Tumor-Residing Batf3 Dendritic Cells Are Required for Effector T Cell Trafficking and Adoptive T Cell Therapy

NCOA3 impairs the efficacy of anti-PD-L1 therapy via HSP90α/EZH2/CXCL9 axis in colon cancer

Immune checkpoint inhibitors (ICIs) have revolutionized colon cancer treatment, but their efficacy is largely restricted by the limited presence of CD8+ cytotoxic T lymphocytes (CTLs). However, the specific genetic alterations that impact the CD8+ CTL infiltration in colon cancer remain poorly understood. Here, we analyzed clinical and multi-omics data from the Memorial Sloan-Kettering Cancer Center (MSKCC) ICIs-treated and The Cancer Genome Atlas (TCGA) colon adenocarcinoma (COAD) cohorts to screen the key mutations that may influence the efficacy of immunotherapy. We found that patients with NCOA3 mutations exhibit better response to immunotherapy and higher CD8+ CTL infiltration. In vitro and in vivo experiments revealed that mutant NCOA3 increases the efficacy of anti-PD-L1 and CD8+ CTL recruitment by upregulating C-X-C motif chemokine ligand 9 (CXCL9), which is dependent on its impaired intrinsic histone acetyltransferase activity. Mechanistically, wild-type NCOA3 as histone acetyltransferase upregulates Heat shock protein 90 alpha (HSP90α) by enhancing histone H3 lysine 27 acetylation (H3K27ac) at its promoter region. Increased HSP90α stabilizes Enhancer of zeste homolog 2 (EZH2), which then increase the histone H3 lysine 27 trimethylation (H3K27me3) at the CXCL9 promoter region, thereby suppressing the expression of CXCL9. Targeted inhibition of NCOA3 by small molecular inhibitor SI-2 improves the efficacy of PD-L1 blockade therapy. NCOA3 could serve as a novel biomarker and potential target to improve the efficacy of immunotherapy.

STAT5 and STAT3 balance shapes dendritic cell function and tumour immunity

Immune checkpoint blockade (ICB) has transformed cancer therapy1,2. The efficacy of immunotherapy depends on dendritic cell-mediated tumour antigen presentation, T cell priming and activation3,4. However, the relationship between the key transcription factors in dendritic cells and ICB efficacy remains unknown. Here we found that ICB reprograms the interplay between the STAT3 and STAT5 transcriptional pathways in dendritic cells, thereby activating T cell immunity and enabling ICB efficacy. Mechanistically, STAT3 restrained the JAK2 and STAT5 transcriptional pathway, determining the fate of dendritic cell function. As STAT3 is often activated in the tumour microenvironment5, we developed two distinct PROTAC (proteolysis-targeting chimera) degraders of STAT3, SD-36 and SD-2301. STAT3 degraders effectively degraded STAT3 in dendritic cells and reprogrammed the dendritic cell-transcriptional network towards immunogenicity. Furthermore, STAT3 degrader monotherapy was efficacious in treatment of advanced tumours and ICB-resistant tumours without toxicity in mice. Thus, the crosstalk between STAT3 and STAT5 transcriptional pathways determines the dendritic cell phenotype in the tumour microenvironment and STAT3 degraders hold promise for cancer immunotherapy.

Phase II Trial of Pembrolizumab in Combination With Bevacizumab for Untreated Melanoma Brain Metastases

PURPOSE

Anti-vascular endothelial growth factor therapy enhances PD-1 inhibitor activity in preclinical models and has been used to treat perilesional cerebral edema and radiation necrosis.

METHODS

We conducted a two-institution phase II trial of bevacizumab and pembrolizumab in patients with untreated melanoma brain metastasis (MBM) (ClinicalTrials.gov identifier: NCT02681549). Patients were anti-PD-(L)-1-naïve, and had ≥one asymptomatic, nonhemorrhagic 5-20 mm MBM, not requiring immediate local therapy or steroids.

RESULTS

Thirty-seven patients received four doses of bevacizumab and pembrolizumab every 3 weeks followed by up to 2 years of pembrolizumab. The brain metastasis response rate (primary end point) was 54.1% (95% CI, 36.9 to 70.5). The extracranial response rate was 56.3% (95% CI, 37.7 to 73.6). Median intracranial progression-free survival was 2.2 years (95% CI, 0.41 to not reached [NR]). Median overall survival (OS) was 4.3 years (95% CI, 1.6 to NR). Four-year OS rate was 51.6%. Grade 3 treatment-related adverse event rates from bevacizumab and pembrolizumab were 10.8% and 18.9%, respectively. Higher pretreatment vessel density in metastatic tumors and smaller on-therapy increases in circulating angiopoietin-2 were associated with response.

CONCLUSION

Pembrolizumab with bevacizumab was well tolerated and demonstrated substantial activity in patients with untreated MBM with promising OS, justifying further evaluation of this regimen.

Defects in the necroptosis machinery are a cancer resistance mechanism to checkpoint inhibitor immunotherapy

BACKGROUND

Immune checkpoint inhibitors (ICIs) of programmed cell death protein-1 (PD-1) or cytotoxic T-lymphocytes-associated protein 4 (CTLA-4) reinvigorate strong polyclonal T-cell immune responses against tumor cells. For many patients, these therapies fail because the development of spontaneous immune responses is often compromised, as the tumor microenvironment (TME) lacks proinflammatory signals resulting in suboptimal activation of antigen-presenting cells (APCs). Necroptosis is a special form of programmed cell death associated with leakage of inflammatory factors that can lead to APC maturation. However, it is unclear to which extent functional necroptosis in tumor cells contributes to ICI immunotherapy.

METHODS

With genetically engineered tumor cell lines that lack specific components of the necroptosis machinery (mixed lineage kinase domain-like pseudokinase (MLKL), receptor interacting protein kinase 3 (RIPK3)), we addressed the importance of necroptotic tumor cell death for the efficacy of ICI immunotherapy in murine models. Preclinical data were aligned with genome-wide transcriptional programs in patient tumor samples at diagnosis and during ICI treatment for the activity of these pathways and association with treatment outcome.

RESULTS

Mice bearing MLKL-deficient or RIPK3-deficient tumors failed to control tumor growth in response to anti-PD-1/anti-CTLA-4 immunotherapy. Mechanistically, defects in the necroptosis pathway resulted in reduced tumor antigen cross-presentation by type 1 conventional dendritic cells (DCs) in tumor-draining lymph nodes, and subsequently impaired immunotherapy-induced expansion of circulating tumor antigen-specific CD8+ T cells and their accumulation and activation in the TME. In vitro, co-culture of tumor cells undergoing necroptotic but not apoptotic programmed cell death resulted in increased uptake by phagocytic cells, associated with maturation and activation of DCs. Treatment of tumors with the epigenetic modulator azacytidine enhanced intrinsic transcriptional activity of the necroptosis machinery, and hence their susceptibility to ICI immunotherapy. In humans, transcriptome analysis of melanoma samples revealed a strong association between high expression of MLKL and prolonged overall survival and durable clinical response to immunotherapy with anti-PD-1 and/or anti-CTLA-4 checkpoint inhibitors.

CONCLUSIONS

Defective necroptosis signaling in tumor cells is a cancer resistance mechanism to ICI immunotherapy. Reversion of epigenetic silencing of the necroptosis pathway can render tumors susceptible to checkpoint inhibition.

Oncolytic viruses as cancer therapeutics: From mechanistic insights to clinical translation

Oncolytic virotherapy is a therapeutic approach that leverages genetically engineered or naturally occurring viruses to selectively target and destroy cancer cells while sparing normal tissues. This review provides an overview of the mechanisms of action by oncolytic viruses (OVs), including direct oncolysis, immune activation, and tumor microenvironment (TME) modulation. Despite significant progress, challenges such as immune resistance, tumor evasion mechanisms, and delivery barriers continue to limit the efficacy of OVs. To address these obstacles, recent advances in OV engineering have focused on arming viruses with immunomodulatory molecules, utilizing tumor-specific promoters, and employing CRISPR-based genome editing. Emerging strategies, such as dual-targeting OVs and viral enhancer drugs, have demonstrated promising potential in preclinical and clinical settings. This review also highlights findings from recent clinical trials, underscoring the translational challenges in scaling OVs for widespread therapeutic application. By exploring these innovations and their implications, we aim to shed light on the future directions of oncolytic virotherapy and its transformative potential in cancer treatment.

