miRNA-mediated targeting of human cytomegalovirus reveals biological host and viral targets of IE2

We introduce target sites for the microRNA (miRNA) miR-142 into the 3'-untranslated region of the human cytomegalovirus (HCMV) IE2 to study the transcriptional effect of IE2 knock-down on both viral and host genes in cells that express miR-142. When comparing transcriptional data from miR-142 expressing macrophages infected with HCMV to macrophages infected with IE2-miR-142 targeted HCMV, we see a knock-down of IE2 and differential regulation of predicted viral targets of IE2 including IE1, vIL-10 and US29. We then generated fibroblasts expressing miR-142 to study the knock-down of IE2 in a different cellular system and find drastic differences in loss of IE2 on the host transcriptional profile in the two different cell types. Overall design: BW series: Fibroblasts (MRC-5) and macrophages (THP-1) infected with HCMV and miR-142 targeted HCMV for 24h to see immediate effect of IE2-knock down. CK series: Fibroblasts and macrophages infected with HCMV and miR-142 targeted HCMV for 9 days done in duplicate. EX series: miR-142 expressing fibroblasts infected with HCMV and miR-142 targeted HCMV for 9 days done in duplicate.