ABSTRACT
BACKGROUND: Triple-negative breast cancer (TNBC) poses unique challenges due to its complex nature and the need for more effective treatments. Recent studies showed encouraging outcomes from combining paclitaxel (PTX) with programmed cell death protein-1 (PD-1) blockade in treating TNBC, although the exact mechanisms behind the improved results are unclear. METHODS: We employed an integrated approach, analyzing spatial transcriptomics and single-cell RNA sequencing data from TNBC patients to understand why the combination of PTX and PD-1 blockade showed better response in TNBC patients. We focused on toll-like receptor 4 (TLR4), a receptor of PTX, and its role in modulating the cross-presentation signaling pathways in tumor-associated macrophages (TAMs) within the tumor microenvironment. Leveraging insights obtained from patient-derived data, we conducted in vitro experiments using immunosuppressive bone marrow-derived macrophages (iBMDMs) to validate if PTX could augment the cross-presentation and phagocytosis activities. Subsequently, we extended our study to an in vivo murine model of TNBC to ascertain the effects of PTX on the cross-presentation capabilities of TAMs and its downstream impact on CD8+ T cell-mediated immune responses. RESULTS: Data analysis from TNBC patients revealed that the activation of TLR4 and cross-presentation signaling pathways are crucial for the antitumor efficacy of PTX. In vitro studies showed that PTX treatment enhances the cross-presentation ability of iBMDMs. In vivo experiments demonstrated that PTX activates TLR4-dependent cross-presentation in TAMs, improving CD8+ T cell-mediated antitumor responses. The efficacy of PTX in promoting antitumor immunity was elicited when combined with PD-1 blockade, suggesting a complementary interaction. CONCLUSIONS: This study reveals how PTX boosts the effectiveness of PD-1 inhibitors in treating TNBC. We found that PTX activates TLR4 signaling in TAMs. This activation enhances their ability to present antigens, thereby boosting CD8+ T cell antitumor responses. These findings not only shed light on PTX's immunomodulatory role in TNBC but also underscore the potential of targeting TAMs' antigen presentation capabilities in immunotherapy approaches.
Subject(s)
Paclitaxel , Triple Negative Breast Neoplasms , Tumor-Associated Macrophages , Paclitaxel/pharmacology , Paclitaxel/therapeutic use , Humans , Female , Tumor-Associated Macrophages/immunology , Tumor-Associated Macrophages/drug effects , Tumor-Associated Macrophages/metabolism , Mice , Animals , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/immunology , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Programmed Cell Death 1 Receptor/metabolism , Tumor Microenvironment/drug effects , Toll-Like Receptor 4/metabolism , Immune Checkpoint Inhibitors/pharmacology , Immune Checkpoint Inhibitors/therapeutic use , Cell Line, TumorABSTRACT
Neoantigens are ideal targets for cancer immunotherapy because they are expressed de novo in tumor tissue but not in healthy tissue and are therefore recognized as foreign by the immune system. Advances in next-generation sequencing and bioinformatics technologies have enabled the quick identification and prediction of tumor-specific neoantigens; however, only a small fraction of predicted neoantigens are immunogenic. To improve the predictability of immunogenic neoantigens, we developed the in silico neoantigen prediction workflows VACINUSpMHC and VACINUSTCR: VACINUSpMHC incorporates physical binding between peptides and MHCs (pMHCs), and VACINUSTCR integrates T cell reactivity to the pMHC complex through deep learning-based pairing with T cell receptors (TCRs) of putative tumor-reactive CD8 tumor-infiltrating lymphocytes (TILs). We then validated our neoantigen prediction workflows both in vitro and in vivo in patients with hepatocellular carcinoma (HCC) and in a B16F10 mouse melanoma model. The predictive abilities of VACINUSpMHC and VACINUSTCR were confirmed in a validation cohort of 8 patients with HCC. Of a total of 118 neoantigen candidates predicted by VACINUSpMHC, 48 peptides were ultimately selected using VACINUSTCR. In vitro validation revealed that among the 48 predicted neoantigen candidates, 13 peptides were immunogenic. Assessment of the antitumor efficacy of the candidate neoepitopes using a VACINUSTCR in vivo mouse model suggested that vaccination with the predicted neoepitopes induced neoantigen-specific T cell responses and enabled the trafficking of neoantigen-specific CD8 + T cell clones into the tumor tissue, leading to tumor suppression. This study showed that the prediction of immunogenic neoantigens can be improved by integrating a tumor-reactive TIL TCR-pMHC ternary complex.