TLR5 Signaling Causes Dendritic Cell Dysfunction and Orchestrates Failure of Immune Checkpoint Therapy against Ovarian Cancer

Ovarian cancer accounts for more deaths than any other cancer of the female reproductive system. Patients who have ovarian tumors infiltrated with high frequencies of T cells are associated with a greater survival probability. However, therapies to revitalize tumor-associated T cells, such as PD-L1/PD-1 or CTLA4 blockade, are ineffective for the treatment of ovarian cancer. In this study, we demonstrate that for ovarian cancer, Toll-like receptor 5 (TLR5) signaling, for which the only known ligand is bacterial flagellin, governed failure of PD-L1 and CTLA4 blockade. Mechanistically, chronic TLR5 signaling on CD11c+ cells in vivo and in vitro impaired the differentiation of functional IL-12-producing XCR1+CD103+ conventional type 1 dendritic cells, biasing CD11c+ precursor cells toward myeloid subsets expressing high levels of PD-L1. This culminated in impaired activation of CD8+ T cells, reducing CD8+ T-cell function and ability to persist within the ovarian tumor microenvironment. Expansion of XCR1+CD103+ conventional type 1 dendritic cells in situ using Flt3L-Ig in combination with PD-L1 blockade achieved significant survival benefit in TLR5 knockout mice bearing ovarian tumors, whereas no benefit was observed in the presence of TLR5 signaling. Thus, we have identified a host-intrinsic mechanism leading to the failure of PD-L1 blockade for ovarian cancer, demonstrating that chronic TLR5 signaling on CD11c+ cells is a barrier limiting the efficacy of checkpoint therapy.

PAR2 deficiency impairs antitumor immunity and attenuates anti-PD1 efficacy in colorectal cancer

A T cell-inflamed tumor microenvironment is predictive of better prognosis and clinical response to immunotherapy. Proteinase-activated receptor 2 (PAR2), a member of G-protein coupled receptors is involved in inflammatory process and the progression of various cancers. However, the role of PAR2 in modulating the tumor microenvironment remains unclear. Here, we found that PAR2 high-expression was associated with a favorable prognosis in patients with colorectal cancer. Intriguingly, PAR2 expression in human colorectal cancer was mainly confined to tumor cells and was significantly associated with CD8+ T cell infiltration. Tumor-intrinsic PAR2 deficiency blunted antitumor immune responses to promote tumor growth and attenuated the therapeutic efficacy of anti-PD1 in a mouse model of colon cancer. Tumors with downregulated PAR2 showed decreased CD8+ T cell infiltration and impaired effector function. Mechanistically, PAR2 activation in tumor cells induced CXCL9 and CXCL10 production via PI3K/AKT/mTOR signaling, thereby enhancing CD8+ T cell recruitment in the tumor microenvironment. In addition, PAR2 was essential for dendritic cell activation and differentiation towards conventional type 1 subset. PAR2 deficiency in dendritic cells markedly impaired their ability to prime CD8+ T cells and control tumor growth in vivo. Thus, our findings identify new roles for PAR2 in promoting antitumor immunity and provide a promising target to improve immunotherapy efficacy in colorectal cancer.

Advances in dendritic cell-based therapeutic tumor vaccines

Dendritic cell-based therapeutic tumor vaccines are an active immunotherapy that has been commonly tried in the clinic,traditional treatment modalities for malignant tumors, such as surgery, radiotherapy and chemotherapy, have the disadvantages of high recurrence rates and side effects. The dendritic cell vaccination destroys cells from tumors by means of the patient's own system of immunity, a very promising treatment. However, due to the suppression of the tumor immune microenvironment, the difficulty of screening for optimal specific antigens, and the high technical difficulty of vaccine production. Most tumor vaccines currently available in the clinic have failed to produce significant clinical therapeutic effects. In this review, the fundamentals of therapeutic dendritic cells vaccine therapy are briefly outlined, with a focus on the progress of therapeutic Dendritic cells vaccine research in the clinic and the initiatives undertaken to enhance dendritic cell vaccinations' anti-tumor effectiveness. It is believed that through the continuous exploration of novel therapeutic strategies, therapeutic dendritic cells vaccines can play a greater role in improving tumor treatment for tumor patients.

Cancer immune evasion, immunoediting and intratumour heterogeneity

Cancers can avoid immune-mediated elimination by acquiring traits that disrupt antitumour immunity. These mechanisms of immune evasion are selected and reinforced during tumour evolution under immune pressure. Some immunogenic subclones are effectively eliminated by antitumour T cell responses (a process known as immunoediting), which results in a clonally selected tumour. Other cancer cells arise to resist immunoediting, which leads to a tumour that includes several distinct cancer cell populations (referred to as intratumour heterogeneity (ITH)). Tumours with high ITH are associated with poor patient outcomes and a lack of responsiveness to immune checkpoint blockade therapy. In this Review, we discuss the different ways that cancer cells evade the immune system and how these mechanisms impact immunoediting and tumour evolution. We also describe how subclonal antigen presentation in tumours with high ITH can result in immune evasion.

Resistance to PD-1/PD-L1 immune checkpoint blockade in advanced non-small cell lung cancer

Lung cancer is one of the most common malignant tumors, of which non-small cell lung cancer (NSCLC) accounts for about 85 %. Although immune checkpoint inhibitors (ICIs), particularly PD-1/PD-L1 inhibitors, have significantly improved the prognosis of patients with NSCLC. There are still many patients do not benefit from ICIs. Primary resistance remains a major challenge in advanced NSCLC. The cancer-immunity cycle describes the process from antigen release to T cell recognition and killing of the tumor, which provides a framework for understanding anti-tumor immunity. The classical cycle consists of seven steps, and alterations at each stage can result in resistance. This review examines the current status of PD-1/PD-L1 blockade in the treatment of advanced NSCLC and explores potential mechanisms of resistance. We summarize the latest clinical trials of PD-1/PD-L1 inhibitors combined with other therapies and explore potential targets for overcoming primary resistance to PD-1/PD-L1 inhibitors.

Inhibition of MBTPS1 enhances antitumor immunity and potentiates anti-PD-1 immunotherapy

Despite advances in cancer immunotherapy, colorectal cancer patients exhibit limited therapeutic responses. Therefore, the exploration of strategies combining immunotherapy with adjuvant approaches to enhance adaptive immune responses is in demand. Here, we perform a customized in vivo CRISPR-Cas9 screen to target genes encoding membrane and secreted proteins in CRC mouse models with different immune characteristics. We observe that loss of membrane-bound transcription factor site-1 protease (MBTPS1) in tumor cells enhances antitumor immunity and potentiates anti-PD-1 therapy. Mechanistic studies reveal that tumor cell-intrinsic MBTPS1 competes with USP13 for binding to STAT1, thereby disrupting the USP13-dependent deubiquitination-mediated STAT1 stabilization. The upregulated STAT1-transcribed chemokines including CXCL9, CXCL10, and CXCL11, promote CXCR3+CD8+ T cell infiltration. Notably, the regulatory role of MBTPS1 in antitumor immunity operates independently of its classic function in cleaving membrane-bound transcription factors. Collectively, our results provide a theoretical basis for MBTPS1 as a potential immunotherapy target.

Lymphotropic Virotherapy Engages DC and High Endothelial Venule Inflammation to Mediate Cancer In Situ Vaccination

Intratumor (IT) inoculation of the rhino:poliovirus chimera, PVSRIPO, yielded objective radiographic responses with long-term survival in 20% of patients with recurrent glioblastoma (rGBM). PVSRIPO infects dendritic cells (DCs) and sets up non-cytopathogenic viral (v)RNA replication, which triggers sustained type-I IFN (IFN-I) signaling and antitumor T cell priming. Here we identify IFN-I signaling in glioma-draining cervical lymph nodes (cLN) as a mediator of polio virotherapy. Transient IFN-I signaling after IT therapy was rescued by cervical perilymphatic injection (CPLI) of PVSRIPO, targeting cLN directly. Dual-site (IT+CPLI) PVSRIPO induced profound inflammatory reprogramming of cLN, enhanced vRNA replication and IFN-I signaling in DCs and High Endothelial Venules (HEV), augmented anti-glioma efficacy in mice, and was associated with T cell activation in rGBM patients. A Ph2 clinical trial of IT+CPLI PVSRIPO is ongoing ( NCT06177964 ). This work implicates the lymphatic system as a novel virotherapy target and demonstrates the CPLI concept to complement brain tumor immunotherapy.

Microwave ablation combined with α-PD-L1 enhances abscopal effect and promotes CTL activation and intratumoral homing by a cytokine network involving IFN-γ and CXCL9

BACKGROUND AND PURPOSE

Microwave ablation (MWA) has demonstrated promising potential in instigating an anti-tumor immune response, potentially resulting in the regression of distant tumors. Nevertheless, the observed abscopal effect remains modest, and its underlying mechanism remains poorly elucidated. This study aims to systematically examine the utilization of α-PD-L1 to enhance the abscopal effect induced by MWA and to comprehensively investigate the associated mechanisms.

