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Aim To screen novel NS5 inhibitors a-gainst dengue virus ( DENV) replication. Methods His-tagged DENV2 NS5 RNA-dependent polymerase ( NS5 RdRp ) was expressed and purified in BL21 cells. The binding ability of the small molecules to NS5 polymerase was determined by SPR assay. The activity of dengue inhibition by Z1 was determined by CPE, LDH and plaque assay. RNA synthesis was as-sessed by Real-time PCR. The dsRNA synthesis and viral proteins were detected by immunofluorescence as-say. The level of viral proteins was examined by West-ern blot. The stage of DENV life cycle was evaluated by time of drug-addition assay. Results A small mo-lecular Z1 was discovered, which could bind to NS5 RdRp. Z1 inhibited DENV2 RNA replication, synthe-sis of dsRNA and protein synthesis in post-entry stage of dengue life-cycle. Cell based assay confirmed that Z1 inhibited DENV-induced cell death with EC50 val-ues of 4. 75μmol·L-1 . Conclusions The novel NS5 inhibitor Z1, inhibits DENV2 RNA replication, protein synthesis and release of progeny virus, which may be severed as an anti-DENV2 antiviral drug for further de-velopment.
RESUMEN
<p><b>OBJECTIVE</b>To investigate the effect of semen-derived enhancer of virus infection (SEVI) on the infection of transmitted/founder (TF) HIV-1 and its matched chronic control (CC) viruses and the antagonism of ADS-J1 on SEVI-mediated enhancement of TF and CC virus infection in vitro.</p><p><b>METHODS</b>PAPself-assembling into SEVI amyloid fibrils was validated by ThT assay. We generated the virus stocks of TF and CC virus pair. TZM-bl cells were infected with the mixture of SEVI and TF or CC viruses for 72 h. Luciferase activity was used to observe the enhancement of SEVI. SEVI was treated with different concentrations of ADS-J1 and incubated with TF or CC viruses. TZM-bl cells were then infected with the mixture and luciferase activity was detected 72 h after infection to analyze the antagonism of ADS-J1 on the enhancing effect of SEVI. ADS-J1 was also incubated with TF and CC viruses directly and TZM-bl cells were infected for 72 h to evaluate the antiviral effect using luciferase assay. SEVI was treated with ADS-J1 and Zeta potential was determined to explore the antagonistic mechanism of ADS-J1.</p><p><b>RESULTS</b>ThT assay showed that PAPwas capable of self-assembly into SEVI amyloid fibrils. SEVI significantly accelerated TF and CC viruses infection (P<0.05), and ADS-J1 not only significantly antagonized the enhancement of SEVI (P<0.05) but also directly inhibited the infection of TF and CC viruses (P<0.05). ADS-J1 neutralized the positive charge of SEVI in a dose-dependent manner.</p><p><b>CONCLUSIONS</b>SEVI promotes the infection of TF and CC strains, and ADS-J1 antagonizes SEVI-mediated enhancement of TF and CC viruses by neutralizing the positive charge of SEVI.</p>