Analysis of the properties of neutralizing monoclonal antibodies against the hemagglutinating encephalomyelitis virus and inhibition of HEV infection by specific MAb.

Eleven monoclonal antibodies (MAbs) that were reactive against the hemagglutinating encephalomyelitis virus (HEV), as seen in the enzyme-linked immunosorbent assay, were obtained. All of these MAbs showed neutralizing activity (1:20,000 to 1:800,000) against the 67N strain of HEV. They also showed hemagglutination inhibition activity (1:400 to 1:409,600). Western blotting tests revealed that all of these 11 MAbs were specific for the S protein of HEV. All MAbs with neutralizing activity showed the same fluorescent staining pattern. Ten-day-old mice pups were immunized with MAb, inoculated with the 105 tissue culture-infective dose of HEV at 3 days after immunization, and then examined to determine the viral inhibition. The 1:800-diluted MAb120 inhibited the viral infection in mice pups, though the 1:1,000-diluted MAb120 failed to inhibit the viral infectivity. These MAbs would be a useful tool for rapid and specific diagnosis of HEV and also for antibody-based treatment of the disease.