Cancer Immunology, Immunotherapy

CD47 is a "dont eat me" signal that suppresses macrophage-mediated phagocytosis. Its upregulation in lung and other cancers facilitates tumour immune escape, making CD47 a promising immunotherapeutic target. Studies have demonstrated anti-tumour efficacy of CD47 blockade in preclinical lung cancer models, but monoclonal antibodies targeting CD47 have had limited efficacy as monotherapy in solid tumour patients to date. This discrepancy may in part reflect the use of human tumour xenografts in mice that do not have fully-functioning immune systems in preclinical efficacy studies. Thus, understanding tumour responses to CD47 inhibition using immune competent lung cancer models is needed to inform strategies to harness its therapeutic potential. Here, we characterized the effects of CD47 knockout (KO) on tumour growth and immune responses in two syngeneic, orthotopic murine lung cancer models, LLC-Luc (LLC) and CMT167 (CMT). As expected, CD47 KO impaired the fitness of LLC and CMT cells in vivo. Mice with CD47-deficient tumours exhibited prolonged survival and increased infiltration of anti-tumour leukocytes. However, although CD47 KO impaired lung tumour growth in syngeneic mice, KO tumours were ultimately lethal. Immunophenotyping revealed an increased prevalence of PD-L1+ cells in CD47-deficient tumours, nominating PD-L1-mediated suppression of tumour immunity as an acquired mechanism of resistance to CD47 blockade. Concordantly, dual inhibition of CD47 and PD-L1 extended the survival of CMT tumour-bearing mice compared to inhibition of either alone. These findings suggest that PD-L1 blockade could be leveraged to overcome resistance and potentiate the efficacy of CD47-targeted immunotherapy in lung cancer.

Abstract/SummaryImmune checkpoint blockade can produce long-lasting responses in patients with metastatic melanoma; notably, combined CTLA-4/PD-1 blockade has been associated with approximately 52% melanoma specific 10-year survival (1). Yet, nearly half of patients experience minimal clinical benefit, and intensified regimens come with substantial risk of severe immune-related toxicity. The precise determinants of immunotherapy response are incompletely defined, reflecting a complex interplay between tumor biology and host immunity. This is especially consequential for patients whose disease progresses on checkpoint blockade, for whom effective salvage options are limited. In a series of patients with NRAS-mutated melanoma refractory to checkpoint inhibitors, we found that intratumoral administration of talimogene laherparepvec (T-VEC) combined with MEK inhibitor binimetinib induced exceptional clinical responses by amplification of pre-existing T cell responses and induction of de novo tumor-reactive immunity.

BackgroundTumour-associated macrophages (TAMs) play critical roles within the tumour microenvironment regulating immune evasion and therapeutic response. Previously, we have shown that the combination of Checkpoint kinase 1 inhibitor (CHK1i) with a subclinical dose of hydroxyurea (LDHU) reprograms the tumour immune microenvironment to a pro-inflammatory status. MethodsWe investigated a tumour-restricted Fcgr4 (Cd16.2) expressing macrophage population in multiple murine tumour models and the impact of CHK1i+LDHU on this population, using conventional and imaging flow cytometry as well as single-cell sequencing. ResultsTranscriptional profiling using CITE-seq and single-cell RNA sequencing reveals that Fcgr4 TAMs closely resemble Fcgr4- TAMs but display modest enrichment of interferon-associated and inflammatory gene programs, consistent with a functionally biased state rather than a distinct lineage. Importantly, we show that a highly tumour selective CHK1i+LDHU therapy shifts TAMs toward a more inflammatory phenotype while preserving dominant immunosuppressive features. Depletion of CSF1R macrophages enhanced CD8 T cell activation without influencing tumour growth but significantly augmented therapeutic efficacy of CHK1i+LDHU. ConclusionTogether, these findings define a novel TAM population and establish how targeted therapy reshapes, but does not fully overcome, TAM-mediated immune regulation.

