Type I interferons in anticancer immunity

The role of cisplatin in modulating the tumor immune microenvironment and its combination therapy strategies: a new approach to enhance anti-tumor efficacy

Cisplatin is a platinum-based drug that is frequently used to treat multiple tumors. The anti-tumor effect of cisplatin is closely related to the tumor immune microenvironment (TIME), which includes several immune cell types, such as the tumor-associated macrophages (TAMs), cytotoxic T-lymphocytes (CTLs), dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), and natural killer (NK) cells. The interaction between these immune cells can promote tumor survival and chemoresistance, and decrease the efficacy of cisplatin monotherapy. Therefore, various combination treatment strategies have been devised to enhance patient responsiveness to cisplatin therapy. Cisplatin can augment anti-tumor immune responses in combination with immune checkpoint blockers (such as PD-1/PD-L1 or CTLA4 inhibitors), lipid metabolism disruptors (like FASN inhibitors and SCD inhibitors) and nanoparticles (NPs), resulting in better outcomes. Exploring the interaction between cisplatin and the TIME will help identify potential therapeutic targets for improving the treatment outcomes in cancer patients.

A pH-responsive PROTAC-based nanosystem triggers tumor-specific ferroptosis to construct in situ tumor vaccines

Bromodomain-containing protein 4 (BRD4) is a key protein that drives the development of malignant melanoma and is closely associated with the ferroptosis signaling pathway. Degradation of BRD4 can downregulate the expression of ferroptosis-related genes such as GPX4, thereby promoting tumor-specific ferroptosis. Therefore, targeting BRD4 for degradation is a promising strategy for inhibiting tumor growth. We constructed a PROTAC drug-based tumor antigen capture system to protect the activity of antigen-presenting cells (APCs) and promote antigen capture. The selected PROTAC drug (ARV-825) can specifically degrade BRD4 without harming immune cells. Specifically, magnetic nanoclusters (MNC) coated with calcium-doped manganese carbonate (Ca/MnCO3), were used to load PROTAC drug (ARV-825) and anti-PD1, forming the MNC@Ca/MnCO3/ARV/anti-PD1 system. ARV-825 can specifically degrade BRD4 and GPX4, significantly inducing ferroptosis in tumor cells and releasing tumor-associated antigens. The MNC@Ca/MnCO3 particles, with their large specific surface area, adsorbed the tumor antigens, preventing antigen loss and enhancing antigen presentation. Additionally, Mn2+ served as an adjuvant to promote the maturation and cross-presentation of APCs. Together with the PD1 antibody, this further enhanced the anti-tumor response of the in situ tumor vaccine and reversed the suppressive immune microenvironment. This antigen capture system provides a novel strategy to improve the anti-tumor efficacy of in situ tumor vaccines.

Pairing tumor cell vesicle antigens with cationic nano-adjuvants by electrostatic adherence for personalized cancer vaccine

Simultaneous co-delivery of both antigens and adjuvants is crucial for the efficient activation of dendritic cells (DCs), but it has often been overlooked in the context of tumor cell-based vaccines. Building on the significant advancements in cationic nano-adjuvants, we proposed a straightforward and effective strategy for crafting personalized cancer vaccines, in which tumor cell vesicle antigens were paired with cationic nano-adjuvants to form nano-network through electrostatic adherence. Our pioneering research indicates that densely arranged nanoparticles can be simultaneously taken up by DCs, thus facilitating the co-delivery of adjuvants and antigens. To further enhance the interaction between DCs and antigens, the antigens-adjuvants nano-network was reconstructed using high aspect ratio silicon dioxide (SiO2) rods to generate 3D structures with ample interparticle spaces. This fosters a conducive environment for DCs infiltration, thereby optimizing the spatial and temporal orchestration of antigen cross-presentation. When combined with programmed death ligand 1 (PD-L1) immune checkpoint inhibitors, the dual-scale cancer vaccine effectively inhibits tumor proliferation through T cell-mediated mechanisms, resulting in a survival rate of 60 % in mice for over 40 days. In summary, our study introduces an innovative approach to the spatiotemporal orchestration of antigen cross-presentation, providing fresh insights into the construction of cancer vaccines based on tumor cells.

Photothermal therapy combined with a STING agonist induces pyroptosis, and gasdermin D could be a new biomarker for guiding the treatment of pancreatic cancer

PURPOSE

Although photothermal therapy (PTT) can induce antitumour immunity, the mechanisms underlying its effects in pancreatic cancer (PC) require further exploration. In this study, the mechanism of action of PTT and its connection to pyroptosis as well as the therapeutic potential of PTT alone and in combination with STING agonists, were investigated. In addition, a biomarker of PC was found to stratify patients who are suitable for PTT.

EXPERIMENTAL DESIGN

We explored whether PTT can induce pyroptosis in vitro and evaluated the therapeutic efficacy and antitumour immunity-inducing ability of PTT combined with STING agonist (c-di-GMP) as immune adjuvant in vivo in PC. We also evaluated gasdermin D (GSDMD) expression in tumour tissues and investigated drug sensitivity in patient-derived organoids (PDOs) with differential GSDMD expression.

RESULTS

Our study demonstrated that local PTT induces pyroptosis via the caspase-1/GSDMD pathway and elicits antitumour immunity. PTT combined with a STING agonist exhibits better therapeutic efficacy than PTT alone while limiting distant tumour metastasis, and enhances the immune response by promoting dendritic cell maturation, increasing the frequency of tumour infiltrating T cells, and converting macrophages from the M2 to the M1 phenotype. In addition, we found that GSDMD is highly expressed in tumour tissues and that overexpression of GSDMD in PC might suggest increased resistance to chemotherapy and the potential benefits of local therapy. We further confirmed that PDOs with higher GSDMD expression are less sensitive to a chemotherapeutic agent (5-Fluorouracil) than PDOs with lower GSDMD expression, making GSDMD a new biomarker for identifying patients who may benefit from PTT.

CONCLUSIONS

In this work, c-di-GMP was used as an immune adjuvant for PTT to treat PC for the first time, and the results provide clues for the development of novel combination immunotherapies that simultaneously suppress primary tumours and distant metastases. GSDMD has great potential as a new biomarker for the selection of individualized treatment modalities.

MiRNA affects the advancement of breast cancer by modulating the immune system's response

Breast cancer (BC), which is the most common tumor in women, has greatly endangered women's lives and health. Currently, patients with BC receive comprehensive treatments, including surgery, chemotherapy, radiotherapy, endocrine therapy, and targeted therapy. According to the latest research, the development of BC is closely related to the inflammatory immune response, and the immunogenicity of BC has steadily been recognized. As such, immunotherapy is one of the promising and anticipated forms of treatment for BC. The potential values of miRNA in the diagnosis and prognosis of BC have been established, and aberrant expression of associated miRNA can either facilitate or inhibit progression of BC. In the tumor immune microenvironment (TME), miRNAs are considered to be an essential molecular mechanism by which tumor cells interact with immunocytes and immunologic factors. Aberrant expression of miRNAs results in reprogramming of tumor cells actively, which may suppress the generation and activation of immunocytes and immunologic factors, avoid tumor cells apoptosis, and ultimately result in uncontrolled proliferation and deterioration. Therefore, through activating and regulating the immunocytes related to tumors and associated immunologic factors, miRNA can contribute to the advancement of BC. In this review, we assessed the function of miRNA and associated immune system components in regulating the advancement of BC, as well as the potential and viability of using miRNA in immunotherapy for BC.

STING in cancer immunoediting: Modeling tumor-immune dynamics throughout cancer development

Cancer immunoediting is a dynamic process of tumor-immune system interaction that plays a critical role in cancer development and progression. Recent studies have highlighted the importance of innate signaling pathways possessed by both cancer cells and immune cells in this process. The STING molecule, a pivotal innate immune signaling molecule, mediates DNA-triggered immune responses in both cancer cells and immune cells, modulating the anti-tumor immune response and shaping the efficacy of immunotherapy. Emerging evidence has shown that the activation of STING signaling has dual opposing effects in cancer progression, simultaneously provoking and restricting anti-tumor immunity, and participating in every phase of cancer immunoediting, including immune elimination, equilibrium, and escape. In this review, we elucidate the roles of STING in the process of cancer immunoediting and discuss the dichotomous effects of STING agonists in the cancer immunotherapy response or resistance. A profound understanding of the sophisticated roles of STING signaling pathway in cancer immunoediting would potentially inspire the development of novel cancer therapeutic approaches and overcome the undesirable protumor effects of STING activation.

