Immune Checkpoint Blockade Immunotherapy Research Articles

Preferential activation of type I interferon-mediated antitumor inflammatory signaling by CuS/MnO2/diAMP nanoparticles enhances anti-PD-1 therapy for sporadic colorectal cancer.

Converting the "cold" tumor microenvironment (TME) to a "hot" milieu has become the prevailing approach for enhancing the response of immune-excluded/immunosuppressed colorectal cancer (CRC) patients to immune checkpoint blockade (ICB) therapy. During this process, inflammation accompanied by different kinds of chemokines/cytokines inevitably occurs. However, some activated inflammatory signals exhibit protumor potency. Therefore, strategies that preferentially activate antitumor inflammatory signaling rather than tumor-promoting signaling need to be developed. Herein, we constructed a STING agonist-loaded CuS/MnO2 bimetallic nanosystem, termed diAMP-BCM. BCM with an optimized Cu/Mn ratio efficiently promoted the activation of proinflammatory signaling, and in combination with the STING agonist diAMP, diAMP-BCM controllably activated tumoricidal inflammatory signaling in APCs. DiAMP-BCM can efficiently generate ROS and promote the activation of STING, which induces the apoptosis of cancer cells and promotes the recruitment of monocytes while facilitating the polarization of macrophages and maturation of DCs. MC38 and CT26 CRC models were established to evaluate the in vivo antitumor effects of diAMP-BCM. Combined with ICB therapy, diAMP-BCM enables the rebuilding of tumor milieus with efficient tumor growth inhibition and alleviation of T-cell exhaustion, particularly in distal tumors, in sporadic colorectal cancer therapy. This study established a nanoplatform to promote the preferential activation of antitumor inflammatory signaling, rebuild the T-cell repertoire and alleviate T-cell exhaustion to enhance cancer ICB immunotherapy.

PD-L1 blockade immunotherapy rewires cancer-induced emergency myelopoiesis.

Immune checkpoint blockade (ICB) immunotherapy has revolutionized cancer treatment, demonstrating exceptional clinical responses in a wide range of cancers. Despite the success, a significant proportion of patients still fail to respond, highlighting the existence of unappreciated mechanisms of immunotherapy resistance. Delineating such mechanisms is paramount to minimize immunotherapy failures and optimize the clinical benefit. In this study, we treated tumour-bearing mice with PD-L1 blockage antibody (aPD-L1) immunotherapy, to investigate its effects on cancer-induced emergency myelopoiesis, focusing on bone marrow (BM) hematopoietic stem and progenitor cells (HSPCs). We examined the impact of aPD-L1 treatment on HSPC quiescence, proliferation, transcriptomic profile, and functionality. Herein, we reveal that aPD-L1 in tumour-bearing mice targets the HSPCs in the BM, mediating their exit from quiescence and promoting their proliferation. Notably, disruption of the PDL1/PD1 axis induces transcriptomic reprogramming in HSPCs, observed in both individuals with Hodgkin lymphoma (HL) and tumour-bearing mice, shifting towards an inflammatory state. Furthermore, HSPCs from aPDL1-treated mice demonstrated resistance to cancer-induced emergency myelopoiesis, evidenced by a lower generation of MDSCs compared to control-treated mice. Our findings shed light on unrecognized mechanisms of action of ICB immunotherapy in cancer, which involves targeting of BM-driven HSPCs and reprogramming of cancer-induced emergency myelopoiesis.

Dual genes manipulation enhanced chemotherapy potentiates antitumor immunity based on extracellular vesicle system for glioblastoma treatment