Cancer remains a major therapeutic challenge despite substantial advances in diagnosis and treatment, including immune checkpoint blockade. Among emerging immunotherapeutic approaches, adoptive cell transfer (ACT) has attracted growing interest. Human peripheral V{gamma}9V{delta}2 T cells are promising candidates for ACT because they combine rapid and potent antitumor functions with major histocompatibility complex (MHC)-independent tumor recognition, enabling allogeneic use with limited risk of graft-versus-host disease. This raises the possibility of generating standardized V{gamma}9V{delta}2 T-cell banks from healthy donors for off-the-shelf immunotherapy. Here, we provide preclinical evidence supporting the suitability of allogeneic human V{gamma}9V{delta}2 T cells for ACT. We characterized peripheral blood V{gamma}9V{delta}2 T cells from healthy donors after successive antigen-specific and non-specific amplification steps, assessing their phenotype, effector functions, and metabolic state. Amplified cells maintained a strong pro-inflammatory Th1-like profile, preserved cytotoxic activity, and did not produce immunoregulatory cytokines. They also displayed high purity, a predominant effector memory phenotype, reduced expression of several inhibitory immune checkpoints, and sustained antitumor reactivity. Altogether, these findings support the development of allogeneic V{gamma}9V{delta}2 T-cell products as a scalable platform for next-generation cancer immunotherapies.

BackgroundCutaneous melanoma (CM) is an aggressive skin cancer with rising incidence, representing a growing public health concern. Despite the remarkable success of immune-checkpoint inhibitors (ICIs) in the management of advanced disease, mortality remains high due to therapy resistance. Identifying reliable prognostic and predictive biomarkers is therefore essential to improve patient stratification, optimize treatment selection, and minimize unnecessary toxicity. MethodsWe comprehensively profiled the circulating immune landscape of 54 treatment-naive CM patients by integrating flow cytometry immunophenotyping with clinicopathological data, and performed tumor gene expression analysis in a subset of 26 patients. ResultsElevated HLA-DR and CD69 expression on circulating CD4+ T cells, together with reduced circulating CD8+ T cell frequency, emerged as candidate prognostic biomarkers associated with improved survival. Prognostic models combining these immune variables with clinical covariates accurately stratified patients by overall survival (89.5% sensitivity, 72.7% specificity; AUC = 0.872, p < 0.0001) and progression/recurrence risk (75% sensitivity and 71.4% specificity; AUC = 0.763, p = 0.001). In a subset of 43 patients subsequently treated with ICIs, elevated baseline HLA-DR and CD69 expression on circulating CD4+ T cells was also associated with therapeutic benefit. A predictive model integrating these markers with clinical covariates achieved good discriminatory performance (65.2% sensitivity, 88.9% specificity; AUC = 0.775, p = 0.0027). Tumor gene expression profiling supported the role of IFN-{gamma}-related signatures, previously linked to ICI response, as complementary prognostic and predictive tools. ConclusionThese findings highlight systemic CD4+ T cell activation status as a promising, easily measurable biomarker in CM, laying the foundation for future strategies to refine patient stratification and guiding immunotherapy decisions.

