Recombinant adenovirus carrying a core neutralizing epitope of porcine epidemic diarrhea virus and heat-labile enterotoxin B of Escherichia coli as a mucosal vaccine

Abstract

Porcine epidemic diarrhea virus (PEDV) targets the intestinal mucosa in pigs. To protect against PEDV invasion, a mucosal vaccine is utilized effectively. In this study, we generated a recombinant adenovirus vaccine encoding the heat-labile enterotoxin B (LTB) and the core neutralizing epitope (COE) of PEDV (rAd-LTB-COE). The fusion protein LTB-COE was successfully expressed by the recombinant adenovirus in HEK293 cells, and the immunogenicity of the vaccine candidate was assessed in BALB/c mice and piglets. Three intramuscular or oral vaccinations with rAd-LTB-COE at two-week intervals induced robust humoral and mucosal immune responses. Moreover, a cell-mediated immune response was promoted in immunized mice, and the neutralizing antibody inhibited both the vaccine strain and the emerging PEDV isolate. Immunization experiments in piglets revealed that rAd-LTB-COE was immunogenic and induced good immune responses in piglets. Further studies are required to evaluate the efficacy of rAd-LTB-COE against a highly virulent PEDV challenge.

Future perspectives on swine viral vaccines: where are we headed?

“…This resulted in induction of ASFV specific antibody and T-cell responses demonstrating the feasibility of generating a safe and immunogenic vaccine against this devastating pig disease [ 79 ]. Adenovirus vectors have been experimentally used in pigs to protect them against PRRSV [ 80 ] or PEDV in the form of a mucosal vaccine [ 81 ]. The adenovirus platform was also recently used to develop PRRSV species 2 subunit vaccines by expressing swine leukocyte antigen (SLA) class I and class II allele-specific antigens [ 82 ].…”

Coronavirus Pandemic—Therapy and Vaccines

“…In many cases, strong humoral and cellular immune responses have been observed as well as protection against challenges with lethal doses of pathogenic viruses. In the context of coronaviruses, a recombinant adenovirus vector expressing the heat-labile enterotoxin B (LTB) and the core neutralizing epitope (COE) of PEDV was administered intramuscularly or orally into BALB/c mice and piglets [150]. Three vaccinations at two-week intervals generated robust humoral and cellular immune responses.…”

Porcine deltacoronavirus and its prevalence in China: a review of epidemiology, evolution, and vaccine development

“…Porcine adenovirus was used to deliver the core neutralizing epitope of PEDV, and this resulted in robust humoral and mucosal immune responses in piglets [ 100 ]. A recombinant vesicular stomatitis virus expressing the PEDV spike protein was developed, and sows immunized with this recombinant vaccine provided protective lactogenic immunity against a virulent G2b PEDV challenge to their piglets [ 104 ].…”

“…Vectored vaccines function as viral gene delivery systems that rely on a host viral genome from a different virus, such as adenovirus, poxvirus, measles virus, parainfluenza virus, rabies virus, or vesicular stomatitis virus, and they have been used in the development of vaccines for CoVs [100][101][102][103][104][105][106].…”