Analysis Of Long Noncoding RNA Expression Profiles In Avibirnavirus-infected And H7N9 Influenza Virus-infected Cells

Long non-coding RNA(lncRNA) is a type of non-coding RNA with more than 200 nucleotides,and does not translate a protein.Because of its important regulatory role in biological activities,lncRNA has attracted wide attention.However,there are still few reports on the regulatory role of lncRNA in the process of viral infection in the host.Both avian cells and mammalian cells can produce lncRNA,but the similarities and differences of lncRNA expression profiles produced by different species of cells in response to viral infections,as well as the role of the differentially expressed lncRNAs induced by viral infections,are not known.In order to explore the similarities and differences of lncRNA expression profiles and functions of avian cells and mammalian cells after viral infection,we used IBDV and H7N9 to infect avian source DF-1 cell and human source A549 cell.Then the differentially expressed lncRNAs in infected cells and uninfected cells were analyzed through high-throughput sequencing of,and their role in the process of viral infection and regulatory mechanisms were explored.The results showed that there were 958 differentially expressed lncRNAs in IBDV-infected DF-1 cells compared with control cells.Among them,728 were up-regulated and 230 were down-regulated.Differentially expression of 9 randomly selected lncRNAs were verified by real-time quantitative polymerase chain reaction(qRT-PCR).The results were consistent with high throughput sequencing data.At the same time,there were 3785 lncRNAs in H7N9-infected A549 cells displayed differential expression compared to normal cells.Among them,3484 were up-regulated and 301 were down-regulated.11 randomly selected lncRNAs were verified by qRT-PCR,and the results showed that their expression changes were consistent with high-throughput sequencing data.Target genes of the differentially expressed lncRNAs were predicted,the functional annotation and enrichment analysis using Gene Oncology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)provided more comprehensive understanding in DF-1 cell and A549 cell intracellular response to IBDV and H7N9 infection,respectively.The results showed that the target genes of dysregulated lncRNAs in DF-1 cells were mainly involved in immune response,metabolism and apoptosis,while the target genes of dysregulated lncRNAs in A549 cells were involved in natural immune-related signaling pathway,metabolism and mitochondrial autophagy.We screened lncRNA-AC024267.1 which was significantly up-regulated in H7N9-infected A549 cells.Overexpression of lncRNA-AC024267.1 promoted H7N9 replication,while knockdown of lncRNA-AC024267.1 inhibited H7N9 replication.It was confirmed by RNA immunoprecipitation(RIP)and luciferase reporter assay that lncRNA-AC024267.1 could bind to hsa-miR-370-3p.Western blot and TCID50 assay verified that hsa-miR-370-3p had an inhibitory effect on H7N9 replication,while inhibition of hsa-miR-370-3p was beneficial for viral replication.In summary,this experiment was the first to analyze and compare the effects of lncRNAs in the infection process of different host cells by IBDV and H7N9 influenza viruses,respectively,and concluded that both avian source cells DF-1 and human cells A549,after viral infection,mainly resisted the invasion of the virus through the natural immunity and the metabolic pathway of intracellular substances.LncRNA-AC024267.1 was screened from A549 cells infected with H7N9,which could act as an endogenous competing RNA to promote H7N9 replication by binding to hsa-miR-370-3p.This study provided a reference for the further study of the role of lncRNA in the process of infection of IBDV and H7N9.