BackgroundAntibody-mediated blockade of innate receptor-MHC-I interactions represents a promising strategy to enhance anti-tumor immunity, particularly against metastatic cancers resistant to conventional checkpoint inhibitors. In this study, we investigated the effects of the pan anti-MHC-I monoclonal antibody M1/42, which targets MHC-I interactions with Ly49, selectively expressed on murine NK cell subsets. MethodsWe administered M1/42 to mice and assayed the proliferation and activation immune cells. Anti-tumor activity of growth and metastasis of checkpoint inhibitor-resistant pancreatic ductal adenocarcoma (PDAC) and B16F10 melanoma were assessed, complemented by extensive cellular phenotypic and RNA expression analysis. Binding and cryo-electron microscopic (cryo-EM) and X-ray crystallographic structural studies of M1/42 complexed with the mouse MHC-I molecule, H2-Dd, examined the Ab interaction site in comparison with those of Ly49 inhibitory receptors. ResultsM1/42 administration in mice robustly unleashed the proliferation and activation of natural killer (NK) cells, memory CD4+ and CD8+ T cells, dendritic cells, and macrophages in both lymphoid and non-lymphoid tissues, independent of Fc{gamma} receptors. M1/42 significantly restricted the growth and metastasis of checkpoint inhibitor-resistant pancreatic ductal adenocarcinoma (PDAC) and B16F10 melanoma in the liver and lungs, accompanied by increased tumor infiltration of effector CD8+ T cells, reduction of T regulatory cells, and a pro-inflammatory cytokine milieu. The anti-tumor effects of M1/42 depend on NK cells and are associated with upregulation of genes involved in antigen processing, interferon gamma responsiveness, and Th1 cytokine production, while downregulating inhibitory PD1/11 signaling. Structural analysis indicated that the effect of M1/42 on Ly49/MHC-I interactions was not due to direct steric competition. ConclusionsCollectively, these findings demonstrate that M1/42 unleashes coordinated innate and adaptive immune responses, overcoming tumor-induced immunosuppression and resistance to checkpoint blockade. This approach represents a paradigm shift in cancer immunotherapy, offering potential for more effective treatment of metastatic cancers that evade immune surveillance through MHC-I modulation. KEY MESSAGESO_ST_ABSWhat is already known on this topicC_ST_ABSA pan anti-mouse MHC-I mAb (M1/42) blocks interaction with several NK inhibitory receptors (Ly49A or Ly49C) resulting in NK cell activation and anti-viral and anti-tumor responses in vitro and in vivo. Other pan anti-human MHC-I mAbs (DX17 and W6/32) function similarly, blocking LILRB inhibitory receptor interaction of myeloid cells and NK cells. These stimulate human immune cells in humanized mouse models. What this study addsThis study analyzes the effects of the pan anti-mouse MHC-I mAb on NK and myeloid cell activation in detail, in the absence of T or B cells, and independent of FcR interaction. Additionally we analyze several mouse models of metastatic tumor progression, indicative of the progressive activation not only of the innate immune response, but also adaptive responses. The molecular mechanism of the mAb blocking of inhibitory receptors is revealed by cryo-EM and X-ray structures of M1/42 Fab/MHC-I (H2-Dd) complexes. How this study might affect research, practice, or policyElucidation of the details of the inhibitory effects of the mouse pan anti-mouse MHC-I mAb provides not only a more advanced understanding of the murine model system, but suggests additional functional avenues to be explored using the parallel an anti-human MHC-I mAbs.

BackgroundBreast cancer remains a significant therapeutic challenge due to the heterogeneity of tumor antigens and the presence of "immunologically cold" tumor microenvironments (TME) that resist conventional immunotherapy. mRNA vaccines offer a versatile platform for multi-epitope targeting, but their clinical utility is often limited by inherent instability and poor cellular internalization. ObjectiveTo design, characterize, and evaluate an R8-stabilized multi-epitope mRNA vaccine targeting HER2, MUC1, and Survivin for the treatment of aggressive breast cancer. MethodsA multi-epitope mRNA construct (R8-CTL1- 7-HTL1- 2) was designed and synthesized via in vitro transcription (IVT). The mRNA was complexed with an octa-arginine (R8) domain at an N/P ratio of 4:1 to form stable nanoparticles. Characterization included Minimum Free Energy (MFE) modeling and Dynamic Light Scattering (DLS). In vitro uptake and antigen expression were quantified in breast cancer cell lines. In vivo efficacy was assessed in female BALB/c mice (n=6) challenged with 4T1 cells, focusing on tumor growth inhibition, CD8+ T cell cytotoxicity, and intratumoral T cell infiltration (counts/mm2) over a 28-day period. ResultsThe mRNA construct exhibited high structural stability (MFE = -450 kcal/mol) and formed uniform nanoparticles (mean diameter [~]92 nm). R8-complexation significantly enhanced cellular uptake to 88%, resulting in robust relative expression of HER2 and MUC1. In vivo results demonstrated potent systemic immunity with a marked increase in CD8+ T cell cytotoxicity (p<0.05). Most notably, vaccinated mice showed a 65% increase in intratumoral T cell recruitment (from 1.4 to 2.3 counts/mm2), correlating with significant tumor growth suppression compared to the control group by Day 28. ConclusionThe R8-stabilized mRNA platform effectively overcomes the delivery barriers and "warms up" the immunosuppressive tumor microenvironment. By inducing high-density T cell infiltration and systemic cytotoxicity, this multi-epitope approach provides a promising therapeutic strategy for converting "cold" breast tumors into immunologically active, treatable targets.