Glioblastoma is one of the most malignant tumors in the central nervous system, which the conventional therapeutic modalities fail to cure the disease but improve the treatment outcome slightly. In the past decades, immune checkpoint blockade (ICB) and cytokine-regulated immunotherapy have ushered in a new era for glioblastoma treatment. However, the immunosuppressive tumor microenvironment hinders and opposite the therapeutic outcomes. Therefore, the increased importance and necessary for better modality in urgent. Moreover, many novel methods and strategies are searching for more effectively therapeutic outcomes. In this study, the glioblastoma cells derived extracellular vesicles (EVs) were adopted as a delivery platform for the chemotherapy agent (doxorubicin, Dox), gene editing platform of CD47 downregulation and IL-9 overexpression (EVs@Dox/sgCD47/IL-9), due to its excellent blood brain barrier (BBB) crossing rate and specifically targeting capability. The as-prepared EVs@Dox/sgCD47/IL-9 was capable to deliver the Dox and gene editing platform into glioblastoma tissue and was assimilated by cancer cells efficiently, where the Dox induce the immunogenic cell death (ICD) of glioblastoma cells, the CRISPR-Cas9 platform down-regulated the expression of CD47 and the over-expression system up-regulated the expression of IL-9, both enhanced the immunity of biological system. Collectively, EVs@Dox/sgCD47/IL-9 demonstrated remarkable anti-tumor effects and reshaped the immunosuppressive tumor microenvironment that polarized the tumor-associated macrophages and activated CD8+ T cells with good biosafety. Thus, it establishes a strong foundation for the development of more effective strategies against glioblastoma.

Injectable hydrogel assisted formation of hydroxyl radical generating bioreactor enables photothermally enhanced chemodynamic and immunotherapy

Photothermal therapy and chemodynamic therapy (CDT), two recently invented cancer treatments, have shown to be effective in potentiating immunotherapy through causing immunogenic cancer cell death. The rational integration of these two therapeutic modalities poses a formidable challenge in eliciting robust immunotherapy. Herein, an injectable hydrogel based bioreactor comprising of glucose oxidase (GOx), copper sulfide (CuS) nanoparticles, and poly (ethylene glycol) double acrylate (PEGDA) is prepared to potentiate immune checkpoint blockade (ICB) therapy. GOx can in situ convert glucose to hydrogen peroxide (H2O2) and gluconic acid, the latter of which further promotes the decomposition of H2O2 to hydroxyl radicals by creating an acidic microenvironment to benefit the pH-dependent Fenton-like catalytic reaction of Cu+, particularly in synergizing with near infrared (NIR) light exposure. Such catalytic couple of GOx and CuS together with NIR light exposure is efficient in inducing immunogenic cancer cell death. Additionally, GOx reprogrammed tumor immunosuppressive microenvironment by reducing lactate levels. Upon being fixed inside tumors with PEGDA hydrogel, such in situ formed bioreactor effectively suppresses the growth of 4T1 orthotopic murine breast cancers in Balb/c mice together with 808 nm laser exposure. Furthermore, such bioreactor enabled photothermally enhanced CDT could also synergize with anti-PD-L1 immunotherapy to more effectively suppress the growth of primary tumors and distant tumors. This study highlights that such NIR light and reactive oxygen species dual responsive bioreactor is robust to potentiate ICB immunotherapy.

Multi-Functional AIE Phototheranostic Agent Enhancing αPD-L1 Response for Oral Squamous Cell Carcinoma Immunotherapy.

Oral squamous cell carcinoma (OSCC) represents a prevalent head and neck malignancy with surgical intervention as the primary clinical option. Immunotherapy, particularly immune checkpoint blockade (ICB) targeting PD-1/PD-L1 shows great promise but is impeded by the immunosuppressive tumor microenvironment and low PD-L1 expression in OSCC. Herein, the "all-in-one" phototherapeutic nanoparticles (TSD NPs) are reported with balanced reactive oxygen species and photothermal conversion capacity for combined photoimmunotherapy and ICB immunotherapy against OSCC. A novel electron acceptor, 3-(dicyanomethylene)-2,3-dihydrobenzothiophene-1,1-dioxide (DTM), is introduced to develop the phototherapeutic agent with aggregation-induced emission (AIE) feature and NIR-II fluorescence centered at 1000nm. Benefiting from the AIE feature and the DTM acceptor, the resultant TSD NPs also exhibit strong type I reactive oxygen species (ROS) generation and high photothermal conversion efficiency (45.3%), which can profoundly induce immunogenic cell death (ICD), activate cytotoxic T lymphocytes, and convert the immunosuppressive tumor microenvironment into an immune-supportive one. Additionally, TSD NPs upregulate the PD-L1 expression on OSCC cells, thus enhancing the efficacy of combined treatment with αPD-L1 ICB immunotherapy. This results show that the synergistic treatment of TSD NPs and αPD-L1 effectively eradicates solid OSCC tumors without adverse effects on normal tissues, proving a novel and promising strategy for OSCC management.

