Recombinant Newcastle Disease Virus (NDV) Expressing Sigma C Protein of Avian Reovirus (ARV) Protects against Both ARV and NDV in Chickens

Abstract

Newcastle disease (ND) and avian reovirus (ARV) infections are a serious threat to the poultry industry, which causes heavy economic losses. The mesogenic NDV strain R2B is commonly used as a booster vaccine in many Asian countries to control the disease. In this seminal work, a recombinant NDV strain R2B expressing the sigma C (σC) gene of ARV (rNDV-R2B-σC) was generated by reverse genetics, characterized in vitro and tested as a bivalent vaccine candidate in chickens. The recombinant rNDV-R2B-σC virus was attenuated as compared to the parent rNDV-R2B virus as revealed by standard pathogenicity assays. The generated vaccine candidate, rNDV-R2B-σC, could induce both humoral and cell mediated immune responses in birds and gave complete protection against virulent NDV and ARV challenges. Post-challenge virus shedding analysis revealed a drastic reduction in NDV shed, as compared to unvaccinated birds.

Newcastle Disease Virus Vectored Chicken Infectious Anaemia Vaccine Induces Robust Immune Response in Chickens

“…The cells were then blocked with 5% bovine serum albumin for 30 min at room temperature. They were washed three times with PBS and incubated for 1 h with a mixture of anti-NDV and anti-CIAV primary antibodies, as mentioned previously [ 9 ]. At the end of incubation period, cells were washed thrice with PBS and incubated with a mixture of FITC labelled rabbit anti-chicken IgG and Alexa Fluor 568 labelled goat anti-chicken IgG and kept for one hour at room temperature.…”

“…At the end of incubation period, cells were washed thrice with PBS and incubated with a mixture of FITC labelled rabbit anti-chicken IgG and Alexa Fluor 568 labelled goat anti-chicken IgG and kept for one hour at room temperature. Nucleus staining was performed using DAPI at 1:1000 dilution and finally the cells were visualised for corresponding fluorescence a images were taken using Fluoview FV 1000 confocal microscope (Olympus, Tokyo, Japan) at the matching excitation and emission filters for FITC and Alexa Fluor 568, as described [ 9 ].…”

“…Growth patterns of the recombinant viruses were evaluated by multi cycle of growth conditions in monolayers of Vero cells in six-well plates at an MOI of 0.01. The growth kinetics study was performed as per established protocols and the titles of the virus were calculated using the standard method [ 9 ]. Further, titration of the recombinant viruses was expressed as 50% tissue culture infectious dose and was carried out by established protocols [ 22 ].…”

“…Hence the amino acids at the fusion protein cleavage site of the virus, which are a major determinant of the virulence, have been modified to resemble a lentogenic backbone and they have been rescued recently [ 8 ]. The rescued viruses in our laboratory have been used in designing vaccine candidates against avian reovirus and rabies virus and have been shown to work in multiple host species [ 9 , 10 ].…”

Preclinical Evaluation of a Newcastle Disease Virus-Vectored Intranasal SARS-CoV-2 Vaccine

“…NDV has been used as a vector for vaccine development since the late 1990s. The efficiency of vaccines based on this vector has been demonstrated against respiratory viruses, in chickens against infectious bronchitis virus and avian reovirus, in monkeys against SARS-CoV and in camels against MERS-CoV [33][34][35][36] . These studies have demonstrated that it is feasible to produce S protein from other viruses, especially of SARS-CoV and MERS, which conferred strong immunogenicity and protection in mice and nonhumans primates 35,36 .…”