Background: Immune checkpoint inhibitors have transformed cancer treatment, yet a large number of patients fail to respond. Identifying molecular characteristics that predict response before treatment initiation remains an unmet need. Towards that end, this study presents a large-scale integrative analysis of existing single-cell and bulk tissue datasets, aimed at identifying predictive features while providing insights into their cellular origin and potential function within the tumor microenvironment. Methods: A stepwise analysis was performed using single-cell RNA-sequencing data from 60 melanoma patients at baseline, separated into discovery (n=41) and validation (n=19) sets. An integrated bulk transcriptomics dataset (n=128) from melanoma patients and a bladder cancer dataset (n=298) were used for further validation. Results: Integrative analysis of melanoma single-cell datasets revealed that responders exhibit distinct molecular profiles across multiple cell types compared to non-responders. Notably, these included downregulation of the TNFR superfamily and other immunosuppressive genes (TNFRSF18, TNFRSF9, TNFRSF4, LGALS1, BATF, IL12RB2, LINGO1, DUSP4, SDC4, VCAM1) in T-cells. By investigating the findings from the immune cell populations in the bulk tumor context, 13 transcripts were found to be consistently associated with response across all cohorts. These were differentially expressed in T-cells (SELL, EPB41, CD96, UHFR2, LINGO1, LGALS1), B-cells (ALDH5A1), NK cells (PLEC, PDGFRB) and Monocytes (TLR10, ST6GAL1, IKZF1, MPRIP). A predictive model based on these features effectively discriminated responders from non-responders in melanoma (AUC=0.73). The model maintained significant predictive power in an independent bladder cancer dataset (IMvigor210; AUC=0.64). Of high clinical relevance, it demonstrated enhanced performance in identifying responders among patients with low tumor mutational burden (AUC=0.75). Conclusion: Our study reveals pre-treatment molecular features related to immune-cancer crosstalk that are associated with response to immunotherapy. A 13-gene model demonstrates potential added clinical value in stratifying responders, particularly in patients with low tumor mutational burden, meriting further validation.

BackgroundDespite extensive characterization of key oncogenic drivers, pancreatic ductal adenocarcinoma (PDAC) continues to exhibit profound molecular heterogeneity and inconsistent responses to standard therapies, including gemcitabine. The role of pathway-level alterations, particularly in the context of age at onset and therapeutic exposure, remains insufficiently defined. MethodsIn this study, we leveraged a conversational artificial intelligence framework (AI-HOPE-TP53 and AI-HOPE-PI3K) to enable precision oncology, driven interrogation of clinical and genomic data from 184 PDAC tumors, stratified by age at diagnosis and gemcitabine exposure. Using AI-enabled cohort construction and pathway-centric analyses, we evaluated alterations in TP53 and PI3K signaling networks, with findings validated through conventional statistical methods. ResultsTP53 pathway analysis revealed a significantly higher frequency of TP53 mutations in early-onset compared to late-onset PDAC among gemcitabine-treated patients (86.7% vs. 57.1%, p = 0.04), with a similar trend observed between treated and untreated early-onset cases (86.7% vs. 40%, p = 0.07). Notably, in late-onset PDAC patients not treated with gemcitabine, absence of TP53 pathway alterations was associated with improved overall survival (p = 0.011). Complementary analyses of the PI3K pathway demonstrated a higher prevalence of pathway alterations in late-onset gemcitabine-treated tumors compared to untreated counterparts (13.2% vs. 2.7%, p = 0.02). Importantly, among late-onset patients not receiving gemcitabine, those without PI3K pathway alterations exhibited significantly improved overall survival (p < 0.0001). ConclusionTogether, these findings identify distinct TP53 and PI3K pathway dependencies that are modulated by both age-of-onset and treatment exposure in PDAC. This work highlights the utility of conversational artificial intelligence in enabling rapid, integrative, and hypothesis-generating analyses within a precision oncology framework, supporting the identification of clinically relevant molecular stratification strategies for this aggressive disease.

