Lymph node targeting strategy using a hydrogel sustained-release system to load effector memory T cells improves the anti-tumor efficacy of anti-PD-1.

Communication between tumors and lymph nodes carries substantial significance for antitumor immunotherapy. Remodeling the immune microenvironment of tumor-draining lymph nodes (TdLN) plays a key role in enhancing the anti-tumor ability of immunotherapy. In this study, we constructed a biomimetic artificial lymph node structure composed of F127 hydrogel loading effector memory T (TEM) cells and PD-1 inhibitors (aPD-1). The biomimetic lymph nodes facilitate the delivery of TEM cells and aPD-1 to the TdLN and the tumor immune microenvironment, thus realizing effective and sustained anti-tumor immunotherapy. Exploiting their unique gel-forming and degradation properties, the cold tumors were speedily transformed into hot tumors via TEM cell supplementation. Meanwhile, the efficacy of aPD-1 was markedly elevated compared with conventional drug delivery methods. Our finding suggested that the development of F127@TEM@aPD-1 holds promising potential as a future novel clinical drug delivery technique. STATEMENT OF SIGNIFICANCE: F127@TEM@aPD-1 show unique advantages in cancer treatment. When injected subcutaneously, F127@TEM@aPD-1 can continuously supplement TEM cells and aPD-1 to tumor draining lymph nodes (TdLN) and the tumor microenvironment, not only improving the efficacy of ICB therapy through slow release, but also exhibiting dual regulatory effects on the tumor and TdLN.

Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer.

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

Manganese drives ferroptosis of cancer cells via YAP/TAZ phase separation activated ACSL4 in OSCC.

OBJECTIVE: Ferroptosis has been defined as a novel form of regulated cell death characterized by iron-dependent lipid peroxidation. Manganese has been used to induce ferroptosis in cancer cells recently. This study aims to investigate whether manganese can induce ferroptosis in oral squamous cell carcinoma (OSCC) and the underlying biological mechanisms. MATERIALS AND METHODS: Cancer cells with or without manganese treatment were analyzed by RNA-sequencing to identify ferroptosis-related genes. Next, the activation of YAP/TAZ/ACSL4-ferroptosis signaling pathway was detected. Bioinformatic analysis and immunofluorescence assay were used to explore the phase separation of YAP/TAZ. Finally, specimens of OSCC patients were applied to analyze the clinical significance of YAP/TAZ/ACSL4. RESULTS: RNA-sequencing analysis showed the ferroptosis-related genes and YAP/TAZ were upregulated after manganese treatment. The results of immunofluorescence, ELISA, western blotting, etc. further confirmed that manganese-induced ferroptosis depends on YAP/TAZ/ACSL4 signaling pathway. Moreover, the activation of ACSL4 was achieved by YAP/TAZ phase separation. The survival analysis in OSCC specimen suggested that the higher level of YAP/TAZ-ACSL4 axis expression indicates longer survival. CONCLUSIONS: Manganese induces YAP/TAZ phase separation and subsequent ACSL4 activation via YAP/TAZ nuclear translocation, which facilitates ferroptosis of OSCC. Then YAP/TAZ-ACSL4 axis can be used as a potential prognostic predictor of OSCC patients.

Microwave-responsive gadolinium metal-organic frameworks nanosystem for MRI-guided cancer thermotherapy and synergistic immunotherapy.

The clinical application of cancer immunotherapy is unsatisfied due to low response rates and systemic immune-related adverse events. Microwave hyperthermia can be used as a synergistic immunotherapy to amplify the antitumor effect. Herein, we designed a Gd-based metal-organic framework (Gd-MOF) nanosystem for MRI-guided thermotherapy and synergistic immunotherapy, which featured high performance in drug loading and tumor tissue penetration. The PD-1 inhibitor (aPD-1) was initially loaded in the porous Gd-MOF (Gd/M) nanosystem. Then, the phase change material (PCM) and the cancer cell membrane were further sequentially modified on the surface of Gd/MP to obtain Gd-MOF@aPD-1@CM (Gd/MPC). When entering the tumor microenvironment (TME), Gd/MPC induces immunogenic death of tumor cells through microwave thermal responsiveness, improves tumor suppressive immune microenvironment and further enhances anti-tumor ability of T cells by releasing aPD-1. Meanwhile, Gd/MPC can be used for contrast-enhanced MRI. Transcriptomics data revealed that the downregulation of MSK2 in cancer cells leads to the downregulation of c-fos and c-jun, and ultimately leads to the apoptosis of cancer cells after treatment. In general, Gd/MPC nanosystem not only solves the problem of system side effect, but also achieves the controlled drug release via PCM, providing a promising theranostic nanoplatform for development of cancer combination immunotherapy.

