Cytokine And Chemokine Gene Expression In The Oviduct Of Layers Infected With The Velogenic Genotype Ⅶ Newcastle Disease Virus

The newcastle disease virus(NDV)is a member of the family Paramyxoviridae and belonging to the Rubulavirus that has been widespread in domestic poultry in Asian countries,causing severe economic losses in domestic poultry, especially chickens. It not only causes the death of chickens, but also causes serious damage to the reproductive tracts of egg-laying hens. Previous studies have revealed the significant oviduct inflammation and decline of egg production caused by the variance. This leads to an overall decrease in egg production with40%-60% percentage decrease, and increases percentage of deformed, sand-shelled, and soft-shelled eggs. The genotype VII NDV is dominant in Asia and poses a great threat to its poultry industry. Previous studies have revealed the characteristics of this pathogen. However,its relation with cytokine, chemokine gene expression infected by this agent has not been well elucidated. Thus, the aim of this study is to investigate the cytokine and chemokine release in oviduct of infected layers, these laid a theoretical foundation for biological function of immune-related genes and viral pathogenesis in the oviducts of egg-laying hens after NDV infection. The results are as follows:1. Thirty-week old egg-laying hens inoculated with VII NDV strain NDV/Chicken /TC/1 / 2011) through combined intra-ocular and intra-nasal routes. Five egg-laying hens were used as mock groups with non-treatment. Animals sacrificed at 1 day post infection(dpi), 3dpi, 5 dpi, 7 dpi, 7dpi, 9dpi, 11 dpi. The oviducts along with the five parts(infundibulum,magnum, isthmus, uterus and vagina) from mock and experimental groups were collected immediately and placed on ice.2. HN protein staining indicated that NDV had spread through blood circulation and the virus is capable of replication in the oviduct. However, in the infundibulum, magnum, and isthmus, HN proteins were observed in the glandular epithelial cells of the lamina propria, and found scattered in the submucosa. Contrastingly, in the uterus, the HN proteins were present in the submucosa, and scattered in the lamina propria. In the vagina, they were located in the mucosal epithelium.2. Real-time RT-PCR was carried out to exam the chemokines IL-2,IL-6,IL-1β,IFN-α,IFN-β and chemokines CXCLi1, CXCLi2, CCR5 mRNAs. IL-2, IL-6,IFN-β and IL-1β wasup-regulated with fluctuating mRNA levels. The up-regulated change of IL-2, IFN-β, IL-1βis 137, 95 and 16 fold respectively. While the mRNA expression of CXCLi1, CXCLi2 and CCR5 increased in the oviduct during the whole infection process, especially significant in magnum.In conclusion, this study confirmed that the virus replication in hens’ oviduct. Also,genotype VIId NDV infection lead to oviductal inflammatory pathological changes. Futher more, NDV induced differential immune-related genes expression. These result laid a theoretical foundation for the oviductal dysfunction of egg-laying hens infected by genotype VII NDV.