Identification of interferon-stimulated response elements (ISREs) in canines

Interferon (IFN) responses are vital for antiviral defense, with interferon-stimulated response elements (ISREs) crucial for regulating IFN signaling. While ISREs are well-studied in humans and mice, research on canine ISREs is limited. This study aimed to clarify the role of canine ISREs and create a new method for detecting IFN activity. Canine IFN α (CaIFNα) was produced using the Pichia pastoris (P. pastoris) system, and an ISRE-based flow cytometry method was developed to measure its activity. ISREs for CaIFNα were predicted via bioinformatics analysis. Subsequently, viral suppression assays were conducted using vesicular stomatitis virus, canine influenza virus, and H9N2 to evaluate the antiviral activity of recombinant CaIFNα. Fluorescence analysis confirmed that CaIFNα activates ISRE2, ISRE8, and ISRE10, thereby enhancing the transcription and expression of the enhanced green fluorescent protein (EGFP) fusion gene. A novel ISRE and EGFP based flow cytometry method enabled precise quantification of CaIFNα levels through fluorescence cell counts, with a detection sensitivity reaching 0.1 × 10- 7 mg/mL. Results demonstrate that CaIFNα possesses multiple antiviral activity and activates specific ISREs, augmenting gene expression. This approach advances the study of canine ISREs and supports the development and clinical application of CaIFNα for diagnosing viral infections and monitoring treatment efficacy.

Vax-Innate: improving therapeutic cancer vaccines by modulating T cells and the tumour microenvironment

T cells have a critical role in mediating antitumour immunity. The success of immune checkpoint inhibitors (ICIs) for cancer treatment highlights how enhancing endogenous T cell responses can mediate tumour regression. However, mortality remains high for many cancers, especially in the metastatic setting. Based on advances in the genetic characterization of tumours and identification of tumour-specific antigens, individualized therapeutic cancer vaccines targeting mutated tumour antigens (neoantigens) are being developed to generate tumour-specific T cells for improved therapeutic responses. Early clinical trials using individualized neoantigen vaccines for patients with advanced disease had limited clinical efficacy despite demonstrated induction of T cell responses. Therefore, enhancing T cell activity by improving the magnitude, quality and breadth of T cell responses following vaccination is one current goal for improving outcome against metastatic tumours. Another major consideration is how T cells can be further optimized to function within the tumour microenvironment (TME). In this Perspective, we focus on neoantigen vaccines and propose a new approach, termed Vax-Innate, in which vaccination through intravenous delivery or in combination with tumour-targeting immune modulators may improve antitumour efficacy by simultaneously increasing the magnitude, quality and breadth of T cells while transforming the TME into a largely immunostimulatory environment for T cells.

Intratumoral antigen-presenting cell activation by a nanovesicle for the concurrent tertiary lymphoid structure de novo neogenesis

Tertiary lymphoid structures (TLSs) usually lead to significantly improved clinical benefits in immunotherapy but are rarely observed within native tumors. The current approaches are difficult in effectively inducing TLS formation, let alone fully exploiting its anticancer efficacy. Here, a biomimetic nanovesicle (ADU-S@M1) is constructed to target tumors and then to produce abundant activated antigen-presenting cells (APCs) in situ by polarizing the tumor-associated macrophages toward M1 phenotype and promoting dendritic cell maturation. These activated APCs effectively initiate the TLS de novo neogenesis by acting as lymphoid tissue inducer cells that secrete lymphotoxin α and tumor necrosis factor α while normalizing the intratumoral vasculatures. In addition, they induce robust in situ adaptive immune responses by presenting the antigens released from the M1 cell-destroyed tumors and transporting them to the nearby TLS. Therefore, the development of tumors in mice, especially immune-cold tumors, was efficiently prevented, providing a promising strategy for promoting cancer immunotherapy.

Design, Synthesis, and Pharmacological Evaluation of Quinazoline and Quinoline Derivatives as Potent ENPP1 Inhibitors for Cancer Immunotherapy

ENPP1, a transmembrane glycoprotein overexpressed in various cancers, has become a promising target for tumor immunotherapy. Several ENPP1 inhibitors have been reported, but only a few have been validated in vivo. Herein, based on the reported inhibitors 3 and 6, we carried out a structural optimization by designing a variety of 8-methoxyquinazoline and its equivalent 8-methoxy-3-cyano-quinoline derivatives featuring bridged- or spirobicycles as the linker. Compound 30 was identified as a promising ENPP1 inhibitor. This compound exhibited IC50 values of 8.05 nM against ENPP1 and 1.53 nM in MDA-MB-231 cells with no significant inhibitory effects against both hERG and a panel of 97 kinases. It effectively activated the intracellular STING pathway by inhibiting cGAMP degradation. In the murine CT-26 tumor model, 30 inhibited tumor growth with increased immune cell infiltration in the tumor microenvironment and enhanced type I interferon responses. Meanwhile, compound 30 synergically enhanced the antitumor efficacy of anti-PD-L1 antibody.

AlbiCDN: albumin-binding amphiphilic STING agonists augment the immune activity for cancer immunotherapy

The stimulator of interferon genes (STING) has been an attractive target in cancer immunotherapy. However, natural ligand cyclic dinucleotides (CDNs) and CDN derivatives have demonstrated limited efficacy in clinical trials. This limitation stems from the inherent structure of CDNs, which leads to enzymatic degradation, poor cell internalisation, rapid clearance from the tumour microenvironment, and dose-limiting toxicity. In this study, we developed an amphipathic STING agonist, termed albumin-binding CDNs (AlbiCDNs), to enhance the efficacy of c-di-GMP (CDG) via a lipid-conjugated strategy. The lipid provided a platform for albumin hitchhiking, which facilitated the cytoplasmic delivery of CDG without the use of any exogenous components. In addition, incorporating a stimuli-responsive lipid motif further enhanced the cellular release of CDG. Our results indicated that CDG-1C14, an AlbiCDN, efficiently stimulated the maturation and activation of antigen-presenting cells through STING activation. Furthermore, CDG-1C14 exhibited a significant inhibitory effect on the tumour therapeutic model. Therefore, AlbiCDN is a potent platform for cancer immunotherapy that can expedite clinical translation.

Metabolic deficiencies underlie reduced plasmacytoid dendritic cell IFN-I production following viral infection

Type I Interferons (IFN-I) are central to host protection against viral infections, with plasmacytoid dendritic cells (pDC) being the most significant source, yet pDCs lose their IFN-I production capacity following an initial burst of IFN-I, resulting in susceptibility to secondary infections. The underlying mechanisms of these dynamics are not well understood. Here we find that viral infection reduces the capacity of pDCs to engage both oxidative and glycolytic metabolism. Mechanistically, we identify lactate dehydrogenase B (LDHB) as a positive regulator of pDC IFN-I production in mice and humans; meanwhile, LDHB deficiency is associated with suppressed IFN-I production, pDC metabolic capacity, and viral control following infection. In addition, preservation of LDHB expression is sufficient to partially retain the function of otherwise exhausted pDCs, both in vitro and in vivo. Furthermore, restoring LDHB in vivo in pDCs from infected mice increases IFNAR-dependent, infection-associated pathology. Our work thus identifies a mechanism for balancing immunity and pathology during viral infections, while also providing insight into the highly preserved infection-driven pDC inhibition.

The UBA1-STUB1 Axis Mediates Cancer Immune Escape and Resistance to Checkpoint Blockade

SIGNIFICANCE

Our study reveals UBA1 as a predictive biomarker for clinical outcomes in ICB cohorts, mediating cancer immune evasion and ICB resistance. We further highlight JAK1 stabilization as a key mechanism of UBA1 inhibition and nominate the UBA1-STUB1 axis as an immuno-oncology therapeutic target to improve the efficacy of ICB.

Phosphatidylserine (PS)-targeting chimeric Interferon (IFN) fusion proteins for anti-tumor applications

In viable healthy cells, membrane phospholipids are asymmetrically distributed across the lipid bilayer, whereby the anionic phospholipid phosphatidylserine is virtually all distributed on the inner leaflet of the plasma membrane. During apoptosis, phospholipid asymmetry collapses and PS is externalized to the external leaflet where it serves as an "eat-me" signal for efferocytosis, the process whereby dying cells are engulfed and degraded by phagocytes. PS is also externalized on viable activated tumor endothelial cells, stromal cells and cancer cells in the tumor microenvironment reflecting a pathophysiological state of solid cancers that function to suppress host anti-tumor immunity. Several strategies have been envisioned to target dysregulated PS in the tumor microenvironment including PS binding proteins such as Annexin V and PS-targeting monoclonal antibodies (Bavituximab) with promising preclinical results. Here, in an attempt to enhance the efficacy of PS-targeting therapeutics, we have generated a series of recombinant chimeric fusion proteins that fuse type I and type III IFNs (IFN-β-IFN-λ) into a single polypeptide chain separated by a short linker. The IFN-β-IFN-λ fusion proteins retain functions of both type I and type III IFNs but show combined effects to improve biological function as well as enhance anti-tumor activities. To localize IFNs to sites of externalized PS, we next fused the IFN-β-IFN-λ chimeric protein to the PS-targeting gamma-carboxyglutamic acid-rich (Gla) domain of Growth Arrest Specific factor 6 (Gas-6), rendering these IFN biologics as PS targeting modalities. Gas6-IFN-β-IFN-λ proteins selectively bind PS as evident by solid-phase ELISA assays as well as bind PS-positive cells, including apoptotic cells and cells that express CDC50 subunit mutant of the ATP11C flippase. In vivo, Gas6-IFN-β-IFN-λ retain strong anti-tumor activities in a syngeneic model when expressed ectopically in a E0771 breast cancer model and B16-F10 melanoma models. Collectively, we report on the generation and utility of a series of novel in class IFN fusion proteins that target the immune stimulatory features of IFNs to the PS externalization in the tumor microenvironment.

