Generation and Efficacy of Two Chimeric Viruses Derived from GPE- Vaccine Strain as Classical Swine Fever Vaccine Candidates

Loc Tan Huynh; Norikazu Isoda; Lim Yik Hew; Saho Ogino; Yume Mimura; Maya Kobayashi; Taksoo Kim; Tatsuya Nishi; Katsuhiko Fukai; Takahiro Hiono; Yoshihiro Sakoda

doi:10.3390/v15071587

Generation and Efficacy of Two Chimeric Viruses Derived from GPE^- Vaccine Strain as Classical Swine Fever Vaccine Candidates

Viruses. 2023 Jul 20;15(7):1587. doi: 10.3390/v15071587.

Authors

Loc Tan Huynh^{1

2}, Norikazu Isoda^{1

3

4

5}, Lim Yik Hew¹, Saho Ogino¹, Yume Mimura¹, Maya Kobayashi¹, Taksoo Kim¹, Tatsuya Nishi⁶, Katsuhiko Fukai⁶, Takahiro Hiono^{1

3

5}, Yoshihiro Sakoda^{1

3

4

5}

Affiliations

¹ Laboratory of Microbiology, Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Hokkaido, Japan.
² Faculty of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho 900000, Vietnam.
³ One Health Research Center, Hokkaido University, Sapporo 060-0818, Hokkaido, Japan.
⁴ International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Hokkaido, Japan.
⁵ Institute for Vaccine Research and Development (HU-IVReD), Hokkaido University, Sapporo 001-0021, Hokkaido, Japan.
⁶ Kodaira Research Station, National Institute of Animal Health, National Agriculture and Food Research Organization, Kodaira 187-0022, Tokyo, Japan.

Abstract

A previous study proved that vGPE^- mainly maintains the properties of classical swine fever (CSF) virus, which is comparable to the GPE^- vaccine seed and is a potentially valuable backbone for developing a CSF marker vaccine. Chimeric viruses were constructed based on an infectious cDNA clone derived from the live attenuated GPE^- vaccine strain as novel CSF vaccine candidates that potentially meet the concept of differentiating infected from vaccinated animals (DIVA) by substituting the glycoprotein E^rns of the GPE^- vaccine strain with the corresponding region of non-CSF pestiviruses, either pronghorn antelope pestivirus (PAPeV) or Phocoena pestivirus (PhoPeV). High viral growth and genetic stability after serial passages of the chimeric viruses, namely vGPE^-/PAPeV E^rns and vGPE^-/PhoPeV E^rns, were confirmed in vitro. In vivo investigation revealed that two chimeric viruses had comparable immunogenicity and safety profiles to the vGPE^- vaccine strain. Vaccination at a dose of 10^4.0 TCID₅₀ with either vGPE^-/PAPeV E^rns or vGPE^-/PhoPeV E^rns conferred complete protection for pigs against the CSF virus challenge in the early stage of immunization. In conclusion, the characteristics of vGPE^-/PAPeV E^rns and vGPE^-/PhoPeV E^rns affirmed their properties, as the vGPE^- vaccine strain, positioning them as ideal candidates for future development of a CSF marker vaccine.

Keywords: GPE−; chimeric virus; classical swine fever virus; pestivirus; vaccine efficacy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Antibodies, Viral
Classical Swine Fever Virus* / genetics
Classical Swine Fever*
Pestivirus* / genetics
Swine
Vaccines, Attenuated
Vaccines, Marker
Viral Vaccines*

Substances

Vaccines, Marker
Antibodies, Viral
Viral Vaccines
Vaccines, Attenuated

Grants and funding

This work was conducted under the research project “Regulatory Research Projects for Food Safety, Animal Health and Plant Protection (JPJ008617.20319390)”, funded by the Ministry of Agriculture, Forestry and Fisheries of Japan. The work was also partly funded by the Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan (MEXT KAKENHI grant number JP22H02504). Support was also provided by the WISE Grant-in-Aid for Graduate Students, Program for One Health Frontier of the Graduate School of Excellence, Hokkaido University (grant number PH36210001).