Subject(s)
Antigens, Neoplasm , Lymphocytes, Tumor-Infiltrating , Receptors, Antigen, T-Cell , Antigens, Neoplasm/immunology , Animals , Humans , Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/metabolism , Mice , Receptors, Antigen, T-Cell/immunology , Receptors, Antigen, T-Cell/metabolism , Cell Line, Tumor , Melanoma, Experimental/immunology , Melanoma, Experimental/therapy , Major Histocompatibility Complex/immunology , Liver Neoplasms/immunology , Liver Neoplasms/therapy , Carcinoma, Hepatocellular/immunology , Carcinoma, Hepatocellular/therapy , CD8-Positive T-Lymphocytes/immunology , Female , Immunotherapy/methodsABSTRACT
Cancer vaccines offer a promising avenue in cancer immunotherapy by inducing systemic, tumor-specific immune responses. Tumor extracellular vesicles (TEVs) are nanoparticles naturally laden with tumor antigens, making them appealing for vaccine development. However, their inherent malignant properties from the original tumor cells limit their direct therapeutic use. This study introduces a novel approach to repurpose TEVs as potent personalized cancer vaccines. The study shows that inhibition of both YAP and autophagy not only diminishes the malignancy-associated traits of TEVs but also enhances their immunogenic attributes by enriching their load of tumor antigens and adjuvants. These revamped TEVs, termed attenuated yet immunogenically potentiated TEVs (AI-TEVs), showcase potential in inhibiting tumor growth, both as a preventive measure and a possible treatment for recurrent cancers. They prompt a tumor-specific and enduring immune memory. In addition, by showing that AI-TEVs can counteract cancer growth in a personalized vaccine approach, a potential strategy is presented for developing postoperative cancer immunotherapy that's enduring and tailored to individual patients.
Subject(s)
Cancer Vaccines , Extracellular Vesicles , Precision Medicine , Extracellular Vesicles/immunology , Cancer Vaccines/immunology , Cancer Vaccines/therapeutic use , Animals , Mice , Precision Medicine/methods , Humans , Disease Models, Animal , Immunotherapy/methods , Neoplasms/immunology , Neoplasms/therapy , Cell Line, Tumor , Antigens, Neoplasm/immunology , FemaleABSTRACT
In this study, extracellular vesicles (EVs) are reimagined as more than just a cellular waste disposal system and are repurposed for cancer immunotherapy. Potent oncolytic EVs (bRSVF-EVs) loaded with misfolded proteins (MPs) are engineered, which are typically considered cellular debris. By impairing lysosomal function using bafilomycin A1 and expressing the respiratory syncytial virus F protein, a viral fusogen, MPs are successfully loaded into the EVs expressing RSVF. bRSVF-EVs preferentially transplant a xenogeneic antigen onto cancer cell membranes in a nucleolin-dependent manner, triggering an innate immune response. Furthermore, bRSVF-EV-mediated direct delivery of MPs into the cancer cell cytoplasm initiates endoplasmic reticulum stress and immunogenic cell death (ICD). This mechanism of action leads to substantial antitumor immune responses in murine tumor models. Importantly, when combined with PD-1 blockade, bRSVF-EV treatment elicits robust antitumor immunity, resulting in prolonged survival and complete remission in some cases. Overall, the findings demonstrate that utilizing tumor-targeting oncolytic EVs for direct cytoplasmic delivery of MPs to induce ICD in cancer cells represents a promising approach for enhancing durable antitumor immunity.
Subject(s)
Extracellular Vesicles , Neoplasms , Mice , Animals , Extracellular Vesicles/metabolism , Neoplasms/pathology , Cytoplasm , Cytosol , Immunotherapy/methodsABSTRACT
Extracellular vesicles (EVs) are nanovesicles that are naturally released from cells in a lipid bilayer-bound form. A subset population with a size of 200 nm, small EVs (sEVs), is enticing in many ways. Initially perceived as mere waste receptacles, sEVs have revealed other biological functions, such as cell-to-cell signal transduction and communication. Besides their notable biological functions, sEVs have profound advantages as future drug modalities: (i) excellent biocompatibility, (ii) high stability, and (iii) the potential to carry undruggable macromolecules as cargo. Indeed, many biopharmaceutical companies are utilizing sEVs, not only as diagnostic biomarkers but as therapeutic drugs. However, as all inchoate fields are challenging, there are limitations and hindrances in the clinical translation of sEV therapeutics. In this review, we summarize different types of sEV therapeutics, future improvements, and current strategies in large-scale production.
