T-cell epitopes identified by BALB/c mice immunized with vaccinia expressing HIV-1 gag lie within immunodominant regions recognized by HIV-infected Indian patients

• Main Authors: Ashwini V Shete, Madhuri R Thakar, Srikanth P Tripathy, C G Raut, Sekhar Chakrabarti, Ramesh S Paranjape
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2011-01-01
• Series: Journal of Global Infectious Diseases
• Subjects: Cellular immune response; T-cell epitopes; Vgag
• Online Access: http://www.jgid.org/article.asp?issn=0974-777X;year=2011;volume=3;issue=3;spage=246;epage=253;aulast=Shete

Background: Human immunodeficiency virus (HIV) antigens from transmitted strains of HIV would prove crucial in vaccine designing for prevention of HIV infection. Immune response generated by Vaccinia construct expressing the HIV-1 gag gene from transmitted Indian HIV-1 subtype C strain (Vgag) in BALB/c mice is reported in the present study along with the identification of epitopes responsible for induction of the immune response. Aims: The aim of this study was to determine immune response generated by the constructs in a mouse model and to understand the epitope specificities of the response. Settings and Design: This was an observational study carried out in BALB/c mice. Materials and Methods: The immunogenecity of Vgag construct was evaluated in BALB/c mice after multiple immunizations. T-cell response was monitored by the interferon-γ ELISPOT assay using HIV-1 C Gag overlapping peptides and anti-P24 antibodies were estimated by ELISA. Statistical Analysis Used: Graphpad prism software was used for statistical analysis and for plotting graphs. Results: IFN-γ-secreting T cells and antibodies were detected against HIV Gag in mice after immunization. Although after repeated immunizations, antibody-mediated immune response increased or remained sustained, the magnitude of IFN-γ-secreting T cell was found to be decreased over time. The Gag peptides recognized by mice were mainly confined to the P24 region and had a considerable overlap with earlier reported immunodominant regions recognized by HIV-infected Indian patients. Conclusion: Vaccinia construct with a gag gene from transmitted HIV-1 virus was found to be immunogenic. The Gag regions identified by mice could have important implications in terms of future HIV vaccine designing.