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

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.

Modified boosted – p24 antigen can predict HIV-1 RNA viral load (Ampiclor HIV-1 Monitor).

Objective : To evaluate the prediction of HIV-1 RNA viral load (Ampiclor) in log_copies per ml by each level of modified boosted-p24 antigen in log_ fg per ml. , Methods : 283 plasma samples were collected and blindly determined the HIV-1 RNA Amplicor Monitor, Roche as standard test with modified boosted p24 antigen assay. Likelihood ratio positive analyses of multiple levels of p24 were calculated as well as the post-test probability in predicting the amount of virus (log_copies/ ml). Results: Subject were between 18 to 73 years old with the range of virus 1.75 to 5.92 log-copies per ml. By the calculation of likelihood ratio positive and positive predictive value, it was demonstrated that modified boosted p24 antigen (Ag in log-fg per ml) might predict the viral load (VL in log-copies per ml) as follow. Ag 2.0-3.0 log-fg per ml corresponding to 2.0 or lower log-copies per ml VL Ag 3.0-3.5 log-fg per ml corresponding to 2.5 or lower log-copies per ml VL Ag 3.5-4.0 log-fg per ml corresponding to 3.5 or lower log-copies per ml VL Ag 4.0-over log-fg per ml corresponding to 4.5 or lower log-copies per ml VL Conclusions: In countries with limited financial resources, the modified p24 antigen may be clinically applied in antiretroviral management programmes, instead of the HIV-1 RNA Amplicor Monitor, Roche.