Platinum-based chemotherapy promotes antigen presenting potential in monocytes of patients with high-grade serous ovarian carcinoma.

Ovarian cancer (OC) is the most lethal gynecologic malignancy worldwide. The major clinical challenge includes the asymptomatic state of the disease, making diagnosis possible only at advanced stages. Another OC complication is the high relapse rate and poor prognosis following the standard first-line treatment with platinum-based chemotherapy. At present, numerous clinical trials are being conducted focusing on immunotherapy in OC; nevertheless, there are still no FDA-approved indications. Personalized decision regarding the immunotherapy, including immune checkpoint blockade and immune cell-based immunotherapies, can depend on the effective antigen presentation required for the cytotoxic immune response. The major aim of our study was to uncover tumor-specific transcriptional and epigenetic changes in peripheral blood monocytes in patients with high-grade serous ovarian cancer (HGSOC). Another key point was to elucidate how chemotherapy can reprogram monocytes and how that relates to changes in other immune subpopulations in the blood. To this end, we performed single-cell RNA sequencing of peripheral blood mononuclear cells (PBMCs) from patients with HGSOC who underwent neoadjuvant chemotherapeutic treatment (NACT) and in treatment-naïve patients. Monocyte cluster was significantly affected by tumor-derived factors as well as by chemotherapeutic treatment. Bioinformatical analysis revealed three distinct monocyte subpopulations within PBMCs based on feature gene expression - CD14.Mn.S100A8.9hi, CD14.Mn.MHC2hi and CD16.Mn subsets. The intriguing result was that NACT induced antigen presentation in monocytes by the transcriptional upregulation of MHC class II molecules, but not by epigenetic changes. Increased MHC class II gene expression was a feature observed across all three monocyte subpopulations after chemotherapy. Our data also demonstrated that chemotherapy inhibited interferon-dependent signaling pathways, but activated some TGFb-related genes. Our results can enable personalized decision regarding the necessity to systemically re-educate immune cells to prime ovarian cancer to respond to anti-cancer therapy or to improve personalized prescription of existing immunotherapy in either combination with chemotherapy or a monotherapy regimen.

Tumor-intrinsic CDC42BPB confers resistance to anti-PD-1 immune checkpoint blockade in breast cancer

Immune checkpoint blockade has been used to treat breast cancer, but the clinical responses remain relatively poor. We have used the CRISPR-Cas9 kinome knockout library consisting of 763 kinase genes to identify tumor-intrinsic kinases conferring resistance to anti-PD-1 immune checkpoint blockade. We have identified the CDC42BPB kinase as a potential target to overcome the resistance to anti-PD-1 immune checkpoint blockade immunotherapy. We found that CDC42BPB is highly expressed in breast cancer patients who are non-responsive to immunotherapy. Furthermore, a small-molecule pharmacological inhibitor, BDP5290, which targets CDC42BPB, synergized with anti-PD-1 and enhanced tumor cell killing by promoting Tcell proliferation in both invitro and invivo assays. Moreover, anti-PD-1-resistant breast cancer cells showed higher expression of CDC42BPB, and its inhibition rendered the resistant cells more susceptible to Tcell killing in the presence of anti-PD-1. We also found that CDC42BPB phosphorylated AURKA, which in turn upregulated PD-L1 through cMYC. Our results have revealed a robust link between tumor-intrinsic kinase and immunotherapy resistance and have provided a rationale for a unique combination therapy of CDC42BPB inhibition and anti-PD-1 immunotherapy for breast cancer.

Metal-Coordinated NIR-II Nanoadjuvants with Nanobody Conjugation for Potentiating Immunotherapy by Tumor Metabolism Reprogramming.

