An optimized protocol for purification of virus-like particles of foot-and-mouth disease virus produced in the baculovirus expression system

Foot-and-mouth disease is a highly endemic, economically significant disease of livestock population across the world. Higher antigenic variation and short-lived immunity possess the threat of its recurrent incidence. Developments are underway to produce bio-safe and more stable vaccines using virus-like particles to enhance immunity duration without handling live infectious viruses. Besides this, VLPs possess an inherent property of differentiation of infected and vaccinated animals (DIVA) as they do not carry any non-structural proteins along with them. Here we demonstrate such a bio-safe platform to produce VLPs using a baculovirus expression system and its efficient purification. The purification protocol combines the process of filtration and isodensity centrifugation to separate the assembled VLPs from the host cellular components and demonstrated the presence of pure and concentrated VLPs of expected buoyant density for further structural and functional studies.