Structural and functional analysis of a potent human neutralizing antibody against enterovirus A71

摘要

Enterovirus A71(EV-A71) causes major outbreaks of hand,foot,and mouth disease(HFMD) in many countries,most frequently affecting children,and a small proportion of cases may lead to death.Currently,no vaccine is available in most endemic regions,and no licenced treatments for EV-A71 infection are available.Here,we characterize a human monoclonal antibody(Hu MAb),E1,by screening a Fab antibody phage library derived from patients who recovered from EV-A71 infection.E1 exhibits strong neutralizing activity against EV-A71 virus in cells.The cryo-electron microscopy(cryo-EM) structures of the EV-A71 virion in complex with E1 Fab fragments demonstrated that E1 recognized an epitope formed by residues in the BC and HI loops of VP1.In a mouse model,E1 effectively protected against lethal EV-A71 challenge in both prophylactic and therapeutic treatment.In particular,E1 significantly reduces virus titers and muscle damage.E1 might represent a potential adjunct to EV-A71 treatment.