Immune checkpoint blockade (ICB) immunotherapy remains hampered by insufficient immunogenicity and a high-lactate immunosuppressive tumor microenvironment (TME). Herein, a nanobody-engineered NIR-II nanoadjuvant with targeting metabolic reprogramming capability is constructed for potentiating NIR-II photothermal-ferroptosis immunotherapy. Specifically, the nanoadjuvant (2DG@FS-Nb) is prepared by metallic iron ion-mediated coordination self-assembly of D-A-D type NIR-II molecules and loading of glycolysis inhibitor, 2-deoxy-D-glucose (2DG), followed by modification with aPD-L1 nanobody (Nb), which can effectively target the immunosuppressive TME and trigger in situ immune checkpoint blockade. The nanoadjuvants responsively release therapeutic components in the acidic TME, enabling the precise tumor location by NIR-II fluorescence/photoacoustic imaging while initiating NIR-II photothermal-ferroptosis therapy. The remarkable NIR-II photothermal efficiency and elevated glutathione (GSH) depletion further sensitize ferroptosis to induce severe lipid peroxidation, provoking robust immunogenic cell death (ICD) to trigger anti-tumor immune response. Importantly, the released 2DG markedly inhibits lactate generation through glycolysis obstruction. Decreased lactate efflux remodels the immunosuppressive TME by suppressing M2 macrophage proliferation and downregulating regulatory T cell levels. This work provides a new paradigm for the integration of NIR-II phototheranostics and lactate metabolism regulation into a single nanoplatform for amplified anti-tumor immunotherapy combined with ICB therapy.

PiSTING: A Pocket-Independent Agonist Based on Multivalency-Driven STING Oligomerization.

The stimulator of interferon genes (STING) pathway is a potent therapeutic target for innate immunity. Despite the efforts to develop pocket-dependent small-molecule STING agonists that mimic the endogenous STING ligand, cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), most of these agonists showed disappointing results in clinical trials owing to the limitations of the STING pocket. In this study, we developed novel pocket-independent STING-activating agonists (piSTINGs), which act through multivalency-driven oligomerization to activate STING. Additionally, a piSTING-adjuvanted vaccine elicited a significant antibody response and inhibited tumour growth in therapeutic models. Moreover, a piSTING-based vaccine combination with aPD-1 showed remarkable potential to enhance the effectiveness of immune checkpoint blockade (ICB) immunotherapy. In particular, piSTING can strengthen the impact of STING pathway in immunotherapy and accelerate the clinical translation of STING agonists.

PiSTING: A Pocket‐Independent Agonist Based on Multivalency‐Driven STING Oligomerization

AbstractThe stimulator of interferon genes (STING) pathway is a potent therapeutic target for innate immunity. Despite the efforts to develop pocket‐dependent small‐molecule STING agonists that mimic the endogenous STING ligand, cyclic guanosine monophosphate–adenosine monophosphate (cGAMP), most of these agonists showed disappointing results in clinical trials owing to the limitations of the STING pocket. In this study, we developed novel pocket‐independent STING‐activating agonists (piSTINGs), which act through multivalency‐driven oligomerization to activate STING. Additionally, a piSTING‐adjuvanted vaccine elicited a significant antibody response and inhibited tumour growth in therapeutic models. Moreover, a piSTING‐based vaccine combination with aPD‐1 showed remarkable potential to enhance the effectiveness of immune checkpoint blockade (ICB) immunotherapy. In particular, piSTING can strengthen the impact of STING pathway in immunotherapy and accelerate the clinical translation of STING agonists.

Nanodrug modified with engineered cell membrane targets CDKs to activate aPD-L1 immunotherapy against liver metastasis of immune-desert colon cancer

