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Pre-treatment T cell features and immune-milieu characteristics shape treatment-induced exhaustion and resistance to Blinatumomab in B-cell acute lymphoblastic leukemia.

BACKGROUND: Blinatumomab (Blina), a CD19×CD3 bispecific T cell engager, is approved for the treatment of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), yet resistance remains a major challenge and the mechanisms driving treatment failure remain poorly understood. METHODS: To define the immunological determinants of resistance, we performed longitudinal profiling of peripheral blood T cells and the immune milieu of 34 patients receiving Blina using flow cytometry (n=19), single-cell CITE-seq (n=13), ex vivo Blina-induced cytotoxicity (n=26) and serum proteomics (n=17). RESULTS: At baseline, Responders (R) were enriched for CD8+ effector memory T cells (TEM) expressing higher levels of cytotoxic genes and their transcriptional regulator ZNF683. Conversely, CD8+ TEM from Non-Responders (NR) displayed transcriptional features of activation without proportionate cytotoxic commitment. Over the course of the first treatment cycle, NR exhibited a progressive expansion of TIM3+CD8+ T cells that correlated with a rapid loss of ex vivo cytotoxic function. Linking baseline state to post-treatment T-cell exhaustion, the magnitude of TIM3+CD8+ expansion correlated inversely with baseline ZNF683 expression in CD8+TEM. Beyond T-cell-intrinsic features, NR harbored an immunosuppressive milieu characterized by higher circulating levels of M2-polarizing factors (CSF-1, HGF) and the TIM-3 ligand Galectin-9, which correlated positively with the magnitude of TIM3+CD8+ T-cell expansion. CONCLUSIONS: These findings indicate that post-Blina CD8+ T-cell exhaustion is associated with resistance and it is shaped by both reduced ZNF683-dependent cytotoxic programming in CD8+ TEM and an immunosuppressive milieu. This provides a rationale for risk stratification based on baseline transcriptional profiling of CD8+ TEM and for combinatorial strategies targeting the suppressive microenvironment.

Humans

Differences between mitotically old and young endometrial tumors.

Human tumors likely differ in their mitotic ages, reflecting how many divisions elapse between the final tumor progenitor cell and surgical removal. We used a rapidly fluctuating CpG (fCpG) methylation clock to infer relative endometrial adenocarcinomas (EAC) mitotic ages. Experimentally, young tumors initiated from single cells show low-diversity, high-variance fCpG distributions with trimodal peaks near 0%, 50%, and 100%, reflecting inherited progenitor methylation states. fCpG methylation becomes polymorphic with divisions, and older tumors exhibit higher diversity, lower variance, and unimodal distributions centered around 50%. Mitotic ages varied across EAC samples. Synchronous hyperplasia and invasive regions generally shared similar ages, and primary-metastatic EAC pairs showed both synchronous and stepwise progression. The Cancer Genome Atlas (TCGA) EACs also showed variable mitotic ages: younger tumors were enriched for proliferation pathways, whereas older tumors showed more immune infiltration, immune-pathway activation, and evidence of T-cell exhaustion. These results show that human tumors can be ranked by mitotic age and suggest that the growth of older cancers is restrained by immune surveillance. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Humans

CRISPR-Engineered CAR-T Cell Therapy for Epstein-Barr Virus-Associated Nasopharyngeal Carcinoma: A Review of Emerging Therapeutic Prospects.

Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) remains a clinically challenging malignancy, particularly in recurrent or metastatic disease where durable responses to chemoradiotherapy and immune checkpoint blockade are limited. The viral aetiology of NPC provides a strong biological rationale for immune-based treatment; however, translation of chimaeric antigen receptor (CAR) T-cell therapy into this solid tumour setting is constrained by poor tumour trafficking, antigen heterogeneity, limited surface accessibility of EBV latent antigens, T-cell exhaustion, and an immunosuppressive tumour microenvironment. This review critically evaluates the emerging therapeutic prospects of CRISPR-engineered CAR-T cell therapy for EBV-associated NPC. It synthesises evidence on EBV latency biology, NPC immune evasion, solid-tumour CAR-T limitations, and genome-engineering strategies including conventional CRISPR-Cas9, base editing, prime editing, and double-strand-break-sparing targeted integration. Particular attention is given to genotoxicity, chromosomal rearrangements, chromosome loss, bystander and off-target editing, manufacturing heterogeneity, and the regulatory and biological barriers that currently separate technical feasibility from NPC-specific clinical implementation. Available clinical evidence from checkpoint blockade, EBV-specific adoptive T-cell therapy, base-edited CAR-T cells in haematologic malignancy, and early CRISPR-edited T-cell trials supports the feasibility of immune and genetic redirection but does not establish efficacy of a clinically validated CRISPR-engineered CAR-T platform for NPC. Future development should prioritise surface-accessible antigen validation, fit-for-purpose selection of editing technology, genomic safety, scalable manufacturing, and biomarker-driven early-phase trials.

Humans

Integrated pan-cancer profiling highlights OSR2 as a prognostic indicator and immune-associated biomarker.

BACKGROUND: Odd-skipped-related 2 (OSR2), encoded by the OSR2 gene, has been reported to function as a checkpoint associated with CD8⁺ T-cell exhaustion in the tumor microenvironment of solid malignancies, suggesting its potential as a therapeutic target to improve immunotherapeutic responses. Nevertheless, the molecular and clinical significance of OSR2 across diverse cancer types has not yet been systematically investigated, and its pan-cancer expression profile, prognostic implications, and associations with tumor immunity remain to be fully elucidated. METHODS: In this study, we integrated datasets from The Cancer Genome Atlas (TCGA), the Genotype-Tissue Expression (GTEx) portal, and the Human Protein Atlas to construct a systematic pan-cancer profile of OSR2. The prognostic value of OSR2 was comprehensively assessed using univariate Cox regression, survival analysis, and receiver operating characteristic (ROC) curve analysis. In addition, we performed an in-depth analysis of the relationships between OSR2 and multiple molecular and immunological features, including copy number variation (CNV), DNA methylation, tumor mutational burden (TMB), microsatellite instability (MSI), immune-related gene expression, immune cell infiltration, and drug sensitivity, with the aim of exploring its potential immunological associations with the tumor microenvironment. RESULTS: OSR2 expression was significantly upregulated or downregulated in the majority of tumor tissues relative to normal counterparts and exhibited distinct cancer-type-specific patterns across clinical stages. CNV alterations and aberrant DNA methylation were closely associated with abnormal OSR2 mRNA expression in multiple cancers. Prognostic analyses indicated that OSR2 expression was significantly associated with overall survival, disease-specific survival, disease-free interval, and progression-free interval across multiple cancer types, showing either risk-associated or protective associations in a tumor-context-dependent manner. Furthermore, OSR2 expression showed strong associations with immune cell infiltration, particularly T-cell subsets, and was significantly correlated with the expression of multiple immune checkpoint-related genes across diverse malignancies. OSR2 expression was also closely associated with TMB, MSI, and sensitivity to multiple anticancer agents. CONCLUSION: Taken together, these findings suggest that OSR2 is associated with prognosis and immune-related features across multiple cancer types. OSR2 may be linked to features of the tumor immune microenvironment through its relationships with immune cell infiltration, immune checkpoint gene expression, and genomic instability, and thus may serve as a candidate biomarker for further investigation in cancer immunotherapy.

CD8⁺ T-cell

FLT3-ITD Induces CMTM6 and Enhances Immune Escape in Acute Myeloid Leukemia.

