Infectious bronchitis virus (IBV) infection causes significant economic losses to various sectors of the poultry industry worldwide. Over the past few years, the incidence of false layer syndrome in Eastern Canadian layer flocks has been associated with the increased prevalence of the IBV Delmarva (DMV)/1639 strain. In this study, 1-day-old specific-pathogen-free (SPF) hens were infected with the Canadian DMV/1639 strain and observed until 16 weeks of age in order to determine if the IBV DMV/1639 strain is causing false layer syndrome. Early after infection, the virus showed a wide tissue distribution with characteristic gross and histopathological lesions in the respiratory tract and kidney. Around 60–70% of the infected hens demonstrated continuous cloacal viral shedding until the end of the experiment (at 16 weeks) which was associated with high IBV genome loads detected in the cecal tonsils. The experiment confirmed the field observations that the Canadian DMV/1639 strain is highly pathogenic to the female reproductive tract causing marked cystic lesions in the oviduct. Moreover, significant histopathological damage was observed in the ovary. Our study provides a detailed description of the pathological consequences of the IBV DMV/1639 strain circulating in an important poultry production sector.

Vaccination is the most important way to control infectious bronchitis (IB) in chickens. Since the end of 2015, the Delmarva (DMV)/1639 strain of infectious bronchitis virus (IBV) has caused significant damage to the layer flocks in Eastern Canada. The efficacy of a combination of existing IB vaccines licensed in Canada was assessed against experimental challenge with this IBV strain. The layer pullets were vaccinated during the rearing phase with live attenuated IB vaccines of Massachusetts (Mass) + Connecticut (Conn) types followed by an inactivated IB vaccine of Mass + Arkansas (Ark) types and then challenged with the Canadian IBV DMV/1639 strain at 30 weeks of age. Protection was evaluated based on the egg laying performance, immune responses, viral shedding, and viral genome loads and lesions in IBV target organs. The vaccinated challenged hens were protected from the drop in egg production observed in the non-vaccinated challenged hens. Early (5 dpi) anamnestic serum antibody response was measured in the vaccinated challenged hens as well as a significant level of antibodies was detected in the oviduct washes (14 dpi). In contrast, hens in the non-vaccinated challenged group showed delayed (12 dpi) and significantly lower serum antibody response. Viral RNA loads were reduced in the respiratory, alimentary, and reproductive tissues of the vaccinated challenged hens compared to the non-vaccinated challenged hens. Compared to the control groups, the vaccinated challenged hens had less marked microscopic lesions in the trachea, kidney, magnum, and uterus. Our experimental model demonstrated inconclusive results for cell-mediated immune responses and viral shedding. Overall, the vaccination program used in this study minimized viral replication and histopathological changes in most IBV target organs and protected challenged hens against drop in egg production.

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The ETS-related gene (ERG) is proto-oncogene that is classified as a member of the ETS transcription factor family, which has been found to be consistently overexpressed in about half of the patients with clinically significant prostate cancer (PCa). The overexpression of ERG can mostly be attributed to the fusion of the ERG and transmembrane serine protease 2 (TMPRSS2) genes, and this fusion is estimated to represent about 85% of all gene fusions observed in prostate cancer. Clinically, individuals with ERG gene fusion are mostly documented to have advanced tumor stages, increased mortality, and higher rates of metastasis in non-surgical cohorts. In the current review, we elucidate ERG’s molecular interaction with downstream genes and the pathways associated with PCa. Studies have documented that ERG plays a central role in PCa progression due to its ability to enhance tumor growth by promoting inflammatory and angiogenic responses. ERG has also been implicated in the epithelial–mesenchymal transition (EMT) in PCa cells, which increases the ability of cancer cells to metastasize. In vivo, research has demonstrated that higher levels of ERG expression are involved with nuclear pleomorphism that prompts hyperplasia and the loss of cell polarity.

For decades, vaccinations have been used to limit infectious bronchitis (IB) in both the broiler and layer industries. Depending on the geographical area, live attenuated vaccines are used either alone or in combination with inactivated vaccines to control infectious bronchitis virus (IBV) infections. It has been shown that administering inactivated vaccines preceded by priming with live attenuated vaccines in pullets protects laying hens against IB. However, the immunological basis of this protective response has not been adequately investigated. The objective of the study was to compare two vaccination strategies adapted by the Canadian poultry industry in terms of their ability to systemically induce an adequate immune response in IBV-impacted tissues in laying hens. The first vaccination strategy (only live attenuated IB vaccines) and second vaccination strategy (live attenuated and inactivated IB vaccines) were applied. Serum anti-IBV antibodies were measured at two time points, i.e., 3 weeks and 10 weeks post last vaccination. The recruitment of T cell subsets (i.e., CD4+ and CD8+ T cells), and the interferon (IFN)-γ mRNA expression were measured at 10 weeks post last vaccination. We observed that vaccination strategy 2 induced significantly higher serum anti-IBV antibody responses that were capable of neutralizing an IBV Mass variant associated with a flock history of shell-less egg production better than a Delmarva (DMV)1639 variant, as well as a significantly higher IFN-γ mRNA expression in the lungs, kidneys, and oviduct. We also observed that both vaccination strategies recruited CD4+ T cells as well as CD8+ T cells to the examined tissues at various extents. Our findings indicate that vaccination strategy 2 induces better systemic and local host responses in laying hens.