A Phase II Study of Denileukin Diftitox in Patients with Advanced Treatment Refractory Breast Cancer

Background/Objectives: Regulatory T cells (Treg) suppress immunity in the tumor microenvironment, are linked to poor prognosis across breast cancer subtypes, and suppress the cytolytic function of cytotoxic CD8+ T cells. Denileukin diftitox, a diphtheria toxin (DT)/IL-2 fusion protein, targets and depletes Tregs. This Phase II study aimed to assess the safety of denileukin diftitox and its effect on Tregs and tumor growth in patients with advanced breast cancer. Methods: This single-arm Phase II study of denileukin diftitox enrolled patients with refractory stage IV breast cancer. Patients received denileukin diftitox 18 mcg/kg/day IV for Days 1-5 every 21 days for up to six cycles. Toxicity was assessed using CTCAE v3.0 and tumor response was evaluated per RECIST criteria. Blood samples were collected to analyze Tregs by flow cytometry and anti-DT antibodies by ELISA. Results: Fifteen patients with stage IV breast cancer were enrolled. Four patients completed all planned denileukin diftitox infusions and achieved stable disease (27%, 95% CI [0.08, 0.55]). Two patients (13%) discontinued due to toxicity, and nine patients (60%) discontinued due to progressive disease. Eleven patients experienced at least one grade 3 or 4 adverse event. Although there was a general reduction in peripheral blood Tregs, the difference in CD4+CD25+FOXP3+ Tregs levels post-treatment was not statistically significant (p = 0.10). Six patients (40%) achieved ≥25% reductions in Tregs. A significant increase in anti-DT IgG antibodies was observed post-treatment (p < 0.005). Conclusions: Denileukin diftitox demonstrated moderate toxicity in this advanced breast cancer cohort. Denileukin diftitox modulated regulatory T cells. However, the majority of patients experienced disease progression in the study.

NLRC3 Attenuates Antiviral Innate Immune Response by Targeting IRF7 in Grass Carp (Ctenopharyngodon idelus)

NLRC3 belongs to the NOD-like receptor family and is recognized as a modulator of innate immune mechanisms. In this study, we firstly report that Ctenopharyngodon idelus NLRC3 (CiNLRC3) acts as a negative regulator in the antiviral immune response. Cinlrc3 is ubiquitously expressed across tested tissues, displaying particularly high expression in the intestine, spleen, gill and kidney. Notably, Cinlrc3 expression is markedly upregulated following grass carp reovirus (GCRV) infection both in vivo and in vitro. Functional assays reveal that the overexpression of CiNLRC3 hampers cellular antiviral responses, thereby facilitating viral replication. Conversely, the silencing of CiNLRC3 through siRNA transfection enhances these antiviral activities. Additionally, CiNLRC3 substantially diminishes the retinoic acid-inducible gene I (RIG-I)-like receptor (RLR)-mediated interferon (IFN) response in fish. Subsequent molecular investigations indicates that CiNLRC3 interacts with the RLR molecule node, IRF7 but not IRF3, by degrading the IRF7 protein in a proteasome-dependent manner. Furthermore, CiNLRC3 co-localizes with CiIRF7 in the cytoplasm and impedes the IRF7-induced IFN response, resulting in impairing IRF7-mediated antiviral immunity. Summarily, these findings underscore the critical inhibitory role of teleost NLRC3 in innate immunity, offering new perspectives on its regulatory functions and potential as a target for resistant breeding in fish.

Pyrithione zinc alters mismatch repair to trigger tumor immunogenicity

Mismatch repair deficiency (dMMR) cancers are highly sensitive to immunotherapy, but only account for a small fraction of cancer patients. How to increase immunotherapy efficacy on MMR-proficient (pMMR) cancer is still a major challenge. This study demonstrates that pyrithione zinc (PYZ), an FDA-approved drug, can enhance tumor immunogenicity via altering MMR and activating STING signaling. Mechanistically, PYZ elevates levels of ROS, leading to the upregulation of HIF-1α and DNA damage, while also inhibiting the expression of DNA mismatch repair proteins MSH2 and MSH6, together promoting DNA damage accumulation. Therefore, the administration of PYZ results in the accumulation of DNA damage, leading to the activation of STING signaling, which enhances tumor immunogenicity. Knockout of Sting diminishes the activation of IFN-I signaling induced by PYZ and reduces tumor immunogenicity. Furthermore, in vivo administration of PYZ promotes the infiltration of CD8+ T cells into the tumor and inhibits tumor growth, an effect that is attenuated in Nude mice or mice with CD8+ T cell depletion or deficiency of Ifnar. Overall, our findings showed that pyrithione zinc could trigger tumor immunogenicity by downregulating MMR machinery and activating STING pathway in tumor cells, and provide a translational approach to improve immunotherapy on pMMR cancer.

Injectable supramolecular hydrogel co-loading abemaciclib/NLG919 for neoadjuvant immunotherapy of triple-negative breast cancer

The efficacy of cancer immunotherapy relies on a sufficient amount of functional immune cells. Triple-negative breast cancer lacks enough immune cell infiltration, and adjuvant therapy is necessary to prime anti-tumor immunity. However, the improvement in efficacy is unsatisfactory with concern about inducing systemic immunotoxicity. Herein, we create an abemaciclib-loaded supramolecular peptide hydrogel formed by peptide-drug amphiphiles for neoadjuvant immunotherapy of triple-negative breast cancer, where the amphiphile is a conjugate of a β-sheet-forming peptide with 1-cyclohexyl-2-(5H-imidazo[5,1-a]isoindol-5-yl)ethanol (NLG919), an inhibitor of indoleamine 2,3-dioxygenase 1. The hydrogel can be injected into the tumor site and retained for at least one week for the sustained release of both abemaciclib and NLG919. The abemaciclib is able to induce immunogenic cell death of cancer cells and increase interleukin-2 secretion by cytotoxic T lymphocytes. Abemaciclib adversely upregulates indoleamine 2,3-dioxygenase 1, whose kynurenine production activity is inhibited by NLG919. The neoadjuvant immunotherapy reduces tumor recurrence and pulmonary metastasis and prolongs the survival of animals. This hydrogel provides a potential platform for neoadjuvant immunotherapy of triple-negative breast cancer with reduced toxicity compared with free abemaciclib.

A trinity STING-activating nanoparticle harnesses cancer cell STING machinery for enhanced immunotherapy

The cGAS-STING axis is a promising therapeutic target against cancer. However, most activators require STING signaling in the host, especially within antigen-presenting cells, which are rare in a cold tumor microenvironment. The cGAS-STING cascade is also present within cancer cells but with suppressed activity. Such a paradoxical situation may account for the clinical failures. Herein, we develop a trinity STING-activating nanoparticle (CMTP) coordinated with cGAMP, Mn3+, and porphyrin to awaken autologous STING signaling in cancer cells. CMTP disintegrates into Mn2+ and TCPP upon elevated glutathione in cancer cells, where TCPP triggers mitochondrial DNA leakage, enhancing cGAS enzymatic activity in coordination with Mn2+, while concurrent cGAMP release from framework synergizes to amply STING activity. Consequently, CMTP exploits cancer cells as reservoirs for cGAS-STING signaling to promote DC maturation and T cell priming. A single administration of CMTP demonstrates robust efficacy in both hot MC38 and cold 4 T1 murine tumors. Genetic knockout studies confirm that STING in cancer cells, rather than in the host, is critical for antitumor performance. The feasibility of immune modulation is further validated in resected human patient tissues. This work presents a potent STING-activating nanomedicine based on coordination chemistry and underscores the potential of harnessing cancer cells' autologous cGAS-STING machinery in immunotherapy.

Combination with oxaliplatin improves abscopal effect of oncolytic virotherapy through reorganization of intratumoral macrophages

Intratumoral administration is a widely used method for oncolytic virotherapy, as it enables immediate access of virus particles to the target tumor and potentially lead to the suppression of untreated distant tumors via in situ vaccination. However, because the injection volume and concentration of the virus solution are physically limited, the dose level cannot be increased. Additionally, efficacy in distant tumors needs improvement to prolong patient survival. Here, we demonstrate the benefit of oxaliplatin, with detailed mechanisms revealed through transcriptome analysis, which may provide a solution for the crucial deficiencies of oncolytic virotherapy. In virus-injected tumors, oxaliplatin improved virus retention through suppression of type I interferons. In distant virus-naive tumors, oxaliplatin induced alterations in the intratumoral macrophage characteristics, leading to the chemotaxis and recruitment of activated T cells and subsequently inducing an inflammatory state in the non-injected tumors. Our findings can be a trigger to change the therapeutic paradigm of oncolytic virotherapy for patients with systemic metastases.