UNLABELLED: FMS-like tyrosine kinase-3 internal tandem duplication (FLT3-ITD) mutations are frequent in acute myeloid leukemia (AML) and are associated with a high risk of relapse. CKLF-like MARVEL transmembrane domain containing member 6 (CMTM6) stabilizes PD-L1 surface expression and modulates tumor immunity in solid cancer. In this study, we found a role for FLT3-induced CMTM6 in hematologic malignancies. FLT3 drove CMTM6 and PD-L1 expression in AML cells, whereas FLT3 inhibition reduced expression of CMTM6 and PD-L1. In three distinct allogeneic hematopoietic cell transplantation mouse models, transplantation of Cmtm6-deficient FLT3-ITD+ leukemia cells resulted in prolonged survival, reduced leukemia burden, enhanced T-cell effector function, and decreased expression of T-cell exhaustion markers compared with Cmtm6-proficient FLT3-ITD+ leukemia cells. Furthermore, combination therapy with anti-PD-L1 and tandutinib significantly improved survival, suppressed leukemia cell expansion, and augmented the anti-leukemia T-cell response in mice bearing FLT3-ITD+ leukemia. Mechanistically, protein-protein interaction of FLT3 and CMTM6 within their transmembrane domains, which was not phosphorylation dependent, enhanced CMTM6 stability in leukemia cells, whereas FLT3-ITD did not increase CMTM6 and PD-L1 expression at the RNA level. Furthermore, CMTM6 upregulation and protein interaction with FLT3 were validated in primary leukemia cells from two independent cohorts of patients with FLT3-ITD+ AML. Collectively, these findings uncover FLT3-mediated stabilization of CMTM6 in AML cells, which results in enhanced PD-L1 cell surface expression and leukemia immune escape. SIGNIFICANCE: Activation of the CMTM6/PD-L1 axis in FLT3-ITD-driven acute myeloid leukemia mediates immunosuppression, providing the basis for potential inhibition of this pathway to harness antitumor immunity.

Animals

Beyond genes: EpiSwitch® and Orion platform-powered 3D genome architecture biomarkers reveal shared biology across ME/CFS, long COVID, PTSD, rheumatoid arthritis, and multiple sclerosis.

BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), Long COVID (LC19), post-traumatic stress disorder (PTSD), rheumatoid arthritis (RA), and multiple sclerosis (MS) are clinically distinct disorders that share substantial symptom overlap, including persistent fatigue, cognitive impairment, autonomic dysfunction, and immune dysregulation. Although these conditions differ in diagnosis and clinical presentation, their underlying biological mechanisms remain poorly understood and may involve convergent regulatory pathways. METHODS: The EpiSwitch® 3D genomics platform and Orion knowledgebase were used to integrate chromosome conformation signatures with genome-wide association study (GWAS)-derived datasets across ME/CFS, LC19, PTSD, RA, and MS. Three-dimensional genomic anchors were mapped to coding genes and analysed using STRING protein-protein interaction networks and Cytoscape-based systems biology approaches. Disease-specific anchor datasets were generated and compared at both gene and network levels to identify shared biological processes and regulatory mechanisms. RESULTS: Analysis of the ME/CFS dataset identified 552 unique 3D genomic anchors mapped to 567 genes, with analogous disease-specific anchor sets generated for LC19, PTSD, RA, and MS. Direct overlap between disease-associated genes was limited; however, higher-order network analyses revealed substantial interconnectivity and convergence across conditions. Shared biological pathways included immune and cytokine signalling, interferon responses, mitochondrial function, metabolic regulation, and neuroendocrine processes. Highly connected hub genes included immune regulatory nodes such as LAG3 and components of the mTOR signalling pathway, implicating T-cell exhaustion, chronic immune activation, and immunometabolic dysregulation as common mechanisms underlying these disorders. CONCLUSIONS: These findings support a systems-level model in which clinically overlapping fatigue-associated syndromes arise from perturbations of interconnected regulatory networks rather than discrete disease-specific pathways. Despite limited genetic overlap, substantial convergence at the network level suggests shared biological architecture across ME/CFS, LC19, PTSD, RA, and MS. The identification of common regulatory pathways provides a mechanistic framework for the development of cross-disease diagnostic and therapeutic strategies. By capturing dynamic regulatory states, 3D genomic biomarkers offer significant potential for objective blood-based diagnostics, patient stratification, and the identification of shared therapeutic targets across complex chronic disorders. These findings support the application of precision medicine approaches and may accelerate the development of novel interventions for fatigue-associated multisystem diseases.

