A human herpesvirus 6A-encoded microRNA: role in viral lytic replication.
Nukui Masatoshi,Mori Yasuko,Murphy Eain A
Journal of virology
UNLABELLED:Human herpesvirus 6A (HHV-6A), a member of the betaherpesvirus family, is associated with several human diseases. Like all herpesviruses, HHV-6A establishes a lifelong, latent infection in its host. Reactivation of HHV-6A is frequent within the immunosuppressed and immunocompromised populations and results in lytic viral replication within multiple organs, often leading to severe disease. MicroRNAs (miRNAs) are key regulators of multiple cellular processes that regulate the translation of specific transcripts. miRNAs carried by herpesviruses play important roles in modulating the host cell, thereby facilitating a suitable environment for productive viral infection and/or latency. Currently, there are approximately 150 known human herpesvirus-encoded miRNAs, although an miRNA(s) encoded by HHV-6A has yet to be reported. We hypothesized that HHV-6A, like other members of the human herpesvirus family, encodes miRNAs, which function to promote viral infection. We utilized deep sequencing of small RNA species isolated from cells harboring HHV-6A to identify five novel small noncoding RNA species that originate from the viral genome, one of which has the characteristics of a viral miRNA. These RNAs are expressed during productive infection by either bacterial artificial chromosome (BAC)-derived virus in Jjhan cells or wild-type HHV-6A strain U1102 virus in HSB2 cells and are associated with the RNA induced silencing complex (RISC) machinery. Growth analyses of mutant viruses that lack each individual miRNA revealed that a viral miRNA candidate (miR-U86) targets the HHV-6A IE gene U86, thereby regulating lytic replication. The identification and biological characterization of this HHV-6A-specific miRNA is the first step to defining how the virus regulates its life cycle. IMPORTANCE:A majority of the human population is infected with human herpesvirus 6A (HHV-6A), a betaherpesvirus family member. Infections usually occur in young children, and upon resolution, the virus remains in a latent state within the host. Importantly, during times of weakened immune responses, the virus can reactivate and is correlated with significant disease states. Viruses encode many different types of factors that both undermine the host antiviral response and regulate viral replication, including small RNA species called microRNAs (miRNAs). Here we report that HHV-6A encodes at least one miRNA, which we named miR-U86. We have characterized the requirement of this viral miRNA and its impact on the viral life cycle and found that it functions to regulate a viral protein important for efficient viral replication. Our data suggest that viral miRNAs are important for HHV-6A and that they may serve as an important therapeutic target to inhibit the virus.
10.1128/JVI.02007-14
Are miRNAs critical determinants in herpes simplex virus pathogenesis?
Bhela Siddheshvar,Rouse Barry T
Microbes and infection
miRNAs are small noncoding RNA that play a crucial role in gene regulation by inhibiting translation or promoting mRNA degradation. Viruses themselves express miRNAs that can target either the host or viral mRNA transcriptome. Moreover, viral infection of cells causes a drastic change in host miRNAs. This complex interaction between the host and viruses often favors the virus to evade immune elimination and favors the establishment and maintenance of latency. In this review we discuss the function of both host and viral miRNAs in regulating herpes simplex virus pathogenesis and also discuss the prospect of using miRNAs as biomarkers and therapeutic tools.
10.1016/j.micinf.2017.12.007
Role of Viral and Host microRNAs in Immune Regulation of Epstein-Barr Virus-Associated Diseases.
Iizasa Hisashi,Kim Hyoji,Kartika Andy Visi,Kanehiro Yuichi,Yoshiyama Hironori
Frontiers in immunology
Epstein-Barr virus (EBV) is an oncogenic human herpes virus that was discovered in 1964. Viral non-coding RNAs, such as HI-A rightward fragment-derived microRNAs (BART miRNAs) or HI-H rightward fragment 1-derived miRNAs (BHRF1 miRNA) in EBV-infected cells have been recently reported. Host miRNAs are also upregulated upon EBV infection. Viral and host miRNAs are important in maintaining viral infection and evasion of host immunity. Although miRNAs in EBV-infected cells often promote cell proliferation by targeting apoptosis or cell cycle, this review focuses on the regulation of the recognition of the host immune system. This review firstly describes the location and organization of two clusters of viral miRNAs, then describes evasion from host immune surveillance systems by modulating viral gene expression or inhibiting innate and acquired immunity by viral miRNAs as well as host miRNAs. Another topic is the enigmatic depletion of viral miRNAs in several types of EBV-infected tumor cells. Finally, this review introduces the strong correlation of nasopharyngeal cancer cases with a newly identified single nucleotide polymorphism that enhances BART miRNA promoter activity.