Immunotherapy based on the PD-1/PD-L1 axis blockade has no benefit for patients diagnosed with colon cancer liver metastasis (CCLM) for the microsatellite stable/proficient mismatch repair (MSS/pMMR)) subtype, which is known as an immune-desert cancer featuring poor immunogenicity and insufficient CD8+ T cell infiltration in the tumor microenvironment. Here, a multifunctional nanodrug carrying a cyclin-dependent kinase (CDK)1/2/5/9 inhibitor and PD-L1 antibody is prepared to boost the immune checkpoint blockade (ICB)-based immunotherapy against MSS/pMMR CCLM via reversing the immunosuppressive tumor microenvironment. To enhance the MSS/pMMR CCLM-targeting efficacy, we modify the nanodrug with PD-L1 knockout cell membrane of this colon cancer subtype. First, CDKs inhibitor delivered by nanodrug down-regulates phosphorylated retinoblastoma and phosphorylated RNA polymerase II and meanwhile arrests the G2/M cell cycle in CCLM to promote immunogenic signal release, stimulate dendritic cell maturation, and enhance CD8+ T cell infiltration. Moreover, CDKi suppresses the secretion of immunosuppressive cytokines in tumor-associated myeloid cells sensitizing ICB therapy in CCLM. Notably, the great efficacy to activate immune responses is demonstrated in the patient-derived xenograft model and the patient-derived organoid model as well, revealing a clinical application potential. Overall, our study represents a promising therapeutic approach for targeting liver metastasis, remolding the tumor immune microenvironment (TIME), and enhancing the response of MSS/pMMR CCLM to boost ICB immunotherapy.

Abstract 5100: Multimodal real world data reveals immunogenomic drivers of acquired and primary resistance to immune checkpoint blockade

Abstract Background: Why some patients fail or have short lived response to immune checkpoint blockade (ICB) immunotherapy remains largely unknown. While baseline molecular assessments have provided clues to prognostic factors, insights into resistance drivers remains elusive. This is partially due to the difficulty in getting access to post progression samples from patients that were either primary resistant or developed acquired resistance after an initial response to ICB. Thus, the tumor-intrinsic and -extrinsic features that are selected for during progression and potentially drive primary and acquired resistance to immunotherapy remain underexplored. Methods: To compare clinical features and immunogenomic drivers of acquired and primary resistance to ICB across major cancers, we analysed and annotated de-identified patient records in the Tempus real-world database. We built an immuno-oncology cohort consisting of >2500 multimodal (DNA, RNA and clinical outcome data) pre-treatment baseline with >1500 post-treatment tumour biopsy samples from mainly NSCLC, TNBC, HNC and Bladder cancer patients. We used bulk RNA-seq data to estimate activation of the hallmark oncogenic pathways and immune cell composition and used panel DNA-seq data (>500 genes) to quantify mutation selection at the gene and pathway levels using dndscv. Results: Compared to acquired, primary resistant patients tended to have a higher observation of liver lesions at progression. Post-ICB, acquired resistant NSCLC and HNC patients showed a significantly inflamed tumour microenvironment (TME) characterised by higher estimation of infiltration of T cells and myeloid cells and higher activation of interferon gamma (IFNg) signalling as compared to primary resistant patients. In addition, in post-ICB acquired resistance in NSCLC we observed selection for mutations in genes involved in known immunomodulatory pathways, including loss-of-function mutations in B2M. Consistently, acquired resistance patients showed stronger selection for mutations in Hedgehog and Notch pathways as compared to primary resistance patients across NSCLC, HNC and TNBC post-ICB. Conclusions: Acquired and primary ICB resistant patients have distinct clinical and molecular features at progression. Their tumours’ TME is fundamentally different with acquired resistance TMEs being infiltrated with immune cells albeit escaped post progression. In addition, ICB selects mutations that potentially activate pathways such as Notch and Hedgehog. This multi-modal Real-World Data with post therapy biopsies has given insights for patient selection strategies and provides rational into combination treatment options for acquired resistant patients. Citation Format: Mohamed Reda Keddar, Sebastian Carrasco Pro, Kathleen Burke, Ana Camelo Stewart, Mark Cobbold, Ross Stewart, Sajan Khosla, Ben Sidders, Scott Hammond, Douglas C. Palmer, Jonathan Dry, Martin L. Miller. Multimodal real world data reveals immunogenomic drivers of acquired and primary resistance to immune checkpoint blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5100.