Enhanced Tumor Immunotherapy by Triple Amplification Effects of Nanomedicine on the STING Signaling Pathway in Dendritic Cells

Insufficient activation of stimulator of interferon genes (STING) signaling pathway in tumor-associated dendritic cells limits the efficiency of tumor immunotherapy. Herein, the "three-in-one" IAHA-LaP/siPTPN6 NPs containing lanthanum ions (La3+), cGAMP, and PTPN6 siRNA are developed for triple amplification of the STING pathway. In vitro results demonstrate that La3+ significantly promotes cGAMP-mediated activation of the STING pathway by enhancing the phosphorylation of STING, TBK1, IRF3, and NF-κB p65. Moreover, the IAHA-LaP/siPTPN6 NPs further significantly enhance the phosphorylation of STING and NF-κB p65 and augment K63-linked ubiquitination of STING protein via siPTPN6-mediated downregulation of SHP-1 protein. Furthermore, NPs improve the secretion of IFNβ (2.4-fold), IL-6 (1.5-fold), and TNF-α (1.4-fold), thereby promoting DCs maturation compared to the mixture of La3+ and cGAMP. In vivo results show that the IAHA-LaP/siPTPN6 NPs remarkably inhibit primary tumor growth by increasing the percentage of mature DCs in tumor-draining lymph nodes, polarizing M2/M1 phenotype in TME, and promoting the infiltration of CD8+T cells into tumors. Moreover, these NPs dramatically prevent the growth of distal tumor by inducing systemic anti-tumor immunity and generating a long-term anti-tumor memory for protection against tumor recurrence in mice bearing bilateral B16F10. These IAHA-LaP/siPTPN6 NPs may offer a promising platform for robust anti-tumor immune responses.

Efficacy and pharmacodynamic effect of anti-CD73 and anti-PD-L1 monoclonal antibodies in combination with cytotoxic therapy: observations from mouse tumor models

CD73 is a cell surface 5'nucleotidase (NT5E) and key node in the catabolic process generating immunosuppressive adenosine in cancer. Using a murine monoclonal antibody surrogate of Oleclumab, we investigated the effect of CD73 inhibition in concert with cytotoxic therapies (chemotherapies as well as fractionated radiotherapy) and PD-L1 blockade. Our results highlight improved survival in syngeneic tumor models of colorectal cancer (CT26 and MC38) and sarcoma (MCA205). This therapeutic outcome was in part driven by cytotoxic CD8 T-cells, as evidenced by the detrimental effect of CD8 depleting antibody treatment of MCA205 tumor bearing mice treated with anti-CD73, anti-PD-L1 and 5-Fluorouracil+Oxaliplatin (5FU+OHP). We hypothesize that the improved responses are tumor microenvironment (TME)-driven, as suggested by the lack of anti-CD73 enhanced cytopathic effects mediated by 5FU+OHP on cell lines in vitro. Pharmacodynamic analysis, using imaging mass cytometry and RNA-sequencing, revealed noteworthy changes in specific cell populations like cytotoxic T cells, B cells and NK cells in the CT26 TME. Transcriptomic analysis highlighted treatment-related modulation of gene profiles associated with an immune response, NK and T-cell activation, T cell receptor signaling and interferon (types 1 & 2) pathways. Inclusion of comparator groups representing the various components of the combination allowed deconvolution of contribution of the individual therapeutic elements; highlighting specific effects mediated by the anti-CD73 antibody with respect to immune-cell representation, chemotaxis and myeloid biology. These pre-clinical data reflect complementarity of adenosine blockade with cytotoxic therapy, and T-cell checkpoint inhibition, and provides new mechanistic insights in support of combination therapy.

N-Dihydrogalactochitosan Drives Conventional and Alternative Activations of STING to Synergize Type I IFN and IL-1β Productions for Antitumor Immunity

N-dihydrogalactochitosan (GC) is an immune stimulant/adjuvant. Synthesized from chitosan and galactose, GC is a new chemical entity that significantly enhances the immune-stimulating properties of its parental material, chitosan, making it a promising therapeutic agent. When used in combination with antigenic material, GC stimulates innate and adaptive antitumor and antiviral immunities. However, its mechanism has not been fully investigated. Herein we demonstrate that GC drives type I IFN activation in antigen-presenting cells (APCs). More importantly, GC drives alternative STING pathways, leading to inflammatory cell death that enhances dendritic cell (DC) activation. GC-activated DCs trigger a variety of nucleic acid sensing pattern recognition receptors (PRRs) pathways and IL-1β production via the activation of the inflammasome. In vivo, GC induces a potent response of type I IFNs and upregulates genes associated with STING signaling within the tumor microenvironment (TME). Moreover, intratumoral delivery of GC reduces the numbers of M2-like macrophages and increases M1-like macrophages residing within the TME, while subsequently increasing the number of activated DCs. Our findings demonstrate that GC acts as a multimodal immune stimulant via STING to generate a broad type I IFN response. This uniquely broad response holds therapeutic promise in generating enhanced antitumor and antiviral immunities.

Clinical and prognostic effects of microvascular density and FOXP3 positive T cells in breast cancer

There are conflicting data regarding the prognostic effect of microvascular density (MVD) in breast cancer and its molecular subtypes. It is thought that high levels of FOXP3 + T cells in breast cancer are associated with poor prognosis. However, data regarding FOXP3 show significant variability in the literature. In our study, we aim to measure MVD and FOXP3 + T cells in breast cancer cases and investigate their relationship with each other and their effects on breast cancer patients' clinical and prognostic features. In our study, the results of 207 female breast cancer patients whose excisional tumoral tissue was obtained are presented. The study evaluated the findings under a light microscope using antibodies against CD34 for measuring MVD and FOXP3 for measuring FOXP3-positive T cells. CD34 ≥ 17 was categorized as high MVD, and CD34 < 17 was classified as low MVD. FOXP3 + cell count ≥ 20/mm2 was categorized as high FOXP3 positivity and < 20/mm2 as low FOXP3 positivity. The SPSS program (version 22) was used to evaluate the results statistically, and p < 0.05 was considered significant. The median age was 54.0 (27-86) years, and the median follow-up period was 60.0 (IQR: 42.6-86.5) months. In the high MVD group, a higher progesterone receptor (PR) positivity rate was detected (p = 0.035). High FOXP3 positivity was significantly associated with high nuclear grade (p = 0.003). High FOXP3 positivity was significantly associated with PR negativity and high Ki67 values ​​(p = 0.009, p = 0.012, respectively). No statistically significant correlation was found between MVD elevation and FOXP3 positivity (r = 0.063, p = 0.36). A weakly significant positive correlation was detected between high Ki67 and FOXP3 positivity (r = 0.0146, p = 0.04). A weak inverse correlation was detected between high FOXP3 positivity and PR percentage values ​​(r=-0.182, p = 0.01). While there was no significant difference in disease-free survival in cases with high MVD and high FOXP3 + T cells compared to groups with low levels, the results were not mature enough because the median values ​​in overall survival could not be reached. A significant correlation was found between high FOXP3 positivity and some aggressive tumor features; no effect on survival was detected. In contrast to literature data on luminal A breast cancer, high MVD in the luminal B (HER2-) subgroup was associated with a lower risk of recurrence. Our study is the first in the literature to evaluate the relationship between MVD measured using CD34 and FOXP3 positive T cells in breast cancer. Our study found no correlation between MVD and FOXP3 positivity, while literature data show significant correlations in some other cancers.

The importance of type I interferon in orchestrating the cytotoxic T-cell response to cancer

Both type I interferon (IFN-I) and CD4+ T-cell help are required to generate effective CD8+ T-cell responses to cancer. We here outline based on existing literature how IFN-I signaling and CD4+ T-cell help are connected. Both impact on the functional state of dendritic cells (DCs), particularly conventional (c)DC1. The cDC1s are critical for crosspresentation of cell-associated antigens and for delivery of CD4+ T-cell help for cytotoxic T-lymphocyte (CTL) effector and memory differentiation. In infection, production of IFN-I is prompted by pathogen-associated molecular patterns (PAMPs), while in cancer it relies on danger-associated molecular patterns (DAMPs). IFN-I production by tumor cells and pDCs in the tumor micro-environment (TME) is often limited. IFN-I signals increase the ability of migratory cDC1s and cDC2s to transport tumor antigens to tumor-draining lymph nodes (tdLNs). IFN-I also enables cDC1s to form and sustain the platform for help delivery by stimulating the production of chemokines that attract CD4+ and CD8+ T cells. IFN-I promotes delivery of help in concert with CD40 signals by additive and synergistic impact on cross-presentation and provision of critical costimulatory and cytokine signals for CTL effector and memory differentiation. The scenario of CD4+ T-cell help therefore depends on IFN-I signaling. This scenario can play out in tdLNs as well as in the TME, thereby contributing to the cancer immunity cycle. The collective observations may explain why both IFN-I and CD4+ T-cell help signatures in the TME correlate with good prognosis and response to PD-1 targeting immunotherapy in human cancer. They also may explain why a variety of tumor types in which IFN-I signaling is attenuated, remain devoid of functional CTLs.

