Figure 5. Induction of adaptive immune responses by DNA vaccines.

DNA vaccines are administered by multiple routes. The injected DNA enters the somatic cells and/or APCs to produce target antigens, which is the subject of immune surveillance by both MHC class I and class II molecules of APCs. Following the presentation of antigens, activated APCs travel to the draining lymph nodes to present antigenic peptides to CD4 and CD8 T cells. This interaction allows activation and expansion of T cells, as well as antibody-producing B cells. Both humoral and cellular immune responses are induced to trigger a robust response against the target antigens.

APCs: Antigen-presenting cells; BCR: B-cell receptor; MHC: Major histocompatibility complex; TCR: T-cell receptor.