Vaccination of seronegative volunteers with a human immunodeficiency virustype 1 env/rev DNA vaccine induces antigen-specific proliferation and lymphocyte production of beta-chemokines

There is a pressing need to test novel vaccine concepts in an effort to dev elop an effective vaccine for human immunodeficiency virus (HIV) type 1. A phase I clinical study was done to test the immunogenicity of an HIV env/re v DNA vaccine, which was administered intramuscularly to HIV-1-seronegative persons. Subjects received 3 doses of vaccine at a single concentration (1 00 or 300 mu g) at 0, 4, 8, and 24 weeks. In at least 1 of multiple assays, the 6 subjects who received the 300-mu g dose had DNA vaccine-induced anti gen-specific lymphocyte proliferative responses and antigen-specific produc tion of both interferon-gamma and beta-chemokine. Furthermore, 4 of 5 subje cts in the 300 mu g-dose group responded to both the rev and env components of the vaccine. The responses did not persist within inoculated individual s and scored in different individuals at different times in the trial. This study supports that HIV-1 DNA vaccine antigens can stimulate multiple immu ne responses in vaccine-naive individuals, and it warrants additional studi es designed to enhance DNA vaccine immunogenicity.