Changes in miRNA expression during infection with strong IBDV strains
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ABSTRACT: In our previous studies, we found that the bursae of Fabricius in chickens infected with IBDV were severely atrophied and resulted in immune suppression in the chickens. Therefore, we decided to detect the differential expression of miRNA in chickens infected with IBDV by RNA-seq. We then used the data obtained from bursa of Fabricius RNA-seq for gene expression profiling. Our ultimate goal is to study the regulatory mechanisms of host mirnas on IBDV viruses or cells.
Project description:Infectious bursal disease virus (IBDV) belongs to the family Birnaviridae and is economically important to the poultry industry worldwide. IBDV infects B cells in the bursa of Fabricius (BF), which can cause severe immunosuppression and mortality in young chickens. Earlier studies have shown that strains of IBDV lose their virulence potential after serial passage in non-B lymphoid cells, for reasons that are poorly understood. This study aimed to investigate the gene expression profiles of one cell-culture adapted attenuated IBDV strain (D78) and one very virulent IBDV strain (UK661) in chicken primary B cells cultured ex vivo from the bursa of Fabricius. The viruses were studied in B cells over 48h and their gene expression was initially evaluated with qPCR. The mRNA was isolated from the cells at 18 hours post-infection and screened with Affymetrix microarrays in triplicate. The study included mock controls which were conducted in triplicate.
Project description:Purpose: To explore the interaction between host and IBDV, RNA-Seq was applied to analyse the transcriptional profiles of the responses of chickens' bursas of Fabricius in the early stage of IBDV infection. Method: Eighteen SPF white leghorn chickens were randomly divided into two groups with 9 chickens for each group: the mock group (the healthy group) and the IBDV-inoculated group (the infection group). Chickens from the infection group were inoculated with 0.1 mL of 103 EID50 IBDV CJ801 stock through eye-nose drops. The chickens from the mock group were kept in a separate isolator and mock challenged with PBS. On days 1, 3 and 7 after infection, 3 chickens from each group were killed for bursa collection. Each bursa was immediately put into liquid nitrogen and then stored in 80 ℃ refrigerator. RNA sequencing was performed with total RNA from bursae from each group at the first two time points and completed by a commercial company. Results: The results displayed that a total of 15546 genes were identified in the chicken bursa libraries. Among the annotated genes, there were 2006 and 4668 differentially expressed genes in the infection group compared with the mock group on day 1 and day 3 post inoculation (1 and 3 dpi), respectively. Moreover, there were 676 common up-regulated and 83 common down-regulated genes in the bursae taken from the chickens infected with IBDV on both 1 and 3 dpi. Meanwhile, there were also some characteristic differentially expressed genes on 1 and 3 dpi. On day 1 after inoculation with IBDV, host responses mainly displayed immune response processes, while metabolic pathways played an important role on day three post infection. Six genes were confirmed by quantitative reverse transcription-PCR. Conclusions: In conclusion, the differential gene expression profile demonstrated with RNA-Seq might offer a better understanding of the molecular interactions between host and IBDV during the early stage of infection.
Project description:We used a chicken immune-targeted gene array to analyse the differences in gene expression in the bursa of Fabricius from genetically resistant and susceptible animals infected with Infectious Bursal Disease Virus (IBDV).
Project description:Infectious bursal disease virus (IBDV) causes a highly contagious, immunosuppressive disease in chickens. The virus mainly infects immature B lymphocytes in the bursa of Fabricius (BF). Chicken B cell line DT40, an avian leukosis virus-induced B cell line, supports very virulent IBDV (vvIBDV) infection in vitro and thereby serves as a good model for investigating the infection and pathogenesis of this virus. However, a transcriptome-wide understanding of the interaction between vvIBDV and B cells has not yet been achieved. This study aimed to employ time-course DNA microarrays to investigate gene expression patterns in DT40 cells after infection with vvIBDV strain LX.
Project description:Infectious bursal disease virus (IBDV) is a highly contagious dsRNA virus (Birnaviridae) which causes immuno-suppression in chickens. Although largely controlled by vaccination, new, virulent strains of the virus mean that infectious bursal disease (IBD or ëGumboroí disease) still remains a threat to the poultry industry. The virus infects dividing IgM+ B-lymphocytes and the main site of viral replication is the bursa of Fabricius where B cells are produced. Infection is spread orally via contaminated feed and water. IBDV affects young birds, with the disease usually being diagnosed in 3-6 week old birds. Younger birds do not show clinical signs but are immuno-suppressed. Symptoms include anorexia, depression, diahorrea, ruffled feathers, immuno-suppression and bursal lesions. The disease peaks between 2-5 days post infection and is practically cleared by day 7. Mortality is variable but can be up to around 70% with very virulent strains of the disease. Even if birds survive, the resulting immuno-suppression and effect on egg production in layer birds is significant. Being able to breed commercial lines of birds for enhanced genetic resistance to IBDV is an obvious goal in the fight against the disease. Three-week-old chicks were inoculated with virus via an intra-nasal route and tissue samples were collected at 2, 3 and 4 days post-inoculation. Bursa and spleen tissues were examined from control and infected birds at 2, 3 and 4 days post-infection in birds known to be either susceptible or resistant to the virus. As well as understanding the host immune response to IBDV, we are interested in identifying genes involved in disease resistance and so we have analysed the gene expression profiles at these times, when the innate immune response is active. We assume that genes underlying resistance will be involved at this early stage of the host immune response.
