Identification and analysis of expression of novel microRNAs of murine gammaherpesvirus 68

Murine gammaherpesvirus 68 (MHV-68) is closely related to Epstein-Barr virus (EBV) and Kaposi’s sarcoma-associated herpesvirus (KSHV) and provides a small animal model to study the pathogenesis of gammaherpesvirus (?HV) infections. To completely explore the potential of the MHV-68 system for the investigation of gHV miRNAs, it would be desirable to know the number and expression patterns of all miRNAs encoded by MHV-68. By using small RNA deep sequencing, we systematically investigated the MHV-68 miRNA expression profiles in both lytically and persistently infected cells. In addition to the known nine MHV-68 miRNAs, we identified six novel MHV-68 miRNA genes and analyzed the expression levels of all MHV-68 miRNAs. Furthermore, we also characterized the cellular miRNA expression signatures in MHV-68 infected versus non-infected NIH3T3 fibroblasts and in TPA-treated versus non-treated S11 cells. We found that mmu-mir-15b and mmu-mir-16 are highly upregulated upon MHV-68 infection of NIH3T3 cells, indicating a potential role of cellular miRNAs during MHV-68 infection. Our data will aid to fully explore the functions of gHV miRNAs. Overall design: A mouse fibroblast cell line infected with/without MHV-68 and a MHV-68 infected mouse B lymphoma cell line treated with/without TPA (4 samples in total) were examined.