Fe(III)-Shikonin supramolecular nanomedicines as immunogenic cell death stimulants and multifunctional immunoadjuvants for tumor vaccination.
Immunoadjuvants, as an indispensable component of tumor vaccines, can observably enhance the magnitude, breadth, and durability of antitumor immunity. However, current immunoadjuvants suffer from different issues such as weak immunogenicity, inadequate cellular internalization, poor circulation time, and mono-functional bioactivity. Methods: Herein, we construct Fe3+-Shikonin metal-phenolic networks (FeShik) nanomedicines as immunogenic cell death (ICD) stimulants and multifunctional immunoadjuvants for tumor vaccination. The multifunctionality of FeShik nanomedicines is investigated by loading ovalbumin (OVA) as the model antigen to construct OVA@FeShik nanovaccines or 4T1 tumor cell fragment (TF) as homologous antigen to construct TF@FeShik nanovaccines. In vitro examinations including GSH responsive, •OH generation, colloid stability, cellular uptake, cytotoxicity mechanism of ferroptosis and necroptosis, ICD effect, the promotion of DC maturation and antigen cross-presentation were studied. In vivo observations including pharmacokinetics and biodistribution, antitumor effect, abscopal effect, immune memory effect, and biosafety were performed. Results: The presence of FeShik nanomedicines can significantly prolong the blood circulation time of antigens, increasing the bioavailability of antigens. Upon phagocytosis by tumor cells, FeShik nanomedicines can disassemble into Fe2+ and Shikonin in response to tumor microenvironments, leading to ICD of tumor cells via ferroptosis and necroptosis. Consequently, ICD-released autologous tumor cell lysates and pro-inflammatory cytokines not only stimulate DC maturation and antigen cross-presentation, but also promote macrophage repolarization and cytotoxic T lymphocyte infiltration, resulting in the activation of adaptive immune responses toward solid tumors. Conclusion: In a word, our FeShik supramolecular nanomedicines integrate bioactivities of ICD stimulants and immunoadjuvants, such as eradicating tumor cells, activating antitumor immune responses, modulating immunosuppressive tumor microenvironments, and biodegradation after immunotherapy. Encouraged by the diversity of polyphenols and metal ions, our research may provide a valuable paradigm to establish a large library for tumor vaccination.
Feng W
，Shi W
，Cui Y
，Xu J
，Liu S
，Gao H
，Zhu S
，Liu Y
，Zhang H
... -
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Nanoscale Metal-Organic Frameworks for Cancer Immunotherapy.
Cancer immunotherapy, particularly checkpoint blockade immunotherapy (CBI), has revolutionized the treatment of some cancers by reactivating the antitumor immunity of hosts with durable response and manageable toxicity. However, many cancer patients with low tumor antigen exposure and immunosuppressive tumor microenvironments do not respond to CBI. A variety of methods have been investigated to reverse immunosuppressive tumor microenvironments and turn "cold" tumors "hot" with the goal of extending the therapeutic benefits of CBI to a broader population of cancer patients. Immunostimulatory adjuvant treatments, such as cancer vaccines, photodynamic therapy (PDT), radiotherapy (RT), radiotherapy-radiodynamic therapy (RT-RDT), and chemodynamic therapy (CDT), promote antigen presentation and T cell priming and, when used in combination with CBI, reactivate and sustain systemic antitumor immunity. Cancer vaccines directly provide tumor antigens, while immunoadjuvant therapies such as PDT, RT, RT-RDT, and CDT kill cancer cells in an immunogenic fashion to release tumor antigens . Direct administration of tumor antigens or indirect intratumoral immunoadjuvant therapies as cancer vaccines initiate the immuno-oncology cycle for antitumor immune response.With the rapid growth of cancer nanotechnology in the past two decades, a large number of nanoparticle platforms have been studied, and some nanomedicines have been translated into clinical trials. Nanomedicine provides a promising strategy to enhance the efficacy of immunoadjuvant therapies to potentiate cancer immunotherapy. Among these nanoparticle platforms, nanoscale metal-organic frameworks (nMOFs) have emerged as a unique class of porous hybrid nanomaterials with metal cluster secondary building units and organic linkers. With molecular modularity, structural tunability, intrinsic porosity, tunable stability, and biocompatibility, nMOFs are ideally suited for biomedical applications, particularly cancer treatments.In this Account, we present recent breakthroughs in the design of nMOFs as nanocarriers for cancer vaccine delivery and as nanosensitizers for PDT, CDT, RT, and RT-RDT. The versatility of nMOFs allows them to be fine-tuned to effectively load tumor antigens and immunoadjuvants as cancer vaccines and significantly enhance the local antitumor efficacy of PDT, RT, RT-RDT, and CDT generation of reactive oxygen species (ROS) for cancer vaccination. These nMOF-based treatments are further combined with cancer immunotherapies to elicit systemic antitumor immunity. We discuss novel strategies to enhance light tissue penetration and overcome tumor hypoxia in PDT, to increase energy deposition and ROS diffusion in RT, to combine the advantages of PDT and RT to enable RT-RDT, and to trigger CDT by hijacking aberrant metabolic processes in tumors. Loading nMOFs with small-molecule drugs such as an indoleamine 2,3-dioxygenase inhibitor, the toll-like receptor agonist imiquimod, and biomacromolecules such as CpG oligodeoxynucleotides and anti-CD47 antibody synergizes with nMOF-based radical therapies to enhance their immunotherapeutic effects. Further combination with immune checkpoint inhibitors activates systemic antitumor immune responses and elicits abscopal effects. With structural and compositional tunability, nMOFs are poised to provide a new clinically deployable nanotechnology platform to promote immunostimulatory tumor microenvironments by delivering cancer vaccines, mediating PDT, enhancing RT, enabling RT-RDT, and catalyzing CDT and potentiate cancer immunotherapy.
