Project description:Expression profiling of stably infected epithelial cells using a custom tiling microarray. iSLK was infected with rKSHV.219 and selected with puromycin. Mock infected iSLK served as control for iSLK.219. Lytic reactivation of iSLK.219 was induced with 1 ug/mL doxycycline for 48 hours.
Project description:Purpose: To characterize genome-wide mRNA expression profiles in the context of Kaposi's sarcoma-associated herpesvirus (KSHV) lytic reactivation. Methods: We utilized a well-established model of KSHV reactivation, the doxycycline (Dox)-inducible KSHV producer cell line iSLK.219, which contains a latent KSHV genome and a Dox-inducible KSHV lytic switch protein RTA (replication and transcription activator) to mediate efficient reactivation and entry into the lytic cycle upon Dox treatment. We performed mRNA-sequencing (mRNA-seq) of RNA isolated from latent KSHV-infected iSLK.219 cells at 0 h or lytic iSLK.219 cells at 72 h post Dox-induced KSHV lytic reactivation using Illumina. The mappable reads were aligned to the human genome or the KSHV genome using Bowtie. Results: We analyzed global transcriptome changes in iSLK.219 cells during the latency to lytic transition and found that reactivated lytic iSLK.219 cells exhibited an increased abundance of cellular genes involved in cell cycle, DNA replication, and nuclear division, consistent with lytic infection activating mitogenic signaling to support viral DNA replication. In addition, expression of key viral lytic genes with strong mitogenic activities, including vIL-6 (K2), K1, and the KSHV-encoded chemokines, vCCL1 (K6), vCCL2 (K4) and vCCL3 (K4.1), were markedly induced during lytic KSHV replication. Conclusions: These results confirm that the gene expression profile of reactivated lytic iSLK.219 cells exhibit some key hallmark features of KSHV lytic reactivation.
Project description:Purpose: To characterize genome-wide microRNA (miRNA) expression profiles in the context of Kaposi's sarcoma-associated herpesvirus (KSHV) lytic reactivation. Methods: We utilized a well-established model of KSHV reactivation, the doxycycline (Dox)-inducible KSHV producer cell line iSLK.219, which contains a latent KSHV genome and a Dox-inducible KSHV lytic switch protein RTA (replication and transcription activator) to mediate efficient reactivation upon Dox treatment. We performed small-RNA sequencing of RNA isolated from latent KSHV-infected iSLK.219 cells at 0 h or lytic iSLK.219 cells at 72 h post Dox-induced KSHV lytic reactivation using Illumina HiSeq 2500. To rule out the possibility that Dox itself can affect miRNA expression, we also performed small-RNA sequencing of RNA isolated from KSHV-negative iSLK cells, which lacks the KSHV genome but harbors the Dox-inducible RTA transgene, without Dox treatment at 0 h or at 72 h post Dox treatment. The mappable reads were aligned to the human genome and miRBase using Bowtie. Results: Global cellular miRNA transcriptome analysis has identified changes in the host miRNA expression landscape during the switch from latent to lytic KSHV replication. The top down-regulated miRNAs included miR-31-5p, miR-29a-3p, miR-181a-3p, miR-194-5p, and miR-449c-5p and the top up-regulated miRNAs included miR-139-5p, miR-7-5p, miR-210-3p and miR-3065-5p. We confirmed that Dox treatment in KSHV-negative iSLK cells did not significantly down-regulate or up-regulate these cellular miRNAs, indicating that Dox itself or RTA transgene expression alone does not affect the levels of these miRNAs. In addition, 8 KSHV-encoded miRNAs, including pre-miR-K12-12, were significantly up-regulated upon lytic reactivation in iSLK.219 cells. Notably, the top four up-regulated host miRNAs have been implicated in inflammatory signaling pathways involved in a productive or lytic cycle of infection, suggesting that KSHV exploits these immunomodulatory miRNAs to facilitate lytic reactivation. On the contrary, four out of the top five down-regulated host miRNAs, miR-29a-3p, miR-181a-3p, miR-194-5p, and 449c-5p have been implicated in restricting the infection and replication of RNA and DNA viruses. Taken together with our small-RNA sequencing analysis, these findings suggest that KSHV lytic reactivation impacts the cellular miRNA expression landscape as a strategy to evade or subvert host antiviral responses and ensure efficient lytic replication and persistence. Conclusions: Our study represents the first detailed analysis of genome-wide miRNA transcriptomes during KSHV lytic reactivation, with biological replicates, generated by miRNA-seq technology. Our study provides crucial insights into the impact of lytic KSHV infection on the host and viral miRNA expression landscapes. Moreover, our results identify a previously unappreciated role for miR-31-5p in regulating KSHV lytic reactivation by modulating KHDRBS3 expression.
