Project description:Small RNA libraries were constructed from total RNA from Jasminum sambac plants exhibiting virus-like symptoms. After sequencing, small RNAs were assembled into contigs with MetaVelvet and assembled contigs were aligned against the NR database of NCBI using BLASTx. Top hits that reported a virus as subject were considered putative viral sequences. Based on such alignments, the whole genome of a virus, we tentatively name Jasmine Virus H was recovered and cloned. Two more small RNA libraries were made in a confirmatory experiment. One from Jasminum sambac and another one from Nicotiana benthamiana plants infected with the newly-cloned virus. The small RNA libraries were aligned against the full-length sequence of Jasmine Virus H to determine the spacial distribution of virus-derived small RNAs along the virus genome.
Project description:Small RNA-Seq study comparing Epstein-Barr virus (EBV) infected BJAB-B1 cells to isogenic, but uninfected, BJAB cells. The goal was to deduce differentially expressed small ncRNAs both micro and non-micro (up to 200 nt) between the two cell lines to gain insights into EBV-associated deregulation of host small ncRNAs.
Project description:RNA silencing is one of the main defense mechanisms employed by plants to fight viruses. In change, viruses have evolved silencing suppressor proteins to neutralize antiviral silencing. Since the endogenous and antiviral functions of RNA silencing pathway rely on common components, it was suggested that viral suppressors interfere with endogenous silencing pathway contributing to viral symptom development. In this work, we aimed to understand the effects of the tombusviral p19 suppressor on endogenous and antiviral silencing during genuine virus infection. We showed that ectopically expressed p19 sequesters endogenous small RNAs (sRNAs) in the absence, but not in the presence of virus infection. Our presented data question the generalized model in which the sequestration of endogenous sRNAs by the viral suppressor contributes to the viral symptom development. We further showed that p19 preferentially binds the perfectly-paired ds-viral small interfering RNAs (vsiRNAs) but does not select based on their sequence or the type of the 5’ nucleotide. Finally, co-immunoprecipitation of sRNAs with AGO1 or AGO2 from virus-infected plants revealed that p19 specifically impairs vsiRNA loading into AGO1 but not AGO2. Our findings, coupled with the fact that p19-expressing wild type Cymbidium ringspot virus (CymRSV) overcomes the Nicotiana benthamiana silencing based defense killing the host, suggest that AGO1 is the main effector of antiviral silencing in this host-virus combination. To further support our hypothesis we investigate whether the ability of p19 to bind endogenous sRNA without virus infection has biological important impact on endogenous pathways and is this reduced if the virus is present. To asses this we made mRNA sequencing from mock inoculated and Cym19stop infected p19syn plants. Cym19stop infected wild type plant was sequenced as a control. The sequencing data results supports our claims. An increase in transcriptional levels were found in case of genes known to be under small RNA regulation in uninfected p19syn plants and expressional levels return to normal Cym19stop p19syn plants.
Project description:We sequenced the small RNA profiles in ZIKV-infected and non-infected Ae. aegypti mosquitoes at 2, 7 and 14 days post-infection. ZIKV induced an RNAi response in the mosquito with virus-derived short interfering RNAs dramatically increased in abundance post-infection. Further, we found 17 host miRNAs that were modulated by the ZIKV infection at all time points.
Project description:We previously reported widespread differential expression of long non-protein-coding RNAs (ncRNAs) in response to virus infection. Here, we expanded the study through small RNA transcriptome sequencing analysis of the host response to both severe acute respiratory syndrome coronavirus (SARS-CoV) and influenza virus infections across four founder mouse strains of the Collaborative Cross, a recombinant inbred mouse resource for mapping complex traits. We observed differential expression of over 200 small RNAs of diverse classes during infection. A majority of identified microRNAs (miRNAs) showed divergent changes in expression across mouse strains with respect to SARS-CoV and influenza virus infections and responded differently to a highly pathogenic reconstructed 1918 virus compared to a minimally pathogenic seasonal influenza virus isolate. Novel insights into miRNA expression changes, including the association with pathogenic outcomes and large differences between in vivo and in vitro experimental systems, were further elucidated by a survey of selected miRNAs across diverse virus infections. The small RNAs identified also included many non-miRNA small RNAs, such as small nucleolar RNAs (snoRNAs), in addition to nonannotated small RNAs. An integrative sequencing analysis of both small RNAs and long transcripts from the same samples showed that the results revealing differential expression of miRNAs during infection were largely due to transcriptional regulation and that the predicted miRNA-mRNA network could modulate global host responses to virus infection in a combinatorial fashion. These findings represent the first integrated sequencing analysis of the response of host small RNAs to virus infection and show that small RNAs are an integrated component of complex networks involved in regulating the host response to infection. IMPORTANCE: Most studies examining the host transcriptional response to infection focus only on protein-coding genes. However, mammalian genomes transcribe many short and long non-protein-coding RNAs (ncRNAs). With the advent of deepsequencing technologies, systematic transcriptome analysis of the host response, including analysis of ncRNAs of different sizes, is now possible. Using this approach, we recently discovered widespread differential expression of host long (>200 nucleotide[nt]) ncRNAs in response to virus infection. Here, the samples described in the previous report were again used, but we sequenced another fraction of the transcriptome to study very short (about 20 to 30 nt) ncRNAs. We demonstrated that virus infection also altered expression of many short ncRNAs of diverse classes. Putting the results of the two studies together, we show that small RNAs may also play an important role in regulating the host response to virus infection. The small RNA transcriptome deep sequencing analysis was performed on lung samples from our previously published study (Unique signatures of long noncoding RNA expression in response to virus infection and altered innate immune signaling , X Peng, MBio. 2010 Oct 26;1(5). pii: e00206-10.). We infected four of the eight founder mouse strains used in generating the Collaborative Cross, a recombinant inbred mouse resource for mapping complex traits (41). These strains included 129S1/SvImJ (129/S1), WSB/EiJ (WSB), PWK/PhJ (PWK), and CAST/EiJ (CAST) mice. Ten-week-old mice were intranasally infected with phosphate-buffered saline (PBS) alone or with 1X10^5 PFU of mouse adapted severe acute respiratory syndrome coronavirus (SARS-CoV; rMA15), or 500 PFU of influenza A virus strain A/Pr/8/34 (H1N1; PR8). To match the previous whole-transcriptome analysis, we performed small RNA transcriptome sequencing analysis on the same eight samples from mice with SARS-CoV infections, including one SARS-CoV rMA15-infected mouse and one matched mock-infected mouse from each of the four strains at 2 days postinfection (dpi). In addition, we sequenced the small RNA transcriptome for 12 samples obtained from influenza virus infected mice, including two PR8-infected mice and one matched mockinfected mouse from each of the four strains at 2 dpi.