Abstract 3961: Impact of CD8 resident memory T cells on antitumor immunity and response to cancer immunotherapy

Abstract CD8+ resident memory T (TRM) cells expressing the CD103 integrin accumulate in human lung tumors and are associated with a favorable prognosis. We have previously demonstrated that a high density of CD103+CD8+ T cells in human lung tumors is a biomarker of response to immune checkpoint blockade (ICB) immunotherapy. However, a large fraction of human tumors is only weakly infiltrated by CD8+ TRM cells, and the reason of this TRM desert is not explained. Therefore, defining the molecular signals that give rise and maintain TRM cells within the tumor microenvironment (TME) and the mechanisms that potentiate antitumor TRM functions are important challenges. Data obtained in pre-clinical mouse colorectal cancer and melanoma models demonstrate that knocking-out CD103 impairs antitumor T-cell immunity and response to ICB and therapeutic peptide vaccine. Moreover, immunization of melanoma-bearing mice with the cancer vaccine results in a dramatic decrease in the percentage of CD103+ TRM cells among CD8+ tumor-infiltrating T lymphocytes (TIL). Algorithm analyses applied to spectral cytometry data of TIL support the conclusion that upon activation with the peptide vaccine a TRM subset gives rise to tumor-specific effector T cells. The mechanisms associated with the decrease in CD103 expression on CD8+ T cells and lead to a TRM differentiation shift will be presented as well as the key role of TGF-b in CD8+CD103+ TRM formation and persistence in the TME. Our data demonstrate that tumor CD8+CD103+ TRM are capable of mounting a potent antitumor immunity and suggest that a fine balance between diverse signals in the tumor ecosystem is required to induce their differentiation and thereby optimize response to cancer immunotherapy. Citation Format: Stephanie Corgnac, Isabelle DAMEI, Fathia Mami-Chouaib. Impact of CD8 resident memory T cells on antitumor immunity and response to cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3961.

Lovastatin/SN38 co-loaded liposomes amplified ICB therapeutic effect via remodeling the immunologically-cold colon tumor and synergized stimulation of cGAS-STING pathway

Current immune checkpoint blockade (ICB) immunotherapeutics have revolutionized cancer treatment. However, many cancers especially the “immunologically cold” tumors, do not respond to ICB, prompting the search for additional strategies to achieve durable responses. The cGAS-STING pathway, as an essential immune response pathway, has been demonstrated for a potent target to sensitize ICB immunotherapy. However, the low efficiency of conventional STING agonists limits their clinical application. Recent studies have shown that DNA topoisomerase I (TOPI) inhibitor chemodrug SN38 can activate the cGAS-STING pathway and induce an immune response through DNA damage, while the traditional statins medication lovastatin was found to inhibit DNA damage repair, which may in turn upregulate the damaged DNA level. Herein, we have developed a liposomal carrier co-loaded with SN38 and lovastatin (SL@Lip), which can be accumulated in tumors and efficiently released SN38 and lovastatin, addressing the problem of weak solubility of these two drugs. Importantly, lovastatin can increase DNA damage and enhance the activation of cGAS-STING pathway, coordinating with SN38 chemotherapy and exhibiting the enhanced combinational immunotherapy of PD-1 antibody by remodeling the tumor microenvironment in mouse colorectal cancer of both subcutaneous and orthotopic xenograft models. Overall, this study demonstrates that lovastatin-assisted cGAS-STING stimulation mediated by liposomal delivery system significantly strengthened both chemotherapy and immunotherapy of colorectal cancer, providing a clinically translational strategy for combinational ICB therapy in the “immunologically cold” tumors.

A Cancer Nanovaccine for Co-Delivery of Peptide Neoantigens and Optimized Combinations of STING and TLR4 Agonists.

Immune checkpoint blockade (ICB) has revolutionized cancer treatment and led to complete and durable responses, but only for a minority of patients. Resistance to ICB can largely be attributed to insufficient number and/or function of antitumor CD8+ T cells in the tumor microenvironment. Neoantigen targeted cancer vaccines can activate and expand the antitumor T cell repertoire, but historically, clinical responses have been poor because immunity against peptide antigens is typically weak, resulting in insufficient activation of CD8+ cytotoxic T cells. Herein, we describe a nanoparticle vaccine platform that can overcome these barriers in several ways. First, the vaccine can be reproducibly formulated using a scalable confined impingement jet mixing method to coload a variety of physicochemically diverse peptide antigens and multiple vaccine adjuvants into pH-responsive, vesicular nanoparticles that are monodisperse and less than 100 nm in diameter. Using this approach, we encapsulated synergistically acting adjuvants, cGAMP and monophosphoryl lipid A (MPLA), into the nanocarrier to induce a robust and tailored innate immune response that increased peptide antigen immunogenicity. We found that incorporating both adjuvants into the nanovaccine synergistically enhanced expression of dendritic cell costimulatory markers, pro-inflammatory cytokine secretion, and peptide antigen cross-presentation. Additionally, the nanoparticle delivery increased lymph node accumulation and uptake of peptide antigen by dendritic cells in the draining lymph node. Consequently, nanoparticle codelivery of peptide antigen, cGAMP, and MPLA enhanced the antigen-specific CD8+ T cell response and delayed tumor growth in several mouse models. Finally, the nanoparticle platform improved the efficacy of ICB immunotherapy in a murine colon carcinoma model. This work establishes a versatile nanoparticle vaccine platform for codelivery of peptide neoantigens and synergistic adjuvants to enhance responses to cancer vaccines.