Humans

Cancer Immunotherapy: Therapeutic Limitations and Next-Generation Precision Strategies.

Cancer immunotherapy has reshaped oncology, largely through immune checkpoint inhibitors that release the brakes on tumor-reactive T cells. Yet the benefit remains uneven, and that unevenness traces back to a few basic biological limits. Checkpoint blockade amplifies immunity that is already present; it does not create tumor specificity de novo. Poor Ag quality, defective Ag presentation, a suppressive microenvironment, and epigenetically fixed T-cell exhaustion together set a ceiling on what checkpoint release can achieve. Next-generation strategies try to move past these limits by reorganizing immunotherapy around the functional layers of the immune response. Cancer vaccines define tumor-specific neoantigens and expand the responses against them. Ab-based approaches tune inhibitory signaling, draw immune cells toward the tumor, and trigger immunogenic cell death. Cellular therapies-chimeric Ag receptor T cell, TCR-engineered T cells, and tumor-infiltrating lymphocytes (TILs)-boost effector potency, with TIL therapy notable for preserving tumor-reactive repertoires shaped in vivo. Rather than rivals, these modalities are best seen as complementary layers-Ag definition, immune priming, effector optimization, and microenvironmental conditioning-to be combined in a programmable way. As genomic profiling, immunopeptidomics, and high-dimensional immune monitoring mature, the field is shifting from checkpoint-centered release toward precision immunoengineering, in which tumor-specific immunity is deliberately designed, aligned, and sustained.

Cancer vaccines

SLA2 is Associated With Immune evasion and Exhaustion of CD8+ T Cells in Gastric Cancer.

The Src-like adaptor 2 (SLA2) functions as a negative regulator of T cell receptor signalling. However, its involvement in the tumour microenvironment (TME) of gastric cancer (GC) remains unexplored. In this study, we found that SLA2 expression was significantly elevated in GC tissues, and a high level of SLA2 was associated with poor prognosis in GC patients. Bioinformatics analyses revealed a close association between SLA2 and TME in GC. Single-cell RNA sequencing analysis indicated that SLA2 was significantly enriched in CD8+ T cells in GC tissues. Functional validation demonstrated that SLA2 overexpression contributed to the exhaustion of CD8+ T cells by suppressing their proliferation, upregulating the expression of exhaustion markers, reducing the secretion of effector cytokines (IFN-γ and TNF-α) and impairing cytotoxic function. SLA2 knockdown in in vitro-generated exhausted CD8 T cells significantly alleviated T cell exhaustion. Mechanistically, we found that inverse promoter methylation and active histone marks (H3K27ac, H3K4me3 and H3K4me1) may regulate SLA2 expression. Our findings suggest that SLA2 may modulate the TME and promote immune evasion via CD8+ T cell exhaustion in GC.

Humans

Deciphering CD8+ T cell exhaustion in human cancers through single-cell and spatial transcriptomics.

Exhausted CD8+ T cells (Tex) within the tumor microenvironment (TME) represents a critical barrier limiting anti-tumor immune responses. Tex cells are characterized by upregulated inhibitory immune checkpoint receptors, reduced cytotoxicity, and functional heterogeneity. Their genomic features and regulatory networks remain poorly defined, and only a minority of patients respond to immune checkpoint blockade (ICB) therapy. Single-cell RNA sequencing (scRNA-seq), through high-resolution transcriptomic profiling, has revealed diverse Tex subpopulations, identified subpopulation-specific marker genes and regulatory pathways. Spatial transcriptomics has further mapped the spatial distribution of Tex and their interaction networks with immune cells, tumor cells, and stromal cells, elucidating the impact of spatial heterogeneity on Tex functionality. Current studies indicate that the exhausted state of Tex is dynamic and modifiable, with functional differences among subpopulations closely associated with tumor progression and therapeutic response. However, the genomic characteristics, epigenetic regulation, and spatial interaction mechanisms of Tex require further exploration. This review summarizes recent advances in high-resolution omics technologies for precisely dissecting Tex heterogeneity, functional features, and interactions with other cells. It emphasizes the central value of optimizing Tex-targeted tumor immunotherapy strategies, providing theoretical foundations and directional guidance for developing more effective anti-tumor immunotherapies.

