Epstein‐Barr Viral microRNAs Coordinately Repress Human Transcripts in Inflammatory and Apoptotic Pathways

Abstract

Epstein–Barr virus (EBV) infects 95% of the world population and is involved in the pathogenesis of Burkitt's (B cell) lymphoma, nasopharyngeal carcinoma, and other cancers in humans. In various states of latent infection and disease, EBV differentially expresses at least 49 mature microRNAs (miRNAs) from two major genomic clusters.To identify potential miRNA‐mRNA pairs, we previously employed the high‐throughput sequencing and crosslinking immunoprecipitation (HITS‐CLIP) method to globally identify mRNA targets of both host and viral miRNAs expressed in unperturbed, EBV‐transformed B cells. Among the human transcripts regulated by EBV miRNAs (n = 1664), the most significantly enriched were involved in the regulation of transcription (n = 328) and apoptosis (n = 132). Detailed bioinformatic exploration of these transcripts predicted that the expression of ten or more key inflammatory/apoptosis proteins may be regulated by one or more EBV miRNAs.In the present study, we combined HITS‐CLIP and bioinformatic predictions with luciferase reporter assays and Western blot analyses to identify and experimentally validate at single‐nucleotide resolution the 3′‐untranslated regions of select apoptotic and inflammatory transcripts bound by EBV miRNAs. Our findings suggest that certain EBV miRNAs co‐target specific transcripts to deregulate the host signaling machinery in a very complex manner during latent infection.Support or Funding InformationK.R. is supported by Critchfield Research Grants, the Rollins Student‐Faculty Collaborative Scholarship Program, the Edward W. and Stella C. Van Houten Memorial Fund, and the Herbert E. Hellewege Research Fund.