The Mechanism Of Core-specific Aptamer Anti-HCV Activity

The hepatitis C virus (HCV) is a major causative agent of acute and chronic liverdiseases, approximately180million people are persistently infected with HCVworldwide. There are many disadvantages of the existing detection of HCV infectionby anti-HCV antibody and HCV RNA related RT-qPCR, with long term of anti-HCVantibody production and low viral titers. Current standard therapy is often lesseffective than expected, because of HCV genotypes with highly specificity and drugresistance mutations. In addition, there is no effective vaccine. Novel detections andtherapies are urgently needed against HCV infection, a majo r global health problem.The model of infectious virus particles indicates that core protein was enriched at thesurface of lipid droplets (LD), Which contributes to HCV virions assembly. In thisprocess，HCV virions acquire their envelope at the ER, and e gress through thebudding pathway.Aptamers called "chemical antibody", which exhibit significant advantagescomparing to antibody in terms of size, synthetic accessibility and modification.Aptamers against core protein were screened by the selective evolution of ligands byexponential enrichment (SELEX), which have been demonstrated to have strongpromising application in drug development. In our study, HCV core gene fragment wasamplified and cloned into prokaryotic or eukaryotic protein expression vector. Coreprokaryotic segmented protein was abundantly expressed and purified. Detection ofHCV infection and antiviral activity by core aptamer was examine. To explore howcore-specific aptamer acts its anti-HCV activity. The data showed that selectedaptamers against HCV core specifically recognize the recombinant core protein, butalso can detect serum samples from hepatitis C patients. The data also indicated thataptamers against core do not have effect on HCV RNA replication and virus release inHCV-infected Huh7.5cells, but inhibit the production of infectious viral particles.Transfected with exogenous DNA/RNA may stimulate innate immunity. Interferon beta(IFN-β) and ISGs are not induced in viral infected cells with aptamers treatment,these results suggest aptamers do not activates innate immunity. We dissected that theinhibition of infectious virus production by core-specific aptamers replies ondomainⅠand Ⅱof core protein. Further study showed that these aptamers disrupt thelocalization of core with lipid droplets and NS5A and perturb the association of core protein with viral genomic RNA.All the results suggested that core-specific aptamers inhibit infectious virusproduction through disrupting the localization of core with lipid droplets andpreventing the association of core protein with viral RNA. In summary，we providenovel insights into core-specific aptamers for HCV assembly events. Core-specificaptamers may hold promise for the development as early diagnostic reagents andtherapeutic agents for the treatment of chronic hepatitis C.