Project description:We report the regulatory chromatin of the chromosomally integrated HHV6 genome. Using ChIP-seq analysis, we find that the integrated virus is transcriptionally inactive and is enriched with distinct patterns of posttranslational histone modifications and TRF1/2.
Project description:We report the regulatory chromatin of the chromosomally integrated HHV6 genome. Using MNase-seq titration analysis, we find that the integrated virus in both patient and experimental infections that the HHV6 genome is tightly compacted with limited accessibility.
Project description:Human herpesvirus-6A (HHV-6A) and 6B (HHV-6B) are two closely related betaherpesviruses that are associated with various diseases including seizures and encephalitis. The HHV-6A/B genomes have been shown to be present in an integrated state in the telomeres of latently infected cells. In addition, integration of HHV-6A/B in germ cells has resulted in individuals harboring this inherited chromosomally integrated HHV-6A/B (iciHHV-6) in every cell of their body. Until now, the viral transcriptome and the epigenetic modifications that contribute to the silencing of the integrated virus genome remain elusive. In the current study, we used a patient-derived iciHHV-6A cell line to assess the global viral gene expression profile by RNA-seq, and the chromatin profiles by MNase-seq and ChIP-seq analyses. In addition, we investigated an in vitro generated cell line (293-HHV-6A) that expresses GFP upon the addition of agents commonly used to induce herpesvirus reactivation such as TPA. No viral gene expression including miRNAs was detected from the HHV-6A genomes, indicating that the integrated virus is transcriptionally silent. Intriguingly, upon stimulation of the 293-HHV-6A cell line with TPA, only foreign promoters in the virus genome were activated, while all HHV-6A promoters remained completely silenced. The transcriptional silencing of latent HHV-6A was further supported by MNase-seq results, which demonstrate that the latent viral genome resides in a highly condensed nucleosome-associated state. We further explored the enrichment profiles of histone modifications via ChIP-seq analysis. Our results indicated that the HHV-6 genome is modestly enriched with the repressive histone marks H3K9me3/H3K27me3 and does not possess the active histone modifications H3K27ac/H3K4me3. Overall, these results indicate that HHV-6 genomes reside in a condensed chromatin state, providing insight into the epigenetic mechanisms associated with the silencing of the integrated HHV-6A genome.
Project description:We report the gene expression of HHV6 infected cells using RNA-seq and small RNA-seq. We find that the integrated virus is transcriptionally inactive.
Project description:We report the application of size selection of small RNA species isolated from Jjhan cells harboring the human herpesvirus 6A genome. We ammassed >3.4million reads of sequence from three different sources: Normal Brain cell total RNA, Jjhan total RNA and HHV-6A BAC transfected Jjhan total RNA. Sequences were mapped to the HHV-6A Uganda 1102 strain genome (GenBank: X83413.1) with no less than 100% match for reads >20nt and <23nt. The resulting pool of candidates was mapped to the HHV-6A genome. Single pass 36nt sequencing of samples either with or without HHV-6a genomes present.