Humans

A TIGIT nanotrapping-guided STING-activatable immunometabolic strategy overcomes innate immune silence and T cell exhaustion in breast cancer.

Breast cancer exhibits a profoundly immunosuppressive tumor microenvironment (TME), where innate immune silence prevents antigen sensing and persistent T cell exhaustion limits effector responses, rendering most immunotherapies ineffective. Clinical profiling of 1093 The Cancer Genome Atlas (TCGA) cases identified a glucose-fueled glutathione (GSH)-glutathione peroxidase 4 (GPX4)-dihydrolipoamide S-acetyltransferase (DLAT) axis as a dominant metabolic shield that suppresses oxidative stress, and thereby enforces both stimulator of interferon genes (STING) silence and CD8+ T cell exclusion. To dismantle this barrier, we developed an immunometabolic nanotherapy, GOx/ES-CO-LDH@TIGIT-Nanotrap (TNT). In acidic tumors, proton-driven layered double hydroxide (LDH) disassembly releases glucose oxidase (GOx) and extremely small cuprous oxide (ES-CO). GOx depletes glucose and nicotinamide adenine dinucleotide phosphate (NADPH) to induce disulfidptosis, while ES-CO releases cuprous ions (Cu+) that trigger cuproptosis via binding to lipoylated mitochondrial proteins. Their mutual biochemical amplification produces a cycloacclerated disulfidptosis-cuproptosis cascade that collapses the GSH-GPX4-DLAT axis and restores STING activation. Meanwhile, the macrophage-derived T cell immunoreceptor with Ig and ITIM domains (TIGIT) Nanotrap sequesters CD155 to prevent T cell suppression. Together, this coordinated innate reactivation and adaptive rescue converts immune-cold tumors into STING-inflamed and T cell responsive lesions.

Female

Progressive T cell exhaustion and predominance of aging tissue associated macrophages with advancing disease stage in penile squamous cell carcinoma.

Penile squamous cell carcinoma (PSCC) is a rare malignancy with limited understanding of the tumor immune microenvironment (TIME). The interplay between PSCC and the immune system across disease progression and HPV infection status remains poorly characterized. This study aims to assess the TIME changes from localized to advanced disease and between HPV-positive versus negative tumors to identify potential immune evasion mechanisms in advanced PSCC. scRNA-seq was performed on ten PSCC tissue samples from penile, lymph node and distant metastatic sites with four matched penile and lymph node samples to understand the cellular heterogeneity within PSCC tumors. Analysis of immune cell populations and transcriptional hallmarks were performed stratified by localized (pT1-3, N0) versus advanced (N1-3, M0 or any N, M1) disease states and HPV infection status. We observed significant differences in immune cell infiltration between localized and advanced PSCC disease states and by HPV status. Advanced disease states demonstrated an exhausted immune phenotype, characterized by terminally exhausted CD8+ T cells, M2-like macrophages and hypoxic signature, while localized disease states demonstrated an active innate immune system characterized by increased DCs. HPV-negative tumors displayed low immune cell infiltration while HPV-positive tumors demonstrated an immune exhausted phenotype. These findings offer valuable insights into the evolving PSCC immune landscape, paving the way for the development of potential therapeutic approaches for advanced PSCC.

Humans

ARCADIA reveals spatially dependent transcriptional programs through integration of scRNA-seq and spatial proteomics.