3D-printed bioink loading with stem cells and cellular vesicles for periodontitis-derived bone defect repair.

The suitable microenvironment of bone regeneration is critically important for periodontitis-derived bone defect repair. Three major challenges in achieving a robust osteogenic reaction are the exist of oral inflammation, pathogenic bacteria invasion and unaffluent seed cells. Herein, a customizable and multifunctional 3D-printing module was designed with glycidyl methacrylate (GMA) modified epsilon-poly-L-lysine (EPLGMA) loading periodontal ligament stem cells (PDLSCs) and myeloid-derived suppressive cells membrane vesicles (MDSCs-MV) bioink (EPLGMA/PDLSCs/MDSCs-MVs, abbreviated as EPM) for periodontitis-derived bone defect repair. The EPM showed excellent mechanical properties and physicochemical characteristics, providing a suitable microenvironment for bone regeneration.In vitro, EPMs presented effectively kill the periodontopathic bacteria depend on the natural antibacterial properties of the EPL. Meanwhile, MDSCs-MV was confirmed to inhibit T cells through CD73/CD39/adenosine signal pathway, exerting an anti-inflammatory role. Additionally, seed cells of PDLSCs provide an adequate supply for osteoblasts. Moreover, MDSCs-MV could significantly enhance the mineralizing capacity of PDLSCs-derived osteoblast. In the periodontal bone defect rat model, the results of micro-CT and histological staining demonstrated that the EPM scaffold similarly had an excellent anti-inflammatory and bone regeneration efficacyin vivo. This biomimetic and multifunctional 3D-printing bioink opens new avenues for periodontitis-derived bone defect repair and future clinical application.

The role of oral microbiota in cancer.

Cancer remains a significant global challenge, with an estimated 47% increase in cancer patients from 2020 to 2040. Increasing research has identified microorganism as a risk factor for cancer development. The oral cavity, second only to the colon, harbors more than 700 bacterial species and serves as a crucial microbial habitat. Although numerous epidemiological studies have reported associations between oral microorganisms and major systemic tumors, the relationship between oral microorganisms and cancers remains largely unclear. Current research primarily focuses on respiratory and digestive system tumors due to their anatomical proximity to the oral cavity. The relevant mechanism research mainly involves 47% dominant oral microbial population that can be cultured in vitro. However, further exploration is necessary to elucidate the mechanisms underlying the association between oral microbiota and tumors. This review systematically summarizes the reported correlations between oral microbiota and common cancers while also outlining potential mechanisms that may guide biological tumor treatment.

Porphyromonas gingivalis suppresses oral squamous cell carcinoma progression by inhibiting MUC1 expression and remodeling the tumor microenvironment.

Bacteria are the causative agents of various infectious diseases; however, the anti-tumor effect of some bacterial species has attracted the attention of many scientists. The human oral cavity is inhabited by abundant and diverse bacterial communities and some of these bacterial communities could play a role in tumor suppression. Therefore, it is crucial to find oral bacterial species that show anti-tumor activity on oral cancers. In the present study, we found that a high abundance of Porphyromonas gingivalis, an anaerobic periodontal pathogen, in the tumor microenvironment (TME) was positively associated with the longer survival of patients with oral squamous cell carcinoma (OSCC). An in vitro assay confirmed that P. gingivalis accelerated the death of OSCC cells by inducing cell cycle arrest at the G2/M phase, thus exerting its anti-tumor effect. We also found that P. gingivalis significantly decreased tumor growth in a 4-nitroquinoline-1-oxide-induced in situ OSCC mouse model. The transcriptomics data demonstrated that P. gingivalis suppressed the biosynthesis of mucin O-glycan and other O-glycans, as well as the expression of chemokines. Validation experiments further confirmed the downregulation of mucin-1 (MUC1) and C-X-C motif chemokine 17 (CXCL17) expression by P. gingivalis treatment. Flow cytometry analysis showed that P. gingivalis successfully reversed the immunosuppressive TME, thereby suppressing OSCC growth. In summary, the findings of the present study indicated that the rational use of P. gingivalis could serve as a promising therapeutic strategy for OSCC.

