[HIV vaccine trials]

There has been significant progress on several candidate vaccines against HIV infection over the past few years, i.e., live recombinant virus vaccines, inactivated virus vaccines, and purified antigens (subunit vaccines). There have been many phase I studies in healthy volunteers uninfected with HIV, as well as phase II trials with high-risk uninfected volunteers. Most of them focused on productions of neutralizing antibodies and cytotoxic T lymphocytes (CTLs) against HIV Env proteins. In addition, host immune responses, particularly cell-mediated immunity, were shown to be a major immune defense mechanism which may provide resistance to HIV spread leading to AIDS, indicating the possibility to develop prophylactic vaccine which may prevent the onset of AIDS in HIV carriers. However, various studies have implicated the concurrent activities of several HIV proteins, such as Env gp120, Env gp41, Tat, and Nef, in the induction of immunodeficiency. Therefore, the role of HIV-1 proteins in inducing immunodeficiency after HIV vaccination should be considered. Here, I introduce a recombinant BCG (rBCG) vaccine which expresses the immunodominant gp120 epitope. The tuberculosis vaccine strain Mycobacterium bovis BCG is a widely used vaccines with a low rate of serious complications. To develop a vaccine expressing an immunodominant epitope in the gp120 V3-loop, we used our system to express and secrete an epitope which was fused with an extracellular alpha antigen of Mycobacterium kansasii. Balb/c mice inoculated with this rBCG, rapidly induced HIV-specific CTLs. Target cell lysis was restricted to the murine class I major histocompatibility complex, H-2d.(ABSTRACT TRUNCATED AT 250 WORDS)