Fig. 8: Schematic illustration of the mechanism of ACT-DC for in situ immunization against solid tumors.

By integrating AC-NPs with the adoptive transfer of CD103+ cDC1s, ACT-DC harnesses native tumor antigens to induce potent and long-lasting systemic immune responses against solid tumors. Upon intratumoral administration, AC-NPs capture native tumor antigens in situ (a) and enhance their delivery to migratory CD103+ cDC1s while simultaneously activating them (b). The activated cDC1s then migrate to tDLNs, where they enhance antigen presentation, leading to the induction of potent polyclonal antigen-specific T cells and memory T cells (c2). Meanwhile, activated cDC1s retained within the tumor modulate the tumor microenvironment to reduce immunosuppression and enhance T cell infiltration (c1). The T cells generated in tDLNs effectively infiltrate tumors, leading to the eradication of solid tumors (d). Created in BioRender. Zhao, Z. (2025) https://BioRender.com/qgi6dnp.