10.3389/fimmu.2020.00367
Effect of Loss-of-function of the Herpes Simplex Virus-1 microRNA H6-5p on Virus Replication.
Huang Rongquan,Zhou Xusha,Ren Shuqi,Liu Xianjie,Han Zhiyuan,Zhou Grace Guoying
Virologica Sinica
To date, 29 distinct microRNAs (miRNAs) have been reported to be expressed during herpes simplex virus infections. Sequence analysis of mature herpes simplex virus-1 (HSV-1) miRNAs revealed five sets of miRNAs that are complementary to each other: miR-H6-5p/H1-3p, miR-H6-3p/H1-5p, H2-5p/H14-3p, miR-H2-3p/H14-5p, and miR-H7/H27. However, the roles of individual miRNAs and consequences of this complementarity remain unclear. Here, we focus on two of these complementary miRNAs, miR-H6-5p and miR-H1-3p, using loss-of-function experiments in vitro and in a mouse model of infection using an miRNA sponge approach, including tandem multiplex artificial miRNA-binding sequences that do not match perfectly to the target miRNA inserted downstream of a green fluorescent protein reporter gene. Infection with recombinant virus expressing the miR-H6-5p sponge reduced viral protein levels and virus yield. Decreased accumulation of viral proteins was also observed at early stages of infection in the presence of both an miR-H6-5p inhibitor and plasmid-expressed miR-H1-3p. Moreover, establishment of latency and reactivation did not differ between the recombinant virus expressing the miR-H6-5p sponge and wild-type HSV-1. Taken together, these data suggest that miR-H6-5p has an as-yet-unidentified role in the early stages of viral infection, and its complement miR-H1-3p suppresses this role in later stages of infection. This report extends understanding of the roles of miRNAs in infection by herpes simplex viruses, supporting a model of infection in which the production of virus and its virulent effects are tightly controlled to maximize persistence in the host and population.
10.1007/s12250-019-00111-6
The Role of microRNAs in the Pathogenesis of Herpesvirus Infection.
Piedade Diogo,Azevedo-Pereira José Miguel
Viruses
MicroRNAs (miRNAs) are small non-coding RNAs important in gene regulation. They are able to regulate mRNA translation through base-pair complementarity. Cellular miRNAs have been involved in the regulation of nearly all cellular pathways, and their deregulation has been associated with several diseases such as cancer. Given the importance of microRNAs to cell homeostasis, it is no surprise that viruses have evolved to take advantage of this cellular pathway. Viruses have been reported to be able to encode and express functional viral microRNAs that target both viral and cellular transcripts. Moreover, viral inhibition of key proteins from the microRNA pathway and important changes in cellular microRNA pool have been reported upon viral infection. In addition, viruses have developed multiple mechanisms to avoid being targeted by cellular microRNAs. This complex interaction between host and viruses to control the microRNA pathway usually favors viral infection and persistence by either reducing immune detection, avoiding apoptosis, promoting cell growth, or promoting lytic or latent infection. One of the best examples of this virus-host-microRNA interplay emanates from members of the Herperviridae family, namely the herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2), human cytomegalovirus (HCMV), human herpesvirus 8 (HHV-8), and the Epstein-Barr virus (EBV). In this review, we will focus on the general functions of microRNAs and the interactions between herpesviruses, human hosts, and microRNAs and will delve into the related mechanisms that contribute to infection and pathogenesis.
10.3390/v8060156
Viral miRNAs Alter Host Cell miRNA Profiles and Modulate Innate Immune Responses.