METHODS

The Lewis lung cancer model was employed to investigate the abscopal effect of MWA and α-PD-L1 co-treatment. The maturation status of bone marrow-derived dendritic cells (BMDCs) was observed after stimulating with the fragments of tumor cells harvested by microwave treatment. Flow cytometry analysis was employed to scrutinize the ratio of T cells and dendritic cells, along with the quantification of IFN-γ and GzmB expression levels. The expression of CXCL9 or PD-L1 was detected by immunofluorescence.

RESULTS

Local MWA treatment on one site of tumor did not yield a significant reduction in the volume of distant tumors. However, when combined with intraperitoneal α-PD-L1 injection, a notable abscopal effect was induced, resulting in decreased distant tumor volume and prolonged survival in mice. Flow cytometry analysis revealed an increase in infiltrating and activated CD8+ T cells in distant tumors, with up-regulation of IFN-γ and GzmB expression. Notably, the expression of CXCR3 was increased in CD8+ T cells. The mRNA and protein levels of CXCL9 were elevated within distant tumors, concomitant with increased infiltration of macrophages. Moreover, dendritic cells (DCs) in tumor-draining lymph nodes (TDLNs) exhibited enhanced maturation. Additionally, in vitro experiments showed enhanced maturation of BMDCs following stimulation with fragments of Lewis cells harvested via microwave treatment.

CONCLUSIONS

MWA exhibited the potential to stimulate systemic immune responses, it did not lead to a significant abscopal effect. However, the combination of MWA with α-PD-L1 treatment effectively induced the occurrence of the abscopal effect. This phenomenon appears to be linked to the activation of cytotoxic T lymphocytes (CTLs), phagocytosis by macrophages, and the maturation of DCs, facilitated by a cytokine network involving IFN-γ and CXCL9.

Exploration of the role of immune cells and cell therapy in hepatocellular carcinoma

Hepatocellular carcinoma stands as one of the foremost contributors to cancer-associated fatalities globally, and the limitations of traditional treatment methods have prompted researchers to explore new therapeutic options. Recently, cell therapy has emerged as a promising approach for HCC, showing significant potential in improving patient outcomes. This review article explores the use of cell therapy for HCC, covering different types, the mechanisms behind their effectiveness, recent advancements in clinical trials, and ongoing challenges. This article aims to provide insightful perspectives for future research and clinical applications in treating HCC by synthesizing current knowledge.

Novel bioengineered drugs with immunotherapies for malignant pleural effusion: Remodulate tumor immune microenvironment and activate immune system

Malignant pleural effusion (MPE) remains a clinical issue since it is associated with advanced-stage cancers and dismal survival, with immunosuppressive tumor microenvironment (TME) and ineffective drug delivery. Conventional therapies such as thoracentesis and pleurodesis are for symptom relief but palliative, without inducing immunity and prolonging survival. Emerging new bioengineered drugs, synergizing with immunotherapies, offer a new paradigm by dual-targeting TME remodeling and immune activation. These technologies leverage nanotechnology, gene editing, and biomaterials to offer precise spatiotemporal control. This review illustrates the molecular mechanism of the immunosuppressive TME in MPE. It examines the newest bioengineering platforms-such as cytokine-encapsulated nanoparticles and oncolytic viruses-that can reactivate immune mechanisms. We highlight preclinical and clinical evidence of the effectiveness of combinatorial strategies in overcoming local immune tolerance and potential risks in adverse events. While the clinical transformation challenge remains, future directions necessitate cross-disciplinary convergence to engineer intelligent delivery vehicles and predictive biomarkers for patient stratification. By integrating immunotherapy with bioengineering, this strategy not only restores antitumor immunity but also portends a new epoch of precision medicine for MPE.

Potency-optimized CD28-activating bispecific antibody for the targeted treatment of Nectin-4 positive cancers

BACKGROUND

T-cell costimulation is crucial for an effective and sustained antitumor immune response, and inadequate expression of costimulatory ligands within tumors can impair T-cell function. Bispecific antibodies (bsAbs) targeting a tumor-associated antigen and the T-cell costimulatory receptor CD28 represent a novel class of immune-stimulatory therapeutics designed to enhance antitumor immune responses by selectively delivering T-cell costimulation directly to the tumor microenvironment. This approach holds the potential to improve the survival, proliferation, and cytotoxic function of antitumor T cells while minimizing the risk of systemic immune activation. Urothelial cancer (UC) is associated with significant morbidity and mortality worldwide, particularly in advanced disease settings. Nectin-4, a membrane protein highly expressed in UC with limited expression in healthy tissues, presents a compelling target for therapeutic intervention.

METHODS

Using our proprietary high-throughput antibody discovery pipeline, we identified a panel of novel antibodies with a range of affinities for CD28 and Nectin-4 and successfully engineered them as bsAbs. We tested the T-cell costimulatory function of these molecules in vitro using primary human T cells and human cancer cell lines. Based on these results, we selected a clinical candidate which we assessed in a syngeneic mouse tumor model system and investigated tolerability and pharmacokinetics (PK) in non-human primates (NHP).

RESULTS

Our in vitro studies demonstrated that these bsAbs effectively enhance T-cell activation and cytotoxicity against Nectin-4 positive tumor cells in the presence of T-cell receptor engagement. The bsAb panel exhibited a range of potencies, enabling the selection of a clinical candidate, termed RNDO-564, that maximized antitumor efficacy as well as the likelihood of a broad therapeutic window. Tumor-bearing syngeneic mouse models confirmed the in vivo efficacy of RNDO-564, demonstrating significant tumor regression both as a single agent and in combination with an immune checkpoint inhibitor. We observed favorable PK and tolerability profiles in NHP assessments.

CONCLUSIONS

Our study reports the first CD28 bsAb targeting Nectin-4 and highlights the potential of CD28 × Nectin-4 bsAbs as a new immunotherapeutic modality. The findings support the clinical development of RNDO-564 in patients with locally advanced and metastatic UC and other Nectin-4 positive malignancies.

Nucleic Acid-Locked Smart Carrier for Photothermal/Chemotherapy-Amplified Immunogenic Cell Death to Enhance Systemic Antitumor Efficacy

Immunotherapy holds great promise in the fight against cancer; however, it often encounters poor immunogenicity with limited therapeutic efficacy. Combining multiple treatment modalities provides a trustworthy strategy for achieving a robust antitumor effect. In this study, a nucleic acid-locked smart carrier (NASC) is developed to amplify immunogenic cell death (ICD) through the synergistic integration of photothermal therapy (PTT) and chemotherapy for high-performance monotherapy. Mesoporous silica-coated gold nanorod (MSGNR) serves as the reservoir for anticancer drug doxorubicin (DOX) and is capped with a sequence-specific duplex unit containing a tumor-specific targeting AS1411 fragment, resulting in the formation of NASC. With AS1411 targeting, the NASC can specifically target and be internalized into tumor cells with high expression of nucleolin, where the duplex capping can be unlocked by the intracellularly overexpressed adenosine triphosphate. Subsequently, the released DOX synergized with MSGNR-mediated PTT following laser irradiation induces direct cell killing, which, concurrently, triggers ICD to activate antineoplastic immunity with an increased number of T lymphocytes. This triple-collaborative strategy, further combined with anti-programmed death-1 antibody (αPD-1)-mediated immune checkpoint blockade (ICB) therapy, shows a robust therapeutic efficacy in both unilateral and bilateral tumor models.

The Spatial Organization of cDC1 with CD8+ T Cells is Critical for the Response to Immune Checkpoint Inhibitors in Patients with Melanoma

Dendritic cells (DC) are promising targets for cancer immunotherapies because of their central role in the initiation and control of immune responses. The type 1 conventional DC (cDC1) population is of particular interest because of its ability to cross-present antigens to CD8+ T cells. cDC1s also secrete cytokines that allow Th1 cell polarization and NK cell activation and recruitment. However, the spatial organization and specific functions of cDC1s in response to immunotherapy remain to be clearly characterized in human tumors. In this study, we used a multiplexed immunofluorescence analysis pipeline coupled with computational image analysis to determine the spatial organization of cDC1s in skin lesions from a cohort of patients with advanced melanoma treated with immune checkpoint inhibitors (ICI). For this, we performed a whole-slide image analysis of cDC1 infiltration, distribution, and spatial interaction with key immune partners such as CD8+ T cells and plasmacytoid DCs. We also analyzed LAMP3+ DCs, which correspond to a mature subset of tumor-infiltrating DCs. Distance and cell network analyses demonstrated that cDC1s exhibited a scattered distribution compared with tumor-infiltrating plasmacytoid DCs and LAMP3+ DCs, which were preferentially organized in dense areas with high homotypic connections. The proximity and interactions between CD8+ T cells and cDC1s were positively associated with the response to ICIs. In conclusion, our study unravels the complex spatial organization of cDC1s and their interactions with CD8+ T cells in lesions of patients with melanoma, shedding light on the pivotal role of these cells in shaping the response to ICIs.