Inhalation delivery of dexamethasone with iSEND nanoparticles attenuates the COVID-19 cytokine storm in mice and nonhuman primates.

Dexamethasone (DEX) is the first drug to show life-saving efficacy in patients with severe coronavirus disease 2019 (COVID-19), while DEX is associated with serious adverse effects. Here, we report an inhaled, Self-immunoregulatory, Extracellular Nanovesicle-based Delivery (iSEND) system by engineering neutrophil nanovesicles with cholesterols to deliver DEX for enhanced treatment of COVID-19. Relying on surface chemokine and cytokine receptors, the iSEND showed improved targeting to macrophages and neutralized broad-spectrum cytokines. The nanoDEX, made by encapsulating DEX with the iSEND, efficiently promoted the anti-inflammation effect of DEX in an acute pneumonia mouse model and suppressed DEX-induced bone density reduction in an osteoporosis rat model. Relative to an intravenous administration of DEX at 0.1 milligram per kilogram, a 10-fold lower dose of nanoDEX administered by inhalation produced even better effects against lung inflammation and injury in severe acute respiratory syndrome coronavirus 2-challenged nonhuman primates. Our work presents a safe and robust inhalation delivery platform for COVID-19 and other respiratory diseases.

PFC@O2 Targets HIF-1α to Reverse the Immunosuppressive TME in OSCC.

As a typical hallmark of solid tumors, hypoxia affects the effects of tumor radiotherapy, chemotherapy, and photodynamic therapy. Therefore, targeting the hypoxic tumor microenvironment (TME) is a promising treatment strategy for cancer therapy. Here, we prepared an Albumin Human Serum (HSA)-coated perfluorocarbon (PFC) carrying oxygen (PFC@O2) to minimize OSCC hypoxia. The results showed that PFC@O2 significantly downregulated the expression of HIF-1α and the number of M2-like macrophages in vitro. Furthermore, PFC@O2 effectively inhibited the growth of oral squamous cell carcinoma (OSCC) and reduced the proportion of negative immunoregulatory cells, including myeloid-derived suppressor cells (MDSCs) and M2-like macrophages of TME in a 4-nitroquinoline N-oxide (4NQO)-induced mouse model. Conversely, the infiltration of CD4+ and CD8+ T cells was significantly increased in TME, suggesting that the anti-tumor immune response was enhanced. However, we also found that hypoxia-relative genes expression was positively correlated with CD68+/CD163+ TAMs in human tissue specimens. In summary, PFC@O2 could effectively inhibit the progression of OSCC by alleviating hypoxia, which provides a practical basis for gas therapy and gas synergistic therapy for OSCC.

Advanced materials and technologies for oral diseases.

Oral disease, as a class of diseases with very high morbidity, brings great physical and mental damage to people worldwide. The increasing burden and strain on individuals and society make oral diseases an urgent global health problem. Since the treatment of almost all oral diseases relies on materials, the rapid development of advanced materials and technologies has also promoted innovations in the treatment methods and strategies of oral diseases. In this review, we systematically summarized the application strategies in advanced materials and technologies for oral diseases according to the etiology of the diseases and the comparison of new and old materials. Finally, the challenges and directions of future development for advanced materials and technologies in the treatment of oral diseases were refined. This review will guide the fundamental research and clinical translation of oral diseases for practitioners of oral medicine.

Ferroptosis promotes anti-tumor immune response by inducing immunogenic exposure in HNSCC.

Accumulated evidence indicates that immune cell populations play pivotal roles in the process of tumor initiation, progression, recurrence, metastasis, and immune escape. Ferroptosis is a form of regulating cell death in the nexus between metabolism, redox biology, and human health. Ferroptosis is considered as a vital important event in HNSCC, but the underling mechanism of regulating immune cell populations remains poorly understood. Our tissue microarray study showed that patients with high expression of GPX4 were related to poor survival. Moreover, the expression of GPX4 has been negatively associated with immunogenic cell death-related protein calreticulin in HNSCC tissue cohort. Further, RSL3 was used to induce ferroptosis in HNSCC xenograft of C3H/He mouse. We found that the occurrence of ferroptosis had significantly reduced the number of myeloid-derived suppressor cells (MDSCs) and tumor-associated M2-like macrophages (M2 TAMs) in tumor microenvironment. Meanwhile, the tumor-infiltrating CD4+ and CD8+ T cells were increased. And the calreticulin and HMGB1 may be potential candidate proteins improving the immunosuppressive tumor microenvironment. Taken together, our project suggests that ferroptosis can promote anti-tumor immune response by reversing immunosuppressive microenvironment, indicating that ferroptosis inducer is a promising therapeutic strategy in HNSCC.