MOTIVATION: Cellular states are strongly influenced by spatial context, but single-cell RNA sequencing (scRNA-seq) loses information about local tissue organization, while spatial proteomic assays capture limited marker panels that constrain transcriptomic inference. Integrating these modalities can elucidate how spatial niches shape transcriptional programs, yet existing approaches depend on either feature-level correspondence such as gene-protein linkage or cell-level barcode pairing, which is often unavailable. RESULTS: We present ARCADIA (ARchetype-based Clustering and Alignment with Dual Integrative Autoencoders), a generative framework for cross-modal integration that operates without cell barcode pairing and does not assume direct feature-to-feature correspondence. ARCADIA identifies modality-specific archetypes, that is, convex combinations of cells representing extreme phenotypic states, and aligns these anchors across modalities by minimizing the discrepancy between their cell-type composition profiles. The aligned archetypes define a shared coordinate system that anchors dual variational autoencoders (VAEs) trained with cross-modal geometric regularization, preserving archetype structure and spatial neighborhood information while enabling bidirectional translation between modalities. On semi-synthetic CITE-seq data, ARCADIA outperforms existing weak-linkage methods. Applied to independent human tonsil scRNA-seq and CODEX data, ARCADIA reconstructs known tissue architecture and reveals spatially dependent transcriptional programs linking B-cell maturation and T-cell activation or exhaustion to microenvironmental niches. AVAILABILITY AND IMPLEMENTATION: Source code is accessible at https://github.com/azizilab/ARCADIA_public. Reproducibility scripts and data are available at https://github.com/azizilab/arcadia_reproducibility.

Proteomics

ELN orchestrates prometastatic and immunosuppressive niche in bladder cancer via TGFB1 autocrine signaling.

Bladder cancer (BCa) mortality is mainly driven by metastatic dissemination and an immunosuppressive tumor microenvironment. Here, we identify ELN (tropoelastin), an extracellular matrix protein abundantly secreted by cancer-associated fibroblasts (CAFs), as a critical determinant of these processes and a marker of poor prognosis. ELN promotes epithelial-mesenchymal transition (EMT), facilitates lymphatic spread, and induces immune dysfunction characterized by macrophage polarization toward an M2 phenotype and T cell exhaustion. Mechanistically, ELN functions as a binding partner of TGF-β receptor 2 (TGFBR2), thereby triggering SMAD2/3-dependent TGF-β1 secretion and establishing a feed forward signaling loop. This ELN/TGFBR2/TGF-β1 axis amplifies metastatic capacity and immunosuppressive signaling, ultimately accelerating disease progression and diminishing responsiveness to immune checkpoint blockade. Functional studies in BCa organoids and murine models demonstrated that pharmacologic blockade of the ELN-TGFBR2 interaction effectively suppressed tumor metastasis and restored antitumor immunity. Collectively, our findings establish ELN as a CAF-derived driver of metastasis and immune evasion in BCa. Targeting the ELN-TGFBR2 interaction offers a promising therapeutic strategy to limit metastatic progression and enhance the efficacy of immunotherapy in this lethal disease.

Animals

Benchmarking urinary cell transcriptomes for noninvasive differentiation of BK polyomavirus-associated nephropathy from T cell-mediated rejection.

BK polyomavirus-associated nephropathy (BKVN) adversely impacts kidney allograft survival and often mimics acute T cell-mediated rejection (TCMR), confounding diagnosis and management. To address this conundrum, we performed unbiased RNA sequencing of urinary cells matched to biopsies classified as BKVN with intragraft inflammation (BKVN-P), BKVN without inflammation (BKVN-N), TCMR, or no rejection (NR). BKVN-N displayed dominant host DNA replication, cell cycle, and repair programs, while BKVN-P samples exhibited expansive innate immune activation, antigen presentation, chemokine upregulation, and epithelial injury. Both BKVN subtypes shared signatures of T cell exhaustion and mature and tolerogenic dendritic cell activation but differed in immune orientation - Th1 predominance in BKVN-N versus Treg and CD8 enrichment in BKVN-P. Compared with TCMR samples, BKVN-P lacked robust TCR/CD28 signaling and was enriched for viral and innate modules; BKVN-N lacked alloimmune activation. B cell exhaustion characterized BKVN-N, while BKVN-P displayed robust B cell activation with metabolic downregulation. A ratiometric urinary cell biomarker, CXCL10 mRNA/CD3E mRNA, distinguished both BKVN subtypes from TCMR with diagnostic accuracy, replicated by quantitative reverse transcription PCR for clinical translation, and confirmed in an independent cohort. These findings demonstrate the utility of urinary cell transcriptomics for resolving viral injury from alloimmunity, enabling precision diagnostics and targeted immunomodulation in kidney transplantation.