While prostate cancer (PC) is defined as immunologically cold, limiting the efficacy of immune checkpoint inhibitors, therapeutic vaccination targeting tumor-associated antigens represents an attractive strategy to promote disease control in low volume metastatic patients. The UV1 cancer vaccine is based on immunization with tripeptide fragments from human telomerase reverse transcriptase (hTERT) and a phase II clinical trial demonstrated induction of robust T cell response in men with de novo metastatic castration-sensitive prostate cancer (mCSPC). Comparison with long-term survival data of non-metastatic CSPC patients as reference showed that despite metastatic disease at diagnosis, UV1-treated patients who mounted an early vaccine-induced immune response achieved progression-free and overall survival comparable to non-metastatic patients. We examined biological determinants of clinical benefit following UV1 vaccination including tumor transcriptome and T cell receptor (TCR) profiling from circulating and tissue resident T-cells of the 22 men enrolled. Analysis of diagnostic and post-UV1 treatment biopsies revealed that low baseline exhaustion of T cells and higher CD8+ T cell abundance are associated with early immune response to the vaccine and longer survival. Moreover, we identified specific TCR motifs relative to early responders, that can indicate potential benefit from UV1 vaccination. These findings indicate that baseline intratumoral T cell exhaustion state and repertoire shape responsiveness to hTERT vaccination and long-term outcome. Overall, our study underlines how baseline immune profiling may be used as a companion biomarker to predict mCSPC patients most likely to benefit from therapeutic vaccination.

BackgroundPancreatic ductal adenocarcinoma (PDAC) is the paradigmatic immunotherapy-refractory cancer, with a 5-year survival of approximately 12% and minimal benefit from immune checkpoint blockade (ICB). The dominant mechanistic explanation classifies PDAC as a T cell-excluded "cold" tumor, implying that no functional anti-tumor T cells are available for checkpoint release. Whether this Block-strategy view is correct has not been re-examined under integrated evasion-framework analysis. MethodsWe applied a previously developed 16-module immune evasion framework to TCGA-PAAD (n=183), integrated with hub-cytokine analysis (IL-10/TGF-{beta}), Kv1.3-immune channelome data, and clinical trial mapping (12,007 trials). Single-cell validation used two independent PDAC cohorts retrieved through TISCH2: PAAD_CRA001160 (Peng 2019, 35 samples [24 PDAC + 11 adjacent normal], 57,443 cells) and PAAD_GSE154778 (Lin 2020, 16 samples, 14,953 cells), examined for CD8A, TOX, PRF1, KCNA3, and FAP expression by cell type. ResultsPDAC scored highest in CAF Wall (z=0.768) and Platelet Cloak (z=0.663) modules; strategy classification yielded Brake -- not Block -- driven by a positive KCNA3-survival relationship (HR=0.649, 95% CI 0.43-0.97, p=0.037). Single-cell qualitative analysis of TISCH2 violin plots showed that CD8 exhausted T cells (CD8Tex) carried (i) high CD8A, (ii) the highest TOX expression among annotated cell types, (iii) preserved PRF1, and (iv) high KCNA3 expression. FAP was strongly localized to fibroblasts (peak [~]3.0 vs. <0.5 elsewhere). The pattern was reproduced in the second cohort. The optimal three-module attack (MHC restoration + CAF disruption + VEGF blockade) suppressed 10 of 16 evasion modules in silico (62.5%); zero of 370 PDAC immunotherapy trials test this combination. ConclusionsPDAC may not be T cell-cold but T cell-trapped: CD8 T cells with intact Kv1.3 channels appear immobilized behind a FAP-positive cancer-associated fibroblast wall. ICB monotherapy is mechanistically insufficient because the brake is engaged on T cells that cannot reach the tumor. The framework predicts that triple-targeted intervention -- checkpoint release + CAF wall disruption + vascular normalization -- is the minimum effective strategy. This is a hypothesis-generating computational analysis; prospective experimental and clinical validation are required.

Immune checkpoint inhibitors (ICI) have revolutionized cancer therapy, yet response rates remain suboptimal across many solid tumors, and resistance mechanisms, particularly those involving glycans, are not fully understood. Recent studies have identified sialic acid-containing glycans and their interactions with Siglec receptors on tumor-associated macrophages as an important contributor to immune suppression within the tumor microenvironment (TME). Targeting this sialic acid-Siglec axis by glycan engineering with sialidases and other glycosidases has shown therapeutic potential in preclinical models. However, safe and effective delivery of sialidases to tumors remains a challenge. Here, we present a novel approach using adeno-associated virus (AAV)-mediated therapy to deliver sialidases (AAVSia) and other glycosidases, including fucosidase, directly to the TME. Intratumoral administration of AAVSia in mouse models resulted in significant tumor growth reduction, enhanced survival, and robust systemic antitumor immunity through improved cross-presentation and dendritic cell activation. Furthermore, combining local sialidase expression with fucosidase treatment and classical PD-1 blockade allowed a synergistic effect, amplifying antitumor response. Our findings highlight the therapeutic promise of glycoengineering the TME using local delivery systems and support the development of combination strategies to overcome glycan-mediated resistance in cancer immunotherapy. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=129 SRC="FIGDIR/small/720097v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@dc9d72org.highwire.dtl.DTLVardef@1e4e455org.highwire.dtl.DTLVardef@4a8f93org.highwire.dtl.DTLVardef@11813a3_HPS_FORMAT_FIGEXP M_FIG C_FIG

Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment, but their efficacy has now reached a plateau. ICIs are the first class of treatment targeting the crosstalk between immune and tumor cells, making it crucial to understand the complex interactions within the tumor microenvironment (TME) to enhance therapeutic responses. The elevated consumption of resources by cancer cells, coupled with limited vascularization, often results in a TME that is deficient in nutrients, leading to competition for resources between cancer and stromal cells. Consequently, targeting tumor metabolism has emerged as a promising strategy to improve the efficacy of ICIs. Through metabolomic analysis, we have identified metabolic alterations in melanoma cells that are resistant to ICIs, specifically an increase in arginine synthesis and upregulation of ASS1, the rate-limiting enzyme in this pathway. By using gain and loss of function models, as well as a pharmacological inhibitor specific for ASS1, we demonstrated that modulations in the expression or activity of ASS1 is associated with translational reprogramming, characterized by an inhibition of the cap-dependent mRNA translation mediated through mTORC1/4EBP1 axis. We also demonstrated that targeting ASS1 in vivo, resensitize tumors initially resistant to ICI. Taken together, our results highlight the interaction between modulations of arginine synthesis pathway, mRNA translation reprogramming, antitumor immunity, and restauration of sensitivity to anti-PD-1. Our work also demonstrates the therapeutic potential of targeting arginine synthesis pathway, and especially ASS1, to offer new treatments to patients suffering from cutaneous melanoma resistant to ICIs.

For mRNA-based cancer gene therapy, we engineered a membrane-bound fusion protein combining interferon-{gamma} (IFN{gamma}) with the Fas intracellular domain (FasICD) to couple local IFN{gamma} signaling with Fas-driven apoptotic tumor cell death. IFN{gamma}-FasICD was robustly expressed on the plasma membrane after mRNA transfection. In murine cancer cell lines, IFN{gamma}-FasICD mRNA reduced viability within 24 h, resulting in [~]50% cell death in MC38 cells and [~]75% in B16OVA cells, exceeding the cytotoxicity of the FasICD-deleted control (IFN{gamma}-Fas{Delta}). Mechanistically, IFN{gamma}-FasICD induced predominantly apoptotic rather than necrotic cell death. IFN{gamma}-FasICD also activated IFN{gamma} receptor signaling in both cancer and the immune cells, inducing IFN{gamma}-responsive genes in IFN{gamma}R-high B16OVA cells and triggering STAT1 phosphorylation in co-cultured splenocytes. For in vivo delivery, IFN{gamma}-FasICD mRNA was formulated in lipid nanoparticles (LNPs), enabling strong intratumoral expression that peaked at [~]3 h and persisted for more than 48 h. Repeated intratumoral injections of LNP-formulated IFN{gamma}-FasICD mRNA suppressed the growth of established B16OVA and MC38 tumors and improved survival, with [~]40% and [~]20% of mice surviving beyond 30 days, respectively. IFN{gamma}-FasICD treatment remodeled the tumor microenvironment by increasing tumor-infiltrating CD45+ cells and CD8+ T cells, while further reducing FOXP3+ regulatory T cells. Moreover, NK/NKT cells and cDC1/cDC2 populations were increased, and their activation was enhanced. In tumor-draining lymph nodes, IFN{gamma}-FasICD mRNA promoted dendritic cell migration and increased priming and differentiation of CD8+ T cells toward effector and memory phenotypes, accompanied by enhanced functional activation of IFN{gamma}-producing CD8+ T cells and highly cytotoxic NK cells in peripheral blood. Overall, our findings provide a mechanistic foundation for cytokine-death receptor fusion proteins as an in vivo antitumor strategy that can reprogram tumor cells into localized sources of both apoptotic signals and immune-activating cues.

