Guiyuan Chen,Xiangxia Li,Rui Li,Kecheng Wu,Zhouhang Lei,Ruike Dai,Kyle Roche,Andrew Z. Wang,Yuanzeng Min
Chemotherapeutics have the potential to increase the efficacy of cancer immunotherapies by stimulating the production of damage-associated molecular patterns (DAMPs) and eliciting mutations that result in the production of neoantigens, thereby increasing the immunogenicity of cancerous lesions. However, the dose-limiting toxicity and limited immunogenicity of chemotherapeutics are not sufficient to induce a robust antitumor response. We hypothesized that cancer cells in vitro treated with ultrahigh doses of various chemotherapeutics artificially increased the abundance, variety, and specificity of DAMPs and neoantigens, thereby improving chemoimmunotherapy. The in vitro chemotherapy-induced (IVCI) nanovaccines manufactured from cell lysates comprised multiple neoantigens and DAMPs, thereby exhibiting comprehensive antigenicity and adjuvanticity. Our IVCI nanovaccines exhibited enhanced immune responses in CT26 tumor-bearing mice, with a significant increase in CD4+/CD8+ T cells in tumors in combination with immune checkpoint inhibitors. The concept of IVCI nanovaccines provides an idea for manufacturing and artificial enhancement of immunogenicity vaccines to improve chemoimmunotherapy.
The induction of immunogenic ferroptosis in cancer cell is limited by the complex and delicate antioxidant system in the organism. Synergistic induction of oxidative damage and inhibition of the defensive redox system in tumor cells is critical to promote lethal accumulation of lipid peroxides and activate immunogenic death (ICD). To address this challenge, we present a multifunctional and dual-responsive layered double hydroxide (LDH) nanosheet to enhance immunogenic ferroptosis. The MTX-LDH@MnO 2 nanoplatform is constructed by intercalating methotrexate (MTX) into LDH interlayers and electrostatically absorbing biomineralized ovalbumin (OVA)-MnO 2 onto the LDH surface. Specifically, the released Mn 2+ from the incorporated MnO 2 triggers a Fenton-like reaction, leading to reactive oxygen species (ROS) accumulation, while the depletion of reduced glutathione (GSH) further intensifies oxidative stress , resulting in the induction of ferroptosis. MTX is released in response to the acidic environment of tumor cells and inhibits the regeneration of tetrahydrobiopterin (BH4), modulating the GTP cyclic hydrolase 1 (GCH1)/BH4 axis. MTX disrupts the antioxidant metabolic activity regulated by GCH1/BH4 axis and inhibits ROS consumption, further boosting the ferroptosis effect, which promoted the release of damage-associated molecular patterns (DAMPs) and triggered ICD in the tumor. This activation subsequently leads to significant antitumor immune reactions, including DCs maturation, infiltration of CD4 + /CD8 + T cells and cytokines release. The redox-controllable nanoplatform demonstrates promising anticancer efficacy in a mouse breast model providing a novel strategy for cancer immunotherapy.