Neomycin Exhibits Immunomodulatory and Antiviral Activity Against Influenza B Virus

Viral infections remain a global public health challenge. Stimulating the innate immune system is a potent therapeutic strategy that promotes pathogen clearance, directly impacting disease severity and clinical outcomes. Interferons and interferon-stimulated genes (ISGs) are critical components of this antiviral defense system. Neomycin, an aminoglycoside antibiotic, can induce ISG expression and help establish an antiviral state. In this study, we demonstrated that neomycin induces the production of pro-inflammatory cytokines (IL1β, TNFα, IL6, GM-CSF, and IFN-γ) in peripheral mononuclear blood cells (PBMCs) and activates key antiviral ISGs, including MxA, OAS1, and IRF7. The protein expression profiles elicited by neomycin were comparable to those induced by poly(I:C). Intranasal delivery of neomycin to CBA and BALB/c mice induced various ISGs in both the respiratory tract and splenic tissues. Prophylactic administration of neomycin significantly inhibited influenza B virus replication in the lung and nasal turbinates of CBA mice in a sublethal infection model. Overall, our data suggest that neomycin, when used prophylactically alone or combined with other antiviral strategies, shows considerable potential for the attenuation of influenza B virus infections.