The tumor microenvironment (TME) is a complex ecosystem composed of tumor cells, cancer-associated fibroblasts (CAFs), immune suppressive cells, and the extracellular matrix (ECM), playing a crucial role in tumor development and CAR-T cell therapy efficacy. CAR-T therapy has shown promise in hematological malignancies but faces challenges in solid tumors due to the TMEs ability to suppress CAR-T cell infiltration, proliferation, and cytotoxicity. Traditional drug evaluation models, such as 2D cell cultures and animal models, have significant limitations due to oversimplification of the in vivo environment or physiological differences between species. Organoid models offer a more biomimetic approach but often fail to fully recapitulate the TMEs complexity and heterogeneity. Our research developed a tumor organoid and CAF co-culture model using the IBAC co-culture chip, demonstrating that CAFs significantly impact CAR-T cell therapy efficacy by forming physical (e.g., fibronectin) and chemical (e.g., IL-10) barriers that prevent CAR-T cell infiltration and cytotoxicity. This model provides a high-biomimetic platform for investigating the TMEs effects on CAR-T therapy and highlights the importance of incorporating a comprehensive stromal component into in vitro models to enhance their predictive power for cancer treatment.

Abstract Introduction: MET tyrosine kinase (TKI) therapy has improved outcomes in patients with non-small cell lung cancer (NSCLC) harboring MET alterations. However, primary and acquired resistance ultimately limits durability of response. This study evaluated the safety and efficacy of the MET inhibitor capmatinib with the MEK inhibitor trametinib in patients with metastatic MET-driven NSCLC who had progressed on prior treatment with at least one MET inhibitor. Methods: A multicenter phase I study evaluated capmatinib in combination with trametinib in patients with advanced stage NSCLC harboring activating MET alterations and prior exposure to at least one MET TKI. A 3+3 dose-escalation design was employed to assess safety and tolerability of the combination. Results: Three patients (n = 3) were enrolled in the study and completed a median of 3 cycles of therapy. Dose-limiting toxicities, including rash, edema, and nausea, necessitated dose reductions in the first two patients and initiation of the third patient at a lower dose level. Ultimately, all patients discontinued therapy due to treatment-related adverse events. The study was terminated early due to poor accrual and TRAEs. No radiographic objective responses were observed. Conclusions: In this phase I trial, capmatinib plus trametinib was associated with significant treatment-related adverse events and treatment was discontinued in all participants. Based on these findings, further investigation of this combination of MET and MEK inhibitors is not recommended.

Engineering macrophages with chimeric antigen receptors is emerging as a promising cancer therapeutic. Chimeric antigen receptor-expressing macrophages (CAR-Ms) engineered to recognize tumor-specific antigens have been shown to inhibit tumor growth and activate adaptive immune responses, leading to robust tumor control in animal studies. Based on this work, clinical trials have been initiated. While the trials have shown promise, challenges remain. The dynamic interactions between CAR-Ms and cancer cells and the exact mechanisms driving anti-tumor effects remain poorly defined. Defining the dynamic interactions between CAR-Ms and cancer cells will provide critical insights for optimizing future CAR-M design and improving therapeutic efficacy. We sought to directly visualize CAR-M interactions with glioblastoma cells at high-resolution and in real-time using CAR-Ms engineered to recognize Neural-Glial Antigen 2 (NG2), an antigen expressed on glioblastoma cells. Using patient-derived glioblastoma cells, we formed glioblastoma spheroids and embedded them in a 3D matrix together with CAR-Ms. Using time-lapse microscopy, as expected, we found that NG2-targeting CAR-Ms engulfed glioblastoma cells. However, excitingly, we found that NG2-targeting CAR-Ms blocked >85% of glioblastoma cell invasion in 3D. This inhibition of glioblastoma invasion was not due to a significant change in CAR-M polarization states. Together, these data suggest that NG2-targeting CAR-Ms both engulf glioblastoma cells and block glioblastoma invasive behavior.