Frontiers in immunology
Prevalence of the members of herpesvirus family in oral inflammatory diseases is increasingly acknowledged suggesting their likely role as an etiological factor. However, the underlying mechanisms remain obscure. In our recent miRNA profiling of healthy and diseased human tooth pulps, elevated expression of human herpesvirus encoded viral microRNAs (v-miRs) were identified. Based on the fold induction and significance values, we selected three v-miRs namely miR-K12-3-3p [Kaposi sarcoma-associated virus (KSHV)], miR-H1 [herpes simplex virus 1 (HSV1)], and miR-UL-70-3p [human cytomegalovirus (HCMV)] to further examine their impact on host cellular functions. We examined their impact on cellular miRNA profiles of primary human oral keratinocytes (HOK). Our results show differential expression of several host miRNAs in v-miR-transfected HOK. High levels of v-miRs were detected in exosomes derived from v-miR transfected HOK as well as the KSHV-infected cell lines. We show that HOK-derived exosomes release their contents into macrophages (Mφ) and alter expression of endogenous miRNAs. Concurrent expression analysis of precursor (pre)-miRNA and mature miRNA suggest transcriptional or posttranscriptional impact of v-miRs on the cellular miRNAs. Employing bioinformatics, we predicted several pathways targeted by deregulated cellular miRNAs that include cytoskeletal organization, endocytosis, and cellular signaling. We validated three novel targets of miR-K12-3-3p and miR-H1 that are involved in endocytic and intracellular trafficking pathways. To evaluate the functional consequence of this regulation, we performed phagocytic uptake of labeled bacteria and noticed significant attenuation in miR-H1 and miR-K12-3-3p but not miR-UL70-3p transfected primary human Mφ. Multiple cytokine analysis of challenged Mφ revealed marked reduction of secreted cytokine levels with important roles in innate and adaptive immune responses suggesting a role of v-miRs in immune subversion. Our findings reveal that oral disease associated v-miRs can dysregulate functions of key host cells that shape oral mucosal immunity thus exacerbating disease severity and progression.
10.3389/fimmu.2018.00433
The Diverse Roles of microRNAs at the Host⁻Virus Interface.
Bernier Annie,Sagan Selena M
Viruses
MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression at the post-transcriptional level. Through this activity, they are implicated in almost every cellular process investigated to date. Hence, it is not surprising that miRNAs play diverse roles in regulation of viral infections and antiviral responses. Diverse families of DNA and RNA viruses have been shown to take advantage of cellular miRNAs or produce virally encoded miRNAs that alter host or viral gene expression. MiRNA-mediated changes in gene expression have been demonstrated to modulate viral replication, antiviral immune responses, viral latency, and pathogenesis. Interestingly, viruses mediate both canonical and non-canonical interactions with miRNAs to downregulate specific targets or to promote viral genome stability, translation, and/or RNA accumulation. In this review, we focus on recent findings elucidating several key mechanisms employed by diverse virus families, with a focus on miRNAs at the host⁻virus interface during herpesvirus, polyomavirus, retroviruses, pestivirus, and hepacivirus infections.
10.3390/v10080440
Herpes Simplex Virus 1 Deregulation of Host MicroRNAs.
Cokarić Brdovčak Maja,Zubković Andreja,Jurak Igor
Non-coding RNA
Viruses utilize microRNAs (miRNAs) in a vast variety of possible interactions and mechanisms, apparently far beyond the classical understanding of gene repression in humans. Likewise, herpes simplex virus 1 (HSV-1) expresses numerous miRNAs and deregulates the expression of host miRNAs. Several HSV-1 miRNAs are abundantly expressed in latency, some of which are encoded antisense to transcripts of important productive infection genes, indicating their roles in repressing the productive cycle and/or in maintenance/reactivation from latency. In addition, HSV-1 also exploits host miRNAs to advance its replication or repress its genes to facilitate latency. Here, we discuss what is known about the functional interplay between HSV-1 and the host miRNA machinery, potential targets, and the molecular mechanisms leading to an efficient virus replication and spread.
10.3390/ncrna4040036
MicroRNAs in large herpesvirus DNA genomes: recent advances.
Sorel Océane,Dewals Benjamin G
Biomolecular concepts
MicroRNAs (miRNAs) are small non-coding RNAs (ncRNAs) that regulate gene expression. They alter mRNA translation through base-pair complementarity, leading to regulation of genes during both physiological and pathological processes. Viruses have evolved mechanisms to take advantage of the host cells to multiply and/or persist over the lifetime of the host. Herpesviridae are a large family of double-stranded DNA viruses that are associated with a number of important diseases, including lymphoproliferative diseases. Herpesviruses establish lifelong latent infections through modulation of the interface between the virus and its host. A number of reports have identified miRNAs in a very large number of human and animal herpesviruses suggesting that these short non-coding transcripts could play essential roles in herpesvirus biology. This review will specifically focus on the recent advances on the functions of herpesvirus miRNAs in infection and pathogenesis.
10.1515/bmc-2016-0017
Herpesviruses hijack host exosomes for viral pathogenesis.