PFAS promotes colorectal cancer progression via regulating RIG-I-mediated innate immune signalling

OBJECTIVE

Phosphoribosylformylglycinamidine synthase (PFAS) is a critical enzyme in de novo synthesis of purine. Innate immunity recognizes tumor derived damage-associated molecular patterns (DAMPs) and initiates the anti-tumor adaptive responses. While the function of PFAS catalyzed de novo synthesis of purine is well proved, its effect on innate immune evasion in cancer is unclear and needs to be further explored. The purpose of this study was to investigate the specific mechanisms by which PFAS inhibits RIG-I receptor (RLR) -mediated NF-κB axis in CRC.

MATERIALS AND METHODS

quantitative real-time PCR (qRT-PCR), Immunohistochemical (IHC) staining and western blotting were conducted to study the expression of PFAS in CRC tissues. Survival analysis, COX regression analysis and receiver operating characteristic (ROC) curve analysis were respectively conducted to assess correlation between the PFAS expression and clinicopathological characteristics, investigate the percent survival based on PFAS level in different clinical CRC groups, identify factors influencing the prognosis of CRC, and illustrate the diagnostic ability of PFAS in CRC patients. Furthermore, the CCK8 and transwell assays were carried out to study CRC cell function affected by PFAS. Mechanistically, plaque assay was used to assess the regulation of PFAS on innate immune signalling. The inhibition of PFAS on RIG-I-mediated innate immune signalling was further investigated by qRT-PCR and reporter assays in thepresence of lentiviral-mediated PFAS stably knocking down and stably overexpressing. Lastly, the interaction between PFAS and RIG-I was verified by co-immunoprecipitation assay.

RESULTS

The expression of PFAS in CRC tissue was higher than in adjacent normal colorectal tissue. The level of PFAS expression was significantly associated with stage-AJCC, regional lymph nodes metastasis and recurrence in CRC. Low expression of gene PFAS caused better survival than high expression in CRC patients. PFAS could be considered as an independent prognostic risk factor of CRC. PFAS promote cell proliferation and invasion of CRC cell lines. According to ROC curve analysis, PFAS could be used as a diagnostic biomarker in CRC. Mechanistically, PFAS inhibit interferon-β (IFN-β) gene and interferon-stimulated gene 56 (ISG56) expression. Furthermore, we confirmed that PFAS target RIG-I to inhibit RIG-I-mediated innate immune signalling.

The Generation of Genetically Engineered Human Induced Pluripotent Stem Cells Overexpressing IFN-β for Future Experimental and Clinically Oriented Studies

Induced pluripotent stem cells (iPSCs) can be generated from various adult cells, genetically modified and differentiated into diverse cell populations. Type I interferons (IFN-Is) have multiple immunotherapeutic applications; however, their systemic administration can lead to severe adverse outcomes. One way of overcoming the limitation is to introduce cells able to enter the site of pathology and to produce IFN-Is locally. As a first step towards the generation of such cells, here, we aimed to generate human iPSCs overexpressing interferon-beta (IFNB, IFNB-iPSCs). IFNB-iPSCs were obtained by CRISPR/Cas9 editing of the previously generated iPSC line K7-4Lf. IFNB-iPSCs overexpressed IFNB RNA and produced a functionally active IFN-β. The cells displayed typical iPSC morphology and expressed pluripotency markers. Following spontaneous differentiation, IFNB-iPSCs formed embryoid bodies and upregulated endoderm, mesoderm, and some ectoderm markers. However, an upregulation of key neuroectoderm markers, PAX6 and LHX2, was compromised. A negative effect of IFN-β on iPSC neuroectoderm differentiation was confirmed in parental iPSCs differentiated in the presence of a recombinant IFN-β. The study describes new IFN-β-producing iPSC lines suitable for the generation of various types of IFN-β-producing cells for future experimental and clinical applications, and it unravels an inhibitory effect of IFN-β on stem cell neuroectoderm differentiation.

Evaluating the Causal Association between Circulating Plasma Proteins, 731 Immune Cell Phenotypes, and Atopic Dermatitis: A Mediation Mendelian Randomization Study

INTRODUCTION

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by eczematous lesions and severe itching. However, its pathogenesis has not yet been fully elucidated. The aim of this study was to investigate the causal relationship between plasma proteins and AD, as well as to identify and quantify the potential roles of immune cell phenotypes as mediators.

METHODS

We utilized summary-level data from genome-wide association studies and conducted a two-sample Mendelian randomization (MR) analysis involving 4,907 circulating plasma proteins, 731 immune cell phenotypes, and AD. Initially, we conducted bidirectional univariate MR analyses to forecast causal effects linking circulating plasma proteins and AD. Subsequently, we employed a two-step MR analysis to scrutinize the immune cell phenotypes that could mediate these effects. The inverse variance weighted was the main method employed for MR analysis, while the Cochran's Q test and MR-Egger intercept test were used to assess the presence of heterogeneity and pleiotropy, respectively. We then determined whether our results could be influenced by individual single-nucleotide polymorphisms using the "leave-one-out" test.

RESULTS

Positive correlations were observed between KRT1, IL18R1, and SEMA6A and the risk of AD, whereas BDH2, ADAMTS3, ANKRD1, TIAM1, MID2, and IFNA16 all showed negative correlations with the risk of AD. Mediation analysis indicated that CD8 on CM CD8br cells acted as a mediator between IFNA16 and AD, with a mediation effect proportion of 11.2%. In addition, sensitivity analyses did not reveal significant heterogeneity or level pleiotropy.

CONCLUSION

Our findings indicated the presence of a one-way causal relationship between the circulating plasma protein IFNA16 and AD. This study also explored immune cell phenotypes that may serve as mediators, offering novel insights into the etiology, pathogenesis, and potential clinical interventions in AD. Nevertheless, these findings need to be validated by clinical and laboratory studies.

Bendamustine-rituximab elicits dual tumoricidal and immunomodulatory responses via cGAS-STING activation in diffuse large B-cell lymphoma

BACKGROUND

Bendamustine-rituximab (BR) therapy stands out as a promising alternative for elderly patients with diffuse large B-cell lymphoma (DLBCL), demonstrating notable efficacy when conventional regimens pose challenges. Despite its clinical success, the intricate mechanisms underlying BR therapy have remained elusive.

METHODS

DLBCL cell lines were used to investigate the mechanism of BR therapy in vitro. RNA-seq and Western blot were used to explore the target pathways of BR therapy. STING was knocked out using Crispr-cas9 and inhibited using H-151 to investigate its role in BR therapy. Bulk RNA-seq and single-cell RNA-seq data from patients were analyzed to investigate the association between STING and pyroptosis pathways, validated using STING downregulated cells. Flow cytometry, transwell experiments and co-culture experiments were performed to investigate the inflammatory phenotype of DLBCL cells after BR treatment and its effect on T-cell recruitment and activation.

RESULTS

This study elucidates that BR elicits direct tumoricidal effects by promoting apoptosis and inducing cell cycle arrest. The synergistic impact with rituximab is further potentiated by complement addition, demonstrating the pivotal role of in vivo antibody-dependent cellular cytotoxicity. Moreover, our investigation reveals that, through a cGAS-STING-dependent pathway, prolonged exposure to BR induces pyroptosis in DLBCL cells. Activation of the cGAS-STING pathway by BR therapy triggers the release of inflammatory factors and upregulates major histocompatibility complex molecules, shaping an immunologically hot tumor microenvironment.

CONCLUSIONS

This unique dual influence not only directly targets DLBCL cells but also engages the patient's immune system, paving the way for innovative combination therapies. The study provides comprehensive insights into the multifaceted actions of BR in DLBCL, offering a foundation for refined and personalized treatment strategies in elderly patients.

Single intravenous administration of oncolytic adenovirus TILT-123 results in systemic tumor transduction and immune response in patients with advanced solid tumors

BACKGROUND

A limitation of approved oncolytic viruses is their requirement for intratumoral (i.t.) injection. TILT-123 (igrelimogene litadenorepvec, Ad5/3-E2F-D24-hTNFα-IRES-hIL-2) is a chimeric oncolytic adenovirus suitable for intravenous (i.v.) delivery due to its capsid modification and dual selectivity devices. It is armed with tumor necrosis alpha and interleukin-2 for promoting T-cell activation and lymphocyte trafficking to tumors, thereby enhancing the antitumor immune response. Here, we present the findings after a single i.v. administration of TILT-123 in three phase I dose escalation clinical trials.

METHODS

Patients with advanced solid tumors initially received a single i.v. dose of TILT-123 ranging from 3 × 109 to 4 × 1012 viral particles (VP). Blood was collected at baseline, 1, 16, and 192 h (7 days) post-treatment for bioavailability and serum analysis. Tumor biopsies were collected prior to treatment and 7 days post-treatment for analysis of viral presence and immunological effects. Patients did not receive any other cancer therapies during this period.