Project description:Influenza A virus (IAV) lacks the enzyme for adding 5â caps to its RNAs, and thus snatches the 5â ends of host capped RNAs to prime transcription. Neither the preference of the host RNA sequences snatched, nor the effect of âcap-snatchingâ on host processes has been completely defined. Previous studies of influenza cap-snatching used poly(A)-selected RNA from infected cells or relied solely on annotated host protein-coding genes to define host mRNAs selected by the virus. To examine the substrate-product relationship between all host RNAs, including non-coding RNAs, and viral RNAs, we used an unbiased approach to identify the host and viral capped RNAs from IAV-infected cells. We demonstrate that IAV predominantly snatches caps from non-coding host RNAs, particularly U1 and U2 small nuclear RNAs (snRNAs). Because snRNAs regulate host mRNA processing, cap-snatching of snRNAs may constitute a means by which IAV hijacks host cell metabolism. examine caps snatched by influenza virus A
Project description:Large DNA viruses are known to manipulate and modify host miRNAs during infection. Therefore the aim of this study was to investigate the impact of infection with the large DNA virus; African swine fever virus (ASFV) on host miRNAs. Small RNA sequencing libraries were prepared from RNA extracted from ASFV (Benin 97/1) infected primary porcine macrophages at 0, 6 and 16 hours post infection. Libraries were pooled and sequenced on 1 lane of an Illumina HiSeq, yielding sequences aligning to a total of 247 different mature Sus scrofa miRNAs. On average, 3779095 (± 1911525) miRNA reads were obtained per sample. The results revealed no widespread modification to host miRNAs, though a number of specific miRNAs were differentially expressed during ASFV infection. Notably, a small number of miRNAs (Ssc-miR-10b, Ssc-miR-144 and Ssc-miR-486) were rapidly upregulated 2-6 fold within the first hour of infection.
Project description:Influenza A virus (IAV) lacks the enzyme for adding 5’ caps to its RNAs, and thus snatches the 5’ ends of host capped RNAs to prime transcription. Neither the preference of the host RNA sequences snatched, nor the effect of “cap-snatching” on host processes has been completely defined. Previous studies of influenza cap-snatching used poly(A)-selected RNA from infected cells or relied solely on annotated host protein-coding genes to define host mRNAs selected by the virus. To examine the substrate-product relationship between all host RNAs, including non-coding RNAs, and viral RNAs, we used an unbiased approach to identify the host and viral capped RNAs from IAV-infected cells. We demonstrate that IAV predominantly snatches caps from non-coding host RNAs, particularly U1 and U2 small nuclear RNAs (snRNAs). Because snRNAs regulate host mRNA processing, cap-snatching of snRNAs may constitute a means by which IAV hijacks host cell metabolism.
Project description:Using a crucifer-infecting strain of Tobacco Mosaic Virus (TMV-Cg) and Arabidopsis thaliana as a model system, we analyzed the viral small RNA profile in wild-type plants as well as rdr mutants by applying small RNA deep sequencing technology. Over 100,000 TMV-Cg-specific small RNA reads, mostly of 21- (78.4%) and 22-nucleotide (12.9%) in size and originating predominately (79.9%) from the genomic sense RNA strand, were captured at an early infection stage, yielding the first high-resolution small RNA map for a plant virus. The TMV-Cg genome harbored multiple, highly reproducible small RNA-generating hot spots that corresponded to regions with no apparent local hairpin-forming capacity. Significantly, both the rdr1 and rdr6 mutants exhibited globally reduced levels of viral small RNA production as well as reduced strand bias in viral small RNA population, revealing an important role for these host RDRs in viral siRNA biogenesis. In addition, an informatics analysis showed that a large set of host genes could be potentially targeted by TMV-Cg-derived siRNAs for posttranscriptional silencing, raising the interesting possibility for a hidden layer of widespread virus-host interactions that may contribute to viral pathogenicity and host specificity. Profiling of TMV-Cg derived small RNAs in systemically infected tissues of wild type (Col-0) Arabidopsis as well as the rdr1and rdr6 mutants, at 3 days post-infection.