Viral Protein VP1 Virus-like Particles (VLP) of CVB4 Induces Protective Immunity against Lethal Challenges with Diabetogenic E2 and Wild Type JBV Strains in Mice Model

Several epidemiological studies demonstrated that coxsackievirus B4 (CVB4) causes viral pancreatitis and can ultimately result in type 1 diabetes mellitus (T1D). Prevention of CVB4 infection is therefore highly desirable. There is currently no vaccine or antiviral therapeutic reagent in clinical use. VLP are structurally similar to native virus particles and therefore are far better immunogens than any other subunit vaccines. Many studies have shown the potential of capsid protein VP1 on providing protective effects from different viral strains. In this study, we contributed towards the development of a CVB4 VLP-based vaccine from the total protein VP1 of the diabetogenic CVB4E2 strain and assessed whether it could induce a protective immunity against both the wild-type CVB4JBV and the diabetogenic CVB4E2 strains in mice model. Serum samples, taken from mice immunized with VLP, were assayed in vitro for their anti-CVB4 neutralizing activity and in vivo for protective activity. We show that VLP vaccine generates robust immune responses that protect mice from lethal challenges. Results demonstrate that CVB4 VP1 capsid proteins expressed in insect cells have the intrinsic capacity to assemble into non-infectious VLP, which afforded protection from CVB4 infection to mice when used as a vaccine.