Project description:Highly pathogenic avian influenza virus (HPAIV) is a permanent threat due to its capacity to cross species barriers and generate severe infections and high mortality in humans. Recent findings have highlighted the potential role of PB1-F2, a small accessory influenza protein, in the pathogenesis process mediated by HPAIV in mammals. In this study, using a recombinant H5N1 HPAIV (wt) and its PB1-F2-deleted mutant (ΔF2), we studied the effects of PB1-F2 in a chicken model. Unexpectedly, when using low inoculation dose we observed that the wt-infected chickens had a higher survival rate than the ΔF2-infected chickens, a feature that contrasts with what is usually observed in mammals. High inoculation dose had similar mortality rate for both viruses, and comparison of the bio-distribution of the two viruses indicated that the expression of PB1-F2 allows a better spreading of the virus within chicken embryos. Transcriptomic profiles of lungs and blood cells were characterized at two days post-infection in chickens inoculated with the wild type (wt) or the ΔF2 mutant viruses. In lungs, the expression of PB1-F2 during the infection induced pathways related to calcium signaling and repressed a large panel of immunological functions. In blood cells, PB1-F2 was associated to a gene signature specific for mitochondrial dysfunction and down-modulated leucocytes activation. Finally we compared the effect of PB1-F2 in lungs of chickens and mice. We identified that gene signature associated to tissue damages is a PB1-F2 feature shared by the two species; by contrast, the early inhibition of immune response mediated by PB1-F2 observed in chickens is not seen in mice. In summary, our data suggest that PB1-F2 expression deeply affect the immune host response in chickens in a way that may attenuate pathogenicity, a feature differing from what was previously observed in mammal species.
Project description:Highly pathogenic avian influenza virus (HPAIV) is a permanent threat due to its capacity to cross species barriers and generate severe infections and high mortality in humans. Recent findings have highlighted the potential role of PB1-F2, a small accessory influenza protein, in the pathogenesis process mediated by HPAIV in mammals. In this study, using a recombinant H5N1 HPAIV (wt) and its PB1-F2-deleted mutant (M-NM-^TF2), we studied the effects of PB1-F2 in a chicken model. Unexpectedly, when using low inoculation dose we observed that the wt-infected chickens had a higher survival rate than the M-NM-^TF2-infected chickens, a feature that contrasts with what is usually observed in mammals. High inoculation dose had similar mortality rate for both viruses, and comparison of the bio-distribution of the two viruses indicated that the expression of PB1-F2 allows a better spreading of the virus within chicken embryos. Transcriptomic profiles of lungs and blood cells were characterized at two days post-infection in chickens inoculated with the wild type (wt) or the M-NM-^TF2 mutant viruses. In lungs, the expression of PB1-F2 during the infection induced pathways related to calcium signaling and repressed a large panel of immunological functions. In blood cells, PB1-F2 was associated to a gene signature specific for mitochondrial dysfunction and down-modulated leucocytes activation. Finally we compared the effect of PB1-F2 in lungs of chickens and mice. We identified that gene signature associated to tissue damages is a PB1-F2 feature shared by the two species; by contrast, the early inhibition of immune response mediated by PB1-F2 observed in chickens is not seen in mice. In summary, our data suggest that PB1-F2 expression deeply affect the immune host response in chickens in a way that may attenuate pathogenicity, a feature differing from what was previously observed in mammal species. Three-condition experiment, virus-infected (wt or M-NM-^TF2) vs. Mock-infected chickens. Biological replicates: 2x5 control replicates, 5 wt replicates, 5 M-NM-^TF2 replicates.
Project description:A/Vietnam/1203-CIP048_RG3/2004 (H5N1) is a PB1-F2 deletion in wild type A/Vietnam/1203/2004 (H5N1). The goal of this study was to determine the host response (C57BL/6 mouse model) to the PB1-F2 mutation at a 10^4 PFU dose.
Project description:This study used virological, histological, and global gene expression from an experimental murine model of influenza infection to study the contribution of a specific mutation in the PB1-F2 protein (PB1-F2 N66S) of influenza A to viral pathogenesis.
Project description:A/Vietnam/1203-CIP048_RG3/2004 (H5N1) is a PB1-F2 deletion in wild type A/Vietnam/1203/2004 (H5N1). The goal of this study was to determine the host response (C57BL/6 mouse model) to the PB1-F2 mutation at a 10^4 PFU dose. Groups of 20-week-old female C57BL/6 mice were infected with A/Vietnam/1203-CIP048_RG3/2004 (H5N1). This is a PB1-F2 deletion in wild type A/Vietnam/1203/2004 (H5N1). Infections were with 10^4 PFU or time-matched mock infections. Time points were 1, 2, 4 and 7 d.p.i. There were 1-5 animals/dose/time point. Lung samples were collected for virus load, transcriptional analysis and proteomic analysis. Weight loss and animal survival were also monitored.
Project description:This study used virological, histological, and global gene expression from an experimental murine model of influenza infection to study the contribution of a specific mutation in the PB1-F2 protein (PB1-F2 N66S) of influenza A to viral pathogenesis. 6-8 week old, wild-type, female, C57Bl/6 mice were inoculated individually with 30 μl (10^4 PFU) of virus (recombinant influenza A/WSN/33 carrying the PB1 gene segment from A/Hong Kong/156/97 (H5N1) or a PB1 mutant recombinant virus resulting in an amino acid change at position 66 in the PB1-F2 protein [N66S]) in phosphate-buffered saline (PBS) containing penicillin-streptomycin and bovine serum albumin (PBS-BA-PS). A total of 10^4 PFU of virus was given in all inoculations. Control mice were given PBS-BA-PS. Lung samples were taken for microarray analysis at 12h, 1d, 3d, and 5d post-infection (n=3 animals per group at each time point for virus infected animals; n=2 animals per time point for mock-infected animals).
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola.
Project description:H5N1 subtype highly pathogenic avian influenza virus has been spreading to Asia, Eurasia and African coutries. An original or six of recombinant H5N1 subtype influenza viruses with varying survivability were infected to chickens for elucidating genes correlated with pathogenicity.