Sadeghipour Sara,Mathias Rommel A
Seminars in cell & developmental biology
Herpesviruses are remarkable pathogens possessing elaborate mechanisms to seize various host cellular components for immune evasion, replication, and virion egress. As viruses are dependent upon their hosts, investigating this intricate interplay has revealed that the exosome pathway is utilised by alpha (Herpes Simplex Virus 1), beta (Human Cytomegalovirus, and Human Herpesvirus 6) and gamma (Epstein-Barr Virus, and Kaposi Sarcoma-associated Herpesvirus) herpesviruses. Virions and exosomes share similar properties and functions. For example, exosomes are small membranous nanovesicles (30-150nm) released from cells that contain proteins, DNA, and various coding and non-coding RNA species. Given exosomes can shuttle various molecular cargo from a donor to recipient cell, they serve as important vehicles facilitating cell-cell communication. Therefore, exploitation by herpesviruses impacts several aspects of infection including: i) acquisition of molecular machinery for secondary envelopment and viral assembly, ii) export of immune-related host proteins from infected cells, iii) enhancing infection in surrounding cells via transfer of viral proteins, mRNA and miRNA, and iv) regulation of viral protein expression to promote persistence. Studying the dichotomy that exists between host exosomes and herpesviruses has two benefits. Firstly, it will reveal the precise pathogenic mechanisms viruses have evolved, generating knowledge for antiviral development. Secondly, it will shed light upon fundamental exosome characteristics that remain unknown, including cargo selection, protein trafficking, and non-canonical biogenesis.
10.1016/j.semcdb.2017.03.005
Varicella-Zoster Virus Expresses Multiple Small Noncoding RNAs.
Markus Amos,Golani Linoy,Ojha Nishant Kumar,Borodiansky-Shteinberg Tatiana,Kinchington Paul R,Goldstein Ronald S
Journal of virology
Many herpesviruses express small noncoding RNAs (sncRNAs), including microRNAs (miRNAs), that may play roles in regulating lytic and latent infections. None have yet been reported in varicella-zoster virus (VZV; also known as human herpesvirus 3 [HHV-3]). Here we analyzed next-generation sequencing (NGS) data for small RNAs in VZV-infected fibroblasts and human embryonic stem cell-derived (hESC) neurons. Two independent bioinformatics analyses identified more than 20 VZV-encoded 20- to 24-nucleotide RNAs, some of which are predicted to have stem-loop precursors potentially representing miRNAs. These sequences are perfectly conserved between viruses from three clades of VZV. One NGS-identified sequence common to both bioinformatics analyses mapped to the repeat regions of the VZV genome, upstream of the predicted promoter of the immediate early gene open reading frame 63 (ORF63). This miRNA candidate was detected in each of 3 independent biological repetitions of NGS of RNA from fibroblasts and neurons productively infected with VZV using TaqMan quantitative PCR (qPCR). Importantly, transfected synthetic RNA oligonucleotides antagonistic to the miRNA candidate significantly enhanced VZV plaque growth rates. The presence of 6 additional small noncoding RNAs was also verified by TaqMan qPCR in productively infected fibroblasts and ARPE19 cells. Our results show VZV, like other human herpesviruses, encodes several sncRNAs and miRNAs, and some may regulate infection of host cells. Varicella-zoster virus is an important human pathogen, with herpes zoster being a major health issue in the aging and immunocompromised populations. Small noncoding RNAs (sncRNAs) are recognized as important actors in modulating gene expression, and this study demonstrates the first reported VZV-encoded sncRNAs. Many are clustered to a small genomic region, as seen in other human herpesviruses. At least one VZV sncRNA was expressed in productive infection of neurons and fibroblasts that is likely to reduce viral replication. Since sncRNAs have been suggested to be potential targets for antiviral therapies, identification of these molecules in VZV may provide a new direction for development of treatments for painful herpes zoster.
10.1128/JVI.01710-17
Modulation of bovine herpesvirus 1 infection by virally encoded microRNAs.