ABSTRACT
Protein nanocages have attracted considerable attention in various fields of nanomedicine due to their intrinsic properties, including biocompatibility, biodegradability, high structural stability, and ease of modification of their surfaces and inner cavities. In vaccine development, these protein nanocages are suited for efficient targeting to and retention in the lymph nodes and can enhance immunogenicity through various mechanisms, including excellent uptake by antigen-presenting cells and crosslinking with multiple B cell receptors. This review highlights the superiority of protein nanocages as antigen delivery carriers based on their physiological and immunological properties such as biodistribution, immunogenicity, stability, and multifunctionality. With a focus on design, we discuss the utilization and efficacy of protein nanocages such as virus-like particles, caged proteins, and artificial caged proteins against cancer and infectious diseases such as coronavirus disease 2019 (COVID-19). In addition, we summarize available knowledge on the protein nanocages that are currently used in clinical trials and provide a general outlook on conventional distribution techniques and hurdles faced, particularly for therapeutic cancer vaccines.
Subject(s)
COVID-19 , Humans , COVID-19/prevention & control , Tissue Distribution , COVID-19 Vaccines , Vaccine Development , Antibodies, ViralABSTRACT
The cluster of differentiation 47 (CD47) protein is abundantly expressed on various malignant cells and suppresses the phagocytic function of macrophages and dendritic cells. High CD47 expression levels are correlated with poor cancer survival. Antagonizing CD47 antibodies with potent antitumor effects have been developed in clinical trials, but have critical side effects, inducing anemia and thrombocytopenia. To develop a safe and potent CD47 blockade, we designed extracellular vesicles (EVs) harboring signal regulatory protein alpha (SIPRα)-EV-SIRPα (EVs that express SIPRα). EV-SIRPα showed minimal toxic effects on hematologic parameters and utilized RBCs as delivery vehicles to tumors rather than inducing anemia. EV-SIRPα inhibited ligation of residual CD47 molecules, which attribute to the EV-endocytosis-mediated CD47 depletion and steric hindrance of EV. In an immunologically cold tumor model, EV-SIRPα induced tumor-specific T-cell-mediated antitumor effects. When directly administered to the accessible lesions, EV-SIRPα monotherapy elicited an abscopal effect in the B16F10 tumor model by increasing immune cell infiltration and CD8+-mediated immunity against non-treated tumors. The combinational approach by loading doxorubicin into the EV-SIRPα dramatically reduced the tumor burden and led to 80% complete remission rate. Thus, a potent EV-based CD47 blockade that is hematologically safe, has efficient signaling blocking efficacy, and has systemic antitumor immunity against cancer is recommended.
Subject(s)
Extracellular Vesicles , Neoplasms , Humans , CD47 Antigen , Immunotherapy , Antigens, Differentiation/metabolism , Neoplasms/drug therapy , Neoplasms/metabolism , Macrophages , Extracellular Vesicles/metabolism , PhagocytosisABSTRACT
The SARS-CoV-2 pandemic has created a global public crisis and heavily affected personal lives, healthcare systems, and global economies. Virus variants are continuously emerging, and, thus, the pandemic has been ongoing for over two years. Vaccines were rapidly developed based on the original SARS-CoV-2 (Wuhan-Hu-1) to build immunity against the coronavirus disease. However, they had a very low effect on the virus' variants due to their low cross-reactivity. In this study, a multivalent SARS-CoV-2 vaccine was developed using ferritin nanocages, which display the spike protein from the Wuhan-Hu-1, B.1.351, or B.1.429 SARS-CoV-2 on their surfaces. We show that the mixture of three SARS-CoV-2 spike-protein-displaying nanocages elicits CD4+ and CD8+ T cells and B-cell immunity successfully in vivo. Furthermore, they generate a more consistent antibody response against the B.1.351 and B.1.429 variants than a monovalent vaccine. This leads us to believe that the proposed ferritin-nanocage-based multivalent vaccine platform will provide strong protection against emerging SARS-CoV-2 variants of concern (VOCs).
Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Neutralizing/genetics , CD8-Positive T-Lymphocytes , COVID-19/prevention & control , COVID-19 Vaccines , Ferritins/genetics , Humans , Immunity , Mutation , SARS-CoV-2 , Vaccines, CombinedABSTRACT
The purpose of this study was to determine whether statins can enhance anticancer effects in head and neck squamous cell carcinoma (HNSCC) when used with cisplatin and act as immunogenic cell death (ICD) inducers that can be used in cancer immunotherapy. Statins alone showed both in vitro and in vivo inhibitory effects against HNSCC, and synergistic antitumor effects were observed when combined with cisplatin in a syngeneic murine HNSCC model. Statins increased calreticulin exposure and endoplasmic reticulum stress-related signals in HNSCC cells. In addition, it was confirmed that statins could activate antigen-presenting cells and tumor-specific CD8+ T cells with an increase in their numbers in the tumor tissues and draining lymph nodes, with this effect showing significant improvement following the combination therapy with cisplatin. Moreover, in triple combination with both cisplatin and anti-programmed cell death 1 receptor (anti-PD-1) antibody, statins dramatically induced further tumor eradication and improved the survival of tumor-bearing mice. Taken together, these results demonstrate that statins, administered in combination with anti-PD-1 antibody, could enhance the anticancer effect of cisplatin and potentiate the efficacy of immunotherapy for HNSCC and present a rationale for repurposing statins as an adjuvant immunotherapeutic option for HNSCC.
Subject(s)
Cisplatin/pharmacology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Squamous Cell Carcinoma of Head and Neck/drug therapy , Tumor Microenvironment/drug effects , Animals , Antibodies, Anti-Idiotypic/pharmacology , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , Cell Line, Tumor , Drug Synergism , Humans , Immunotherapy , Mice , Programmed Cell Death 1 Receptor/immunology , Squamous Cell Carcinoma of Head and Neck/immunology , Squamous Cell Carcinoma of Head and Neck/pathology , Tumor Microenvironment/immunology , Xenograft Model Antitumor AssaysABSTRACT
Antigen-presenting cells (APCs), including macrophages and dendritic cells (DCs), play a crucial role in bridging innate and adaptive immunity; thereby, innate immune checkpoint blockade-based therapy is an attractive approach for the induction of sustainable tumor-specific immunity. The interaction between the cluster of differentiation 47 (CD47) on tumor and signal-regulatory protein alpha (SIRPα) on phagocytic cells inhibits the phagocytic function of APCs, acting as a "don't eat me" signal. Accordingly, CD47 blockade is known to increase tumor cell phagocytosis, eliciting tumor-specific CD8+ T-cell immunity. Here, we introduced a nature-derived nanocage to deliver SIRPγ for blocking of antiphagocytic signaling through binding to CD47 and combined it with prophagocytic stimuli using a metabolic reprogramming reagent for APCs (CpG-oligodeoxynucleotides). Upon delivering the clustered SIRPγ variant, the nanocage showed enhanced CD47 binding profiles on tumor cells, thereby promoting active engulfment by phagocytes. Moreover, combination with CpG potentiated the prophagocytic ability, leading to the establishment of antitumorigenic surroundings. This combination treatment could competently inhibit tumor growth by invigorating APCs and CD8+ T-cells in TMEs in B16F10 orthotopic tumor models, known to be resistant to CD47-targeting therapeutics. Collectively, enhanced delivery of an innate immune checkpoint antagonist with metabolic modulation stimuli of immune cells could be a promising strategy for arousing immune responses against cancer.
