Towards construction of viral vectors based on avian coronavirus infectious bronchitis virus for gene delivery and vaccine development

Abstract

a b s t r a c tManipulation of the coronavirus genome to accommodate and express foreign genes is an attractive approach for gene delivery and vaccine development. By using an infectious cloning system developed recently for the avian coronavirus infectious bronchitis virus (IBV), the enhanced green fluorescent protein (EGFP) gene, the firefly luciferase gene and several host and viral genes (eIF3f, SARS ORF6, Dengue virus 1 core protein gene) were inserted into various positions of the IBV genome, and the effects on gene expression, virus recovery, and stability in cell culture were studied. Selected viruses were also inoculated into chicken embryos for studies of foreign gene expression at different tissue level. The results demonstrated the stability of recombinant viruses depends on the intrinsic properties of the foreign gene itself as well as the position at which the foreign genes were inserted. For unstable viruses, the loss of expression of the inserted genes was found to result from a large deletion of the inserted gene and even IBV backbone sequences. This represents a promising system for development of coronavirus-based gene delivery vectors and vaccines against coronavirus and other viral infections in chicken.

Accessory proteins 8b and 8ab of severe acute respiratory syndrome coronavirus suppress the interferon signaling pathway by mediating ubiquitin-dependent rapid degradation of interferon regulatory factor 3

“…The slightly slower growth rates observed for the recombinant viruses at early time points of the infection cycle may be due to the introduction of extra sequences into the IBV genome. This is consistent with our previous observations that such genetic manipulations may alter the replication of IBV in cells (Le et al, 2007;Shen et al, 2009). As expression of proteins 8a, 8b and 8ab did not render growth advantages to IBV in normal cultured cells, these proteins may not have direct functions in viral replication, especially in a heterogeneous genome context.…”

Identification and formation mechanism of a novel noncoding RNA produced by avian infectious bronchitis virus

“…Ten-day-old embryonated, pathogen-free chicken eggs were inoculated with IBV as described previously (Shen et al, 2009). The allantoic fluid and different organs were harvested after the embryos were chilled at 4°C overnight.…”

Characterization of cellular furin content as a potential factor determining the susceptibility of cultured human and animal cells to coronavirus infectious bronchitis virus infection

“…To study further the infection kinetics of IBV infection and to compare the viral infectivity in these cells, the same number of cells (2 Â 10 6 ) was plated. After incubation for 14 h, cells were infected with IBV-Luc at a multiplicity of infection of approximately 2, harvested at 24 h post-infection, and the luciferase activities were measured (Shen et al, 2009). The highest readings were consistently obtained from IBV-infected Huh7 cells, and were considered as 100% infection efficiency for each passage of IBV in this cell line, and the readings in other cells were shown as percentages of that in Huh7 cells (Fig.…”