Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai-625021, 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.
Cardamom mosaic virus (CdMV) is a member of the family Potyviridae under the genus Macluravirus. When overexpressed in E.coli, the CdMV CP forms filamentous aggregates, as observed by immunogold electron microscopy. Each virus like particle of CdMV has about 2000 copies of the coat protein. The N terminal region of the protein is highly variable as seen in the comparison between various strains of the virus. The N and C terminal regions of the protein are likely to be surface exposed as in other potyviruses. These features make the CdMV CP, a suitable system for use as epitope presentation system. The region 731–752 of the gp41 holds a neutralizing epitope, which is highly conserved and is also exposed in the virions. Hence it is a potential region for epitope vaccine development against HIV. The full length coat protein of CdMV has been expressed in E. coli and purified using Ni-NTA column. A restriction site was created in the N terminal region of the coat protein by PCR based mutagenesis. The epitope was engineered into the N terminal region of the coat protein. The chimeric protein was purified and western blotted with CdMV antiserum and also with sera from HIV patients. The chimeric protein reacts with the CdMV antiserum and shows the expected gel shift in comparison with wildtype CP. The chimeric protein also reacts with serum from one of the HIV patients. The above results show that the chimeric protein is displaying the HIV epitope and is capable of reacting with the antibodies in the serum of HIV patient. Further analysis of the ability of the chimeric protein to elicit neutralizing antibodies will be done using animal models.