STAT3 promotes differentiation of monocytes to MDSCs via CD39/CD73-adenosine signal pathway in oral squamous cell carcinoma.

Myeloid-derived suppressor cells (MDSCs) are one of the tumor-infiltrating immune cell population, which play a powerful role in inhibiting anti-tumor immune response. Our previous studies have shown that STAT3 blockade can decrease the number of MDSCs in tumor microenvironment. However, it is unclear for the molecular mechanism of down-regulation MDSCs with STAT3 inhibitor. In this study, we first detected and analyzed the expression of p-STAT3, CD33, CD14, CD39 and CD73 via oral squamous cell carcinoma (OSCC) tissue array. We found that p-STAT3 was positively correlated with CD14, CD33, CD39, and CD73 in OSCC patient specimens. Then we found STAT3 blockade with S3I-201 reduced the expression of CD39/CD73 and the synthesis of adenosine, as well as inhibiting monocytes to MDSCs differentiation in vitro. Furthermore, we found that S3I-201 displayed prominent anti-tumor efficacy in C3H/He OSCC mouse model via inhibiting CD39/CD73-adenosine signal pathway and decreasing MDSCs. These results suggest that STAT3 signal can induce the differentiation of monocytes into MDSCs in tumor microenvironment depending on CD39/CD73-adenosine signal pathway and STAT3 blockade is a promising therapeutic strategy for OSCC.

CD24 blockade promotes anti-tumor immunity in oral squamous cell carcinoma.

OBJECTIVES: Our study elucidates the prognostic role of cluster of differentiation (CD) 24 expression in oral squamous cell carcinoma (OSCC) and determines whether targeting CD24 enhances the anti-tumor immune response by inhibiting tumor-associated macrophages (TAMs). MATERIALS AND METHODS: The expression of CD24 and CD68 was analyzed immunohistochemically via tissue microarrays constructed using 56 cohorts of patients with OSCC and 20 control specimens. Further, CD24 was inhibited in an allograft squamous cell carcinoma (SCC) related mouse model with CD24mAb to determine the tumor volume and weight. Changes in immune cells such as TAMs and T cells in the tumor microenvironment (TME) were analyzed by Flow cytometry. The expression of CD4, CD8, and Ki67 was analyzed via immunohistochemistry. The inhibition of CD24 was confirmed by Western blot and immunohistochemistry. RESULTS: CD24 was overexpressed in OSCC. High expression of CD24 indicated poor survival in patients with OSCC (p = 0.0334). CD24 expression was significantly correlated with CD68 (p = 0.0424). The inhibition of CD24 delayed tumor growth in vivo. A decrease in TAMs number and an increase in T cell number were confirmed, while the ability of tumor proliferation was impaired. CONCLUSION: Targeting CD24 could enhance anti-tumor immune response by inhibiting TAMs.

Three novel MOFs constructed from 1,3,5-tris(1-imidazolyl)benzene and dicarboxylate ligands with selective adsorption for C2H2/C2H4 and C2H6/CH4.

