Detection of viral antigens on the surface of cells infected with Japanese encephalitis virus by modified immunofluorescent technique.

A modified immunofluorescent method employing anti-Japanese encephalitis (JE) virus monoclonal (MoAbs) and polyclonal (immune PF) antibodies was evaluated for the detection of viral antigens expressed on the surface of porcine stable kidney cells infected with JE virus (733913, India). The infected cells showed granular immunofluorescence on the surface with both the MoAbs, Hs-1 and Hx-3 and immune PF 24 hr and 48 hr post virus infection. Interestingly, two strains of JE virus viz. Yoken (Japan) and 755468 (India) which did not react with the MoAb Hs-1 in the standard indirect fluorescent antibody (FA) technique, were positive for surface immunofluorescence (IF) with the same MoAb. Thus, the modified technique will be useful for the detection of more labile and conformational-dependent epitopes which might get lost or denatured by prior fixation of infected cells with acetone.