Relative potency of cellular and humoral immune responses induced by DNA vaccination

DNA vaccines can prime broad-based immune responses in small animal models. In the present study, we sought to evaluate the relative ability of DNA va ccines to induce humoral and cellular immune responses. Using a DNA vaccine encoding HIV gag in mice, we observed that CD8+ T cell responses were prim ed more readily than were antibody responses, particularly at low doses of DNA. These CD8+ T cell responses were detected in spleen cells, as well as at local sites such as the lung and draining lymph nodes. The potency of th e HIV gag DNA vaccine used was sufficient to prime strong CTL responses in macaques, but only low to undetectable antibody responses. Therefore, DNA v accines appear able to prime strong, broad CTL but only modest antibody res ponses. These results may have implications on the development of vaccines against infectious diseases where both CTL and antibody responses are desir ed, such as HIV. Copyright (C) 2001 S. Karger AG, Basel.