Characterization of Enterovirus A71 entry factors in cell lines and Human Enteroids using CRISPR-Cas9 Knock-Out

Abstract

Enterovirus A71 (EV-A71), one of the main causative agents of hand, foot and mouth disease (HFMD), is a highly neurotoxic enterovirus belonging to the Picornaviridae family. EV-A71 results in outbreaks globally and is rising as a major public health concern. Despite its pathogenic potential, the entry pathway by which EV-A71 enters the host cell is still not fully understood. In this study, we characterized the role of two EV-A71 entry factors, SCARB2 and HSPG2, in cell lines and human intestinal organoids using CRISPR-Cas9 knock-out (KO) technology. Here, we show SCARB2 does not act as an entry receptor for EV-A71 as previously reported, since it is not involved in either binding nor internalization of viral particles. However, SCARB2 does play an essential role in later stages of EV-A71 infection, following internalization. Furthermore, HSPG2 is neither an entry receptor nor involved in EV-A71 infection in cell lines and human intestinal organoids. Our findings disprove the role of SCARB2 as an entry receptor and show HSPG2 as a non-essential factor for EV-A71 infection. This research further stresses the need to fully characterize the entry pathway of EV-A71, as the current understanding of viral pathogenesis is incomplete.