Subject(s)
Antigens, Differentiation/administration & dosage , Antigens, Differentiation/immunology , Ferritins/administration & dosage , Melanoma, Experimental/immunology , Melanoma, Experimental/therapy , Nanostructures/therapeutic use , Oxidoreductases/administration & dosage , Receptors, Immunologic/administration & dosage , Receptors, Immunologic/immunology , Animals , Antigens, Differentiation/chemistry , Antigens, Differentiation/genetics , Cell Line, Tumor , Disease Models, Animal , Ferritins/chemistry , Ferritins/genetics , Humans , Immunotherapy/methods , Male , Mice , Mice, Inbred C57BL , Nanostructures/chemistry , Neoplastic Cells, Circulating/immunology , Oxidoreductases/chemistry , Oxidoreductases/genetics , Phagocytosis/immunology , Receptors, Immunologic/chemistry , Receptors, Immunologic/geneticsABSTRACT
BACKGROUND: Statins preferentially promote tumor-specific apoptosis by depleting isoprenoid such as farnesyl pyrophosphate and geranylgeranyl pyrophosphate. However, statins have not yet been approved for clinical cancer treatment due, in part, to poor understanding of molecular determinants on statin sensitivity. Here, we investigated the potential of statins to elicit enhanced immunogenicity of KRAS-mutant (KRASmut) tumors. METHODS: The immunogenicity of treated cancer cells was determined by western blot, flow cytometry and confocal microscopy. The immunotherapeutic efficacy of mono or combination therapy using statin was assessed in KRASmut tumor models, including syngeneic colorectal cancer and genetically engineered lung and pancreatic tumors. Using NanoString analysis, we analyzed how statin influenced the gene signatures associated with the antigen presentation of dendritic cells in vivo and evaluated whether statin could induce CD8+ T-cell immunity. Multiplex immunohistochemistry was performed to better understand the complicated tumor-immune microenvironment. RESULTS: Statin-mediated inhibition of KRAS prenylation provoked severe endoplasmic reticulum (ER) stress by attenuating the anti-ER stress effect of KRAS mutation, thereby resulting in the immunogenic cell death (ICD) of KRASmut cancer cells. Moreover, statin-mediated ICD enhanced the cross-priming ability of dendritic cells, thereby provoking CD8+ T-cell immune responses against KRASmut tumors. Combination therapy using statin and oxaliplatin, an ICD inducer, significantly enhanced the immunogenicity of KRASmut tumors and promoted tumor-specific immunity in syngeneic and genetically engineered KRASmut tumor models. Along with immune-checkpoint inhibitors, the abovementioned combination therapy overcame resistance to PD-1 blockade therapies, improving the survival rate of KRASmut tumor models. CONCLUSIONS: Our findings suggest that KRAS mutation could be a molecular target for statins to elicit potent tumor-specific immunity.
Subject(s)
Endoplasmic Reticulum Stress/genetics , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Proto-Oncogene Proteins p21(ras)/drug effects , Animals , Humans , Male , Mice , Mutation , TransfectionABSTRACT
The effective chemotherapeutic drug, doxorubicin (DOX), elicits immunogenic cell death (ICD) and additional anticancer immune responses during chemotherapy. However, it also induces severe side effects and systemic immunosuppression, hampering its wide clinical application. Herein, we constructed cancer-activated DOX prodrug by conjugating the cathepsin B-cleavable peptide (Phe-Arg-Arg-Gly, FRRG) to a doxorubicin (DOX), resulting in FRRG-DOX that self-assembled into cancer-activated DOX prodrug nanoparticles (CAP-NPs). The resulting CAP-NPs were further stabilized with the FDA-approved compound, Pluronic F68. CAP-NPs formed stable prodrug nanoparticles and they were specifically cleaved to cytotoxic DOX molecules only in cathepsin B-overexpressing cancer cells, inducing a cancer cell-specific cytotoxicity. In particular, the CAP-NPs induced ICD through cathepsin B-cleavage mechanism only in targeted cancer cells in vitro. In colon tumor-bearing mice, selectively accumulated CAP-NPs at tumors enhanced antitumor immunity without DOX-related severe toxicity, inflammatory response and systemic immunosuppression. Moreover, cytotoxicity against immune cells infiltrated into tumor microenvironment was significantly reduced compared to free DOX, leading to increased response to checkpoint inhibitor immunotherapy. The combinatorial treatment of CAP-NPs with anti-PD-L1 exhibited high rate of complete tumor regression (50%) compared to free DOX with anti-PD-L1. Concurrently, DOX-related side effects were greatly reduced during chemoimmunotherapy. Collectively, our results suggest that cancer-activated DOX prodrug nanoparticles provide a promising approach to increase clinical benefit by inducing an immune response preferentially only to targeted cancer cells, not to normal cells and immune cells, and potentiates checkpoint inhibitor immunotherapy.