The urothermal reactions of Co(II)/Zn(II) salts with the diverse carboxylic acid and 1,3,5,-tris(1-imidazolyl)benzene(tib) ligands afforded three novel MOFs, namely, [Co3(tib)2(abdc)2(ox)]2·6H2O (1), [Co3O(tib)(abdc)2(DMI)]·2DMI·2H2O (2) and [Zn3I2(tib)2(napdc)2]·2DMI·2H2O (3), (H2abdc = 5-amino-1,3-benzenedicarboxylate, H2napdc = 1,4-naphthalene dicarboxylic acid and DMI = 1,3-dimethyl-2-imidazolidinone). In compounds 1 and 2, the Co(II) atoms are connected by polycarboxylate ligands to form two-dimensional (2D) layers that are pillared by tib ligands leading to the formation of 3D porous frameworks. In compound 3, the Zn(II) atoms are linked by tib ligands to form one-dimensional ribbon-like chains which are further connected by polycarboxylate ligands, making a 3D framework possible. Compound 1 can selectively adsorb unsaturated hydrocarbon molecules (C2H2 and C2H4) and saturated hydrocarbon molecules (C2H6 and CH4). Specifically, compound 1 has high IAST selectivity for acetylene and methane (0.50 : 0.50, v/v) at 273 K and 1 bar. DFT calculations reveal that the π-conjugated hexagonal carbon ring may be the primary adsorption site because there are π-π interactions between the unsaturated hydrocarbon molecules (C2H2 and C2H4) and the π-conjugated hexagonal carbon ring in the framework of compound 1.

Genetically Programmable Fusion Cellular Vesicles for Cancer Immunotherapy.

Herein, we report that genetically programmable fusion cellular vesicles (Fus-CVs) displaying high-affinity SIRPα variants and PD-1 can activate potent antitumor immunity through both innate and adaptive immune effectors. Dual-blockade of CD47 and PD-L1 with Fus-CVs significantly increases the phagocytosis of cancer cells by macrophages, promotes antigen presentation, and activates antitumor T-cell immunity. Moreover, the bispecific targeting design of Fus-CVs ensures better targeting on tumor cells, but less on other cells, which reduces systemic side effects and enhances therapeutic efficacies. In malignant melanoma and mammary carcinoma models, we demonstrate that Fus-CVs significantly improve overall survival of model animals by inhibiting post-surgery tumor recurrence and metastasis. The Fus-CVs are suitable for protein display by genetic engineering. These advantages, integrated with other unique properties inherited from source cells, make Fus-CVs an attractive platform for multi-targeting immune checkpoint blockade therapy.

Genome-Wide Enhancer Analysis Reveals the Role of AP-1 Transcription Factor in Head and Neck Squamous Cell Carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers in the world, but its epigenomic features have not been determined. Here, we studied the chromatin landscape of active enhancers of HNSCC head tumor tissues by performing H3K27ac and H3K4me1 ChIP-Seq with a Tgfbr1/Pten double conditional knockout HNSCC mouse model. We identified 1,248 gain variant enhancer loci (VELs) and 2,188 lost VELs, as well as 153 gain variant super enhancer loci (VSELs) and 234 lost VSELs. Potentially involved transcription factors were predicted with motif analysis, and we identified AP-1 as one of the critical oncogenic transcription factors in HNSCC and many other types of cancer. Combining transcriptomic and epigenomic data, our analysis also showed that AP-1 and histone modifications coordinately regulate target gene expression in HNSCC. In conclusion, our study provides important epigenomic information for enhancer studies in HNSCC and reveals new mechanism for AP-1 regulating HNSCC.

Hybrid cellular membrane nanovesicles amplify macrophage immune responses against cancer recurrence and metastasis.

Effectively activating macrophages against cancer is promising but challenging. In particular, cancer cells express CD47, a 'don't eat me' signal that interacts with signal regulatory protein alpha (SIRPα) on macrophages to prevent phagocytosis. Also, cancer cells secrete stimulating factors, which polarize tumor-associated macrophages from an antitumor M1 phenotype to a tumorigenic M2 phenotype. Here, we report that hybrid cell membrane nanovesicles (known as hNVs) displaying SIRPα variants with significantly increased affinity to CD47 and containing M2-to-M1 repolarization signals can disable both mechanisms. The hNVs block CD47-SIRPα signaling axis while promoting M2-to-M1 repolarization within tumor microenvironment, significantly preventing both local recurrence and distant metastasis in malignant melanoma models. Furthermore, by loading a stimulator of interferon genes (STING) agonist, hNVs lead to potent tumor inhibition in a poorly immunogenic triple negative breast cancer model. hNVs are safe, stable, drug loadable, and suitable for genetic editing. These properties, combined with the capabilities inherited from source cells, make hNVs an attractive immunotherapy.

Molecular Targeting Nanoprobes with Non-Overlap Emission in the Second Near-Infrared Window for in Vivo Two-Color Colocalization of Immune Cells.

