The Cellular Mirna, Mir-190, is Upregulated in Type I Ebv Latency by Ebers and Modulates Cellular Mrnas involved in Cell Survival and Viral Reactivation

Loading...
Thumbnail Image
Degree type
Doctor of Philosophy (PhD)
Graduate group
Cell & Molecular Biology
Discipline
Subject
EBERs
EBV
miRNA
Type I latency
Cell Biology
Molecular Biology
Virology
Funder
Grant number
License
Copyright date
2016-11-29T00:00:00-08:00
Distributor
Related resources
Author
Cramer, Elizabeth Mary
Contributor
Abstract

Epstein-Barr Virus (EBV) is a highly prevalent human pathogen infecting over 90% of the population. Much of the success of the virus is attributed to its ability to maintain latency through different programs in host cells. MicroRNAs (miRNA) are small, non-coding RNAs capable of post-transcriptionally regulating mRNA expression. A microarray comparison of EBV type I latency and type III latency infected cells yielded evidence of differential cellular microRNA expression. I hypothesized that one of these differentially upregulated type I latency miRNAs, miR-190, is important in maintenance of latency I, and miR-190 upregulation is due to viral gene expression. Lentiviral overexpression systems were used to overexpress miR-190 and a microarray of gene expression revealed candidate miR-190 targets, including: TP53INP1 and NR4A3. The modulation of these targets by miR-190 was confirmed through evaluating mRNA and protein level changes in the presence or absence of miR-190. In the case of TP53INP1, a 3’UTR target site was identified through mutagenesis. The effect of miR-190 expression was evaluated for markers of cell cycle and cell death by flow cytometry, western blot and RT-PCR. Measures of viral reactivation were lowered in the presence of miR-190 after induction by anti-IgG stimulation. I also observed upregulation of miR-190/Talin2 promoter activity or miR-190 expression in the presence of EBERs, Epstein-Barr encoded RNAs. Interestingly, a panel of type I latency cell lines had higher EBER1 expression compared to their type III latency counterparts. Work by others has indicated that EBERs activate the double-stranded RNA (dsRNA) sensor, retinoic acid-inducible gene 1 (RIG-I). Transiently expressed, constitutively activated RIG-I induced miR-190 expression and promoter activity. Knockdown of RIG-I in the type I latency cells yielded lowered miR-190 expression levels. To investigate how miR-190 is upregulated I generated miR-190/Talin2 promoter reporters that lacked YinYang1 (YY1) and Nuclear factor-κB (NF-kB) binding motifs. In the presence of EBERs, promoters with these deleted binding motifs had lowered activation compared to the full miR-190/TLN2 promoter. This work describes a mechanism by which EBERs upregulate a cellular miRNA, miR-190, which aids in type I latency preservation by preventing apoptosis, promoting cell cycle and maintaining virus in its latent state.

Advisor
Yan Yuan
Date of degree
2015-01-01
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Volume number
Issue number
Publisher
Publisher DOI
Journal Issue
Comments
Recommended citation