Description
Antibiotic-treated (ABX) mice exhibit an impaired innate and adaptive antiviral immune response and substantially delayed viral clearance following exposure to systemic LCMV or mucosal influenza virus. Genome-wide transcriptional profiling of macrophages isolated from ABX mice revealed decreased expression of genes associated with antiviral immunity. Moreover, macrophages from ABX mice exhibited defective responses to type I and type II IFNs and impaired capacity to limit viral replication. Collectively, these data indicate that commensal-derived signals provide tonic immune stimulation that establishes the activation threshold of the innate immune system required for optimal antiviral immunity.