RESULTS

Across all three trials (TUNIMO, TUNINTIL, and PROTA), 52 total patients were treated with i.v. TILT-123. Overall, TILT-123 was found to be well-tolerated, with no dose-limiting toxicities observed. Post-treatment tumor biopsies showed expression of viral genes, presence of TILT-123 adenovirus proteins or DNA, and changes in immune cell infiltration from baseline. Increased virus dose did not lead to increased virus detection in tumors. Median overall survival was longer in patients with confirmed presence of TILT-123 in post-treatment biopsies (280 versus 190 days, p = 0.0405).

CONCLUSION

TILT-123 demonstrated safety and significant intratumoral immunomodulation following a single i.v. administration, warranting further investigation.

TRIAL REGISTRATIONS

TUNIMO-NCT04695327. Registered 4 January 2021, https://clinicaltrials.gov/study/NCT04695327 . TUNINTIL-NCT04217473. Registered 19 December 2019, https://clinicaltrials.gov/study/NCT04217473 . PROTA-NCT05271318. Registered 4 February 2022, https://clinicaltrials.gov/study/NCT05271318 .

Spleen-Targeted mRNA Vaccine Doped with Manganese Adjuvant for Robust Anticancer Immunity In Vivo

The successful application of mRNA vaccines in preventing and treating infectious diseases highlights their potential as therapeutic vaccines for cancer treatment. However, unlike infectious diseases, effective antitumor therapy, particularly for solid tumors, necessitates the activation of more powerful cellular and humoral immunity to achieve clinical efficacy. Here, we report a spleen-targeted mRNA vaccine (Mn@mRNA-LNP) designed to deliver tumor antigen-encoding mRNA and manganese adjuvant (Mn2+) simultaneously to dendritic cells (DCs) in the spleen. This delivery system promotes DC maturation and surface antigen presentation and stimulates the production of cytotoxic T cells. Additionally, Mn2+ codelivered in the system serves as a safe and effective immune adjuvant, activating the stimulator of interferon genes (STING) signaling pathway and promoting the secretion of type I interferon, further enhancing the antigen-specific T cell responses. Mn@mRNA-LNP effectively inhibits tumor progression in established melanoma and colon tumor models as well as in a model of tumor recurrence after resection. Notably, the combination of Mn@mRNA-LNP with immune checkpoint inhibitors further enhances complete tumor suppression and prolonged the overall survival in mice. Overall, this "All-in-One" mRNA vaccine significantly boosts antitumor immunity responses by improving spleen targeting and immune activation, providing an attractive strategy for the future clinical translation of therapeutic mRNA vaccines.

Identification of genetic fingerprint of type I interferon therapy in visceral metastases of melanoma

Malignant melanoma is a difficult-to-treat skin cancer with increasing incidence worldwide. Although type-I interferon (IFN) is no longer part of guidelines, several melanoma patients are treated with type-I interferon (IFN) at some point of the disease, potentially affecting its genetic progression. We run genome-wide copy number variation (CNV) analysis on previously type-I IFN-treated (n = 17) and control (n = 11) visceral metastases of melanoma patients. Results were completed with data from the TCGA and MM500 databases. We identified metastasis- and brain metastasis-specific gene signatures mostly affected by CN gains. Some cases were genetically resistant to IFN showing characteristic gene alterations (e.g. ABCA4 or ZEB2 gain and alterations of DNA repair genes). Analysis of a previously identified type-I IFN resistance gene set indicates that only a proportion of these genes was exclusive for the IFN-treated metastases reflecting a possible selective genomic pressure of endogenous IFNs during progression. Our data suggest that previous type-I IFN treatment and/or endogenous IFN production by immune response affect genomic progression of melanoma which may have clinical relevance, potentially influence immune checkpoint regulation in the tumor microenvironment.

Virus nanotechnology for intratumoural immunotherapy

Viruses can be designed to be tools and carrier vehicles for intratumoural immunotherapy. Their nanometre-scale size and shape allow for functionalization with or encapsulation of medical cargoes and tissue-specific ligands. Importantly, immunotherapies may particularly benefit from the inherent immunomodulatory properties of viruses. For example, mammalian viruses have already been tested for oncolytic virotherapy, and bacteriophages and plant viruses can be engineered for immunotherapeutic treatment approaches. In this Review, we discuss how viruses - including oncolytic viruses, immunomodulatory plant viruses and bacteriophages - and virus-like particles can be designed for intratumoural immunotherapy to elicit anti-tumour immunity and induce systemic anti-tumour responses at distant non-injected sites. We further highlight the engineering of viruses and virus-like particles as drug-delivery systems, and outline key translational challenges and clinical opportunities.

An overview of the functions and mechanisms of APOBEC3A in tumorigenesis

The APOBEC3 (A3) family plays a pivotal role in the immune system by performing DNA/RNA single-strand deamination. Cancers mostly arise from the accumulation of chronic mutations in somatic cells, and recent research has highlighted the A3 family as a major contributor to tumor-associated mutations, with A3A being a key driver gene leading to cancer-related mutations. A3A helps to defend the host against virus-induced tumors by editing the genome of cancer-associated viruses that invade the host. However, when it is abnormally expressed, it leads to persistent, chronic mutations in the genome, thereby fueling tumorigenesis. Notably, A3A is prominently expressed in innate immune cells, particularly macrophages, thereby affecting the functional state of tumor-infiltrating immune cells and tumor growth. Furthermore, the expression of A3A in tumor cells may directly affect their proliferation and migration. A growing body of research has unveiled that A3A is closely related to various cancers, which signifies the potential significance of A3A in cancer therapy. This paper mainly classifies and summarizes the evidence of the relationship between A3A and tumorigenesis based on the potential mechanisms, aiming to provide valuable references for further research on the functions of A3A and its development in the area of cancer therapy.

Copper-Based Composites Nanoparticles Improve Triple-Negative Breast Cancer Treatment with Induction of Apoptosis-Cuproptosis and Immune Activation

The synergistic effect of apoptosis and cuproptosis, along with the activation of the immune system, presents a promising approach to enhance the efficacy against triple-negative breast cancer (TNBC). Here, two prodrugs are synthesized: a reactive oxygen species (ROS)-responsive prodrug PEG-TK-DOX and a glutathione (GSH)-responsive prodrug PEG-DTPA-SS-CPT. These prodrugs are self-assembled and chelated Cu2+ to prepare nanoparticle PCD@Cu that simultaneously loaded doxorubicin (DOX), camptothecin (CPT), and Cu2+. The elevated levels of ROS and GSH in TNBC cells disrupted the PCD@Cu structure, leading to the release of Cu+, DOX, and CPT and the depletion of GSH. DOX and CPT triggered apoptosis with immunogenic cell death (ICD) in TNBC cells. Simultaneously, PCD@Cu downregulated the expression of copper transporting ATPase 2 (ATP7B), causing a significant accumulation of copper ions in TNBC cells. This further induced the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT) and downregulation of iron-sulfur (Fe-S) cluster proteins, ultimately leading to cuproptosis and ICD in TNBC. In vitro and in vivo experiments confirmed that PCD@Cu induced apoptosis and cuproptosis in TNBC and activated the immune system, demonstrating strong anti-tumor capabilities. Moreover, PCD@Cu exhibited an excellent biosafety profile. Overall, this study provides a promising strategy for effective TNBC therapy.

cGAS/STING signalling pathway in senescence and oncogenesis

The cGAS/STING signaling pathway is a crucial component of the innate immune system, playing significant roles in sensing cytosolic DNA, regulating cellular senescence, and contributing to oncogenesis. Recent advances have shed new lights into the molecular mechanisms governing pathway activation in multiple pathophysiological settings, the indispensable roles of cGAS/STING signaling in cellular senescence, and its context-dependent roles in cancer development and suppression. This review summarizes current knowledge related to the biology of cGAS/STING signaling pathway and its participations into senescence and oncogenesis. We further explore the clinical implications and therapeutic potential for cGAS/STING targeted therapies, and faced challenges in the field. With a focus on molecular mechanisms and emerging pharmacological targets, this review underscores the importance of future studies to harness the therapeutic potential of the cGAS/STING pathway in treating senescence-related disorders and cancer. Advanced understanding of the regulatory mechanisms of cGAS/STING signaling, along with the associated deregulations in diseases, combined with the development of new classes of cGAS/STING modulators, hold great promises for creating novel and effective therapeutic strategies. These advancements could address current treatment challenges and unlock the full potential of cGAS/STING in treating senescence-related disorders and oncogenesis.

