Project description:Infection with a single influenza A virus (IAV) is only rarely sufficient to initiate productive infection. Here, we exploit both single cell approaches and whole-animal systems to show that the extent of IAV reliance on multiple infection varies with virus strain and host species. Influenza A/guinea fowl/HK/WF10/99 (H9N2) [GFHK99] virus exhibits strong dependence on collective interactions in mammalian systems. This reliance focuses viral progeny production within coinfected cells and therefore results in frequent genetic exchange through reassortment. In contrast, GFHK99 virus has greatly reduced dependence on multiple infection in avian systems, indicating a role for host factors in viral collective interactions. Genetic mapping implicated the viral polymerase as a major driver of multiple infection dependence. Mechanistically, quantification of incomplete viral genomes showed that their complementation only partly accounts for the observed reliance on coinfection. Indeed, even when all polymerase components are detected in single cell mRNA sequencing, robust polymerase activity of GFHK99 virus in mammalian cells is reliant on multiple infection. In sum, IAV collective interactions not only augment reassortment, but can also overcome species-specific barriers to infection. These findings underscore the importance of virus-virus interactions in IAV infection, evolution and emergence. We used a single-cell sequencing platform (10x Genomics) to elucidate the differential infection rate of an avian influenza A virus on an avian cell line (DF1) and a mammalian (MDCK) cell line. Our work on IAV reassortment has raised new questions about the fundamental strategies that drive influenza virus evolution. Our data indicate that a large majority of influenza virus genomesare incomplete within cells, comprising less than the eight complete segments normally found in a replication competent infectious viral particle. This led us to ask: what underlying mechanisms give rise to incomplete genomes? What constitute an infectious unit? What are the implications for viral diversification, evolution and spread. By addressing these questions, we will advance he field by deepening our understanding how viral infections are initiated and propagated.
Project description:In recent years, the roles of microRNAs playing in the regulation of influenza viruses replication caused researchers' much attenion. However, much work focused on the interactions between human, mice or chicken microRNAs with human or avian influenza viruses rather than the interactions of swine microRNAs and swine influenza viruses. To investigate the roles of swine microRNAs playing in the regulation of swine influenza A virus replication, the microRNA microarray was performed to identify which swine microRNAs were involved in swine H1N1/2009 influenza A virus infection.
Project description:Background:Dendritic cells (DCs), have the most important antigen presenting ability and played an irreplaceable role in recognizing and clearing virus. Antiviral responses must rapidly defend against infection while minimizing inflammatory damage, but the mechanisms that regulate the magnitude of response within an infected cell are not well understood. MicroRNA, small non-coding RNAs, that can regulate dendritic cells to inhibit the infection and replication of avian influenza virus. Here, we global analyses how avian DCs response to H9N2 avian influenza virus (AIV) and provide a potential mechanism of how avian microRNA defending H9N2 AIV replication. Results: Here, we global analyses how avian DCs response to H9N2 avian influenza virus (AIV) and provide a potential mechanism of how avian microRNA defending H9N2 AIV replication. First, we found that both active and inactive H9N2 AIV enhance the ability of DCs to present antigens and activate T lymphocytes. Next, total microarray analyses suggested that H9N2 AIV stimulation involved in protein localization, nucleotide binding and leukocyte transendothelial migration and MAPK signal pathways. Moreover, we construct 551 transcription factor (TF)-microRNA-mRNA loops based on the above analyses. Furthermore, we found that HA fragment could not activate DCs, while truncated HA highly increased the immune function of DCs by activating ERK and STAT3 signal pathway. Last, our insight research not only gained that gga-miR1644 might target to MBNL2 to enhanced avian DCs in inhibiting virus replication, but also suggested that gga-miR6675 target to the NLS of PB1 to trigger the silencing of PB1 genes and lead to inhibition of H9N2 avian influenza viral replication. All together, our innovative research will shed new light on the roles of avian microRNA in evoking avian DCs and inhibiting virus replication, which will suggest new strategies to combat avian influenza virus.
Project description:To study miRNA expression profiles during highly pathogenic avian influenza virus infection, we conducted global miRNA expression profiling in human lung epithelial cells (A549) with or without H5N1 IAV infection. .