Amplifying STING Activation and Alleviating Immunosuppression through a Mn2+-Based Metal-Organic Framework Nanosystem for Synergistic Cancer Therapy.

The field of immunotherapy, particularly immune checkpoint blockade (ICB), holds immense potential in mitigating the progression of cancer. However, the challenges of insufficient tumor antigen production and the immunosuppressive state in the tumor microenvironment substantially impede patients from deriving benefits. In this research, we present a tumor-microenvironment-modulation manganese-based nanosystem, PEG-MnMOF@PTX, aiming to improve the responsiveness of ICB. Under acidic conditions, the released Mn2+ accomplishes multiple objectives. It generates toxic hydroxyl radicals (•OH), together with the released paclitaxel (PTX), inducing immunogenic cell death of tumor cells and normalizing tumor blood vessels. Concurrently, it facilitates the insitu generation of oxygen (O2) from hydrogen peroxide (H2O2), ameliorating the microenvironmental immunosuppression and increasing the efficacy of immunotherapy. In addition, this study demonstrates that PEG-MnMOF@PTX can promote the maturation of dendritic cells and augment the infiltration of cytotoxic T lymphocytes through activation of the cyclic guanosine 5'-monophosphate-adenosine 5'-monophosphate synthase (cGAS) and interferon gene stimulator (STING) pathways, namely cGAS-STING pathways, thereby heightening the sensitivity to ICB immunotherapy. The findings of this study present a novel paradigm for the progress in cancer immunotherapy.

TLR9 plus STING Agonist Adjuvant Combination Induces Potent Neopeptide T Cell Immunity and Improves Immune Checkpoint Blockade Efficacy in a Tumor Model.

Immune checkpoint blockade (ICB) immunotherapies have emerged as promising strategies for the treatment of cancer; however, there remains a need to improve their efficacy. Determinants of ICB efficacy are the frequency of tumor mutations, the associated neoantigens, and the T cell response against them. Therefore, it is expected that neoantigen vaccinations that boost the antitumor T cell response would improve ICB therapy efficacy. The aim of this study was to develop a highly immunogenic vaccine using pattern recognition receptor agonists in combination with synthetic long peptides to induce potent neoantigen-specific T cell responses. We determined that the combination of the TLR9 agonist K-type CpG oligodeoxynucleotides (K3 CpG) with the STING agonist c-di-AMP (K3/c-di-AMP combination) significantly increased dendritic cell activation. We found that immunizing mice with 20-mer of either an OVA peptide, low-affinity OVA peptides, or neopeptides identified from mouse melanoma or lung mesothelioma, together with K3/c-di-AMP, induced potent Ag-specific T cell responses. The combined K3/c-di-AMP adjuvant formulation induced 10 times higher T cell responses against neopeptides than the TLR3 agonist polyinosinic:polycytidylic acid, a derivative of which is the leading adjuvant in clinical trials of neoantigen peptide vaccines. Moreover, we demonstrated that our K3/c-di-AMP vaccine formulation with 20-mer OVA peptide was capable of controlling tumor growth and improving survival in B16-F10-OVA tumor-bearing C57BL/6 mice and synergized with anti-PD-1 treatment. Together, our findings demonstrate that the K3/c-di-AMP vaccine formulation induces potent T cell immunity against synthetic long peptides and is a promising candidate to improve neoantigen vaccine platform.

