Surface-displayed porcine reproductive and respiratory syndrome virus from cell culture onto gram-positive enhancer matrix particles.

Vaccine immunization is now one of the most effective ways to control porcine reproductive and respiratory syndrome virus (PRRSV) infection. Impurity is one of the main factors affecting vaccine safety and efficacy. Here we present a novel innovative PRRSV purification approach based on surface display technology. First， a bifunctional protein PA-GRFT (protein anchor-griffithsin)， the crucial factor in the purification process， was successfully produced in Escherichia coli yielding 80 mg/L of broth culture. Then PRRSV purification was performed by incubation of PA-GRFT with PRRSV and gram-positive enhancer matrix (GEM) particles， followed by centrifugation to collect virions loaded onto GEM particles. Our results showed that most of the bulk impurities had been removed， and PA-GRFT could capture PRRSV onto GEM particles. Our lactic acid bacteria-based purification method， which is promising as ease of operation， low cost and easy to scale-up， may represent a candidate method for the large-scale purification of this virus for vaccine production.