BackgroundNon-invasive electromagnetic field (EMF)-based therapies offer a potential route to modulate local tumor-immune interactions but their mechanistic basis remains poorly defined. MethodsWe evaluated Asha therapy, a proprietary low-intensity (50khz, 2 mT, 25% duty cycle) alternating magnetic-field treatment in preclinical breast cancer models. Cellular responses in human triple negative breast cancer cell lines (MDA-MB-231 and MDA-MB-468) were evaluated using bulk RNA sequencing, quantitative proteomics, flow cytometry, and cytokine analysis and proteomics analysis. Tumor microenvironment responses in mouse 4T1 breast cancer model was characterized using single-cell CITE-seq analysis. Functional efficacy was assessed in vivo using the murine 4T1 triple-negative breast cancer model, both as monotherapy and in combination with anti-PD1 checkpoint blockade. Clinical relevance was assessed by deriving a 19-gene neutrophil activation signature from Asha-induced transcriptional changes and projecting it onto two independent TNBC patient cohorts (METABRIC n=338, SCAN-B n=874) for survival analysis. ResultsAsha therapy induced endoplasmic reticulum (ER) stress and activated an adaptive unfolded-protein response in tumor cells, triggering robust NF-{kappa}B and interferon signaling and time-dependent secretion of inflammatory cytokines. In vivo, these tumor-intrinsic changes propagated to the tumor microenvironment (TME), reprogramming fibroblasts from contractile states to immune-recruiting, interferon-responsive phenotypes and enriching for interferon-stimulated, metabolically active neutrophils and macrophages. These coordinated innate immune changes occurred without overt cytotoxicity and were associated with significant reductions in metastasis and improved survival. Combination with anti-PD1 therapy markedly enhanced efficacy, reducing lung metastasis and mortality by 88% compared with control. The neutrophil activation signature derived from Asha-treated tumors was associated with improved overall survival in both METABRIC (log-rank p=0.036) and SCAN-B (p=0.048) TNBC cohorts by Kaplan-Meier analysis, with pooled multivariable Cox regression confirming significant survival benefit (HR=0.75, 95% CI 0.59-0.94, p=0.01). ConclusionsAsha therapy triggers a controlled ER stress response in tumor cells that drives interferon-mediated cytokine release and immune reprogramming of the TME, resulting in anti-metastatic and survival benefits. These findings identify electromagnetic-field exposure as a potential non-pharmacologic strategy to activate innate immunity and sensitize tumors to checkpoint blockade, supporting further clinical development of EMF-based immunotherapy.

Colorectal cancer (CRC) is a leading cause of cancer-related death, with incidence rising substantially among individuals under 50 years of age. Polygenic risk scores (PRS) hold promise for identifying high-risk individuals; when combined with lifestyle factors, they substantially improve prediction accuracy compared with models based on lifestyle factors alone. However, few clinical tools currently exist that facilitate this integrated, PRS-enhanced risk assessment. To bridge this gap, we developed MyGeneRisk Colon, a publicly accessible web portal that delivers individualized CRC risk prediction by incorporating genetic, demographic, family history, and lifestyle factors. This paper details the development of the underlying risk prediction model, the portal's architecture and data security, our reporting framework, and engagement with a community advisory panel. Designed as a user-friendly platform, MyGeneRisk Colon aims to effectively communicate personalized CRC risk profiles and educate users and healthcare providers about prevention strategies.

Diffuse hemispheric gliomas (DHGs) are highly aggressive and infiltrative CNS tumors that are refringent to treatment, and with a 5-year overall survival of around 20%. A fraction of DHGs is driven by mutations in the histones H3.1 and H3.3. In this study, we demonstrate that the expression of histone H3.3 glycine 34 to arginine mutations (H3.3-G34R) result in the epigenetic and transcriptional activation of the NF-{kappa}B signaling pathway in DHG. To target this vulnerability, we designed high density lipoprotein (HDL) nanoparticles loaded with unmethylated CpG dinucleotides, which mimic the immune stimulatory activity of bacterial DNA. CpG are recognized by Toll-like receptor 9 (TLR9), activating the NF-{kappa}B signaling. The CpG-mediated NF-{kappa}B activation results in the release of immuno-stimulating cytokines that promote an antitumoral response. As we previously established that G34-mutant DHGs are characterized by DNA repair impairment, we combined CpG dinucleotides with a PARP (poly (ADP-ribose) polymerase) inhibitor, olaparib, in the HDL nanoparticles.