Fig. 1.

Scheme of the cancer immunotherapy mechanism. After antigens are processed by immature dendritic cells (ImDCs), they are presented to T cells by mature dendritic cells (mDCs) through major histocompatibility complex (MHC) class I or MHC class II complexes binding to CD8⁺ or CD4⁺ T cells, separately. Simultaneously, mDCs also express costimulatory molecules and cytokines such as IFN-γ and IL-12 to synergistically stimulate T cells. CD8⁺ T cells further differentiate into cytotoxic T lymphocytes (CTLs), and CD4⁺ T cells further differentiate into IFN-γ secreting T-helper 1 (Th1) cells to assist in activating CD8 cells and other innate immune cells, such as natural killer (NK) cells, granulocytes or macrophages, to directly kill tumor cells