Structure of human Aichi virus and implications for receptor binding

Area of Science:

• Virology
• Structural Biology
• Picornaviridae

Background:

• Aichi virus (AiV) is an understudied kobuvirus linked to severe gastroenteritis in young children.
• High seroprevalence of AiV underscores its public health importance, particularly in developing nations.
• Currently, no vaccines or effective antiviral therapies exist for AiV infections.

Discussion:

• The first high-resolution structure of a kobuvirus reveals unique features distinct from enteroviruses and cardioviruses.
• AiV possesses a shallow surface depression instead of the typical viral canyon, potentially altering receptor interactions.
• The VP0 capsid protein is not cleaved, resulting in an unusual internal structure within the VP2 barrel.

Key Insights:

• A novel polyproline helix at the VP1 C terminus, previously unseen in picornaviruses, was identified.
• This polyproline motif may play a role in host-cell attachment, as a corresponding peptide partially inhibited infectivity.
• The findings provide a structural basis for understanding AiV pathogenesis and host interactions.

Outlook:

• The determined AiV structure offers a foundation for identifying cellular receptors and developing targeted antiviral strategies.
• Further research into the polyproline helix function could reveal new avenues for therapeutic intervention.
• Structural insights may facilitate the design of novel vaccines against Aichi virus.