Antigenic Relationships among Strains of Japanese Encephalitis Virus by Using Monoclonal Antibodies

Abstract

Antigenic relationships among the 11 strains of Japanese encephalitis (JE) virus were analyzed by using monoclonal antibodies (NARMA) against Nakayama-RFVL strain in the hemagglutination inhibition (HI) and neutralization (Nt) tests. Of the 14 JE virus specific HI antibodies, all except NARMA 5 showed the Nt activities against the homologous strain. The HI and Nt titers of these antibodies were not parallel. They consisted of the following characteristics antibodies: NARMA 3, a species-specific antibody with HI and Nt activities against JE virus; NARMA 13, a species-specific antibody with HI antibody; NARMA 6, a Nakayama strain-specific antibody with HI and Nt activities; NARMA 5, a Nakayama strain-specific HI antibody; 10 other antibodies, all of the intermediate type.
The eleven strains of JE virus were classified into the following antigenic groups:
I-1, Nakayama-RFVL and Nakayama-Yoken strains.
I-2; Nakayama-Yakken strain.
II; G-1 late, JaGAr 01 and JaGAr 02 strains.
III-1, Kamiyama, Mie 44-1 and Kumamoto 80679 strains.
III-2; 691004 strain.
IV; Muar strain.
These results were in reasonably good agreement with the antigenic classification of the JE virus strains performed by the HI test using 5 monoclonal antibodies (NARMA 1, 4, 5, 8 and 13), although slight antigenic differences were found among some strains of the same group.