Single-Dose Physically Cross-Linked Hyaluronic Acid and Lipid Hybrid Nanoparticles Containing Cyclic Guanosine Monophosphate-Adenosine Monophosphate Eliminate Established Tumors

Activating the STING pathway in the cytosol of tumor-infiltrating antigen-presenting cells (APCs) represents a promising strategy to elicit potent antitumor immune responses for cancer therapy. However, STING agonists are mostly small hydrophilic molecules that suffer from rapid clearance and poor cytosolic delivery following systemic administration. While various nanoparticles have been developed to promote cytosolic delivery, they often exhibit premature drug release during circulation. Alternatively, stable nanoparticles with sustained release during circulation have poor cytosolic delivery. In this study, we have developed physically cross-linked hyaluronic acid (HA) and lipid hybrid nanoparticles containing cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), denoted as HLHC, to address these challenges. The HLH delivery system has sustained drug release due to multiple lipid layers physically cross-linked by HA. HLHC efficiently delivers cGAMP to the cytosol of APCs, inducing more IFNβ than cGAMP and liposomal cGAMP. HLH also improves the drug circulation time and biodistribution to the tumor compared with the liposomal formulation and free drug. Strikingly, a single dose of HLHC, but not liposomal cGAMP or free cGAMP, elicits potent antitumor immunity and regresses established MC38 tumors. A single dose of HLHC even regresses established B16F10 tumors upon combination with αPD-L1. Moreover, cured animals were protected from rechallenge with the same tumor cells. HLHC represents an efficient strategy to address delivery challenges associated with STING agonists and may have broad applications for the delivery of drugs acting in the cytosol.

Cellular fate of a plant virus immunotherapy candidate

Cowpea mosaic virus (CPMV) is a plant virus that is currently being developed for intratumoral immunotherapy. CPMV relieves the immune system from tumor-induced immunosuppression; reprograms the tumor microenvironment to an activated state whereby the treated and distant tumors are recognized and eradicated. Toward translational studies, we investigated the safety of CPMV, specifically addressing whether pathogenicity would be induced in mammalian cells. We show that murine macrophage immune cells recognize CPMV; however, there is no indication of de novo viral protein synthesis or RNA replication. Furthermore, we show that CPMV does not induce hemolysis, platelet aggregation and plasma coagulation amongst other assays in human blood and immune cells. Taken together, we anticipate that these results will reinforce the development of CPMV as an immunotherapeutic platform.

Unveiling the Promise: Navigating Clinical Trials 1978-2024 for PDAC

Despite many decades of research, pancreatic ductal adenocarcinoma (PDAC) remains one of the most difficult cancers to diagnose and treat effectively. Although there have been improvements in the 5-year overall survival rate, it is still very low at 12.5%. The limited efficacy of current therapies, even when PDAC is detected early, underscores the aggressive nature of the disease and the urgent need for more effective treatments. Clinical management of PDAC still relies heavily on a limited repertoire of therapeutic interventions, highlighting a significant gap between research efforts and available treatments. Over 4300 clinical trials have been or are currently investigating different treatment modalities and diagnostic strategies for PDAC, including targeted therapies, immunotherapies, and precision medicine approaches. These trials aim to develop more effective treatments and improve early detection methods through advanced imaging techniques and blood-based biomarkers. This review seeks to categorize and analyze PDAC-related clinical trials across various dimensions to understand why so few chemotherapeutic options are available to patients despite the numerous trials being conducted. This review aims to provide a comprehensive and nuanced understanding of the landscape of PDAC-related clinical trials, with the overarching goal of identifying opportunities to accelerate progress in drug development and improve patient outcomes in the fight against this devastating disease.

Targeting IRE1α reprograms the tumor microenvironment and enhances anti-tumor immunity in prostate cancer

Unfolded protein response (UPR) is a central stress response pathway that is hijacked by tumor cells for their survival. Here, we find that IRE1α signaling, one of the canonical UPR arms, is increased in prostate cancer (PCa) patient tumors. Genetic or small molecule inhibition of IRE1α in syngeneic mouse PCa models and an orthotopic model decreases tumor growth. IRE1α ablation in cancer cells potentiates interferon responses and activates immune system related pathways in the tumor microenvironment (TME). Single-cell RNA-sequencing analysis reveals that targeting IRE1α in cancer cells reduces tumor-associated macrophage abundance. Consistently, the small molecule IRE1α inhibitor MKC8866, currently in clinical trials, reprograms the TME and enhances anti-PD-1 therapy. Our findings show that IRE1α signaling not only promotes cancer cell growth and survival but also interferes with anti-tumor immunity in the TME. Thus, targeting IRE1α can be a promising approach for improving anti-PD-1 immunotherapy in PCa.

Preclinical study and phase II trial of adapting low-dose radiotherapy to immunotherapy in small cell lung cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) provide modest but unsatisfactory benefits for extensive-stage small cell lung cancer (ES-SCLC). Developing strategies for treating ES-SCLC is critical.

METHODS

We preliminarily explored the outcomes of salvage low-dose radiotherapy (LDRT) plus ICI on refractory SCLC patients. Next, we evaluated the combinational efficacy in murine SCLC. The tumor immune microenvironment (TIME) was analyzed for mechanistic study. Subsequently, we conducted a multicenter, prospective phase II trial that administered concurrent thoracic LDRT plus chemoimmunotherapy to treatment-naive ES-SCLC patients (MATCH trial, NCT04622228). The primary endpoint was confirmed objective response rate (ORR), and the key secondary endpoints included progression-free survival (PFS) and safety.

FINDINGS

Fifteen refractory SCLC patients treated with LDRT plus ICI were retrospectively reviewed. The ORR was 73.3% (95% confidence interval [CI], 44.9-92.2). We identified a specific dose of LDRT (15 Gy/5 fractions) that exhibited growth retardation and improved survival in murine SCLC when combined with ICIs. This combination recruited a special T cell population, TCF1+ PD-1+ CD8+ stem-like T cells, from tumor-draining lymph nodes into the TIME. The MATCH trial showed a confirmed ORR of 87.5% (95% CI, 75.9-94.8). The median PFS was 6.9 months (95% CI, 5.4-9.3).

CONCLUSIONS

These findings verified that LDRT plus chemoimmunotherapy was safe, feasible, and effective for ES-SCLC, warranting further investigation.

FUNDING

This research was funded by West China Hospital (no. ZYJC21003), the National Natural Science Foundation of China (no. 82073336), and the MATCH trial was fully funded by Roche (China) Holding Ltd. (RCHL) and Shanghai Roche Pharmaceuticals Ltd. (SRPL).

Genomic instability as a driver and suppressor of anti-tumor immunity

Genomic instability is a driver and accelerator of tumorigenesis and influences disease outcomes across cancer types. Although genomic instability has been associated with immune evasion and worsened disease prognosis, emerging evidence shows that genomic instability instigates pro-inflammatory signaling and enhances the immunogenicity of tumor cells, making them more susceptible to immune recognition. While this paradoxical role of genomic instability in cancer is complex and likely context-dependent, understanding it is essential for improving the success rates of cancer immunotherapy. In this review, we provide an overview of the underlying mechanisms that link genomic instability to pro-inflammatory signaling and increased immune surveillance in the context of cancer, as well as discuss how genomically unstable tumors evade the immune system. A better understanding of the molecular crosstalk between genomic instability, inflammatory signaling, and immune surveillance could guide the exploitation of immunotherapeutic vulnerabilities in cancer.

Two-dimensional coordination risedronate-manganese nanobelts as adjuvant for cancer radiotherapy and immunotherapy

The irradiated tumor itself represents an opportunity to establish endogenous in situ vaccines. However, such in situ cancer vaccination (ISCV) triggered by radiation therapy (RT) alone is very weak and hardly elicits systemic anticancer immunity. In this study, we develop two-dimensional risedronate-manganese nanobelts (RMn-NBs) as an adjuvant for RT to address this issue. RMn-NBs exhibit good T2 magnetic resonance imaging performance and enhanced Fenton-like catalytic activity, which induces immunogenic cell death. RMn-NBs can inhibit the HIF-1α/VEGF axis to empower RT and synchronously activate the cGAS/STING pathway for promoting the secretion of type I interferon, thereby boosting RT-triggered ISCV and immune checkpoint blockade therapy against primary and metastatic tumors. RMn-NBs as a nano-adjuvant for RT show good biocompatibility and therapeutic efficacy, presenting a promising prospect for cancer radiotherapy and immunotherapy.

Inhibition of O-GlcNAc transferase activates type I interferon-dependent antitumor immunity by bridging cGAS-STING pathway

The O-GlcNAc transferase (OGT) is an essential enzyme that mediates protein O-GlcNAcylation, a unique form of posttranslational modification of many nuclear and cytosolic proteins. Recent studies observed increased OGT and O-GlcNAcylation levels in a broad range of human cancer tissues compared to adjacent normal tissues, indicating a universal effect of OGT in promoting tumorigenesis. Here, we show that OGT is essential for tumor growth in immunocompetent mice by repressing the cyclic GMP-AMP synthase (cGAS)-dependent DNA sensing pathway. We found that deletion of OGT (Ogt-/-) caused a marked reduction in tumor growth in both syngeneic mice tumor models and a genetic mice colorectal cancer (CRC) model induced by mutation of the Apc gene (Apcmin). Pharmacological inhibition or genetic deletion of OGT induced a robust genomic instability (GIN), leading to cGAS-dependent production of the type I interferon (IFN-I) and IFN-stimulated genes (ISGs). As a result, deletion of Cgas or Sting from Ogt-/- cancer cells restored tumor growth, and this correlated with impaired CD8+ T-cell-mediated antitumor immunity. Mechanistically, we found that OGT-dependent cleavage of host cell factor C1 (HCF-1) is required for the avoidance of GIN and IFN-I production in tumors. In summary, our results identify OGT-mediated genomic stability and activate cGAS-STING pathway as an important tumor-cell-intrinsic mechanism to repress antitumor immunity.

