The immunogenicity of plant-based COE-GCN4pII protein in pigs against the highly virulent porcine epidemic diarrhea virus strain from genotype 2

Thuong Thi Ho; Vy Thai Trinh; Hanh Xuan Tran; Phuong Thu Thi Le; Tra Thi Nguyen; Hang Thu Thi Hoang; Minh Dinh Pham; Udo Conrad; Ngoc Bich Pham; Ha Hoang Chu

doi:10.3389/fvets.2022.940395

The immunogenicity of plant-based COE-GCN4pII protein in pigs against the highly virulent porcine epidemic diarrhea virus strain from genotype 2

Front Vet Sci. 2022 Jul 28:9:940395. doi: 10.3389/fvets.2022.940395. eCollection 2022.

Authors

Thuong Thi Ho^{1

2}, Vy Thai Trinh^{1

2}, Hanh Xuan Tran³, Phuong Thu Thi Le³, Tra Thi Nguyen^{1

2}, Hang Thu Thi Hoang², Minh Dinh Pham², Udo Conrad⁴, Ngoc Bich Pham^{1

2}, Ha Hoang Chu^{1

2}

Affiliations

¹ Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
² Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
³ JSC Central Veterinary NAVETCO, Ho Chi Minh, Vietnam.
⁴ Department Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany.

Abstract

Porcine epidemic diarrhea virus (PEDV) is a serious infectious causative agent in swine, especially in neonatal piglets. PEDV genotype 2 (G2) strains, particularly G2a, were the primary causes of porcine epidemic diarrhea (PED) outbreaks in Vietnam. Here, we produced a plant-based CO-26K-equivalent epitope (COE) variant from a Vietnamese highly virulent PEDV strain belonging to genotype 2a (COE/G2a) and evaluated the protective efficacy of COE/G2a-GCN4pII protein (COE/G2a-pII) in piglets against the highly virulent PEDV G2a strain following passive immunity. The 5-day-old piglets had high levels of PEDV-specific IgG antibodies, COE-IgA specific antibodies, neutralizing antibodies, and IFN-γ responses. After virulent challenge experiments, all of these piglets survived and had normal clinical symptoms, no watery diarrhea in feces, and an increase in their body weight, while all of the negative control piglets died. These results suggest that the COE/G2a-pII protein produced in plants can be developed as a promising vaccine candidate to protect piglets against PEDV G2a infection in Vietnam.

Keywords: COE; GCN4-pII motif; PEDV genotype 2; passive immunity; piglet protection; plant-based vaccine.