• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.600-606
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• 2023

Dengue virus (DENV) is a widespread arbovirus. To efficiently establish infection, DENV evolves multiple strategies to hijack the host innate immune response. Herein, we examined the inhibitory effects of DENV serotype 2 (DENV2) nonstructural proteins on RIG-I-directed antiviral immune response. We found that DENV2 NS2A, NS2B, NS4A, and NS4B significantly inhibited RIG-I-mediated IFN-β promoter activation. The roles of NS2B in RIG-I-directed antiviral immune response are unknown. Our study further showed that NS2B could dose-dependently suppress RIG-I/MAVS-induced activation of IFN-β promoter. Consistently, NS2B significantly decreased RIG-I- and MAVS-induced transcription of IFNB1, ISG15, and ISG56. Mechanistically, NS2B was found to interact with MAVS and IKKε to impair RIG-I-directed antiviral response. Our findings demonstrated a previously uncharacterized function of NS2B in RIG-I-mediated antiviral response, making it a promising drug target for anti-DENV treatments.

• Journal of Life Science
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• v.34 no.6
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• pp.408-417
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• 2024

It was confirmed whether PB-81, a 50% ethanol extract of Daphne genkwa (Siebold & Zucc), had an inhibitory effect on virus proliferation in bovine rotavirus and a therapeutic effect on bovine diarrhea disease. The results showed that PB-81 induced the interferon beta in A549 cells, an epithelial cell line and interferon gamma in NK92 cells, a blood cell line. Furthermore, to confirm the viral proliferation inhibitory effect of PB-81, PB-81 was administered to MBDK cell line before, during, and after infection. Result shows that the virus was suppressed in all cases where PB-81 was administered, and the best virus suppression effect was achieved when PB-81 was administered before virus infection. In the toxicity test in mice, no side effects due to toxicity were observed, even at a maximum dose of 20 mg/mL. To verify the therapeutic effect on 16 cattle with bovine rotavirus diarrhea and 4 cattle in the control group, PB-81 was administered at a dose of 20 mg/5 mL, and No fatality was observed during the treatment. The average recovery duration from the initial administration of PB-81 was 2.25 days in the PB-81 administration group and 6.5 days in the control group without PB-81 administration. No side effects were observed from the tested cattle with rotavirus diarrhea.