Project description:To investigate how Roquin regulates cellular transcripts during Human cytomegalovirus (HCMV) infection, we examined the levels of cellular transcripts in cells treated control or Roquin-targeting siRNA during HCMV replication. Also, we performed Roquin crosslinking and immunoprecipitation followed by high-throughput sequencing (Roquin CLIP-seq) in HCMV-infected cells to identify which transcripts are directly bound by Roquin.
Project description:Primary infection with Human cytomegalovirus (HCMV) results in a persistent lifelong infection due to its ability to establish latent infection. During productive HCMV infection, viral genes are expressed in a coordinated cascade that is characteristic of all herpesviruses and traditionally relies on the dependencies of viral genes on protein synthesis and viral DNA replication. In contrast, the transcriptional landscape associated with HCMV latency is still disputed and poorly understood. Here, we examine viral transcriptomic dynamics during the establishment of both productive and latent HCMV infections. These temporal measurements reveal that viral gene expression dynamics along productive infection and their dependencies on protein synthesis and viral DNA replication, do not fully align. This illustrates that the regulation of herpesvirus genes does not represent a simple sequential transcriptional cascade and surprisingly many viral genes are regulated by multiple independent modules. Using our improved classification of viral gene expression kinetics in conjunction with transcriptome-wide measurements of the effects of a wide array of chromatin modifiers, we unbiasedly show that a defining characteristic of latent cells is the unique repression of immediate early (IE) genes. In particular, we demonstrate that IE1 (a central IE protein) expression is the principal barrier for achieving a full productive cycle. Altogether, our findings provide an unbiased and elaborate definition of HCMV gene expression in lytic and latent infection states.
Project description:Small, compact genomes confer a selective advantage to viruses, yet human cyto-megalovirus (HCMV) expresses the long non-coding RNAs (lncRNAs); RNA1.2, RNA2.7, RNA4.9, and RNA5.0. Little is known about the function of these lncRNAs in the virus life cycle. Here, we dissected the functional and molecular landscape of HCMV lncRNAs. We found that HCMV lncRNAs occupy ~30 % and 50~60 % of to-tal and poly(A)+ viral transcriptome, respectively, throughout virus life cycle. RNA1.2, RNA2.7, and RNA4.9, the three abundantly expressed lncRNAs, appear to be es-sential in all infection states. Among these three lncRNAs, depletion of RNA2.7 and RNA4.9 results in the greatest defect in maintaining latent reservoir and promoting lytic replication, respectively. Moreover, we delineated the global post-transcriptional nature of HCMV lncRNAs by nanopore direct RNA sequencing and interactome analysis. We revealed that the lncRNAs are modified with N⁶-methyladenosine (m6A) and interact with m6A readers in all infection states. In-depth analysis demonstrated that m6A machineries stabilize HCMV lncRNAs, which could account for the over-whelming abundance of viral lncRNAs. Our study lays the groundwork for under-standing the viral lncRNA–mediated regulation of host-virus interaction throughout the HCMV life cycle.
Project description:Small, compact genomes confer a selective advantage to viruses, yet human cyto-megalovirus (HCMV) expresses the long non-coding RNAs (lncRNAs); RNA1.2, RNA2.7, RNA4.9, and RNA5.0. Little is known about the function of these lncRNAs in the virus life cycle. Here, we dissected the functional and molecular landscape of HCMV lncRNAs. We found that HCMV lncRNAs occupy ~30 % and 50~60 % of to-tal and poly(A)+ viral transcriptome, respectively, throughout virus life cycle. RNA1.2, RNA2.7, and RNA4.9, the three abundantly expressed lncRNAs, appear to be es-sential in all infection states. Among these three lncRNAs, depletion of RNA2.7 and RNA4.9 results in the greatest defect in maintaining latent reservoir and promoting lytic replication, respectively. Moreover, we delineated the global post-transcriptional nature of HCMV lncRNAs by nanopore direct RNA sequencing and interactome analysis. We revealed that the lncRNAs are modified with N⁶-methyladenosine (m6A) and interact with m6A readers in all infection states. In-depth analysis demonstrated that m6A machineries stabilize HCMV lncRNAs, which could account for the over-whelming abundance of viral lncRNAs. Our study lays the groundwork for under-standing the viral lncRNA–mediated regulation of host-virus interaction throughout the HCMV life cycle.
Project description:Purpose: to investigate the role of the HCMV immediate early proteins in controlling the HCMV and cellular epigneomes during lytic infectioin
Project description:We have established that human cytomegalovirus (HCMV) infection modulates the biology of target primary blood monocytes, allowing HCMV to use monocytes as 'vehicles' for its systemic spread. HCMV infection of monocytes results in rapid induction of PI(3)K and NF-kB activity. Integrins, which are upstream of the PI(3)K and NF-kB pathways, were shown to be involved in HCMV binding to and entry into fibroblasts, suggesting that receptor-ligand-mediated signaling following viral binding to integrins on monocytes could trigger the functional changes seen in infected monocytes. We now show that integrin engagement and the activation of the integrin/Src-signaling pathway is essential for the induction of HCMV-infected monocyte motility. To investigate how integrin engagement by HCMV triggers monocyte motility, we examined the infected monocyte transcriptome and found that the integrin/Src-signaling pathway regulates the expression of paxillin, which is an important signal transducer in the regulation of actin rearrangement during cell adhesion and movement. Functionally, we observed that paxillin is activated via the integrin/Src-signaling pathway and is required for monocyte motility. Because motility is intimately connected to cellular cytoskeletal organization, a process that is also important in viral entry, we investigated the role paxillin regulation plays in the process of viral entry of monocytes. New results confirmed that HCMV`s ability to enter target monocytes is significantly inhibited in cells deficient in paxillin expression or that had their integrin/Src/paxillin signaling pathway blocked. From our data, HCMV-cell interactions emerge as an essential trigger for the cellular changes that allow for HCMV entry and hematogenous dissemination. Monocytes were mock-infected, HCMV-infected, or pretreated with PP2 inhibitor prior to HCMV infection. There were three samples analyzed per individual replicate. Three replicates are included. comparative studies with a use of the specific Src kinase activity inhibitor
Project description:Peroxisomes are primarily metabolic organelles with important functions in lipid metabolism, such as fatty acid oxidation and ether phospholipid synthesis (e.g. plasmalogens). Certain viruses, such as human cytomegalovirus (HCMV), hijack organelle functions to facilitate their replication and spread. However, the role of peroxisomes in herpesvirus replication remains elusive. Following a discovery that peroxisome proteins are upregulated upon HCMV infection, we quantified the production of plasmalogens, lipids that require peroxisome functions. In agreement with the increase in peroxisome protein abundance, plasmalogen production was increased by HCMV infection.
Project description:Genome-wide profiling establishes that human cytomegalovirus (HCMV) exerts an extensive, unforeseen level of specific control over which cellular mRNAs are recruited to or excluded from polyribosomes. The landscape of translationally-regulated host mRNAs regulates HCMV replication. The HCMV imposed translational signature shares similarities with cancer cells Two biological replicate experiments were performed profiling total and polysomal mRNAs from i) HCMV-infected vs mock-infected cells and ii) uninfected cells transduced with a lentivirus expressing doxycyclin (dox)-inducible HCMV UL38 +/- dox. Analysis of translationally-controlled host genes in HCMV-infected cell and cells expressing the HCMV UL38 gene product
Project description:HCMV treated and control human primary adult neural precursor cells (isolated from hippocampus) were used at passages 2-4 for infection with HCMV and RNA was harvested at indicated times