Antiviral Activity of the MEK1/2 Inhibitor Trametinib Against Lymphocytic Choriomeningitis Virus

ABSTRACT The lymphocytic choriomeningitis virus (LCMV) is a widespread pathogen that causes mild‐to‐severe infections to severe outcomes. In this study, we explored the potential of trametinib, a mitogen‐activated protein kinase (MAPK) inhibitor, as an antiviral agent against LCMV. Trametinib demonstrated significant antiviral activity against two distinct LCMV strains, Armstrong and Cl13, with promising half‐maximal inhibitory concentrations (IC 50 ) and selectivity indices (SI) indicating its potency and safety profile. Mechanistic investigations revealed that trametinib interfered with multiple stages of the LCMV life cycle, including membrane fusion and genomic replication, leading to the robust inhibition of viral proliferation. Furthermore, trametinib disrupted the MEK/ERK signaling pathway, which is crucial for LCMV infection. In both in vitro and in vivo experiments, trametinib effectively reduced viral loads and mitigated pathological damage to the spleen and liver tissues. Overall, our findings suggest that trametinib is a promising novel therapeutic option for combating LCMV infection by targeting key stages of the viral life cycle and disrupting host cellular signaling pathways. Further exploration of the antiviral properties of trametinib is likely to pave the way for its clinical development as a treatment for LCMV infections.