Project description:Expression profiling of stably infected primary endothelial cells using a custom tiling microarray. LEC and BEC were infected with rKSHV.219 and selected with puromycin for 2 weeks. Mock infected LEC and BEC served as controls for their infected counterparts. All cells were harvested after 2 weeks of stable infection.
Project description:The goal of this analysis was to examine the cell-to-cell variation in Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation and type I interferon response after caspase inhibitor treatment. We profiled the levels of host and viral mRNAs at a single-cell level using the iSLK.219 tissue culture model system (Myoung and Ganem, 2011). We examined gene expression in lytically reactivating cells, lytically reactivating cells treated with caspase inhibitors, and lytically reactivating cells treated with casapse inhibitors and neutralizing antibodies against interferons. (we previously described that caspase inhibitors elicit an interferion response in KSHV-infected cells, Tabtieng et al., 2018). We also examined gene expression in a mixture of latently infected cells and uninfected cells as a control.
Project description:We used ac4C-seq to detedc cellular and KSHV transcripts in iSLK-Puro, iSLK-KSHV, iSLK-KSHV (WT), iSLK-KSHV (ΔNAT10) cells after after doxycycline and sodium butyrate treatment.
Project description:Expression profiling of stably infected primary endothelial cells using a custom tiling microarray. LEC, BEC, HUVEC, and HAEC were infected with rKSHV.219 and selected with puromycin for 2 weeks. Mock infected LEC, BEC, HUVEC, and HAEC served as controls for their infected counterparts. All cells were harvested after 2 weeks of stable infection.
Project description:To investigate the regulation of ER stress-related gene expression by KSHV-ORF45 during lytic replication, we performed RNA-sequencing analysis of iSLK-BAC16 vs. iSLK-STOP45 cells under lytic induction for 72h. When the differentially expressed genes were filtered and analyzed, we found that ER stress-related gene expression was much low in iSLK-STOP45 cells compared with iSLK-BAC16 cells, indicating that ORF45 expression is required for induction of ER stress.To further reveal the signal transduction of LAMP3 in KSHV lytic replication, RNA-sequencing analysis was performed to identify the differentially expressed genes (DEGs) in normal vs. LAMP3-silenced cells under lytic replication. A total of 35372 raw read targets were obtained and all DEG clusters were filtered and analyzed by KEGG pathway enrichment analysis. Eleven pathway were significantly enriched over 10 fold in LAMP3-depleted cells compared with control cells, including PI3K-Akt signaling pathway.Given that Akt and ERK activation play the important roles in KSHV lytic replication, we conclude that LAMP3 might promote Akt and ERK activation and then consequently facilitate KSHV lytic replication.
Project description:Methylation at the N6 position of adenosine (m6A) is a highly prevalent reversible modification within eukaryotic mRNAs that has been linked to many stages of RNA processing and fate. Recent studies suggest that m6A deposition and proteins involved in the m6A pathway play a diverse set of roles in either restricting or modulating the lifecycles of select viruses. Here, we report that m6A levels are significantly increased in cells infected with the oncogenic human DNA virus Kaposi’s sarcoma-associated herpesvirus (KSHV). Transcriptome-wide m6A-sequencing of the KSHV-positive renal carcinoma cell line iSLK.219 during lytic reactivation revealed the presence of m6A across multiple kinetic classes of viral transcripts, and a concomitant decrease in m6A levels across much of the host transcriptome.