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

Raihana, Royan Rahimi; Hayakawa, Marie; Sugiura, Emiko; Sugiura, Hiroaki; Hanaki, Ken-Ichi; Taniguchi, Takahide; Honda, Eiichi

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 10(5) 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.