The Bidirectional Interplay between T Cell-Based Immunotherapies and the Tumor Microenvironment

T cell-based therapies, including tumor-infiltrating lymphocyte therapy, T-cell receptor-engineered T cells, and chimeric antigen receptor T cells, are powerful therapeutic approaches for cancer treatment. Whereas these therapies are primarily known for their direct cytotoxic effects on cancer cells, accumulating evidence indicates that they also influence the tumor microenvironment (TME) by altering the cytokine milieu and recruiting additional effector populations to help orchestrate the antitumor immune response. Conversely, the TME itself can modulate the behavior of these therapies within the host by either supporting or inhibiting their activity. In this review, we provide an overview of clinical and preclinical data on the bidirectional influences between T-cell therapies and the TME. Unraveling the interactions between T cell-based therapies and the TME is critical for a better understanding of their mechanisms of action, resistance, and toxicity, with the goal of optimizing efficacy and safety.

Lung Cancer-Intrinsic SOX2 Expression Mediates Resistance to Checkpoint Blockade Therapy by Inducing Treg-Dependent CD8+ T-cell Exclusion

Tumor cell-intrinsic signaling pathways can drastically affect the tumor immune microenvironment, promoting tumor progression and resistance to immunotherapy by excluding immune cell populations from the tumor. Several tumor cell-intrinsic pathways have been reported to modulate myeloid-cell and T-cell infiltration, creating "cold" tumors. However, clinical evidence suggests that excluding cytotoxic T cells from the tumor core also mediates immune evasion. In this study, we find that tumor cell-intrinsic SOX2 signaling in non-small cell lung cancer induces the exclusion of cytotoxic T cells from the tumor core and promotes resistance to checkpoint blockade therapy. Mechanistically, tumor cell-intrinsic SOX2 expression upregulates CCL2 in tumor cells, resulting in increased recruitment of regulatory T cells (Treg). CD8+ T-cell exclusion depended on Treg-mediated suppression of tumor vasculature. Depleting tumor-infiltrating Tregs via glucocorticoid-induced TNF receptor-related protein restored CD8+ T-cell infiltration and, when combined with checkpoint blockade therapy, reduced tumor growth. These results show that tumor cell-intrinsic SOX2 expression in lung cancer serves as a mechanism of immunotherapy resistance and provide evidence to support future studies investigating whether patients with non-small cell lung cancer with SOX2-dependent CD8+ T-cell exclusion would benefit from the depletion of glucocorticoid-induced TNFR-related protein-positive Tregs.

Intratumoral or Subcutaneous MK-2118, a Noncyclic Dinucleotide STING Agonist, with or without Pembrolizumab, for Advanced or Metastatic Solid Tumors or Lymphomas

PURPOSE

We evaluated the noncyclic dinucleotide stimulator of IFN genes agonist MK-2118 ± pembrolizumab in participants with advanced solid tumors or lymphomas.

PATIENTS AND METHODS

This first-in-human study (NCT03249792) enrolled participants with refractory, advanced solid tumors or lymphomas. Participants received intratumoral (IT) MK-2118 100 to 20,000 μg (arm 1), IT MK-2118 900 to 15,000 μg plus intravenous (IV) pembrolizumab 200 mg every 3 weeks (arm 2), or subcutaneous (SC) MK-2118 5,000 to 150,000 μg plus IV pembrolizumab 200 mg every 3 weeks (arm 4); arm 3 (visceral injection of MK-2118) was not pursued. IT dosing used an accelerated titration design and modified toxicity probability interval method; SC dosing (arm 4) was started subsequent to arms 1 and 2. The primary objectives were safety/tolerability. MK-2118 pharmacokinetics was a secondary endpoint; objective responses and biomarkers were exploratory endpoints.

RESULTS

A total of 140 participants were enrolled (arm 1, n = 27; arm 2, n = 57; arm 4, n = 56). Grade 3/4 treatment-related adverse events occurred in 22%, 23%, and 11% of participants, respectively, but no maximum tolerated dose was identified up to MK-2118 20,000, 15,000, and 150,000 μg across the three arms. Dose-dependent increases in MK-2118 systemic exposure were observed following IT and subcutaneous administration. Objective responses were seen in 0%, 6%, and 4% of participants, respectively. IT MK-2118 led to dose-dependent changes in stimulator of interferon genes-based blood RNA expression levels, IFNγ, IFNγ-induced protein 10, and IL6; SC MK-2118 did not generate dose-related immune responses.

CONCLUSIONS

IT MK-2118 ± pembrolizumab and SC MK-2118 plus pembrolizumab had manageable toxicity and limited antitumor activity. IT but not SC administration demonstrated systemic immune effects.

Rejuvenation of Tumor-Specific T Cells via Ultrahigh DAR Antibody-Polymeric Imidazoquinoline Complexes: Coordinated Targeting of PDL1 and Efficient TLR7/8 Activation in Intratumoral Dendritic Cells

Intratumoral dendritic cells (DCs) are pivotal in tumor treatment due to their immature and pro-tumoral state induced by the tumor microenvironment. Clinically, these immature DCs correlate with disease progression and recurrence, adversely affecting prognosis. Activation of DCs by the TLR7/8 agonist imidazoquinoline (IMDQ) has yielded promising results, but they are limited by systemic inflammation risks, and high programmed death ligand 1 (PDL1) expression on DCs impedes CD8+ T cell activity. Thus, the study introduces an antibody-polymeric IMDQ complex (αPDL1-PLG-IMDQ) with an ultrahigh drug-to-antibody ratio, where αPDL1 is conjugated to Fc-binding peptides on polymeric IMDQ. This complex targets high PDL1-expressing intratumoral DCs with high probability, inducing PDL1-mediated endocytosis to deliver IMDQ to TLR7/8 within endosomes, effectively activating DCs (CD11c+MHC II+: 2.33% versus 1.09%, CD11c+CD86+: 2.49% versus 1.00% on tumors compared to phosphate-buffered saline treatment) and priming T cells. It also blocks PDL1/PD1 interactions, enhancing tumor-specific T-cell activation and memory. Notably, αPDL1-PLG-IMDQ achieved a 97% tumor inhibition rate, prevented tumor regrowth in rechallenge experiments, and reduced lung metastases of tumors by 83%. These findings underscore its potential for intratumoral DC-targeted immunotherapy and novel systemic IMDQ and checkpoint inhibitor combinations.

Systemic rewiring of dendritic cells by melanoma-secreted midkine impairs immune surveillance and response to immune checkpoint blockade

Cutaneous melanomas express a high number of potential neoepitopes, yet a substantial fraction of melanomas shift into immunologically cold phenotypes. Using cellular systems, mouse models and large datasets, we identify the tumor-secreted growth factor midkine (MDK) as a multilayered inhibitor of antigen-presenting cells. Mechanistically, MDK acts systemically in primary tumors, lymph nodes and the bone marrow, promoting a STAT3-mediated impairment of differentiation, activation and function of dendritic cells (DCs), particularly, conventional type 1 DCs (cDC1s). Furthermore, MDK rewires DCs toward a tolerogenic state, impairing CD8+ T cell activation. Downregulating MDK improves DC-targeted vaccination, CD40 agonist treatment and immune checkpoint blockade in mouse models. Moreover, we present an MDK-associated signature in DCs that defines poor prognosis and immune checkpoint blockade resistance in individuals with cancer. An inverse correlation between MDK- and cDC1-associated signatures was observed in a variety of tumor types, broadening the therapeutic implications of MDK in immune-refractory malignancies.

Cross-priming in cancer immunology and immunotherapy

Cytotoxic T cell immune responses against cancer crucially depend on the ability of a subtype of professional antigen-presenting cells termed conventional type 1 dendritic cells (cDC1s) to cross-present antigens. Cross-presentation comprises redirection of exogenous antigens taken from other cells to the major histocompatibility complex class I antigen-presenting machinery. In addition, once activated and having sensed viral moieties or T helper cell cooperation via CD40-CD40L interactions, cDC1s provide key co-stimulatory ligands and cytokines to mount and sustain CD8+ T cell immune responses. This regulated process of cognate T cell activation is termed cross-priming. In cancer mouse models, CD8+ T cell cross-priming by cDC1s is crucial for the efficacy of most, if not all, immunotherapy strategies. In patients with cancer, the presence and abundance of cDC1s in the tumour microenvironment is markedly associated with the level of T cell infiltration and responsiveness to immune checkpoint inhibitors. Therapeutic strategies to increase the numbers of cDC1s using FMS-like tyrosine kinase 3 ligand (FLT3L) and/or their activation status show evidence of efficacy in cancer mouse models and are currently being tested in initial clinical trials with promising results so far.

