Regulation of herpesvirus lifecycle by viral microRNAs.

Human herpesviruses have latency and lytic replication phases in their lifecycle. Proper regulation of herpesviral lifecycle is essential for the evasion of host immune surveillance and development of their related diseases. Recent advancements indicate a role of a novel class of viral non-coding RNAs, microRNA (miRNA), in the fine-tuning of herpesviral lifecycle. So far, herpesviral miRNAs appear to promote viral latency by inhibiting viral lytic replication either through direct targeting of key viral replication genes or through manipulation of host pathways that regulate viral lifecycle. The oncogenic Kaposi sarcoma-associated herpesvirus (KSHV) has adapted both strategies to control viral latency. Our recent study has identified a KSHV miRNA that inhibits viral lytic replication by upregulating the NFκB pathway.