Heterogeneity of tertiary lymphoid structures in cancer.

The success of immunotherapy approaches, such as immune checkpoint blockade and cellular immunotherapy with genetically modified lymphocytes, has firmly embedded the immune system in the roadmap for combating cancer. Unfortunately, the majority of cancer patients do not yet benefit from these therapeutic approaches, even when the prognostic relevance of the immune response in their tumor entity has been demonstrated. Therefore, there is a justified need to explore new strategies for inducing anti-tumor immunity. The recent connection between the formation of ectopic lymphoid aggregates at tumor sites and patient prognosis, along with an effective anti-tumor response, suggests that manipulating the occurrence of these tertiary lymphoid structures (TLS) may play a critical role in activating the immune system against a growing tumor. However, mechanisms governing TLS formation and a clear understanding of their substantial heterogeneity are still lacking. Here, we briefly summarize the current state of knowledge regarding the mechanisms driving TLS development, outline the impact of TLS heterogeneity on clinical outcomes in cancer patients, and discuss appropriate systems for modeling TLS heterogeneity that may help identify new strategies for inducing protective TLS formation in cancer patients.

Inhibition of SF3B1 improves the immune microenvironment through pyroptosis and synergizes with αPDL1 in ovarian cancer

Ovarian cancer is resistant to immune checkpoint blockade (ICB) treatment. Combination of targeted therapy and immunotherapy is a promising strategy for ovarian cancer treatment benefit from an improved immune microenvironment. In this study, Clinical Proteomic Tumor Analysis Consortium (CPTAC) and The Cancer Genome Atlas (TCGA) cohorts were used to screen prognosis and cytotoxic lymphocyte infiltration-associated genes in upregulated genes of ovarian cancer, tissue microarrays were built for further verification. In vitro experiments and mouse (C57/BL6) ovarian tumor (ID8) models were built to evaluate the synergistic effect of the combination of SF3B1 inhibitor and PD-L1 antibody in the treatment of ovarian cancer. The results show that SF3B1 is shown to be overexpressed and related to low cytotoxic immune cell infiltration in ovarian cancer. Inhibition of SF3B1 induces pyroptosis in ovarian cancer cells and releases mitochondrial DNA (mtDNA), which is englobed by macrophages and subsequently activates them (polarization to M1). Moreover, pladienolide B increases cytotoxic immune cell infiltration in the ID8 mouse model as a SF3B1 inhibitor and increases the expression of PD-L1 which can enhance the antitumor effect of αPDL1 in ovarian cancer. The data suggests that inhibition of SF3B1 improves the immune microenvironment of ovarian cancer and synergizes ICB immunotherapy, which provides preclinical evidence for the combination of SF3B1 inhibitor and ICB to ovarian cancer treatment.

Augmenting Immunotherapy via Bioinspired MOF-based Ros Homeostasis Disruptor with Nanozyme-Cascade Reaction.

Despite its remarkable clinical breakthroughs, immune checkpoint blockade (ICB) therapy remains limited by the insufficient immune response in the "cold" tumor. Nanozyme-based antitumor catalysis is associated with precise immune activation in the tumor microenvironment (TME). In this study, a cascade-augmented nanoimmunomodulator (CMZM) with multienzyme-like activities, which includes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and glutathione oxidase (GSHOx), that dissociates under an acidic and abundant GSH TME, is proposed for multimodal imaging-guided chemodynamic therapy (CDT)/photodynamic therapy (PDT) enhanced immunotherapy. Vigorous multienzyme-like activities can not only produce O2 to alleviate hypoxia and promote the polarization of M2 to M1 macrophages but also generate ROS (•OH and 1 O2 ) and deplete GSH in the TME to expose necrotic cell fragments and reverse immunosuppressive TME by eliciting the maturation of dendritic cells and infiltration of cytotoxic T lymphocytes in tumors. Therefore, inhibitory effects on both primary and distant tumors were achieved through synergy with an α-PD-L1 blocking antibody. This cascade multienzyme-based nanoplatform provides a smart strategy for highly efficient ICB immunotherapy against "cold" tumors by revising immunosuppressive TME. This article is protected by copyright. All rights reserved.