Factors that affect the intracellular localization and trafficking of African horse sickness virus core protein, VP7.

African horse sickness virus (AHSV) VP7 is the major core protein of the virion. Apart from its role in virus assembly, VP7 forms crystalline-like particles during infection and when expressed in insect cells. The aim of this study was to investigate the process of VP7 crystalline-like particle formation. The intracellular distribution of VP7 was characterized in different systems and the association of VP7 with virus factories during AHSV infection was investigated. It was shown that the majority of VP7 is sequestered into these particles, and is therefore not available for new virion assembly. This is likely to have a negative impact on virus assembly and yield. By using specific markers and inhibitors of host trafficking pathways, VP7 localization was shown to be independent of host trafficking mechanisms and evaded host defenses against aggregation. Studying the process of VP7 crystalline-like particle formation will help us further understand AHSV replication and assembly.