The document summarizes research on expressing HIV-1 antigens in plants as a potential vaccine. The researchers found that transient expression in plants is a viable alternative to transgenic plants. They determined that targeting the HIV-1 Gag protein Pr55Gag and its derivative p17/24 to chloroplasts yielded the highest levels of these proteins. Mice vaccinated with p17/24 produced from chloroplasts developed strong CD4+ and CD8+ T cell responses and HIV-specific antibodies, showing it is a promising vaccine candidate.