High-resolution profiling and analysis of viral and host small RNAs during human cytomegalovirus infection

Small RNA deep sequencing analysis was conducted on primary human fibroblasts infected with human cytomegalovirus (HCMV). HCMV-encoded miRNAs accumulated to ~20% of the total smRNA population at late stages of infection, and our analysis led to improvements in viral miRNA annotations and identification of novel HCMV miRNAs. Through crosslinking and immunoprecipitation of Argonaute-bound RNAs from infected cells, followed by high-throughput sequencing (Ago CLIP-seq), we obtained direct evidence for incorporation of all HCMV miRNAs into the endogenous host silencing machinery. Additionally, significant upregulation was observed during infection for a host miRNA cluster containing miR-96, miR-182 and miR-183. We also identified novel non-miRNA forms of virus-derived smRNAs, revealing greater complexity within the smRNA population during HCMV infection. Overall design: High-throughput profiling of smRNAs, Ago1-, and Ago2-associated miRNAs from HCMV-infected fibroblast cells. Wild-type HCMV Towne (Genbank FJ616285.1) was used for these studies.