Solubilized nonstructural
antigen III from
Saint Louis encephalitis (SLE)-
Japanese B encephalitis (JBE)-West Nile (WN) and dengue-2 arbovirus-infected pig kidney cells was purified by employing
Brij-58 solubilization, organic
solvent extraction, and column chromatography.
Diethylaminoethyl-cellulose column peak C eluate contained only intracellular
viral envelope protein designated
antigen I. Antigen I of SLE virus absorbed homologous
neutralizing antibody; however, the intracellular nonstructural
protein designated
antigen III did not. The antigenic relationships of solubilized
antigens I and III prepared from SLE, JBE, and WN virus-infected cells were determined by
complement-fixation (CF) and immunodiffusion analyses. Solubilized
antigen I of each virus cross-reacted broadly with both homologous and heterologous antibody at high
antigen concentrations in the CF test.
Antigen III of each virus reacted with only homologous antibody by both CF and immunoprecipitation. This study demonstrates that during SLE, JBE, WN, and dengue-2
infections, virus-specific
proteins containing both type-specific and group-reactive determinants are synthesized.
Antigen III, a nonstructural
protein, is serologically virus type specific and may be useful as a type-specific diagnostic
reagent.