Humans

Senescent fibroblasts drive CD8+ T cell dysfunction in colorectal cancer via CD36-mediated lipid transfer and peroxidation.

BACKGROUND: Functional exhaustion of tumor-infiltrating CD8+ T cells represents a hallmark of colorectal cancer (CRC) immunosuppression, though its mechanistic drivers remain elusive. Given the established correlation between CRC progression and stromal senescence characterized by pathological lipid accumulation and impaired immunity, we investigated whether and how senescent fibroblasts actively regulate CD8+ T cell dysfunction. METHODS: Single-cell RNA sequencing (scRNA-seq) analysis was conducted to unveil the diverse fibroblast populations and the significant lipid metabolism changes between senescent fibroblasts and non-senescent fibroblasts in human CRC specimens and adjacent normal mucosa. Machine-learning identified senescent fibroblasts with a distinct gene signature. Cell-cell communication analysis was used to evaluate the interactions between senescent fibroblasts and CD8+ T cells in colorectal cancer. Co-culture experiments were conducted among senescent fibroblasts, CD8+ T cells and patient-derived organoids of CRC (CRC-PDOs), with the results evaluated with high-content imaging and propidium iodide/Hoechst 33,342 staining. Flow cytometry, ELISA and lipid pulse-chase with BODIPY FL C16 were performed to detect the alterations of CD8+ T cell cytotoxic function and metabolic status. AOM/DSS-induced CRC mouse model was used to conduct in vivo validation to evaluate whether senolytics could suppress CRC progression. Patients from the Cancer Genome Atlas colorectal cancer cohort were stratified into CD36-high and CD36-low groups by median expression, and drug sensitivity for GDSC2 compounds was predicted computationally using the oncoPredict R package. RESULTS: ScRNA-seq demonstrated the specific cell population presence and divergence of senescent fibroblasts between neoplastic and histologically normal adjacent cell clusters in CRC. Random Forest was employed for cell senescence classification. Feature importance analysis identified five genes as key contributors to the model’s decision process. Cell-cell communication analysis revealed enhanced interactions between senescent fibroblasts and CD8+ T cells in CRC. Co-culture of senescent fibroblasts significantly impaired the cytotoxic functions of CD8+ T cells on CRC-PDOs, which was reflected by the declined proportions of granzyme B (GZMB) + and interferon gamma (IFNγ) + CD8+ T cells and enhanced viability of CRC-PDOs. Mechanistically, the co-culture with senescent fibroblasts promoted the lipid shuttling into CD8+ T cells to induce lipid peroxidation and downstream impairment of cytotoxicity. Furthermore, the inhibition of CD36, the specific scavenger receptor for lipid uptake of CD8+ T cells, effectively suppressed lipid transfer and peroxidation thereby preserving the effector functions of CD8+ T cells and ultimately promoting tumor apoptosis. Complementarily, in vivo senolytic treatment significantly suppressed CRC progression in AOM-DSS CRC mouse models. Top 12 therapeutic agents were identified significantly enhanced predicted efficacy in CD36-high tumors. CONCLUSIONS: Our study identified a substantial population of senescent fibroblasts in human CRC through single cell transcriptomics, machine-learning and clinical biopsies. These senescent fibroblasts impair CD8+ T cell-mediated killing of CRC-PDOs via CD36-dependent lipid transfer, suggesting senolytic targeting of stromal cells as a promising immunotherapeutic strategy for CRC.

Colorectal Neoplasms

Programmed cell death-1: from a T-cell immune checkpoint to a regulator of Natural Killer cell biology.