Project description:Analysis of gene expression of Bursa of Fabricius samples of 3 male chickens of 6 breeds revealed differential expression of genes related to Ingenuity pathways immune cell trafficking, cell-mediated immune response, humoral immune response and infectious disease.
Project description:Nasal cavity is the main gateway for pathogen infection although it composed of many layers of defending barriers. Pathogens strongly willing to enter and infect from nasal cavity with the dominant form aerosol or respiratory droplets. However, the underlying mechanism of virus nasal infection and transmission are still unknown. Hence, a better understanding of this mechanism may provide insight into the pathogenesis of virus. In this study, IBDV was select as a model virus to study nasal infection and transmission for it could infect chicken from head (nasal) to tail (basal) and lead to massive destruction of bursal IgM+ B-lymphocytes. Initially, we found IBDV mostly entered and infected the interior of chicken’s nasal, where full of lymphoid tissue and easily for virus to transfer into blood. After passing nasal barriers, IBDV was subsequently transmit into blood and infected PBMCs. Following blood circulates, IBDV then infected bursal and hugely destroyed B-lymphocytes. However, the mechanism of how IBDV influenced the bursal cells, especially how virus destroyed B-lymphocytes were still unclear. With the help of single cells RNA sequence, we identified five vigorous clusters, including three immune cells types (B-cells: 64.70%, dendritic cells: 3.32% and T-cells: 6.33%) and two non-immune cell types (epithelial cells: 23.86% and fibroblast cells: 1.80% cells). Further analyses found that B-cells population were serious damaged, especially IgM+ B cells. However, the IgA+ B cells population hugely increased after IBDV infection. Interesting, we first demonstrated that basal cells and other non-immune cells in Bursa of Fabricius (BF) were the main target for IBDV infection and replication. Together, our study not only comprehensive elaborated the airborne IBDV and its transmission via intranasal route into the BF, but also explained its distribution in different immune and nonimmune cells and immunoglobulins rearrangement after immunosuppressive disorder on an age dependent infected organ.
Project description:Duck reovirus (DRV) is well-studied aquatic bird virus belonging to the Orthoreovirus genus of the Reoviridae family. The bursa of Fabricius is an immunologically organ against virus invasion. However, the responses of the bursa of Fabricius of Cairna moschata to DRV infection are largely unknown. To investigate the immune responses, the proteomes from the control and two DRV strain infected samples (NH and DJ) were compared. In total, 7075 protein were identified, of which 5625 protein were quantified. A number of differentially expressed proteins (DEPs), including 210 DEPs under the HN10 infection and 55 DEPs under the JD10 infection, were identified. Protein network analysis showed that the DEPs enriched in the serine protease system and the innate immune response clusters. For the serine protease systems, coagulation factor IX, three chains of fibrinogen, and complement C8, C5, and C2s were significantly up-regulated, suggesting that the serine protease-mediated immune might be involved in the responses to the HN10 infection. For the innate and adaptive immune system, RIG-I, MDA5, MAPK20, and IRF3 were significantly up-regulated, indicating their important role in the reorganization of invaded virus. Furthermore, the DEPs among different visceral organs (liver, spleen, and the bursa of Fabricius) were compared. coagulation factor IX was significantly up-regulated in the bursa of fabricius, not in the liver and spleen samples, suggesting an important role of the bursa of fabricius in antivirus. Our data may give a comprehensive resource for investigating the regulation mechanism involved in the responses of the bursa of Fabricius of duck to the DRV infections.
Project description:Chickens known to be susceptible to IBDV were infected with the virus and resulting gene expression at 4dpi was compared to that of uninfected chickens
Project description:In avian species, maternal blood immunoglobulin Y (IgY) is transferred to the egg yolks of maturing oocytes, but the mechanism underlying this transfer is unknown. IgY-deficient chickens were developed by removal of bursa of Fabricius (Bx group). Since DIG-labeled IgY uptake into egg yolk was approximately 2-fold higher in the Bx group than that of the control, upregulated genes in oocyte of the Bx group were determined to identify IgY receptor responsible for maternal blood IgY transfer by microarray analysis.