Monitoring specific immune cells in vivo will provide significant information for improving the therapeutic effect of immunotherapy. Herein, the in vivo two-color fluorescence molecular imaging of an important immune cell, myeloid-derived suppressor cell (MDSC), was realized by using quantum dot (QD)-based nanoprobes with non-overlap emission in the second near-infrared window (NIR-II, 1000-1700 nm). NIR-IIa and NIR-IIb QDs were conjugated with two MDSC-specific antibodies, respectively, and targeted the in vivo MDSCs together. Due to the suppressed photon scattering and diminished autofluorescence in the NIR-II window, the distribution of MDSCs in different organs and tissues was clearly revealed in a non-invasive way by the colocalization of two-color fluorescence from nanoprobes. The high-resolution imaging further confirmed the exact distribution of MDSCs in tumor immune microenvironment (TIME). Our results demonstrated that NIR-II fluorescence nanoprobes with molecular targeting ability provided a powerful tool for monitoring the dynamic change of immune cell populations in TIME in vivo, thus guiding the choice of clinical medicine and evaluating the therapeutic effect.

Blockade of TIGIT/CD155 Signaling Reverses T-cell Exhaustion and Enhances Antitumor Capability in Head and Neck Squamous Cell Carcinoma.

Immunosuppression is common in head and neck squamous cell carcinoma (HNSCC). In previous studies, the TIGIT/CD155 pathway was identified as an immune-checkpoint signaling pathway that contributes to the "exhaustion" state of infiltrating T cells. Here, we sought to explore the clinical significance of TIGIT/CD155 signaling in HNSCC and identify the therapeutic effect of the TIGIT/CD155 pathway in a transgenic mouse model. TIGIT was overexpressed on tumor-infiltrating CD8+ and CD4+ T cells in both HNSCC patients and mouse models, and was correlated with immune-checkpoint molecules (PD-1, TIM-3, and LAG-3). TIGIT was also expressed on murine regulatory T cells (Treg) and correlated with immune suppression. Using a human HNSCC tissue microarray, we found that CD155 was expressed in tumor and tumor-infiltrating stromal cells, and also indicated poor overall survival. Multispectral IHC indicated that CD155 was coexpressed with CD11b or CD11c in tumor-infiltrating stromal cells. Anti-TIGIT treatment significantly delayed tumor growth in transgenic HNSCC mouse models and enhanced antitumor immune responses by activating CD8+ T-cell effector function and reducing the population of Tregs. In vitro coculture studies showed that anti-TIGIT treatment significantly abrogated the immunosuppressive capacity of myeloid-derived suppressor cells (MDSC), by decreasing Arg1 transcripts, and Tregs, by reducing TGFß1 secretion. In vivo depletion studies showed that the therapeutic efficacy by anti-TIGIT mainly relies on CD8+ T cells and Tregs. Blocking PD-1/PD-L1 signaling increased the expression of TIGIT on Tregs. These results present a translatable method to improve antitumor immune responses by targeting TIGIT/CD155 signaling in HNSCC.

Cancer Cell Membrane Camouflaged Nanoparticles to Realize Starvation Therapy Together with Checkpoint Blockades for Enhancing Cancer Therapy.

Although anti-PD-1 immunotherapy is widely used to treat melanoma, its efficacy still has to be improved. In this work, we present a therapeutic method that combines immunotherapy and starvation therapy to achieve better antitumor efficacy. We designed the CMSN-GOx method, in which mesoporous silica nanoparticles (MSN) are loaded with glucose oxidase (GOx) and then encapsulate the surfaces of cancer cell membranes to realize starvation therapy. By functionalizing the MSN's biomimetic surfaces, we can synthesize nanoparticles that can escape the host immune system and homologous target. These attributes enable the nanoparticles to have improved cancer targeting ability and enrichment in tumor tissues. Our synthetic CMSN-GOx complex can ablate tumors and induce dendritic cell maturity to stimulate an antitumor immune response. We performed an in vivo analysis of these nanoparticles and determined that our combined therapy CMSN-GOx plus PD-1 exhibits a better antitumor therapeutic effect than therapies using CMSN-GOx or PD-1 alone. Additionally, we used the positron emission tomography imaging to measuring the level of glucose metabolism in tumor tissues, for which we investigate the effect with the cancer therapy in vivo.