The development and potent antitumor efficacy of CD44/CD133 dual-targeting IL7Rα-armored CAR-T cells against glioblastoma

Tumor heterogeneity and an immunosuppressive microenvironment pose significant challenges for immunotherapy against solid tumors, particularly glioblastoma multiforme (GBM). Recent studies have highlighted the crucial role of glioma stem cells (GSCs) in tumor recurrence and therapeutic resistance. In this context, we developed a tandem chimeric antigen receptor (CAR)-T cell targeting CD44 and CD133 (PROM1), containing a truncated IL-7 receptor alpha intracellular domain (Δ7R) between the CD28 costimulatory receptor and the CD3ζ signaling chain (Tanζ-T28-Δ7R). Our target identification and validation were carried out using GSCs, samples from GBM patients, and the corresponding sequencing data. The antitumor efficacy of CAR-T cells was evaluated in patient-derived GSCs, intracranial xenograft models, patient-derived xenograft models, and glioblastoma organoids (GBOs). Single-cell RNA sequencing and mass cytometry were used to determine the immune phenotypes of CAR-T cells. We showed that locoregionally administered Tanζ-T28-Δ7R CAR-T cells induced long-term tumor regression with the desired safety outcomes. Patient-derived autologous Tanζ-T28-Δ7R CAR-T cells showed robust antitumor activity against GBOs. Our pre-clinical data has demonstrated the translational potential of Tanζ-T28-Δ7R CAR-T cell against GBM.

Molecular Mechanisms Governing CD8 T Cell Differentiation and Checkpoint Inhibitor Response in Cancer

CD8 T cells play a critical role in antitumor immunity. However, over time, they often become dysfunctional or exhausted and ultimately fail to control tumor growth. To effectively harness CD8 T cells for cancer immunotherapy, a detailed understanding of the mechanisms that govern their differentiation and function is crucial. This review summarizes our current knowledge of the molecular pathways that regulate CD8 T cell heterogeneity and function in chronic infection and cancer and outlines how T cells respond to therapeutic checkpoint blockade. We explore how T cell-intrinsic and -extrinsic factors influence CD8 T cell differentiation, fate choices, and functional states and ultimately dictate their response to therapy. Identifying cells that orchestrate long-term antitumor immunity and understanding the mechanisms that govern their development and persistence are critical steps toward improving cancer immunotherapy.

Pulmonary delivery of dual-targeted nanoparticles improves tumor accumulation and cancer cell targeting by restricting macrophage interception in orthotopic lung tumors

Despite the recognized potential of inhaled nanomedicines to enhance and sustain local drug concentrations for lung cancer treatment, the influence of macrophage uptake on targeted nanoparticle delivery to and within tumors remains unclear. Here, we developed three ligand-coated nanoparticles for pulmonary delivery in lung cancer therapy: phenylboronic acid-modified nanoparticles (PBA-NPs), PBA combined with folic acid (FA-PBA-NPs), and PBA with mannose (MAN-PBA-NPs). In vitro, MAN-PBA-NPs were preferentially internalized by macrophages, whereas FA-PBA-NPs exhibited superior uptake by cancer cells compared to macrophages. Following intratracheal instillation into mice with orthotopic Lewis lung carcinoma tumors, all three nanoparticles showed similar lung retention. However, MAN-PBA-NPs were more prone to interception by lung macrophages, which limited their accumulation in tumor tissues. In contrast, both PBA-NPs and FA-PBA-NPs achieved comparable high tumor accumulation (∼11.3% of the dose). Furthermore, FA-PBA-NPs were internalized by ∼30% of cancer cells, significantly more than the 10-18% seen with PBA-NPs or MAN-PBA-NPs. Additionally, FA-PBA-NPs loaded with icaritin effectively inhibited the Wnt/β-catenin pathway, resulting in superior anti-tumor efficacy through targeted cancer cell delivery. Overall, FA-PBA-NPs demonstrated advantageous competitive uptake kinetics by cancer cells compared to macrophages, enhancing tumor targeting and therapeutic outcomes.

Dendritic cell maturation in cancer

Dendritic cells (DCs) are specialized antigen-presenting cells that are present at low abundance in the circulation and tissues; they serve as crucial immune sentinels by continually sampling their environment, migrating to secondary lymphoid organs and shaping adaptive immune responses through antigen presentation. Owing to their ability to orchestrate tolerogenic or immunogenic responses to a specific antigen, DCs have a pivotal role in antitumour immunity and the response to immune checkpoint blockade and other immunotherapeutic approaches. The multifaceted functions of DCs are acquired through a complex, multistage process called maturation. Although the role of inflammatory triggers in driving DC maturation was established decades ago, less is known about DC maturation in non-inflammatory contexts, such as during homeostasis and in cancer. The advent of single-cell technologies has enabled an unbiased, high-dimensional characterization of various DC states, including mature DCs. This approach has clarified the molecular programmes associated with DC maturation and also revealed how cancers exploit these pathways to subvert immune surveillance. In this Review, we discuss the mechanisms by which cancer disrupts DC maturation and highlight emerging therapeutic opportunities to modulate DC states. These insights could inform the development of DC-centric immunotherapies, expanding the arsenal of strategies to enhance antitumour immunity.

IRF8 and CD2 are potential targets of immunotherapy in non-small cell lung cancer

Background

Immune checkpoint inhibitors (ICIs) are clinically effective in the treatment of non-small cell lung cancer (NSCLC), but the response rate in nonselective NSCLC patients is approximately 20%. It is important to expand the pool of benefits of immunotherapy. However, current solution strategies are limited. Our research is to identify new targets for combined immunotherapy and expand the beneficiary population of immunotherapy.

Methods

Functional enrichment analysis was performed for differentially expressed genes (DEGs) in 175 NSCLC immunotherapy cohorts and 494 non-immunotherapy cohorts, and single-sample gene set enrichment analysis (ssGSEA) was used to quantify the level of infiltration of different immune cell subpopulations. Weighted correlation network analysis (WGCNA), univariate Cox regressions, least absolute shrinkage and selection operator (LASSO) regressions, and gene correlation analysis were applied to identify immune signature genes associated with immune cell infiltration, and a nomogram was constructed to predict the survival rate.

Results

The DEGs were not enriched in the classical antitumour immune response and the dendritic cells (DCs) infiltration level in the tumour microenvironment (TME) was at a low level in the immunotherapy cohort. The high expression of IRF8 and CD2 was positively correlated with the level of DCs infiltration, the core of tumour immune response regulation, and can bring better survival prognosis for patients. Besides, targeted activation of IRF8 and CD2 can improve the efficacy of ICIs.

Conclusions

High expression of IRF8 and CD2 enhances the antitumour immune response, and IRF8 and CD2 may be new prognostic indicators and targets of combined ICIs for lung adenocarcinoma in NSCLC.

Manganese-Driven Plasmid Nanofibers Formed In Situ for Cancer Gene Delivery and Metalloimmunotherapy

While nucleic-acid-based cancer vaccines hold therapeutic potential, their limited immunogenicity remains a challenge due in part to the low efficiency of cytoplasmic delivery caused by lysosomal entrapment. In this work, we found that plasmids encoding both an antigen and a STING agonist protein adjuvant can self-assemble into coordination nanofibers, triggered by manganese ions. We developed a strategy to construct a DNA vaccine, termed MnO2-OVA-CDA-mem, formed by the coencapsulation of manganese dioxide (MnO2), an antigen-expressing plasmid (encoding ovalbumin, OVA), and an adjuvant enzyme-expressing plasmid (encoding STING agonist, CDA) within dendritic cell (DC) membranes. Upon uptake into acidic lysosomes, Mn2+ released from MnO2 triggered the nucleic acids to undergo a morphological change from nanospheres (∼180 nm diameter) to nanofibers (∼1 μm length), resulting in an increase in mechanical strength by about 9-fold and consequently lysosomal membrane disruption. The antigen OVA and adjuvants Mn2+ and CDA in the cytoplasm triggered strong DC activation and antigen-specific CD8+ T cell metalloimmune responses, significantly inhibiting the growth of B16-OVA tumors and inducing long-term immune memory. Altogether, MnO2-OVA-CDA-mem holds potential as a platform for nucleic acid antigen and adjuvant delivery using an in situ self-assembly strategy in a metal-driven, stimulus-responsive, and programmable manner for cancer metalloimmunotherapy.

