Streptomyces Extract Inhibits Enterovirus 71 Replication by Activation of PKB/AKT Signaling

Enterovirus 71 (EV71) is a main pathogen of hand-foot, and mouth disease (HFMD) in children and adults. HFMD is a disease that causes small blisters in the mouth and hands and feet. Although blisters are usually disappeared one to two weeks after infection, HFMD is a serious disease that can lead to encephalitis and manic diseases depending on the patient. However, a representative vaccine and treatment for HFMD have not been developed yet. In this study, we investigated the antiviral effect of Streptomyces sp. zx10-19 (KH29) extract (0.1 ~ 100 g/) using EV71 infected HeLa cells. KH29 extract (100 g/) treatment significantly inhibited expression of EV71 capsid protein VP1 and cleavage of translation initiation factor eIF4G1. In addition, PKB/AKT activity was significantly increased by KH29 extract treatment. In the reverse transcription-PCR, KH29 extract treatment significantly inhibited EV71 a positive and negative-strand RNA genome amplification at 100 ug/ml. Moreover, the downstream signal molecule GSK3-beta and NF-B phosphorylation were significantly increased following AKT activation in KH29 extract treatment. These results suggest that KH29 extract may increases cell survival through AKT signaling and effectively inhibit the proliferation of EV71, which will be used as an effective substance for the development of therapeutic agents for EV71-induced HFMD.