Cellular MicroRNAs 498 and 320d Regulate Herpes Simplex Virus 1 Induction of Kaposi’s Sarcoma-Associated Herpesvirus Lytic Replication by Targeting RTA

Qin Yan,Di Qin,Zhiqiang Bai,Qiao Tang,Yi Zeng,Chun Lu,Ninghan Feng,Shuihong Yao,Xinting Ma,Wan Li,Zhigang Lv

doi:10.1371/journal.pone.0055832

Abstract

Kaposi’s sarcoma-associated herpesvirus (KSHV) infection was necessary but not sufficient for KS development without other cofactors. We have previously reported that herpes simplex virus (HSV)-1 was an important cofactor that reactivated KSHV from latency by inducing the expression of KSHV replication and transcription activator (RTA), the lytic switch protein. Here, we further investigated the possible cellular microRNAs (miRNAs) involved in regulation of RTA during HSV-1-induced KSHV replication. The differential profiles of miRNAs expression between Mock- and HSV-1-infected body cavity-based lymphoma (BCBL-1) cells were identified by miRNA microarray analysis. Bioinformatics and luciferase reporter analyses showed that two of the HSV-1-downregulated cellular miRNAs, miR-498 and miR-320d, directly targeted the 3′ untranslated region (UTR) of KSHV RTA. As a result, overexpression of these two miRNAs significantly inhibited HSV-1-induced KSHV replication, whereas repression of these miRNAs with specific suppressors enhanced HSV-1-mediated KSHV replication. In addition, miR-498 or miR-320d alone, without HSV-1 infection, regulated KSHV replication in BCBL-1 cells. Finally, bioinformatics Gene Ontology (GO) analysis indicated that targets of HSV-1-regulated miRNAs were enriched for proteins, whose roles were involved in protein binding, enzyme activity, biological regulation, and several potential signaling pathways including transforming growth factor (TGF)-β were likely to participate in HSV-1-induced KSHV replication. Collectively, these novel findings demonstrated that host-encoded miR-498 and miR-320d regulated HSV-1 induction of KSHV lytic replication by targeting RTA, which provided further insights into the molecular mechanisms controlling KSHV lytic replication.

Highlights

Kaposi’s sarcoma-associated herpesvirus (KSHV), called human herpesvirus (HHV)-8, was first identified in 1994 [1]
To determine if cellular miRNAs were involved in herpes simplex virus (HSV)-1-induced KSHV replication, we examined the effect of HSV-1 infection of body-cavity-based lymphoma (BCBL)-1 cells on the expression of cellular miRNAs
Since our previous study have shown that HSV-1 infection of BCBL-1 cells increased KSHV gene expression as early as 3 h post-infection [9], we detected the expression of miR-498 and miR-320d after HSV-1 infection of BCBL-1 cells for 0, 3, 6, and 12 h

Summary

Introduction

Kaposi’s sarcoma-associated herpesvirus (KSHV), called human herpesvirus (HHV)-8, was first identified in 1994 [1]. KSHV is strongly associated with the B-cell proliferative disorder primary effusion lymphoma [PEL, termed body-cavity-based lymphoma (BCBL)] and some cases of multicentric Castleman’s disease [2]. KSHV displays two distinct life stages, latency and lytic replication. Once KSHV is reactivated from latency and enters the lytic cycle, most viral genes are expressed in an orderly fashion [immediate-early (IE), early and late], leading to the production of infectious virions [2]. Both latent and lytic genes have a role in KSHV pathogenesis, and the balance between latency and lytic replication contributes to KS development

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