Immunological Study of Japanese Encephalitis Virus-Characterization of Monoclonal Antibodies against Muar and 691004 Strains

Abstract

Based on our previous study using monoclonal antibodies against three Japanese encephalitis (JE) virus strains, Nakayama-RFVL, Beijing 1 and Kamiyama, twenty-five JE virus strains isolated between 1935 and 1979 were classified into four or five serotypes. In the present study, monoclonal antibodies against Muar and 691004 strains which showed different reactivities from the three above strains were produced to analyze immunological characteristics of JE virus in detail and identify isolated viruses accurately. The ten anti-Muar (MUAMA 1-10) and the fourteen anti-691004 (69-MA 1-14) monoclonal antibodies which reacted specifically with the JE virus by the hemagglutination inhibition (HI) test were obtained. In order to clarify the immunological characteristics of MUAMAs and 69-MAs, the HI reactivity of each was tested against the twenty-five JE virus strains. Of the ten MUAMAs, one strain-specific (MUAMA 1), two intermediately reactive and seven JE species-specific antibodies were recognized. Of the fourteen 69-MAs, five intermediately reactive and nine JE speciesspecific antibodies were recognized, but 691004 strain-specific antibody was not obtained. The serological classification of the 25 JE virus strains using MUAMAs and 69-MAs basically corresponded with our previous results. However, 691004 strain would be classified into a subtype of Nakayama serotype according to the reactive pattern. Consequently, the 25 JE virus strains all fell into four serotypes: Nakayama, Beijing 1, Kamiyama and Muar. All twenty-four monoclonal antibodies produced in this study showed neutralization activities and belonged to the IgM class, kappa type.