Programmed cell death protein 1 (PD-1, CD279) is a pivotal inhibitory immune checkpoint receptor that plays a central role in maintaining immune homeostasis and peripheral tolerance. Originally characterized as a negative regulator of T-cell activation, PD-1 limits excessive immune responses and prevents autoimmunity, while its sustained expression under conditions of chronic antigen stimulation contributes to T-cell dysfunction and exhaustion. The discovery that blockade of the PD-1 pathway can restore anti-tumor immunity has revolutionized cancer therapy and established immune checkpoint inhibition as a cornerstone of modern oncology. Although PD-1 has traditionally been viewed as a key regulator of adaptive immunity, accumulating evidence indicates that its biological functions extend beyond T cells. In recent years, PD-1 expression has been identified in several innate immune cell populations, particularly Natural Killer (NK) cells, where it has emerged as an important modulator of effector functions, cytokine production, metabolic fitness, and antitumor activity. These findings have challenged the classical view of PD-1 biology and revealed unexpected similarities between NK-cell dysfunction and the exhausted phenotype described in chronically stimulated T cells. In the tumor microenvironment, PD-1 expression on NK cells has been associated with impaired cytotoxicity and reduced immune surveillance, suggesting that NK cells may also represent relevant targets of PD-1-mediated immunosuppression. At the same time, the mechanisms regulating PD-1 expression and signaling in NK cells appear to differ, at least in part, from those operating in T lymphocytes, highlighting the complexity of this pathway across distinct immune cell subsets. In this review, we summarize the current knowledge of PD-1 biology, from its established role in T-cell regulation to its emerging functions in NK cells. We discuss the molecular mechanisms governing PD-1 expression and signaling, its contribution to immune dysfunction in cancer and chronic diseases, and the potential implications of targeting the PD-1 axis to enhance both adaptive and innate antitumor immunity.

Natural Killer (NK) cells

Treatment Decisions in Multiple Myeloma.

Revolutions in transplantation and targeted and immune therapies have transformed multiple myeloma from a disease with an associated survival of a few years into one for which functional cure is an emerging goal. This abundance of effective therapies has created clinical complexity. Here we provide a practical framework, anchored in trial evidence and informed by emerging biologic discoveries, for the navigation of treatment decisions across the disease spectrum. We outline how cytogenetic and genomic risk stratification, functional fitness, and measurable residual disease status individualize therapy in newly diagnosed disease, in which quadruplet induction therapy is now standard and the role of autologous transplantation is being reevaluated. Regarding relapse, we address the sequencing of B-cell maturation antigen-directed chimeric antigen receptor (CAR) T cells, bispecific antibodies, and antibody-drug conjugates, emphasizing T-cell fitness and multiantigen targeting to counter exhaustion and antigen escape. We also consider early interception in high-risk smoldering myeloma. Throughout, we underscore that enrollment of patients in clinical trials should be considered in order to ensure continued progress.

Humans

CAR-T Cell Therapy: Manufacturing Platforms and Clinical Consequences.

Chimeric antigen receptor (CAR) T-cell therapy has transformed hematological cancer care, yet variability in efficacy, durability, and safety cannot be explained solely by antigen selection or patient factors. We propose that manufacturing platforms are active biological determinants of outcome. Viral vectors, used in all licensed products, provide stable genomic integration and durable expression but are limited by cost, cargo capacity, and centralized production. Nonviral strategies, including transposons, CRISPR knock-ins, and messenger RNA delivery, enable faster, less-expensive manufacturing with larger payloads, while introducing distinct safety and persistence profiles. This review presents a three-layer mechanistic framework that reframes manufacturing as biology: integration biology determines genomic risk and transgene stability; clonal fitness shapes persistence, dominance, and exhaustion; and epigenomic imprinting, influenced by gene transfer method, cytokines, and culture stress, preconfigures functional trajectories. Clinical observations link platform choice to immune recovery, where prolonged B-cell aplasia and delayed T-cell reconstitution contribute to infection-related nonrelapse mortality, and hematopoietic reserve at apheresis emerges as a practical predictor. Finally, manufacturing is positioned as the key to democratizing cell therapy. Decentralized, nonviral production aligned with regulatory standards may enable equitable access and transition CAR-T therapy from innovation to sustainable global care.

Humans