The sticky business of Alphavirus capsid–host interactions

Alphaviruses are a serious threat to global health and can cause lethal encephalitic or arthritogenic disease in humans and animals. As there are no licensed antivirals, it is critical to improve our understanding of alphavirus interactions with the host cell. Here, we focus on the essential alphavirus protein capsid. While its roles in genome packaging and virus assembly have been well-studied, much less is known about capsid's interactions with host proteins and their functional relevance for infection. Recently, several new capsid interactor candidates were identified, collectively emphasising the complexity of capsid–host biology. In this review we summarise these novel interactor candidates, highlight capsid's emerging role in immune evasion, and discuss the challenges and opportunities arising from capsid–host interactions.