Mapping of functional epitopes of Japanese encephalitis virus using monoclonal antibodies.

Epitopes involved in the important functions, hemagglutination (HA) and neutralization (NT), were mapped on Japanese encephalitis (JE) virus proteins by using monoclonal antibodies (MAbs). Fourteen MAbs raised against Nakayama-Yoken strain of JE virus characterized by hemagglutination inhibition (HI) and plaque reduction neutralization test (PRNT) were used to map the epitopes on the JE proteins by Western blot analysis in which non-reducing conditions were used for sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). With these MAbs, at least 8 functional epitopes were demonstrated comprising (i) epitopes recognized by 5 MAbs which gave strong HI but weak NT activities and were mapped on the envelope (E) 53 kDa protein; (ii) epitopes recognized by 2 MAbs which showed weak HI but strong NT activities and were mapped also on the E protein; (iii) epitopes recognized by 2 MAbs which possessed weak HI but no NT activities and were mapped on the E protein; (iv) an epitope recognized by 1 MAb which gave weak NT and no HI activities and was mapped on the nonstructural protein 5 (NS5); (v) an epitope recognized by 1 MAb which showed activities similar to (i) but was mapped on both E and NS5; (vi) an epitope recognized by 1 MAb which had high activities to both HI and NT and was mapped on E and NS5; (vii and viii) epitopes recognized by 1 MAb which also gave low HI but high NT, and strong HI as well as strong NT activities respectively, but their location could not be demonstrated by SDS-PAGE under non-reducing condition.(ABSTRACT TRUNCATED AT 250 WORDS)