A Recombinant Turkey Herpesvirus Expressing the F Protein of Newcastle Disease Virus Genotype XII Generated by NHEJ-CRISPR/Cas9 and Cre-LoxP Systems Confers Protection against Genotype XII Challenge in Chickens

Abstract

In this study, we developed a new recombinant virus rHVT-F using a Turkey herpesvirus (HVT) vector, expressing the fusion (F) protein of the genotype XII Newcastle disease virus (NDV) circulating in Peru. We evaluated the viral shedding and efficacy against the NDV genotype XII challenge in specific pathogen-free (SPF) chickens. The F protein expression cassette was inserted in the unique long (UL) UL45–UL46 intergenic locus of the HVT genome by utilizing a clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 gene-editing technology via a non-homologous end joining (NHEJ) repair pathway. The rHVT-F virus, which expressed the F protein stably in vitro and in vivo, showed similar growth kinetics to the wild-type HVT (wtHVT) virus. The F protein expression of the rHVT-F virus was detected by an indirect immunofluorescence assay (IFA), Western blotting, and a flow cytometry assay. The presence of an NDV-specific IgY antibody was detected in serum samples by an enzyme-linked immunosorbent assay (ELISA) in SPF chickens vaccinated with the rHVT-F virus. In the challenge experiment, the rHVT-F vaccine fully protects a high, and significantly reduced, virus shedding in oral at 5 days post-challenge (dpc). In conclusion, this new rHVT-F vaccine candidate is capable of fully protecting SPF chickens against the genotype XII challenge.

Efficacy of Commercial (HVT-ND) Vector Vaccine Against Newcastle Disease Virus Genotype ‎VII.1.1 Challenge in Commercial Broiler Chickens

“…Versus very high level of viral shedding in G6 (nonvaccinated challenged).Upon that, high protection level based on viral shedding was achieved in G3 vaccinated by combination of vector HVT-ND at 1 day of age, lives NDV at 1&14 and inactivated NDV vaccine at 7 days of age,before challenge, this group had significant antibody titers. The number of infected birds and the amount of vNDV shed decreased as humoral antibody levels rose in vaccinated birds as reported by (Perozo et al, 2012).Our findings were consistent with those of Palya et al (2021), andCalderón et al (2022) also produced a new recombinant virus called rHVT-F by using a Turkey herpesvirus (HVT) vector and expressing the fusion (F) protein of genotype XII and found similar results.…”

Long-Term Protection against Virulent Newcastle Disease Virus (NDV) in Chickens Immunized with a Single Dose of Recombinant Turkey Herpesvirus Expressing NDV F Protein

“…For instance, Jia et al constructed an HVT ND vaccine that expresses the F protein of genotype VII NDV at the US2 site, providing a 70% protection rate against homologous NDV strains at 5 wpv [25]. Calderón et al constructed another HVT ND vaccine that expresses the F protein of the prevalent Peruvian strain (genotype XII) at the UL45/UL46 site, achieving a 100% protection rate against homologous NDV strains at 7 wpv [26]. However, the early protection effect and the long-term protection of both vaccines remain to be clarified.…”

“…In contrast, the rHVT-opti-F vaccine constructed by Jia et al [25] induced only 40% antibody positivity in immunized SPF chickens at 4 wpv. The rHVT-F vaccine developed by Calderón et al [26] achieved an antibody positivity of 85.7% at 5 wpv in SPF chickens. These results suggest that the two candidate vaccines we constructed appeared to be much better in inducing humoral immunity than others.…”

“…For instance, one vaccine expressing the genotype VII NDV F protein at the US2 site has demonstrated a 70% protection rate against a homologous NDV challenge five weeks post-vaccination (wpv) [25]. Another vaccine, expressing the genotype XII F protein at the UL45/UL46 site [26], has shown validated protective efficacy at 7 wpv; their early protection capabilities need further evaluation, and the long-term protective effects of both vaccines still require investigation.…”

Novel extraction technologies and potential applications of egg yolk proteins

“…For example, specific IgY against was reported to be effective in detecting wheat stripe mosaic virus (Santos et al, 2022 ), Furcraea Necrotic Streak Virus in fique plants (Toloza-Moreno et al, 2022 ), rabies viruses (Kubo et al, 2022 ), infectious bursal disease virus (Wibawan et al, 2018 ). IgY antibodies also exhibited protective effect against genotype XII Newcastle disease virus in chicken (Calderon et al, 2022 ), H9N2 avian influenza virus (Wang et al, 2020 ), duck adenovirus 3 (Yin et al, 2019 ), duck hepatitis B virus (Liu et al, 2018 ), etc.…”