Production of foot-and-mouth disease virus SAT2 VP1 protein

Michael Crampton,Mpho Victoria Mamabolo,Jacques Theron,Francois Maree

doi:10.1186/s13568-019-0938-7

Abstract

The seven serotypes of foot-and-mouth disease virus (FMDV) differ on the surface exposed regions on the VP1, 2 and 3 proteins. Amongst the three, the VP1 protein has been produced the most for use in serotyping assays for some of the Euro-Asian serotypes. In this study the VP1 protein of the FMDV SAT2/ZIM/7/83 was expressed in Escherichia coli BL21 cells in Luria broth and EnPresso® B media in shake flasks. Production was further developed and the VP1 protein was produced at 2.15 g L−1 in fed-batch fermentations at 2 L scale. The protein formed insoluble inclusion bodies that were isolated, denatured and refolded. When tested in ELISA, the protein was found to be highly reactive with serum from a SAT2 vaccinated guinea pig, and not reactive to SAT1 and SAT3 antisera. These results open avenues to evaluate recombinantly expressed VP1 proteins for differentiation of the three Southern African Territories serotypes of FMDV that co-occur in Southern and East Africa. In addition, this could mitigate the need for employing virus as reagent, or having to raise reagent antibodies.

Highlights

Over the past 30 years, there have been efforts to produce the VP1 protein and peptides of the foot-and-mouth disease virus (FMDV) for application in diagnostics or as a vaccine for controlling the economically important and highly infectious foot-and-mouth disease (FMD)
Luria Bertani (LB) medium allows bacteria to grow in a batch mode, whereas the latter medium allows bacteria to grow in a fed-batch mode where the carbon source from the complex medium is released over time
Factors that are known to improve the solubility of proteins such as fusing the target protein to negatively charged fusion partners, co-expression of the target protein with chaperone sets, lower growth temperatures and inducer concentrations, using different media, expression of the protein in the E. coli pLysS strain were evaluated for VP1 expression in E. coli

Summary

Introduction

Over the past 30 years, there have been efforts to produce the VP1 protein and peptides of the foot-and-mouth disease virus (FMDV) for application in diagnostics or as a vaccine for controlling the economically important and highly infectious foot-and-mouth disease (FMD). Diagnosis of FMD involve methods that make use of the inactivated virus antigen or, raising of reagent antibodies in laboratory animals. Both vaccine and diagnostic reagents must be produced in high containment facilities to avoid the risk of virus escaping from production facilities to the surrounding environment (Cottam et al 2008). The VP1 protein plays a significant role in serotype specificity in the seven FMDV serotypes (Cheung et al 1983; Jackson et al 2003; Parry et al 1990) This led to the search for inexpensive and alternative methods of diagnosing FMD. The immune response of these experimental animals and natural hosts produced virus neutralizing antibodies and protection from viral challenge (Grubman et al 1993; Wigdorovitz et al 1999a, b)

Methods

Results

Conclusion