Iron Chelation Therapy Elicits Innate Immune Control of Metastatic Ovarian Cancer

Iron accumulation in tumors contributes to disease progression and chemoresistance. Although targeting this process can influence various hallmarks of cancer, the immunomodulatory effects of iron chelation in the tumor microenvironment are unknown. Here, we report that treatment with deferiprone, an FDA-approved iron chelator, unleashes innate immune responses that restrain ovarian cancer. Deferiprone reprogrammed ovarian cancer cells toward an immunostimulatory state characterized by the production of type-I IFN and overexpression of molecules that activate NK cells. Mechanistically, these effects were driven by innate sensing of mitochondrial DNA in the cytosol and concomitant activation of nuclear DNA damage responses triggered upon iron chelation. Deferiprone synergized with chemotherapy and prolonged the survival of mice with ovarian cancer by bolstering type-I IFN responses that drove NK cell-dependent control of metastatic disease. Hence, iron chelation may represent an alternative immunotherapeutic strategy for malignancies that are refractory to current T-cell-centric modalities. Significance: This study uncovers that targeting dysregulated iron accumulation in ovarian tumors represents a major therapeutic opportunity. Iron chelation therapy using an FDA-approved agent causes immunogenic stress responses in ovarian cancer cells that delay metastatic disease progression and enhance the effects of first-line chemotherapy. See related commentary by Bell and Zou, p. 1771.

Unlocking Apoptotic Pathways: Overcoming Tumor Resistance in CAR-T-Cell Therapy

BACKGROUND

Chimeric antigen receptor (CAR)-T-cell therapy has transformed cancer treatment, leading to remarkable clinical outcomes. However, resistance continues to be a major obstacle, significantly limiting its efficacy in numerous patients.

OBJECTIVES

This review critically examines the challenges associated with CAR-T-cell therapy, with a particular focus on the role of apoptotic pathways in overcoming resistance.

METHODS

We explore various strategies to sensitize tumor cells to CAR-T-cell-mediated apoptosis, including the use of combination therapies with BH3 mimetics, Mcl-1 inhibitors, IAP inhibitors, and HDAC inhibitors. These agents inhibit anti-apoptotic proteins and activate intrinsic mitochondrial pathways, enhancing the susceptibility of tumor cells to apoptosis. Moreover, targeting the extrinsic pathway can increase the expression of death receptors on tumor cells, further promoting their apoptosis. The review also discusses the development of novel CAR constructs that enhance anti-apoptotic protein expression, such as Bcl-2, which may counteract CAR-T cell exhaustion and improve antitumor efficacy. We assess the impact of the tumor microenvironment (TME) on CAR-T cell function and propose dual-targeting CAR-T cells to simultaneously address both myeloid-derived suppressor cells (MDSCs) and tumor cells. Furthermore, we explore the potential of combining agents like PPAR inhibitors to activate the cGAS-STING pathway, thereby improving CAR-T cell infiltration into the tumor.

CONCLUSIONS

This review highlights that enhancing tumor cell sensitivity to apoptosis and increasing CAR-T cell cytotoxicity through apoptotic pathways could significantly improve therapeutic outcomes. Targeting apoptotic proteins, particularly those involved in the intrinsic mitochondrial pathway, constitutes a novel approach to overcoming resistance. The insights presented herein lay a robust foundation for future research and clinical applications aimed at optimizing CAR-T cell therapies.

DAMPening Tumor Immune Escape: The Role of Endoplasmic Reticulum Chaperones in Immunogenic Chemotherapy

Significance: Preclinical and clinical research in the past two decades has redefined the mechanism of action of some chemotherapeutics that are able to activate the immune system against cancer when cell death is perceived by the immune cells. This immunogenic cell death (ICD) activates antigen-presenting cells (APCs) and T cells to induce immune-mediated tumor clearance. One of the key requirements to achieve this effect is the externalization of the damage-associated molecular patterns (DAMPs), molecules released or exposed by cancer cells during ICD that increase the visibility of the cancer cells by the immune system. Recent Advances: In this review, we focus on the role of calreticulin (CRT) and other endoplasmic reticulum (ER) chaperones, such as the heat-shock proteins (HSPs) and the protein disulfide isomerases (PDIs), as surface-exposed DAMPs. Once exposed on the cell membrane, these proteins shift their role from that of ER chaperone and regulator of Ca2+ and protein homeostasis to act as an immunogenic signal for APCs, driving dendritic cell (DC)-mediated phagocytosis and T-mediated antitumor response. Critical Issues: However, cancer cells exploit several mechanisms of resistance to immune attack, including subverting the exposure of ER chaperones on their surface to avoid immune recognition. Future Directions: Overcoming these mechanisms of resistance represents a potential therapeutic opportunity to improve cancer treatment effectiveness and patient outcomes.

The importance of IFNα2A (Roferon-A) in HSV-1 latency and T cell exhaustion in ocularly infected mice

Published studies have generated compelling results indicating that type I IFN modulates function of HSV-1 latency-associated transcript (LAT). One member of type I IFN is IFNα2A also called Roferon-A). IFNα2A has been used in monotherapy or in combination therapy with other drugs to treat viral infections and different kinds of cancer in humans. The goal of this study was to determine whether the absence of IFNα2A affects primary and latent infections in ocularly infected mice. Therefore, we generated a mouse strain lacking IFNα2A expression (IFNα2A-/-). Ocular HSV-1 replication, IFN and immune cell expressions on days 3 and 5 post infection (PI), as well as eye disease, survival, latency-reactivation, and T cell exhaustion were evaluated in ocularly infected IFNα2A-/- and wild type (WT) control mice. Absence of IFNα2A did not affect other members of the IFNα family but it affected IFNβ and IFNγ expressions as well as some immune cells on day 5 PI compared to WT mice. Viral replication in the eye, eye disease, and survival amongst ocularly infected IFNα2A-/- mice were similar to that of WT infected mice. The absence of IFNα2A significantly reduced the levels of latency and T cell exhaustion but not time of reactivation compared with control mice. Our results suggest that blocking IFNα2A expression may be a useful tool in reducing latency and the subsequent side effects associated with higher levels of latency.

Safe Induction of Acute Inflammation with Enhanced Antitumor Immunity by Hydrogel-Mediated Outer Membrane Vesicle Delivery

Acute inflammation has the potential for the recruitment of immune cells, inhibiting tumor angiogenesis, metastasis, and drug resistance thereby overcoming the tumor immunosuppressive microenvironment caused by chronic inflammation. Here, an acute inflammation inducer using bacteria outer membrane vesicles (OMVs) loaded in thermal-sensitive hydrogel (named OMVs-gel) for localized and controlled release of OMVs in tumor sites is proposed. OMVs trigger neutrophil recruitment and amplify acute inflammation inside tumor tissues. The hydrogel ensures drastic inflammation is confined within the tumor, addressing biosafety concerns that the direct administration of free OMVs may cause fatal effects. This strategy eradicated solid tumors safely and rapidly. The study further elucidates one of the possible immune mechanisms of OMVs-gel therapy, which involves the assembly of antitumor neutrophils and elastase release for selective tumor killing. Additionally, tumor vascular destruction induced by OMVs-gel results in tumor darkening, allowing for combinational photothermal therapy. The findings suggest that the use of OMVs-gel can safely induce acute inflammation and enhance antitumor immunity, representing a promising strategy to promote acute inflammation application in tumor immunotherapy.

Engineering interferons for cancer immunotherapy

Interferons are a family of cytokines that are famously known for their involvement in innate and adaptive immunity. Type I interferons (IFNs) exert pleiotropic effects on various immune cells and contribute to tumor-intrinsic and extrinsic mechanisms. Their pleiotropic effects and ubiquitous expression on nucleated cells have made them attractive candidates for cytokine engineering to deliver to largely immunosuppressive tumors. Type III interferons were believed to play overlapping roles with type I IFNs because they share a similar signaling pathway and induce similar transcriptional programs. However, type III IFNs are unique in their cell specific receptor expression and their antitumor activity is specific to a narrow range of cell types. Thus, type III IFN based therapies may show reduced toxic side effects compared with type I IFN based treatment. In this review, we focus on the development of IFN-based therapeutics used to treat different tumors. We highlight how the development in cytokine engineering has allowed for efficient delivery of type I and type III IFNs to tumor sites and look ahead to the obstacles that are still associated with IFN-based therapies before they can be fully and safely integrated into clinical settings.