Subject(s)
Nanoparticles , Neoplasms , Prodrugs , Animals , Cell Line, Tumor , Doxorubicin , Immunity , Mice , Neoplasms/drug therapyABSTRACT
Targeted delivery of immunomodulatory molecules to the lymph nodes is an attractive means of improving the efficacy of anti-cancer immunotherapy. In this study, to improve the efficacy of PD-1 blockade-based therapy, nanocages were designed by surface engineering to decorate a programmed cell death protein 1 (PD-1) that is capable of binding against programmed death-ligand 1 (PD-L1) and -ligand 2 (PD-L2). This nanocage-mediated multivalent interaction remarkably increases the binding affinity and improves the antagonistic activity compared to free soluble PD-1. In addition, with the desirable nanocage size for optimal tumor-draining lymph node (TDLN) targeting (approximately 20 nm), rapid draining and increased accumulation into the TDLNs were observed. Moreover, the interference of the PD-1/PD-L axis with ultra-high affinity in the tumor microenvironment (effector phase) and the TDLNs (cognitive phase) significantly enhances the dendritic cell-mediated tumor-specific T cell activation. This characteristic successfully inhibited tumor growth and induced complete tumor eradication in some mice. Thus, the delivery of immunomodulatory molecules with nanocages can be a highly efficient strategy to achieve stronger anti-tumor immunity.
Subject(s)
Neoplasms , Programmed Cell Death 1 Receptor , Animals , Immunotherapy , Lymph Nodes , Mice , Neoplasms/drug therapy , T-Lymphocytes , Tumor MicroenvironmentABSTRACT
Tumor-specific apoptosis-inducing ligands have attracted considerable attention in cancer therapy. But, the evasion of apoptosis by tumors can cause acquired resistance to the therapy. TNF-related apoptosis-inducing ligand (TRAIL) has been investigated as an ideal antitumor agent owing to its inherent tumor cell-specific apoptotic activity. However, there are several barriers to its wider application, including the inability for stable formation of the trimeric structure, poor stability and pharmacokinetics, and differences in the sensitivity of different tumor types. Especially, almost 70% of tumor cells have acquired resistance to TRAIL, leading to failure of TRAIL-based therapeutics in clinical trials. To overcome therapeutic efficiency limitations against TRAIL-resistant tumors, we exploited the characteristic of a naturally derived nanocage that not only delivers TRAIL in its native-like trimeric structure, but also delivers a drug (doxorubicin [DOX]) that re-sensitizes TRAIL-resistant tumor cells. These TRAIL-presenting nanocages (TTPNs) showed high loading efficiency, pH-dependent release profiles, and effective intracellular delivery of the re-sensitizing agent DOX. As a result, DOX-TTPNs efficiently re-sensitized TRAIL-resistant tumor cells to TRAIL-mediated apoptosis in vitro by regulating levels of the TRAIL receptor, DR5, and anti- and pro-apoptotic proteins involved in extrinsic and intrinsic apoptosis pathways. We further demonstrated the antitumor efficacy of DOX-TTPNs in vivo, showing that even at a very low dose, the incorporated DOX successfully re-sensitized tumors to the apoptotic effects of TRAIL, underscoring the potential of this platform as an antitumor agent. Given that other homotrimeric TNF superfamily ligands and immunotherapeutic agents can be substituted for TRAIL ligand and re-sensitizing drugs on the surface and in the inner cavity of the nanocage, respectively, this platform is potentially suitable for development of a broad range of anticancer or immunotherapeutic combinations.
Subject(s)
Neoplasms , TNF-Related Apoptosis-Inducing Ligand , Apoptosis , Cell Line, Tumor , Doxorubicin , Humans , Neoplasms/drug therapy , Receptors, TNF-Related Apoptosis-Inducing LigandABSTRACT
Cancer immunotherapy (CI) represented by immune checkpoint inhibitors (ICIs) presents a new paradigm for cancer treatment. However, the types of cancer that attain a therapeutic benefit from ICIs are limited, and the efficacy of these treatments does not meet expectations. To date, research on ICIs has mainly focused on identifying biomarkers and patient characteristics that can enhance the therapeutic effect on tumors. However, studies on combinational strategies for CI are being actively conducted to overcome the resistance to ICI treatment. Moreover, it has been confirmed that dramatic anticancer effects are achieved through "neoadjuvant" immunotherapy with ICIs in treatment-naïve cancer patients; consequently, it has become necessary to consider how to best apply cancer immunotherapies for patients, even with respect to their tumor stages. In this review, we sought to discuss the right timing of ICI treatment in consideration of the progression of cancer with a changing tumor-immune microenvironment. Furthermore, we investigated which types of combinational treatments and their corresponding sequences of administration could optimize the therapeutic effect of ICIs to expand the applicable target of ICIs and increase their therapeutic efficacy. Finally, we discussed several delivery pathways and methods that can maximize the effect of ICIs.
