Arch Virol (2001) 146: 1427–1435
Monoclonal antibody raised against envelope glycoprotein
peptide neutralizes Japanese encephalitis virus
S. Dewasthaly, V. M. Ayachit, S. A. Sarthi, and M. M. Gore
National Institute of Virology, Pune, India
Accepted September 28, 2000
Summary. Epitopes on envelope glycoprotein of Indian strain of Japanese en-
cephalitis virus were delineated by prediction methods. Monoclonal antibodies
(MAb) raised against a putative B cell epitope peptide, reacted with the virion in
ELISA and immunoﬂuorescence assays. One MAb was also able to neutralize the
virus. The reactivity of this MAb against a Sri Lankan strain was checked, since
this strain had a substitution within the B cell epitope at position Egp 153 (G→W).
The MAb was able to bind to, but was not able to neutralize the Sri Lankan isolate.
The data indicated that the predicted B cell epitope is a neutralizing epitope and
may be included in a peptide-based vaccine against the virus.
The envelope glycoprotein (Egp) of Japanese encephalitis virus (JEV) is a major
targetforneutralizing antiviralimmuneresponse .Protection againstinfection
is mainly antibody-mediated, as seen by the efﬁcacy of killed vaccine. Hence it
implies that B cell epitopes are important determinants of protection. Peptides
derived from ﬂavivirus proteins have been shown to elicit an antiviral immune
response . B cell epitopes can be determined by numerous ways. But the most
cost-effective method is by predicting the B cell epitopes and then experimentally
testing them. In the present communication we have shown that using a predictive
approach, B cell epitopes can be theoretically determined that are able to elicit
virus neutralizing antibody response. This approach was conﬁrmed by developing
and studying monoclonal antibodies (MAb) against this determinant. The JEV
strain used in the present study was a human isolate from Bankura, India that is
very similar to the standard Nakayama strain , unless otherwise mentioned.
Using a propensity based method  and Parker’s method  some re-
gions of Egp were predicted to be epitopes. Amongst them the region 155-
YSAQVGASQ-163 of JEV Egp was interesting because using Chou-Fasman