Project description:The aim of this study is to determine differential gene expression on skin biopsies of experimentally BTV-infected hinds (Cervus elaphus) using serotypes 1 and 8 to understand the possible role that these genes play during BTV infection. Understanding the strategies used by this virus for their cellular uptake, and detection of differentially expressed transcripts in experimentally infected hosts, can provide identification of detailed information that might be used to prevent infection.
Project description:The aim of this study is to determine differential gene expression on skin biopsies of experimentally BTV-infected hinds (Cervus elaphus) using serotypes 1 and 8 to understand the possible role that these genes play during BTV infection. Understanding the strategies used by this virus for their cellular uptake, and detection of differentially expressed transcripts in experimentally infected hosts, can provide identification of detailed information that might be used to prevent infection. Four seven-month-old red deer Cervus elaphus were kept in a P3 facility to be experimentally infected with Bluetongue virus, and 4 more red deer were kept as controls. Skin biopsies were taken at 14 days post-infection to determine gene expression in response to this virus.
Project description:To comprehensively understand the characterization of bluetongue virus (BTV)-host interactome, and BTV infection and pathogenic mechanisms, RNA-seq was performed with BTV serotype 1 Y863 strain-infected and mock-infected sheep embryonic testicular cells (OA3.Ts) at 24 hours post-infection.
Project description:To comprehensively understand the characterization of bluetongue virus (BTV)-host interactome, and BTV infection and pathogenic mechanisms, RNA-seq was performed with BTV serotype 1 Y863 strain-infected and mock-infected sheep embryonic testicular cells (OA3.Ts) at 24 hours post-infection.
Project description:The gene expression in conventional and plasmacytoid dendritic cells (cDC and pDC respectively) during Bluetongue virus (BTV) infection in sheep depends on the lymphoid compartment and suggest that these cell types have a role in the physiopathology We analyzed the gene expression in lymph node pDC and cDC from 3 control and 3 BTV infected sheep at day 6 post infection, in blood pDC from 2 control and 2 BTV infected sheep at day 6 post infection, and in spleen cDC from 3 control and 2 BTV infected sheep at day 6 post infection.
Project description:Typical enteropathogenic Escherichia coli (EPEC) O55:H7 is regarded as the closest relative of enterohemorrhagic E. coli (EHEC) O157:H7. Both serotypes usually express the γ1 intimin subclass and trigger actin polymerazation by the Tir-TccP pathway. However, atypical O55:H7 strains capable of triggering actin polymerization via the Tir-Nck pathway have recently been identified. In this study, we investigated the genotypic differences and phylogenetic relationships between typical and atypical O55:H7 strains. We show that the atypical O55:H7 strains, which express the θ intimin subclass and lack both tccP and tccP2, belong to an E. coli lineage distinct from the typical O55:H7 and from the EPEC O55:H6, which also uses the Tir-Nck actin polymerization pathway. We conducted genomic comparisons of the chromosomal regions covering the O-antigen gene cluster and its flanking regions between the three O55 lineages by restriction fragment length polymorphism analysis of PCR products and DNA sequencing analysis of about 65-kb chromosomal regions. This unexpectedly revealed that horizontal transfer of large fragments (≥ 40 kb) encoding the O55-antigen gene cluster and part of neighboring colanic acid gene cluster is involved in the emergence of the three O55 E. coli lineages. The data provide new insights into the mechanisms involved in the generation of a wide variety of O-serotypes in Gram-negative bacteria. Keywords: comparative genomic hybridization
Project description:Typical enteropathogenic Escherichia coli (EPEC) O55:H7 is regarded as the closest relative of enterohemorrhagic E. coli (EHEC) O157:H7. Both serotypes usually express the γ1 intimin subclass and trigger actin polymerazation by the Tir-TccP pathway. However, atypical O55:H7 strains capable of triggering actin polymerization via the Tir-Nck pathway have recently been identified. In this study, we investigated the genotypic differences and phylogenetic relationships between typical and atypical O55:H7 strains. We show that the atypical O55:H7 strains, which express the θ intimin subclass and lack both tccP and tccP2, belong to an E. coli lineage distinct from the typical O55:H7 and from the EPEC O55:H6, which also uses the Tir-Nck actin polymerization pathway. We conducted genomic comparisons of the chromosomal regions covering the O-antigen gene cluster and its flanking regions between the three O55 lineages by restriction fragment length polymorphism analysis of PCR products and DNA sequencing analysis of about 65-kb chromosomal regions. This unexpectedly revealed that horizontal transfer of large fragments (⥠40 kb) encoding the O55-antigen gene cluster and part of neighboring colanic acid gene cluster is involved in the emergence of the three O55 E. coli lineages. The data provide new insights into the mechanisms involved in the generation of a wide variety of O-serotypes in Gram-negative bacteria. Keywords: comparative genomic hybridization Total 8 test samples were analyzed. Genomic DNA from each test strain and a reference strain (O157 Sakai) were labeled with Cy3 and Cy5, respectively, and were cohybridized on a single array. Labeling and hybridization were performed twice independently.
Project description:Bluetongue virus (BTV), the prototypical Orbivirus that belongs to the Sedoreoviridae family, is transmitted by the bite of infected Culicoides midges and affects domestic and wild ruminants producing great economic losses. The infection induces an IFN response, followed by an adaptive immune response that plays a critical role in disease clearance. BTV can nonetheless impair IFN and humoral responses. The main goal of this study was to gain a more detailed understanding of BTV pathogenesis and its effects on immune cell populations. To this end, we combined flow cytometry and transcriptomic analyses of several immune cells at different times post-infection (pi). Four sheep were infected with BTV serotype 8 and blood samples collected at days 0, 3, 7 and 15pi to isolate peripheral blood mononuclear cells. Transcriptomic analysis of B-cell marker+, CD4+, CD8+, and CD14+ sorted cells showed that the maximum number of differentially expressed genes occurred at day 7pi, which coincided with the peak of infection. KEGG pathway enrichment analysis in B-cell marker+, CD4+, and CD14+ cells indicated that genes belonging to virus sensing and immune response initiation pathways were enriched and day 3 and 7 pi. Transcriptomic analysis also showed that T cell exhaustion pathway was enriched in CD4+ cells at day 7pi, while CD8+ cells showed downregulated immune response initiation pathways at this timepoint. When T cell functionality was assessed, ELISpot assays, intracellular cytokine staining, and proliferation assays demonstrated that BTV produced an acute inhibition of CD4+ and CD8+ T cell activation at the peak of replication. Furthermore, this coincided with PD-L1 upregulation on the surface of CD4+ and CD8+ T cells as well as monocytes. Taken together, these data indicate that BTV exploits the PD1/PD-L1 immune checkpoint to impair T cell responses. These findings identify several mechanisms in the interaction between host and BTV, which could help develop better tools to combat the disease.