Subject(s)
Immunotherapy , Neoplasms , Humans , Immune Checkpoint Inhibitors , Immunologic Factors/therapeutic use , Neoplasms/drug therapy , Tumor MicroenvironmentABSTRACT
BACKGROUND: Uveal melanoma (UM) is the most frequent intraocular malignancy and is resistant to immunotherapy. Nearly 50% of patients with UM develop metastatic disease, and the overall survival outcome remains very poor. Therefore, a treatment regimen that simultaneously targets primary UM and prevents metastasis is needed. Here, we suggest an immunotherapeutic strategy for UM involving a combination of local photodynamic therapy (PDT), rho-kinase (ROCK) inhibitor, and PD-1/PD-L1 immune checkpoint blockade. METHODS: The antitumor efficacy and immune response of monotreatment or combinational treatment were evaluated in B16F10-bearing syngeneic mouse models. Abscopal antitumor immune responses induced by triple-combinational treatment were validated in syngeneic bilateral B16F10 models. After each treatment, the immune profiles and functional examinations were assessed in tumors and tumor draining lymph nodes by flow cytometry, ELISA, and immunofluorescence assays. In orthotopic intraocular melanoma models, the location of the immune infiltrate in the tumor microenvironment (TME) was evaluated after each treatment by multiplex immunohistochemistry and metastatic nodules were monitored. RESULTS: PDT with Ce6-embedded nanophotosensitizer (FIC-PDT) elicited immunogenic cell death and stimulated antigen-presenting cells. In situ immunogenic clearance induced by a combination of FIC-PDT with ripasudil, a clinically approved ROCK inhibitor, stimulated antigen-presenting cells, which in turn primed tumor-specific cytotoxic T cells. Moreover, local immunogenic clearance sensitized PD-1/PD-L1 immune checkpoint blockade responses to reconstruct the TME immune phenotypes of cold tumors into hot tumors, resulting in recruitment of robust cytotoxic CD8+ T cells in the TME, propagation of systemic antitumor immunity to mediate abscopal effects, and prolonged survival. In an immune-privileged orthotopic intraocular melanoma model, even low-dose FIC-PDT and ripasudil combined with anti-PD-L1 antibody reduced the primary tumor burden and prevented metastasis. CONCLUSIONS: A combination of localized FIC-PDT and a ROCK inhibitor exerted a cancer vaccine-like function. Immunogenic clearance led to the trafficking of CD8+ T cells into the primary tumor site and sensitized the immune checkpoint blockade response to evoke systemic antitumor immunity to inhibit metastasis, one of the major challenges in UM therapy. Thus, immunogenic clearance induced by FIC-PDT and ROCK inhibitor combined with anti-PD-L1 antibody could be a potent immunotherapeutic strategy for UM.
Subject(s)
Immune Checkpoint Inhibitors/administration & dosage , Isoquinolines/administration & dosage , Melanoma, Experimental/drug therapy , Melanoma/drug therapy , Photochemotherapy/methods , Sulfonamides/administration & dosage , Uveal Neoplasms/drug therapy , Animals , Antigen-Presenting Cells/metabolism , Cell Line, Tumor , Drug Synergism , Humans , Immune Checkpoint Inhibitors/pharmacology , Isoquinolines/pharmacology , Male , Melanoma/immunology , Melanoma, Experimental/immunology , Mice , Neoplasm Metastasis , Sulfonamides/pharmacology , Transplantation, Isogeneic , Treatment Outcome , Tumor Microenvironment , Uveal Neoplasms/immunology , Xenograft Model Antitumor AssaysABSTRACT
Exosomes are a class of extracellular vesicles of around 100 nm in diameter that are secreted by most cells and contain various bioactive molecules reflecting their cellular origin and mediate intercellular communication. Studies of these exosomal features in tumor pathogenesis have led to the development of therapeutic and diagnostic approaches using exosomes for cancer therapy. Exosomes have many advantages for conveying therapeutic agents such as small interfering RNAs, microRNAs, membrane-associated proteins, and chemotherapeutic compounds; thus, they are considered a prime candidate as a delivery tool for cancer treatment. Since exosomes also provide an optimal microenvironment for the effective function of immunomodulatory factors, exosomes harboring bioactive molecules have been bioengineered as cancer immunotherapies that can effectively activate each stage of the cancer immunity cycle to successfully elicit cancer-specific immunity. This review discusses the advantages of exosomes for treating cancer and the challenges that must be overcome for their successful clinical development.
