Figure 4.

Schematic representation of the mechanism proposed for DNA vaccine delivery into mammalian cells using live bacteria. (A). Following invasion of the host, bacteria are recognized by various cell types, including microfold cells, epithelial cells, or immune cells. (B). The recombinant bacteria are internalized by the phagolysosome complex and subsequently undergo lysis. Within this process, the DNA vaccine is released from the vesicle and translocated into the nucleus, allowing for transcription of the antigen gene. The resulting antigen protein is presented to the immune system, triggering both cellular and humoral immune responses.