Marc Guimera Busquets, The Pirbright Institute

Rosie Hobbs (1), Laura Tugwell (1), Karin Darpel (1)(2), Laura Jones (1), Christopher Sanders (1), Marc Guimera Busquets (1) (1) The Pirbright Institute, Woking, UK (2) Institute of Virology and Immunology, Mittelhäusern, Switzerland

Virus Replication: Entry, Exit and Everything in Between

Bluetongue virus (BTV) is an arthropod-borne virus that causes a hemorrhagic disease in ruminants and is transmitted between susceptible hosts by Culicoides biting midges. Different BTV strains display different infection and dissemination rates in Culicoides. Furthermore, serine proteases, including those from the gut and the saliva of Culicoides, can cleave BTV particles modifying their infectiousness in the vector. Here, viral particles from several BTV strains were cleaved with proteases, and viral replication in vitro and in adult Culicoides was investigated. For specific BTV strains, generation of cleaved viral particles resulted in an increase in infectivity both in vitro and in vivo compared to their respective uncleaved particles. The role and influence of Culicoides gut proteases on viral infection rates was also assessed. All in all, this work highlighted the complex genetic and structural diversity in BTV and the influence of such complexity on Culicoides infection.