Subject(s)
Exosomes/pathology , Immunotherapy/methods , Neoplasms/pathology , Neoplasms/therapy , Cinnamates , Humans , Imidazoles , Neoplasms/immunologyABSTRACT
Many cancer patients not responding to current immunotherapies fail to produce tumor-specific T cells for various reasons, such as a lack of recognition of cancer cells as foreign. Here, we suggest a previously unidentified method for xenogenizing (turning self to non-self) tumors by using fusogenic exosomes to introduce fusogenic viral antigens (VSV-G) onto the tumor cell surface. We found that xenogenized tumor cells were readily recognized and engulfed by dendritic cells; thereby, tumor antigens were efficiently presented to T lymphocytes. Moreover, exosome-VSV-G itself acts as a TLR4 agonist and stimulates the maturation of dendritic cells, leading to CD8+ T cell cross-priming. The administration of these exosomes in multiple tumor mouse models xenogenized tumor cells, resulting in tumor growth inhibition. The combinatorial treatment with anti-PD-L1 exhibited complete tumor regression (30%) and better long-term overall survival. These results suggest that tumor xenogenization by fusogenic exosomes provides a previously unidentified novel strategy for cancer immunotherapy.
Subject(s)
Exosomes , Neoplasms , Animals , CD8-Positive T-Lymphocytes , Dendritic Cells/metabolism , Exosomes/metabolism , Humans , Immunotherapy , Mice , Neoplasms/metabolism , Tumor MicroenvironmentABSTRACT
Exosomes are nanosized vesicles with a lipid membrane that are secreted by most cells and play a crucial role as intermediates of intercellular communication because they carry bioactive molecules. Exosomes are promising for drug delivery of chemicals, proteins, and nucleic acids owing to their inherent properties such as excellent biocompatibility, high tumor targetability, and prolonged circulation in vivo. In this review, we cover recent approaches and advances made in the field of exosome-mediated delivery of bioactive molecules for cancer therapy and factors that affect the clinical use of exosomes. This review can be used as a guideline for further study in expanding the utility of therapeutic exosomes.
Subject(s)
Antineoplastic Agents/administration & dosage , Drug Delivery Systems/methods , Exosomes , Neoplasms/drug therapy , Animals , HumansABSTRACT
Cancer immunotherapy is a powerful approach for cancer treatment, but its clinical effects rely on the tumor's immune conditions. In particular, low response rates to PD-1 blockades are highly correlated with impaired T cell priming. Here, we demonstrate that E. coli-derived monophosphoryl lipid A (EcML) activates dendritic cells in a toll-like receptor-4 (TLR-4)-dependent manner and increases the sensitivity of cancer cells to anti-PD-1 immunotherapy. EcML is a mixture of 4'-monophosphoryl lipids A (MPLAs) produced directly by an engineered Escherichia coli strain; it has a unique congener composition that differentiates it from the well-established MPLA adjuvants, 3-O-desacyl-4'-monophosphoryl lipid A and glucopyranosyl lipid A. Given that active dendritic cells initiate adaptive immune responses, we investigated the anti-tumor activity of an aqueous formulation of EcML. Upon sensing EcML via TLR-4, dendritic cells matured into powerful antigen-presenting cells that could stimulate naïve T cells. EcML reduced tumor growth in the B16F10 mouse model via dendritic cell activation and potentiated PD-1 blockade therapy in the B16F10-OVA melanoma model. These data identify EcML as a promising TLR-4 agonist that can induce anti-tumor immune responses and potentiate PD-1 blockade therapy against tumors.