Ebola Virus Entry: A Curious and Complex Series of Events

Ebola virus (EBOV) belongs to the Filoviridae family of negative-sense RNA viruses. Since its identification in 1976, sporadic outbreaks have occurred in Central Africa. The 2014 outbreak in West Africa provides evidence that EBOV is emerging into new geographic regions. While previous outbreaks have been confined to small areas, the most recent outbreak is atypically widespread with over 25,000 people infected. Evidence from the limited-sequence studies that have been published suggests that the outbreak resulted from a single reservoir-to-human transmission event and subsequent human-to-human spread [1]. As neither an EBOV vaccine nor antivirals are currently available, this outbreak highlights the critical need for the development of effective vaccines and therapeutics. Infection is initiated by virions entering dendritic cells, macrophages, and, perhaps, hepatocytes [2]. Virus replication in these cells is thought to be critical for initiation of systemic infection, leading to virus spread to new sites with infection of additional cell populations. Thus, a better understanding of virus entry will not only provide insight into both host cell and virus biology, but also elucidate therapeutic targets. Here we provide a brief overview of the current understanding of EBOV entry and identify important questions that remain unanswered in the field.