Antiviral protection after DNA vaccination is short lived and not enhancedby CpG DNA

In this study, we investigated the potential of a DNA vaccine expressing th e minimal cytotoxic T lymphocyte (CTL) epitope gp33 of the lymphocytic chor iomeningitis virus glycoprotein to protect against infection of a non-lymph oid organ and compared this to protection against a systemic infection. Fur thermore, since immune stimulatory sequences have been shown to augment CTL responses, we examined the capacity of CpG DNA to enhance CTL memory. The data show that DNA vaccination with a gp33-based gene construct induced sho rt-lived gp33-specific CTL which protected against a systemic infection but not against a peripheral infection. Immune stimulatory sequences were inca pable of either prolonging CTL memory or promoting protection against infec tion of a peripheral organ.