Viral miRNAs alter cellular miRNAs profiles

Prevalence of the members of herpesvirus family in oral inflammatory diseases is increasingly acknowledged suggesting their likely role as etiological factor. However, the underlying mechanisms remains obscure. In our recent miRNA profiling of healthy and diseased human tooth pulpal, elevated expression of HHV encoded v-miRs were identified. Based on the fold induction and significance values, we selected three v-miRs namely miR-K12-3-3p (KSHV), miR-H1 (HSV-1), and miR-UL-70-3p (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 latent KSHV infected cell lines. We show that HOK derived exosomes release their contents into macrophages (Mφ) and alter expression of endogenous miRNAs. Total RNA isolated from v-miRs (miR-H1, miR-K12-3-3p and miR-UL70-3p) or control mimic transfected human oral keratinocytes and primary human macrophages. Microarray ananlysis was performed to assess global changes in miRNA profiles using Exiqon miRCury LNA microarray.