Japanese encephalitis Group, National Institute of Virology, Sus road campus, Pashan, Pune-411 021, India.
Abstracts of the papers presented at the XVIII National Conference of Indian Virological Society at Post Graduate Institute of Medical Education and Research, Chandigarh, India, December 11–13, 2008.
Japanese encephalitis (JE) is a mosquito-borne viral disease of major public health importance in Asia. Vaccination remains one of the most promising approaches in reducing Japanese encephalitis virus (JEV) infections. Mouse Brain derived formalin inactivated vaccine has inherent drawbacks; expensive to manufacture, immunity of uncertain duration, and associated allergic reactions, while the attenuated JEV vaccine, SA14-14-2, is undergoing clinical trials. Various DNA vaccines against JEV expressing structural and nonstructural proteins confer protection of varying degree. Our earlier work on delineation of chimeric B and TH epitope peptides conferring partial protection indicated that multi-epitope approach might be useful. The polytope gene was cloned in mammalian expression vector pCDNA 3.1 expression of recombinant vector in vivo and in vitro was analyzed using different methods like ELISA, Neutralization test, immunofluorescence assay (IFA), Western blot analysis and challenge studies. Transfected cell lines amplified a 400 bp product in RT-PCR. Presence of polytope protein till 72 hours was confirmed by ELISA. Immune sera generated using polytope gene immunization showed reactivity against E protein in Western blot and in IFA. In vitro Neutralizing antibody titre was found to be 1:20 and 70% protection was observed in mice challenge studies. The ability of immune sera to react with JEV in IFA and Western blot suggest the conformation of polytope gene resembling to that of native protein. That may stimulate protective response mimicking the natural course of viral infection.