Tissue-specific properties of type 1 dendritic cells in lung cancer: implications for immunotherapy

Checkpoint inhibitors have led to remarkable benefits in non-small cell lung cancer (NSCLC), yet response rates remain below expectations. High-dimensional analysis and mechanistic experiments in clinical samples and relevant NSCLC models uncovered the immune composition of lung cancer tissues, providing invaluable insights into the functional properties of tumor-infiltrating T cells and myeloid cells. Among myeloid cells, type 1 conventional dendritic cells (cDC1s) stand out for their unique ability to induce effector CD8 T cells against neoantigens and coordinate antitumoral immunity. Notably, lung resident cDC1 are particularly abundant and long-lived and express a unique tissue-specific gene program, underscoring their central role in lung immunity. Here, we discuss recent insights on the induction and regulation of antitumoral T cell responses in lung cancer, separating it from the tissue-agnostic knowledge generated from heterogeneous tumor models. We focus on the most recent studies dissecting functional states and spatial distribution of lung cDC1 across tumor stages and their impact on T cell responses to neoantigens. Finally, we highlight relevant gaps and emerging strategies to harness lung cDC1 immunostimulatory potential.

C. S, Devkota HP, Khadka D. Immune Modulation and Immunotherapy in Solid Tumors: Mechanisms of Resistance and Potential Therapeutic Strategies

Understanding the modulation of specific immune cells within the tumor microenvironment (TME) offers new hope in cancer treatments, especially in cancer immunotherapies. In recent years, immune modulation and resistance to immunotherapy have become critical challenges in cancer treatments. However, novel strategies for immune modulation have emerged as promising approaches for oncology due to the vital roles of the immunomodulators in regulating tumor progression and metastasis and modulating immunological responses to standard of care in cancer treatments. With the progress in immuno-oncology, a growing number of novel immunomodulators and mechanisms are being uncovered, offering the potential for enhanced clinical immunotherapy in the near future. Thus, gaining a comprehensive understanding of the broader context is essential. Herein, we particularly summarize the paradoxical role of tumor-related immune cells, focusing on how targeted immune cells and their actions are modulated by immunotherapies to overcome immunotherapeutic resistance in tumor cells. We also highlight the molecular mechanisms employed by tumors to evade the long-term effects of immunotherapeutic agents, rendering them ineffective.

LSD1 inhibition corrects dysregulated MHC-I and dendritic cells activation through IFNγ-CXCL9-CXCR3 axis to promote antitumor immunity in HNSCC

Poor infiltration of CD8+ T cells and dysregulated MHC-I confer resistance to anticancer clinical therapies. This study aimed to elucidate the mechanisms of lysine-specific demethylase 1 (LSD1, encoded by KDM1A gene) in antitumor immunity in Head and Neck Squamous cell carcinoma (HNSCC). LSD1 inhibition in syngeneic and chronic tobacco carcinogen-induced HNSCC mice recruited activated dendritic cells (DCs), CD4+ and CD8+ T cells, enriched interferon-gamma (IFNγ) in T cells, CXCL9 in DCs, and CXCR3 in T cells, as evaluated using flow cytometry and single-cell RNA-seq analysis. Humanized HNSCC mice and TCGA data validated the inverse correlation of KDM1A with DC markers, CD8+ T cells, and their activating chemokines. Kdm1a knockout in mouse HNSCC and LSD1 inhibitor treatment to co-culture of human HNSCC cells with human peripheral blood mononuclear cells (PBMCs) resulted in MHC-I upregulation in cancer cells for efficient antigen presentation in tumors. Overall, LSD1 inhibition in tumor cells upregulates MHC class I and induces DCs to produce CXCL9, which in turn activates CD8+ T cells through the CXCL9-CXCR3 axis to produce IFNγ. Finally, we identified a novel mechanism by which LSD1 inhibition promotes the activation of H3K4me2 and its direct interaction with MHC-I to induce antitumor immunity. This may have implications in poorly immunogenic and immunotherapy-resistant cancers.

Statement of Significance

LSD1-mediated unique mechanisms have impact on epigenetic therapy, MHC-I resistant HNSCC therapies, and poor CD8+ and dendritic cell infilterated tumors.

The fibroinflammatory response in cancer

Fibroinflammation refers to the highly integrated fibrogenic and inflammatory responses mediated by the concerted function of fibroblasts and innate immune cells in response to tissue perturbation. This process underlies the desmoplastic remodelling of the tumour microenvironment and thus plays an important role in tumour initiation, growth and metastasis. More specifically, fibroinflammation alters the biochemical and biomechanical signalling in malignant cells to promote their proliferation and survival and further supports an immunosuppressive microenvironment by polarizing the immune status of tumours. Additionally, the presence of fibroinflammation is often associated with therapeutic resistance. As such, there is increasing interest in targeting this process to normalize the tumour microenvironment and thus enhance the treatment of solid tumours. Herein, we review advances made in unravelling the complexity of cancer-associated fibroinflammation that can inform the rational design of therapies targeting this.

Cross-Talk Between Cancer and Its Cellular Environment-A Role in Cancer Progression

The tumor microenvironment is a dynamic and complex three-dimensional network comprising the extracellular matrix and diverse non-cancerous cells, including fibroblasts, adipocytes, endothelial cells and various immune cells (lymphocytes T and B, NK cells, dendritic cells, monocytes/macrophages, myeloid-derived suppressor cells, and innate lymphoid cells). A constantly and rapidly growing number of studies highlight the critical role of these cells in shaping cancer survival, metastatic potential and therapy resistance. This review provides a synthesis of current knowledge on the modulating role of the cellular microenvironment in cancer progression and response to treatment.

Current state of cancer immunity cycle: new strategies and challenges of using precision hydrogels to treat breast cancer

The cancer-immunity cycle provides a framework for a series of events in anti-cancer immune responses, initiated by T cell-mediated tumor cell killing, which leads to antigen presentation and T cell stimulation. Current immunomodulatory therapies for breast cancer are often associated with short duration, poor targeting to sites of action, and severe side effects. Hydrogels, with their extracellular matrix-mimicking properties, tunable characteristics, and diverse bioactivities, have garnered significant attention for their ability to locally deliver immunomodulators and cells, providing an immunomodulatory microenvironment to recruit, activate, and expand host immune cells. This review focuses on the design considerations of hydrogel platforms, including polymer backbone, crosslinking mechanisms, physicochemical properties, and immunomodulatory components. The immunomodulatory effects and therapeutic outcomes of various hydrogel systems in breast cancer treatment and tissue regeneration are highlighted, encompassing hydrogel depots for immunomodulator delivery, hydrogel scaffolds for cell delivery, and immunomodulatory hydrogels dependent on inherent material properties. Finally, the challenges that persist in current systems and future directions for immunomodulatory hydrogels are discussed.

Therapeutic potential of isochlorogenic acid A from Taraxacum officinale in improving immune response and enhancing the efficacy of PD-1/PD-L1 blockade in triple-negative breast cancer

Introduction

Taraxacum officinale, a traditional medicinal herb, has garnered significant attention for its potential role in the prevention and treatment of breast cancer. Although clinical recognition of its efficacy has gradually increased, research has shown that Taraxacum officinale contains a variety of chemical components, including triterpenes, carbohydrates, flavonoids, phenolic acids, sesquiterpenes, coumarins, fatty acids, and organic acids. However, the pharmacological mechanisms underlying Taraxacum officinale's effects and the identification of its key bioactive components warrant further investigation.

Methods

Flow cytometry was utilized to investigate the effects of Taraxacum officinale extract (TOE) in combination with PD-1/PD-L1 inhibitor 2 on the immune microenvironment of triple-negative breast cancer (TNBC). Active compounds and their potential targets were identified through an integrative approach involving GeneCards, OMIM, and DisGeNET databases, as well as UPLC-Q-Orbitrap MS analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted, followed by molecular docking to explore compound-target interactions. The anti-proliferative effects of isochlorogenic acid A (ICGA-A) and chicoric acid (CRA) on MDA-MB-231 and 4T1 cells were evaluated using the CCK-8 assay. In vivo validation was performed using a 4T1 murine model and flow cytometry.

