Monoclonal antibody against EV71 3D(pol) inhibits the polymerase activity of RdRp and virus replication

BACKGROUND: Enterovirus A 71 (EV71) is a neurotropic virus that may lead to acute flaccid paralysis, encephalitis, cardiopulmonary failure or even death. No vaccine and defensive drug controlling EV71 is currently available, novel and efficient antiviral drug or vaccine is therefore urgently needed. 3D(pol) (RNA-dependent RNA polymerase (RdRp)) has been an important target for anti-EV71 drug development. METHODS: A panel of monoclonal IgG antibodies (mAbs) against EV71 3D(pol) were generated by traditional cell fusion methods. And the antibody affinity and specificity to EV71 3D(pol) were evaluated by Enzyme-linked Immunosorbent Assay (ELISA), Indirect Fluorescent Assay (IFA) and Western blotting. Antiviral activities of these antibodies were also determined in vitro and in vivo. RESULTS: Two mAbs towards EV71 3D(pol) were able to effectively suppress EV71 replication in Vero-1008 cell when intracellarly delivered. And they also dampened the RNA polymerase activity of 3D(pol) in vitro. More importantly, these mAbs provided partial protection in EV71-challenged neonatal murine challenge model. CONCLUSIONS: These results showed that two of mAbs against EV71 3D(pol) inhibited EV71 replication and could be utilized as promising therapeutic drug candidate. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12865-019-0288-x) contains supplementary material, which is available to authorized users.