Detection of enterovirus 70 with monoclonal antibodies

To improve the ability to identify enterovirus-70 (EV-70) from patients with acute hemorrhagic conjunctivitis, we developed four monoclonal antibodies (MAbs) to EV-70. We reacted the four MAbs against nine previously characterized strains of EV-70 and heterologous viruses by virus neutralization, indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA). Two of the MAbs neutralized all nine strains of EV-70 and none of the other enterovirus types tested. Two of the MAbs gave a positive reaction with all nine strains by indirect immunofluorescence, and three reacted with all nine strains by ELISA. None of the MAbs gave a positive reaction with heterologous viruses, including those associated with eye disease, by indirect immunofluorescence or ELISA. The two neutralizing MAbs failed to give a positive reaction with some of the strains of EV-70 by indirect immunofluorescence and ELISA, yet they neutralized these viruses. By ELISA with a polyclonal serum as capture antibody and a mixture of MAbs as detector antibody, we were able to detect from 10(2.2) to 10(5.8) 50% tissue culture infective doses of virus and to type lyophilized isolates of EV-70 sent from Taiwan from which we could not recover infectious virus. By choosing the appropriate MAb, or mixture of MAbs, we could construct a test which had the type specificity and strain sensitivity needed to type isolates of EV-70.