Results

TOE and its active constituents, ICGA-A and CRA, demonstrate potential in augmenting PD-1 blockade therapy for TNBC. This study investigated the combination of ICGA-A and PD-1/PD-L1 inhibitor 2, which significantly enhanced the infiltration of macrophages and CD8+ T cells into tumors in murine models, while concurrently reducing the population of exhausted T cells. Furthermore, CRA notably increased the frequency of CD8+ T cells. Both ICGA-A and CRA therapies were also found to suppress tumor proliferation by inhibiting the FAK/PI3K/AKT/mTOR signaling pathway. These findings highlight the potential of ICGA-A and CRA as effective adjuvants to improve the therapeutic efficacy of PD-1 inhibitor-based immunotherapy in TNBC.

Discussion

ICGA-A and CRA, bioactive compounds from Taraxacum officinale, exhibit significant antitumor activity in TNBC by targeting the FAK/PI3K/AKT/mTOR pathway, a critical regulator of cancer progression. Their ability to modulate the tumor immune microenvironment highlights their potential as immune modulators that enhance the efficacy of immunotherapy. These findings suggest that ICGA-A and CRA could serve as promising adjuncts in TNBC treatment, offering a novel strategy to overcome challenges such as therapeutic resistance and limited treatment options. Further investigation is warranted to explore their synergistic effects with immunotherapies in improving TNBC outcomes.

The XCL1-XCR1 axis supports intestinal tissue residency and antitumor immunity

Tissue-resident memory T cells (TRM) provide frontline protection against pathogens and emerging malignancies. Tumor-infiltrating lymphocytes (TIL) with TRM features are associated with improved clinical outcomes. However, the cellular interactions that program TRM differentiation and function are not well understood. Using murine genetic models and targeted spatial transcriptomics, we found that the CD8+ T cell-derived chemokine XCL1 is critical for TRM formation and conventional DC1 (cDC1) supported the positioning of intestinal CD8+ T cells during acute viral infection. In tumors, enforced Xcl1 expression by antigen-specific CD8+ T cells promoted intratumoral cDC1 accumulation and T cell persistence, leading to improved overall survival. Notably, analysis of human TIL and TRM revealed conserved expression of XCL1 and XCL2. Thus, we have shown that the XCL1-XCR1 axis plays a non-cell autonomous role in guiding intestinal CD8+ TRM spatial differentiation and tumor control.

Cancer stem cells: Masters of all traits

Cancer is a heterogeneous disease, which contributes to its rapid progression and therapeutic failure. Besides interpatient tumor heterogeneity, tumors within a single patient can present with a heterogeneous mix of genetically and phenotypically distinct subclones. These unique subclones can significantly impact the traits of cancer. With the plasticity that intratumoral heterogeneity provides, cancers can easily adapt to changes in their microenvironment and therapeutic exposure. Indeed, tumor cells dynamically shift between a more differentiated, rapidly proliferating state with limited tumorigenic potential and a cancer stem cell (CSC)-like state that resembles undifferentiated cellular precursors and is associated with high tumorigenicity. In this context, CSCs are functionally located at the apex of the tumor hierarchy, contributing to the initiation, maintenance, and progression of tumors, as they also represent the subpopulation of tumor cells most resistant to conventional anti-cancer therapies. Although the CSC model is well established, it is constantly evolving and being reshaped by advancing knowledge on the roles of CSCs in different cancer types. Here, we review the current evidence of how CSCs play a pivotal role in providing the many traits of aggressive tumors while simultaneously evading immunosurveillance and anti-cancer therapy in several cancer types. We discuss the key traits and characteristics of CSCs to provide updated insights into CSC biology and highlight its implications for therapeutic development and improved treatment of aggressive cancers.

Radiomic analysis of patient and interorgan heterogeneity in response to immunotherapies and BRAF-targeted therapy in metastatic melanoma

Variability in treatment response may be attributable to organ-level heterogeneity in tumor lesions. Radiomic analysis of medical images can elucidate non-invasive biomarkers of clinical outcome. Organ-specific radiomic comparison across immunotherapies and targeted therapies has not been previously reported. We queried the UPMC Hillman Cancer Center registry for patients with metastatic melanoma (MEL) treated with immune checkpoint inhibitors (ICI) (anti-programmed cell death protein-1 (PD-1)/cytotoxic T-lymphocyte associated protein 4 (CTLA-4) (ipilimumab+nivolumab; I+N) or anti-PD-1 monotherapy) or BRAF-targeted therapy. The best overall response was measured using Response Evaluation Criteria in Solid Tumors V.1.1. Lesions were segmented into discrete volume-of-interest with 400 radiomics features extracted. Overall and organ-specific machine-learning models were constructed to predict disease control (DC) versus progressive disease (PD) using XGBoost. 291 patients with MEL were identified, including 242 ICI (91 I+N, 151 PD-1) and 49 BRAF. 667 metastases were analyzed, including 541 ICI (236 I+N, 305 PD-1) and 126 BRAF. Across cohorts, baseline demographics included 39-47% women, 24%-29% M1C, 24-46% M1D, and 61-80% with elevated lactate dehydrogenase. Among ICI patients experiencing DC, the organs with the greatest reduction were liver (-66%±8%; mean±SEM) and lung (-63%±5%). For patients with multiple same-organ target lesions, the highest interlesion heterogeneity was observed in brain among patients who received ICI while no intraorgan heterogeneity was observed in BRAF. 221 ICI patients were included for radiomic modeling, consisting of 86 I+N and 135 PD-1. Models consisting of optimized radiomic signatures classified DC/PD across I+N (area under curve (AUC)=0.85) and PD-1 (0.71) and within individual organ sites (AUC=0.72~0.94). Integration of clinical variables improved the models' performance. Comparison of models between treatments and across organ sites suggested mostly non-overlapping DC or PD features. Skewness, kurtosis, and informational measure of correlation (IMC) were among the radiomic features shared between overall response models. Kurtosis and IMC were also used by multiple organ-site models. In conclusion, differential organ-specific response was observed across BRAF and ICI with within organ heterogeneity observed for ICI but not for BRAF. Radiomic features of organ-specific response demonstrated little overlap. Integrating clinical factors with radiomics improves the prediction of disease course outcome and prediction of tumor heterogeneity.

Contrasting cytotoxic and regulatory T cell responses underlying distinct clinical outcomes to anti-PD-1 plus lenvatinib therapy in cancer

Combination of anti-PD-1 with lenvatinib showed clinical efficacy in multiple cancers, yet the underlying immunological mechanisms are unclear. Here, we compared T cells in hepatocellular carcinoma (HCC) patients before and after combination treatment using single-cell transcriptomics and T cell receptor (scTCR) clonotype analyses. We found that tumor-infiltrating GZMK+ CD8+ effector/effector memory T (Teff/Tem) cells, showing a favorable response to combination therapy, comprise progenitor exhausted T (Tpex) cells and also unappreciated circulating Tem (cTem) cells enriched with hepatitis B virus (HBV) specificity. Further integrated analyses revealed that cTem cells are specifically associated with responsiveness to the combination therapy, whereas Tpex cells contribute to responses in both combination therapy and anti-PD-1 monotherapy. Notably, an underexplored KIR+ CD8+ T cell subset in the tumor and FOXP3+ CD4+ regulatory T cells are specifically enriched in non-responders after the combination therapy. Our study thus elucidated T cell subsets associated with clinical benefits and resistance in cancer immunotherapy.

Chemokines that govern T cell activity in tumors

Local regulation of T cell-mediated immunity to solid tumors occurs at multiple levels, including their recruitment from the bloodstream to the tumor microenvironment (TME), coordinated crosstalk with different subsets of antigen-presenting cells (APCs) controlling their local survival, proliferation, and effector differentiation, as well as their egress from tumors via lymphatics. At each level, chemokines play essential roles, for instance, by guiding directional T cell migration across blood and lymphatic endothelial barriers or by promoting their spatial proximity and direct physical interactions with APCs to enable functional crosstalk. In this article, we will review recent mechanistic insights into the chemokine axes that guide T cell functions in TMEs in light of the emerging functional state heterogeneity of CD8+ effector T cells and our growing understanding of how regulatory T cells restrain antitumor activity.

Meteorin-like protein/METRNL/Interleukin-41 ameliorates atopic dermatitis-like inflammation

BACKGROUND

Meteorin-like protein (METRNL)/Interleukin-41 (IL-41) is a novel immune-secreted cytokine/myokine involved in several inflammatory diseases. However, how METRNL exerts its regulatory properties on skin inflammation remains elusive. This study aims to elucidate the functionality and regulatory mechanism of METRNL in atopic dermatitis (AD).

METHODS

METRNL levels were determined in skin and serum samples from patients with AD and subsequently verified in the vitamin D3 analogue MC903-induced AD-like mice model. The cellular target of METRNL activity was identified by multiplex immunostaining, single-cell RNA-seq and RNA-seq.

