Identification of a Conserved, Linear Epitope on VP3 of Enterovirus A Species Recognized by a Broad-Spectrum Monoclonal Antibody

Outbreaks of hand, foot and mouth disease (HFMD) have occurred frequently in the Asian-Pacific region over the last two decades, caused mainly by the serotypes in species. High-quality monoclonal antibodies (mAbs) are needed to improve the accuracy and efficiency of the diagnosis of enteroviruses associated HFMD. In this study, a mAb 1A11 was generated using full particles of CV-A5 as an immunogen. In indirect immunofluorescence and Western blotting assays, 1A11 bound to the viral proteins of CV-A2, CV-A4, CV-A5, CV-A6, CV-A10, CV-A16, and EV-A71 of the and targeted VP3. It has no cross-reactivity to strains of and . By mapping with over-lapped and truncated peptides, a minimal and linear epitope PILPGF was identified, located at the N-terminus of the VP3. A BLAST sequence search of the epitope in the NCBI genus (taxid: 12059) protein database indicates that the epitope sequence is highly conserved among the species, but not among the other enterovirus species, first reported by us. By mutagenesis analysis, critical residues for 1A11 binding were identified for most serotypes of . It may be useful for the development of a cost-effective and pan- antigen detection for surveillance, early diagnosis and differentiation of infections caused by the species.