Effect of KSHV lytic reactivation on host mRNA m5C modification landscape in lymphoma B cell

Herpesviruses are a group of double-stranded DNA viruses known to develop versatile viral strategies to escape host immune surveillance for promoting their replication and propagation. This is illustrated by Kaposi’s sarcoma-associated herpesvirus (KSHV), an oncogenic gamma-herpesvirus that overcomes host immune suppression by multiple mechanisms. In this study, we reported that KSHV dysregulates 5-methylcytosine (m5C) modification and mRNA stability of host antiviral factors to benefit its lytic replication. KSHV lytic reactivation or de novo challenge led to downregulation of m5C RNA methyltransferases, NSUN2 and NSUN1 (NSUN2/1), while NSUN2/1 depletion promoted KSHV lytic replication. We further performed the RNA bisulfite sequencing (RNA-BS-seq) to identify KSHV-dependent m5C modification of host mRNAs. Overall, our results highlighted a new strategy for human gamma-herpesviruses to counteract host antiviral factors and promote their lytic replication by manipulating host m5C RNA methylation. To study the impact of KSHV lytic reactivation on host mRNA modifications, we utilize TREx.BCBL1.Rta cell, a cell line with Doxcycline induced RTA expression system. TREx.BCBL1.Rta cells were treated with Doxcycline (2 ug/ml) for 48 hours to induce RTA expression and Lytic reactivation. We then perform RNA-BS-seq on the samples (with or without Dox treatment) with two biological repeats. Differential m5c sites were identified using meRanTk package between samples.