RESULTS

METRNL was significantly upregulated in lesions and serum of patients with dermatitis compared to healthy controls (p <.05). Following repeated MC903 exposure, AD model mice displayed elevated levels of METRNL in both ears and serum. Administration of recombinant murine METRNL protein (rmMETRNL) ameliorated allergic skin inflammation and hallmarks of AD in mice, whereas blocking of METRNL signaling led to the opposite. METRNL enhanced β-Catenin activation, limited the expression of Th2-related molecules that attract the accumulation of Arginase-1 (Arg1)hi macrophages, dendritic cells, and activated mast cells.

CONCLUSIONS

METRNL can bind to KIT receptor and subsequently alleviate the allergic inflammation of AD by inhibiting the expansion of immune cells, and downregulating inflammatory gene expression by regulating the level of active WNT pathway molecule β-Catenin.

Cyclic nucleotide phosphodiesterases as drug targets

Cyclic nucleotides are synthesized by adenylyl and/or guanylyl cyclase, and downstream of this synthesis, the cyclic nucleotide phosphodiesterase families (PDEs) specifically hydrolyze cyclic nucleotides. PDEs control cyclic adenosine-3',5'monophosphate (cAMP) and cyclic guanosine-3',5'-monophosphate (cGMP) intracellular levels by mediating their quick return to the basal steady state levels. This often takes place in subcellular nanodomains. Thus, PDEs govern short-term protein phosphorylation, long-term protein expression, and even epigenetic mechanisms by modulating cyclic nucleotide levels. Consequently, their involvement in both health and disease is extensively investigated. PDE inhibition has emerged as a promising clinical intervention method, with ongoing developments aiming to enhance its efficacy and applicability. In this comprehensive review, we extensively look into the intricate landscape of PDEs biochemistry, exploring their diverse roles in various tissues. Furthermore, we outline the underlying mechanisms of PDEs in different pathophysiological conditions. Additionally, we review the application of PDE inhibition in related diseases, shedding light on current advancements and future prospects for clinical intervention. SIGNIFICANCE STATEMENT: Regulating PDEs is a critical checkpoint for numerous (patho)physiological conditions. However, despite the development of several PDE inhibitors aimed at controlling overactivated PDEs, their applicability in clinical settings poses challenges. In this context, our focus is on pharmacodynamics and the structure activity of PDEs, aiming to illustrate how selectivity and efficacy can be optimized. Additionally, this review points to current preclinical and clinical evidence that depicts various optimization efforts and indications.

Architects of immunity: How dendritic cells shape CD8+ T cell fate in cancer

Immune responses against cancer are dominated by T cell exhaustion and dysfunction. Recent advances have underscored the critical role of early priming interactions in establishing T cell fates. In this review, we explore the importance of dendritic cell (DC) signals in specifying CD8+ T cell fates in cancer, drawing on insights from acute and chronic viral infection models. We highlight the role of DCs in lymph nodes and tumors in maintaining stem-like CD8+ T cells, which are critical for durable antitumor immune responses. Understanding how CD8+ T cell fates are determined will enable the rational design of immunotherapies, particularly therapeutic cancer vaccines, that can modulate DC-T cell interactions to generate beneficial CD8+ T cell fates.

Progress and prospects of the combination of BMI1-targeted therapy and immunotherapy in cervical cancer

Cervical cancer is one of the most prevalent gynecologic malignancies, posing a significant threat to women's health and survival. Despite advancements in early screening and diagnosis, which have led to cervical cancer being termed a "preventable" cancer, treatment options for advanced and recurrent cervical cancer remain limited. Consequently, identifying new therapeutic targets and treatments is crucial for advancing the research and management of cervical cancer. In recent years, targeted therapy and immunotherapy have become focal points in oncology research, offering new avenues and directions for the treatment of cancer. Preclinical studies have demonstrated that targeting BMI1 can inhibit cervical cancer progression, while immunotherapy has advanced to phase III clinical trials, showing promising results. To date, there have been no reports on the combination of BMI1-targeted therapy and immunotherapy in cervical cancer. This review, therefore, elucidates the current state of research and explores the potential and perspectives of combining targeted therapy with immunotherapy for cervical cancer.

Cytokines in cancer

Cytokines are proteins used by immune cells to communicate with each other and with cells in their environment. The pleiotropic effects of cytokine networks are determined by which cells express cytokines and which cells express cytokine receptors, with downstream outcomes that can differ based on cell type and environmental cues. Certain cytokines, such as interferon (IFN)-γ, have been clearly linked to anti-tumor immunity, while others, such as the innate inflammatory cytokines, promote oncogenesis. Here we provide an overview of the functional roles of cytokines in the tumor microenvironment. Although we have a sophisticated understanding of cytokine networks, therapeutically targeting cytokine pathways in cancer has been challenging. We discuss current progress in cytokine blockade, cytokine-based therapies, and engineered cytokine therapeutics as emerging cancer treatments of interest.

XCL1-secreting CEA CAR-T cells enhance endogenous CD8+ T cell responses to tumor neoantigens to confer a long-term antitumor immunity

BACKGROUND

Therapeutic efficacy of carcinoembryonic antigen (CEA)-specific chimeric antigen receptor (CAR) T cells against colorectal cancer (CRC) remains limited due to the unique characteristics and distinct microenvironments of tumor tissues. We modified CEA-specific CAR-T cells, aiming to stimulate endogenous CD8+ T cell responses against neoantigens that were derived from CEA-positive tumors destroyed by the CAR T cells.

METHODS

In a conventional CEA CAR (reg-CAR), we modified it to express lymphotactin XCL1 and interleukin (IL)-7 genes, constructing a modified 7XCL1-CAR. By generating the CEA-specific 7XCL1-CAR T cells, we assessed their antitumor efficacy against CRC cells with varying levels of CEA expression, both in cell-cultures and in two strains of tumor-bearing syngeneic mice.

RESULTS

Following retroviral transduction, 7XCL1-CAR T cells and reg-CAR T cells exhibited similar positive proportions of CEA-CAR and CD4:CD8 ratios. In co-culture system with CEA-negative CT26 cells, no differences in cytotoxicity were observed between 7XCL1-CAR and reg-CAR T cells. However, in co-culture with CT26.CEAhigh and CT26.CEAint cells, 7XCL1-CAR T cells displayed higher cytotoxicity than that reg-CAR T cells after 60 hours. On interaction with CT26.CEA-positive cells, 7XCL1-CAR T cells secreted higher levels of XCL1 and IL-7, effectively recruited the most potent cross-presenting cDC1s (type-I conventional dendritic cells), and sustained the antitumor activity of CAR-T cells. In treating mice that carried tumors derived from universally CEA-positive cells, 7XCL1-CAR T cells exhibited no difference compared with reg-CAR T cells. However, in treating mice with tumors containing both CEA-positive and CEA-negative cells, 7XCL1-CAR T cells displayed greater inhibition than that of reg-CAR-T cells. After treatment of 7XCL1-CAR T cells, tumor-bearing mice exhibited enhanced infiltration of cDC1s, maintained CAR-T activity, and generation of endogenous neoantigen-specific T cells. Consequently, 7XCL1-CAR T cell-treated mice demonstrated resistance to challenge with CEA-negative CT26 cells.

CONCLUSION

Treatment with CEA-specific, XCL1-secreting CAR-T cells for CEA-positive tumors promoted the generation of CD8+ T cells against tumor neoantigens, mediating a long-term antitumor immunity against heterogeneous CRCs.

Looking Beyond Checkpoint Inhibitor Monotherapy: Uncovering New Frontiers for Pancreatic Cancer Immunotherapy

Pancreatic ductal adenocarcinoma (PDAC) stands out as one of the most aggressive and challenging tumors, characterized by a bleak prognosis with a mere 11% survival rate over 5 years in the United States. Its formidable nature is primarily attributed to its highly aggressive behavior and poor response to existing therapies. PDAC, being notably resistant to immune interventions, presents a significant obstacle in treatment strategies. While immune checkpoint inhibitor therapies have revolutionized outcomes for various cancers, their efficacy in PDAC remains exceedingly low, benefiting less than 1% of patients. The consistent failure of these therapies in PDAC has prompted intensive investigation, particularly at the preclinical level, to unravel the intricate mechanisms of resistance inherent in this cancer type. This pursuit aims to pave the way for the development of novel immunotherapeutic strategies tailored to the distinct characteristics of PDAC. This review endeavors to provide a comprehensive exploration of these emerging immunotherapy approaches in PDAC, with a specific emphasis on elucidating their underlying immunological mechanisms. Additionally, it sheds light on the recently identified factors driving resistance to immunotherapy and evasion of the immune system in PDAC, offering insights beyond the conventional drivers that have been extensively studied.