Recombinant duck enteritis viruses expressing major structural proteins of the infectious bronchitis virus provide protection against infectious bronchitis in chickens

Abstract

To design an alternative vaccine for control of infectious bronchitis in chickens, three recombinant duck enteritis viruses (rDEVs) expressing the N, S, or S1 protein of infectious bronchitis virus (IBV) were constructed using conventional homologous recombination methods, and were designated as rDEV-N, rDEV-S, and rDEV-S1, respectively. Chickens were divided into five vaccinated groups, which were each immunized with one of the rDEVs, covalent vaccination with rDEV-N & rDEV-S, or covalent vaccination with rDEV-N & rDEV-S1, and a control group. An antibody response against IBV was detectable and the ratio of CD4(+)/CD8(+) T-lymphocytes decreased at 7 days post-vaccination in each vaccinated group, suggesting that humoral and cellular responses were elicited in each group as early as 7 days post-immunization. After challenge with a homologous virulent IBV strain at 21 days post-immunization, vaccinated groups showed significant differences in the percentage of birds with clinical signs, as compared to the control group (p < 0.01), as the two covalent-vaccination groups and the rDEV-S group provided better protection than the rDEV-N- or rDEV-S1-vaccinated group. There was less viral shedding in the rDEV-N & rDEV-S- (2/10) and rDEV-N & rDEV-S1- (2/10) vaccinated groups than the other three vaccinated groups. Based on the clinical signs, viral shedding, and mortality rates, rDEV-N & rDEV-S1 covalent vaccination conferred better protection than use of any of the single rDEVs.

Construction of a highly efficient CRISPR/Cas9-mediated duck enteritis virus-based vaccine against H5N1 avian influenza virus and duck Tembusu virus infection

“…To date, DEV has been widely applied for delivering protective antigens of avian pathogens including HPAIV H5N1, AIV H9N2, DTMUV, as well as duck hepatitis A virus 12 , 14 , 35 , 36 . It is noteworthy that DEV has also been explored as a replicating candidate vaccine vector in chickens to confer protection against the avian infectious bronchitis virus infection and HPAIV H5N1 15 , 37 , which has greatly extended the application of DEV. To the best of our knowledge, DEV has not been evaluated as a vaccine vector simultaneously against H5N1 and DTMUV to date.…”

“…The DEV C-KCE strain, attenuated in the embryonated chicken egg strain, has routinely been used as live vaccine in ducks for over 50 years without concerns for human or animal safety. Recombinant avirulent DEV is currently being explored as a candidate vaccine carrier for multiple pathogens, both in ducks and chickens 12 – 15 . Several advantages associated with DEV vectors make them highly attractive as viral vector platforms, including their safety profile, ease of generation, ability to induce broad and strong immune responses, safety profile, and the ability to differentiate between infected and vaccinated animals 13 .…”

SARS-CoV-2 will continue to circulate in the human population: an opinion from the point of view of the virus-host relationship

“…Earlier, a pivotal role for virusspecific memory T-cells in broad and long-term protection against SARS-CoV infection was elucidated [21,22]. Indeed, the crucial protective role of T-cell immune responses in coronavirus infections has been clearly documented in several animal models, e.g., feline infectious peritonitis virus (FIPV), mouse hepatitis virus (MHV), and avian infectious bronchitis virus (IBV) [23][24][25]. Moreover, reinfection did not occur in SARS-CoV-2 infected rhesus macaques with the same strain [26].…”

T-cell immunity of SARS-CoV: Implications for vaccine development against MERS-CoV

“…The clinical features of patients infected by MERS-CoV are very similar to SARS, i.e., severe pneumonia (Feng and Gao, 2007;Zaki et al, 2012). SARS-CoV-like viruses have been discovered in insectivorous Rhinolophid bats, and viruses genetically related to MERS-CoV have also been detected in Neoromicia capensis bats from Africa (Corman et al, 2014;Lau et al, 2013;Li et al, 2005b;. Recently, the bat origins of MERS-CoV were further supported by evidence that bat coronavirus HKU4 also uses the human MERS-CoV receptor CD26 for virus entry .…”