Evaluation of the Mucosal Immunity Effect of Bovine Viral Diarrhea Virus Subunit Vaccine E2Fc and E2Ft

Abstract

Classified as a class B infectious disease by the World Organization for Animal Health (OIE), bovine viral diarrhea/mucosal disease is an acute, highly contagious disease caused by the bovine viral diarrhea virus (BVDV). Sporadic endemics of BVDV often lead to huge economic losses to the dairy and beef industries. To shed light on the prevention and control of BVDV, we developed two novel subunit vaccines by expressing bovine viral diarrhea virus E2 fusion recombinant proteins (E2Fc and E2Ft) through suspended HEK293 cells. We also evaluated the immune effects of the vaccines. The results showed that both subunit vaccines induced an intense mucosal immune response in calves. Mechanistically, E2Fc bonded to the Fc γ receptor (FcγRI) on antigen-presenting cells (APCs) and promoted IgA secretion, leading to a stronger T-cell immune response (Th1 type). The neutralizing antibody titer stimulated by the mucosal-immunized E2Fc subunit vaccine reached 1:64, which was higher than that of the E2Ft subunit vaccine and that of the intramuscular inactivated vaccine. The two novel subunit vaccines for mucosal immunity developed in this study, E2Fc and E2Ft, can be further used as new strategies to control BVDV by enhancing cellular and humoral immunity.

Immune evasion strategies of bovine viral diarrhea virus

“…However, the neutralizing activity of antibodies targeting E rns was limited ( Donis, 1995 ). E2 was the largest glycoprotein and antigenic target for the induction of neutralizing antibodies ( Liang et al., 2005 ; Li et al., 2013 ; Cheng et al., 2023 ). After natural infection or inoculation with a modified live vaccine, the B cell response, as measured by serum antibody levels, was predominantly directed against viral E2 and NS2/3 proteins, with lesser responses directed against E rns and E1 proteins.…”

The combination of vaccines and adjuvants to prevent the occurrence of high incidence of infectious diseases in bovine

“…Subunit vaccines contain only a part of the pathogen and lack viral nucleic acids, making them highly safe and non-pathogenic ( 26 ). E2Fc and E2Ft are subunit vaccines for BVDV ( 27 ). Despite their high safety profile, subunit vaccines usually show lower immunogenicity compared to other types of vaccines and therefore require multiple doses or the use of adjuvants.…”