Kanokudom Sitthichai,Mahony Timothy J,Smith Duncan R,Assavalapsakul Wanchai
Virus research
Bovine herpesvirus 1 (BoHV-1), is a member of the subfamily Alphaherpesvirinae in the order Herpesviridae and is a ubiquitous pathogen of cattle responsible for significant economic loss worldwide. The BoHV-1 genome encodes at least 10 BoHV-1 microRNA (miRNA) genes, whose functions remain poorly understood. This study sought to understand the role of three BoHV-1 miRNA genes, Bhv1-miR-B6, Bhv1-miR-B8 and Bhv1-miR-B9, which are located proximal to the BoHV-1 origins of replication (OriS). Therefore, plasmids expressing the precursor miRNA hairpins for the Bhv1-miR-B6, Bhv1-miR-B8, and Bhv1-miR-B9 genes were constructed and transfected into Madin-Darby bovine kidney cells prior to BoHV-1 infection. Interestingly, transient expression of either Bhv1-miR-B8 or Bhv1-miR-B9 in Madin-Darby bovine kidney cells prior to infection resulted in partial suppression of BoHV-1 replication, quantified through estimating levels of glycoprotein C mRNA and protein levels. Putative interactions between the mature miRNA bhv1-miR-B8-3p and bhv1-miR-B9 and BoHV-1 transcripts were identified providing plausible pathways for these molecules to affect virus replication. Therefore, these two miRNAs are implicated in the post-transcriptional regulation of BoHV-1 transcripts important for virus replication and could be used to limit BoHV-1 replication.
10.1016/j.virusres.2018.08.022
Role of microRNAs in herpesvirus latency and persistence.
Grey Finn
The Journal of general virology
The identification of virally encoded microRNAs (miRNAs) has had a major impact on the field of herpes virology. Given their ability to target cellular and viral transcripts, and the lack of immune response to small RNAs, miRNAs represent an ideal mechanism of gene regulation during viral latency and persistence. In this review, we discuss the role of miRNAs in virus latency and persistence, specifically focusing on herpesviruses. We cover the current knowledge on miRNAs in establishing and maintaining virus latency and promoting survival of infected cells through targeting of both viral and cellular transcripts, highlighting key publications in the field. We also discuss potential areas of future research and how novel technologies may aid in determining how miRNAs shape virus latency in the context of herpesvirus infections.
10.1099/vir.0.070862-0
[Progress on the Function of Herpesvirus-encoded MicroRNAs].
Cai Zhenzhen,Jia Renyong
Bing du xue bao = Chinese journal of virology
Since Epstein Barr virus was shown to encode microRNAs(miRNAs) in 2004, more than 470 miRNAs have been discovered in α-, β-, and γ-herpesviruses. MiRNAs are small non-coding RNA molecules and generally only have 18-25 nucleotides in length, which can regulate the expression of target genes by targeting its transcripts. Herpesvirus-encoded miRNAs not only target the key genes from latency to lytic replication, but also regulate various host cellular genes. Current data manifest that herpesvirus-encoded miRNAs can regulate viral latent infection and lytic replication, immune recognition, apoptosis, and tumorigenesis. The purpose of this paper is to summarize the targets and their fuction of hepesvirus-encoded miRNAs, in order to provide theoretical support for further analysis herpesviral pathogenesis.
Bovine herpesvirus 5 encodes a unique pattern of microRNAs compared with bovine herpesvirus 1.
Tang Qi,Wu Yi-Quan,Chen Dong-Sheng,Zhou Qing,Chen Huan-Chun,Liu Zheng-Fei
The Journal of general virology
Bovine herpesvirus type 5 (BoHV-5) and bovine herpesvirus 1 (BoHV-1) are two closely related viruses. However, BoHV-5 is responsible for fatal meningitis in calves, while BoHV-1 is associated with infectious rhinotracheitis in cattle, and the mechanism by which the two viruses cause different symptoms is not well understood. In this study, we identified 11 microRNA (miRNA) genes, encoded by the BoHV-5 genome, that were processed into 16 detectable mature miRNAs in productive infection as determined by deep sequencing. We found that 6 out of 16 miRNA genes were present as two copies in the internal repeat and terminal repeat regions, resulting in a total of 17 miRNA-encoding loci distributed in both DNA strands. Surprisingly, BoHV-5 shared only one conservative miRNA with BoHV-1, which was located upstream of the origin of replication. Furthermore, in contrast to BoHV-1, no miRNAs were detected in the unique short region and locus within or near the bovine infected-cell protein 0 and latency-related genes. Variations in both the 5' and 3' ends of the reference sequence were observed, resulting in more than one isoform for each miRNA. All of the 16 miRNAs were detectable by stem-loop reverse transcriptase-PCR. The miRNAs with high read numbers were subjected to Northern blot analysis, and all pre-miRNAs and one mature miRNA were detected. Collectively, the data suggest that BoHV-5 encodes a different pattern of miRNAs, which may regulate the life cycle of BoHV-5 and might account for the different pathogenesis of this virus compared with BoHV-1.
10.1099/vir.0.061093-0