Enhancement of cell-mediated immune response in mice by whole HIV-1 gag in mycobacterium bovis BCG as a live vaccine candidate

• Main Authors: Duanthanorm Promkhatkaew, Nadthanan Pinyosukhee, Wilai Thongdeejaroen, Reungpung Sutthent, Pathom Sawanpanyalert, Paijit Warachit
• Other Authors: Thailand Ministry of Public Health
• Format: Article
• Published: 2018
• Subjects: Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/28261
• Institution: Mahidol University

In this study, we employed a recombinant Mycobacterium bovis Bacille Calmette-Guerin (BCG) harboring whole HIV-1 CRF01-AE gag DNA as a candidate vaccine to investigate specific cell-mediated immunity in BALB/c mice. Construction of the stable expression recombinant BCG was achieved by demonstrating by Western blot detection of protein of approximately 55 kDa. By a single injection of 0.1 mg of the recombinant HIV-1 gag protein expressing BCG subcutaneously into mice, after 2 weeks various specific cytotoxic T-lymphocyte (CTL) responses were exhibited against a single gag epitope of amino acid positions 294-304, and also against various peptide regions along the entire gag protein with moderate CTL activities (10-35% specific cell lysis), which increased to relatively high levels (50-68%) after one month. However, after two months activities were 3-3.7 fold lower. On the other hand, gag-specific lymphocyte proliferation was detected 9.3 fold higher than that of non-immunized mouse spleen cells. Our results indicate that in mice, BCG can be used as a recombinant live vector to induce cellular immune responses to HIV-1 gag antigen.