A Vaccine Strain of the A/ASIA/Sea-97 Lineage of Foot-and-Mouth Disease Virus with a Single Amino Acid Substitution in the P1 Region That Is Adapted to Suspension Culture Provides High Immunogenicity.

Min Ja Lee,Byounghan Kim,Ji-Hyeon Hwang,Su-Mi Kim,Gyeongmin Lee,Aro Kim,Jong-Hyeon Park

doi:10.3390/vaccines9040308

Abstract

There are seven viral serotypes of foot-and-mouth disease virus (FMDV): A, O, C, Asia 1, and Southern African Territories 1, 2, and 3 (SAT 1–3). Unlike serotype O FMDV vaccine strains, vaccine strains of serotype A FMDV do not provide broad-range cross-reactivity in serological matching tests with field isolates. Therefore, the topotype/lineage vaccine strain circulating in many countries and a highly immunogenic strain might be advantageous to control serotype A FMDV. We developed a new vaccine strain, A/SKR/Yeoncheon/2017 (A-1), which belongs to the A/ASIA/Sea-97 lineage that frequently occurs in Asian countries. Using virus plaque purification, we selected a vaccine virus with high antigen productivity and the lowest numbers of P1 mutations among cell-adapted virus populations. The A/SKR/Yeoncheon/2017 (A-1) vaccine strain has a single amino acid mutation, VP2 E82K, in the P1 region, and it is perfectly adapted to suspension culture. The A/SKR/Yeoncheon/2017 (A-1) experimental vaccine conferred high immunogenicity in pigs. The vaccine strain was serologically matched with various field isolates in two-dimensional virus neutralization tests using bovine serum. Vaccinated mice were protected against an A/MAY/97 virus that was serologically mismatched with the vaccine strain. Thus, A/SKR/Yeoncheon/2017 (A-1) might be a promising vaccine candidate for protection against the emerging FMDV serotype A in Asia.

Highlights

Foot-and-mouth disease (FMD) is an acute contagious disease that affects clovenhoofed animals such as cows, pigs, sheep, goats, and deer
We developed a novel vaccine strain using the A/SKR/Yeoncheon/2017 isolate, which belongs to the A/ASIA/Sea-97 lineage, a G2 sublineage circulating in the pool 1 region
We showed that a A/SKR/Yeoncheon/2017 (A-1) vaccine strain harboring only the VP2 E82K substitution in the P1 region uses heparan sulfate (HS) as a receptor in baby hamster kidney (BHK)-21 suspension cells and that its 146S antigen production was suitable for large-scale production as the purified 146S antigen was > 2 μg/mL of culture supernatant

Summary

Introduction

Foot-and-mouth disease (FMD) is an acute contagious disease that affects clovenhoofed animals such as cows, pigs, sheep, goats, and deer. It induces fever; lameness; and vesicles on the mouth, tongue, snout, teats, and feet [1,2]. The FMDV, O1 Manisa, and O PanAsia vaccine strains of serotype O provide broad-spectrum protection. Vaccine strains of serotype A FMDV do not provide broad-range cross-reactivity in serological matching tests with field isolates because unlike serotype O, serotype A FMDV is antigenically diverse [4,5,6]. The topotype/lineage vaccine strain circulating in many countries might be advantageous to control serotype A FMDV. More immunogenic vaccines are necessary to improve the range of protection [7]

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Discussion

Conclusion