Encephalomyocarditis Virus Entry Unveiled

Picornaviruses are a widespread group of pathogens that can cause diverse pathologies. Pathogenesis is thought to be driven by the tissue-specific tropisms displayed by these viruses. For example, many picornaviruses can infect the heart and cause viral myocarditis. Encephalomyocarditis virus (EMCV) is a rodent pathogen that causes myocarditis in rodent models and has been used to model this biology. However, the receptor and entry requirements for this virus are poorly understood. L. E. Bazzone, M. King, C. R. MacKay, P. P. Kyawe, et al. (mBio 10:e02734-18, 2019, https://doi.org/10.1128/mBio.02734-18) tackled this problem using CRISPR knockout screening in human cells that are susceptible to EMCV and identified ADAM9 as an essential entry factor for EMCV in mouse and human cells. Since the extracellular domain but not the enzymatic activity or intracellular domain is required for infection, the data suggest that ADAM9 acts as an entry receptor or at an early step in the process, shedding light on the biology of EMCV infection and pathogenesis.