Ni K
，Luo T
，Nash GT
，Lin W
... -
《-》
Engineered exosomes as an in situ DC-primed vaccine to boost antitumor immunity in breast cancer.
Dendritic cells (DCs) are central for the initiation and regulation of innate and adaptive immunity in the tumor microenvironment. As such, many kinds of DC-targeted vaccines have been developed to improve cancer immunotherapy in numerous clinical trials. Targeted delivery of antigens and adjuvants to DCs in vivo represents an important approach for the development of DC vaccines. However, nonspecific activation of systemic DCs and the preparation of optimal immunodominant tumor antigens still represent major challenges.
We loaded the immunogenic cell death (ICD) inducers human neutrophil elastase (ELANE) and Hiltonol (TLR3 agonist) into α-lactalbumin (α-LA)-engineered breast cancer-derived exosomes to form an in situ DC vaccine (HELA-Exos). HELA-Exos were identified by transmission electron microscopy, nanoscale flow cytometry, and Western blot analysis. The targeting, killing, and immune activation effects of HELA-Exos were evaluated in vitro. The tumor suppressor and immune-activating effects of HELA-Exos were explored in immunocompetent mice and patient-derived organoids.
HELA-Exos possessed a profound ability to specifically induce ICD in breast cancer cells. Adequate exposure to tumor antigens and Hiltonol following HELA-Exo-induced ICD of cancer cells activated type one conventional DCs (cDC1s) in situ and cross-primed tumor-reactive CD8+ T cell responses, leading to potent tumor inhibition in a poorly immunogenic triple negative breast cancer (TNBC) mouse xenograft model and patient-derived tumor organoids.
HELA-Exos exhibit potent antitumor activity in both a mouse model and human breast cancer organoids by promoting the activation of cDC1s in situ and thus improving the subsequent tumor-reactive CD8+ T cell responses. The strategy proposed here is promising for generating an in situ DC-primed vaccine and can be extended to various types of cancers. Scheme 1. Schematic illustration of HELA-Exos as an in situ DC-primed vaccine for breast cancer. (A) Allogenic breast cancer-derived exosomes isolated from MDA-MB-231 cells were genetically engineered to overexpress α-LA and simultaneously loaded with the ICD inducers ELANE and Hiltonol (TLR3 agonist) to generate HELA-Exos. (B) Mechanism by which HELA-Exos activate DCs in situ in a mouse xenograft model ofTNBC. HELA-Exos specifically homed to the TME and induced ICD in cancer cells, which resulted in the increased release of tumor antigens, Hiltonol, and DAMPs, as well as the uptake of dying tumor cells by cDC1s. The activated cDC1s then cross-primed tumor-reactive CD8+ T cell responses. (C) HELA-Exos activated DCs in situ in the breast cancer patient PBMC-autologous tumor organoid coculture system.
DCs: dendritic cells; α-LA: α-lactalbumin; HELA-Exos: Hiltonol-ELANE-α-LA-engineered exosomes; ICD: immunogenic cell death; ELANE: human neutrophil elastase; TLR3: Toll-like receptor 3; TNBC: triple-negative breast cancer; TME: tumor microenvironment; DAMPs: damage-associated molecular patterns; cDC1s: type 1 conventional dendritic cells; PBMCs: peripheral blood mononuclear cells.
Huang L
，Rong Y
，Tang X
，Yi K
，Qi P
，Hou J
，Liu W
，He Y
，Gao X
，Yuan C
，Wang F
... -
《Molecular Cancer》
ResearchGate
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钛学术
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