alveolar macrophages (AMs) constitute the first line of airway defense against opportunistic bacteria. Our study reveals that virus-induced IFNAR1 (IFN-I receptor) signaling directly impairs AM-dependent antibacterial protection. Using Ifnar1 conditional knockout mouse models, in vivo antibodies, bone marrow chimeric mice, and AM reconstitution, we demonstrate that IFN-I intrinsically targets AMs to drive hypersusceptibility to SPn following influenza A virus infection. Importantly, we show that respiratory syn

SUBMITTER: Palani S 

PROVIDER: S-EPMC12334883 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature