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Protective effect of active immunization with purified Escherichia coli heat-labile enterotoxin in rats.

The protective effect of active immunization by different routes with a purified preparation of the polymyxin-release form of Escherichia coli heat-labile toxin was evaluated in rats. Immunized animals were challenged by placing toxin into ligated ileal loops at dosages which produced either 50% or the maximum secretory response in unimmunized rats. Immunization exclusively by the parenteral route yielded significant protection. Rats were also protected when parenteral priming was followed by boosting given either directly into the duodenum or perorally 2 h after intragastric cimetidine, but not when the peroral boosts were given with bicarbonate. Immunization administered entirely by the peroral route with cimetidine yielded protection but only when the immunizing dosage was fivefold greater than that found effective in the parenteral-peroral approach. Rats immunized exclusively by the parenteral route and those boosted perorally with cimetidine were also tested, and found to be protected, against challenge with viable organisms of strains that produce either heat-labile toxin alone or both heat-labile and heat-stable toxin, but they were not protected against a strain which produces just heat-stable toxin. Geometric mean serum antibody titers were increased by 16-fold or more over control values in those groups of rats in which protection was achieved, with the exception of those immunized exclusively by the peroral route. These observations demonstrate that (i) active immunization with purified E. coli heat-labile toxin results in significant protection against both this toxin as well as viable organisms which produce it, but not against viable strains which produce heat-stable toxin only, and (ii) concomitant ablation of gastric secretion by the use of cimetidine renders the peroral route of immunization effective. They suggest that prophylactic immunization against diarrheal disease caused by heat-labile toxin-producing strains of E. coli may be feasible in humans.

Animals

Profiling tumor immune microenvironment of epithelial ovarian carcinoma.

BACKGROUND: Epithelial ovarian carcinoma (EOC) comprises five main histological subtypes: high-grade serous (HGSOC), low-grade serous (LGSOC), clear cell (CCOC), mucinous (MOC), and endometrioid (ENOC). Each histotype harbors specific genomic alterations and clinical outcome. Few studies systematically compared the tumor immune microenvironment across the five subtypes. METHODS: We performed 7-plex (CD45, CD8, CD68, CD163, FoxP3, CD20, and cytokeratin) sequential immunohistochemistry on a clinically annotated tissue microarray including 139 EOC representing the five subtypes and 26 borderline tumors (serous and mucinous). Digital pathology was used to quantify immune cell abundance, their spatial distribution (stroma vs tumor core), and correlation with survival. RESULTS: Immune cells were dominated by macrophages and more abundant in the stroma than tumor core across the five subtypes, consistent with immune excluded pattern. Compared to HGSOC, CCOC displayed the highest infiltration by CD45+ leukocytes and CD68+ macrophages, particularly M2-like CD163+ cells, suggesting a macrophage-rich, immunosuppressive phenotype. LGSOC exhibited the highest infiltration by intraepithelial FoxP3+ regulatory T cells. Comparison of borderline tumors with invasive carcinoma (LGOSC and MOC) revealed that malignant progression is accompanied by loss of CD8+ T cells, enrichment in regulatory T cells and increase of CD163+/CD68+ ratio, consistent with immune evasion during tumorigenesis. There was a trend toward better survival in HGSOC highly infiltrated by lymphocytes, either intraepithelial (CD8+ and FoxP3+) or stromal (FoxP3+ and CD20+). CONCLUSIONS: EOC is characterized by histotype-specific immune milieux defined by macrophage dominance, epithelial immune exclusion and dynamic immune remodeling during progression from borderline tumors to invasive carcinomas.

Humans

Machine learning and multi-omics clustering to map cellular rewiring and immune evasion in ccRCC.

Immune checkpoint blockade (ICB) efficacy in clear cell renal cell carcinoma (ccRCC) is limited by tumor microenvironment (TME) heterogeneity. Because traditional bulk-derived models lack spatial resolution, we developed an integrated framework connecting macroscopic survival risks to microscopic TME structures. We applied ten algorithms to establish multi-omics subtypes and evaluated 101 machine-learning combinations across three independent cohorts to generate a Consensus Machine Learning-driven Signature (CMLS). The signature's spatial and cellular origins were decoded using spatial transcriptomics (ST) and a 140,000-cell scRNA-seq atlas. Expression of key genes was experimentally validated via RT-qPCR in 17 paired ccRCC clinical tissues. We identified two molecular subtypes with distinct clinical and epigenetic profiles. SuperPC optimization yielded a 24-gene CMLS serving as an independent prognostic factor. scRNA-seq and ST deconvolution revealed these signals predominantly originate from cancer-associated fibroblasts (CAFs) and malignant epithelial cells, which collaborate to drive spatial immune exclusion. RT-qPCR confirmed significant overexpression of five core CMLS genes in ccRCC versus adjacent normal tissues. Low CMLS scores correlated with enhanced ICB responsiveness, whereas high-CMLS tumors demonstrated specific vulnerability to dasatinib and dabrafenib. The CMLS translates spatial immune-exclusion dynamics into a quantifiable metric, outperforming tumor mutational burden in predicting ICB benefits, providing a robust tool for patient stratification in ccRCC.

Humans

A novel lactylation-related gene signature deciphers the immunosuppressive microenvironment and stratifies precision therapy in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) remains a leading cause of cancer mortality, largely due to the heterogeneity of the tumor microenvironment (TME) and the limited efficacy of immunotherapy in microsatellite stable (MSS) tumors. Histone lactylation, a post-translational modification derived from the Warburg effect, serves as a critical bridge linking metabolic reprogramming to gene regulation and immune evasion; however, its specific prognostic value and clinical implications in CRC remain to be fully elucidated. METHODS: In this study, we systematically analyzed transcriptome profiling data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) cohorts, supplemented by single-cell RNA sequencing (scRNA-seq) analysis and Human Protein Atlas (HPA) protein-level validation. By integrating univariate Cox regression, Least Absolute Shrinkage and Selection Operator (LASSO) analysis, and multivariate Cox regression, we constructed a novel lactylation-related gene (LRG) risk signature. We extensively evaluated the association between this risk signature and patient prognosis, immune infiltration patterns, somatic mutations, and therapeutic sensitivity. RESULTS: A robust 9-gene prognostic signature (DHRS7, SPR, MBD2, RBM17, CSRP2, S100A4, TMSB4X, TKT, COPS4) was identified and corroborated at the protein level. Patients with high risk scores exhibited significantly worse overall survival (OS) across the training and two independent validation cohorts. Immunogenomic and scRNA-seq analyses revealed that high-risk tumors were characterized by an immunosuppressive and stromal-dense microenvironment-with stromal cells exhibiting the highest lactylation risk scores-enriched with regulatory T cells (Tregs), and frequently harbored PIK3CA mutations. Differential expression analysis indicated that this immune exclusion is structurally maintained by enriched extracellular matrix (ECM) organization and TGF-β signaling. Conversely, low-risk tumors displayed an inflamed phenotype with active antitumor immunity. Pharmacogenomic prediction identified distinct therapeutic stratifications: low-risk patients exhibited significant sensitivity to standard chemotherapeutics (fluorouracil, oxaliplatin) and EGFR/HER2 inhibitors (e.g., lapatinib, erlotinib). In contrast, high-risk patients showed specific vulnerabilities to novel targeted agents, including PI3K pathway inhibitors (TG-100-115, XL765), microenvironment-modulating agents (sildenafil, GANT-61), and epigenetic inhibitors (UNC0638). CONCLUSION: We established a novel lactylation-related risk signature that effectively stratifies CRC patients by prognosis and TME characteristics. By elucidating the crosstalk between metabolic dysregulation, stromal barriers, and immune exclusion, this study provides potential biomarkers and stratified therapeutic strategies-ranging from standard chemotherapy to targeted metabolic and stromal interventions-to optimize precision medicine for CRC patients.

Colorectal cancer

The extracellular matrix in cancer-associated fibrosis: molecular mechanisms and clinical relevance.

The ECM is a dynamic component of the tumor microenvironment with a critical role in cancer progression, invasion, metastasis, immune exclusion, and response to therapy. Recent advances in proteomic analyses investigating the insoluble ECM fractions (termed "matrisome analysis"), along with single-cell RNA sequencing and spatial transcriptomics, have revealed cancer-specific patterns of ECM remodeling. These studies have identified a panel of recurrently upregulated ECM proteins, including annexin A1, fibrillin-1, fibronectin, periostin, and tenascin-C, actively contributing to tumor growth, invasion, angiogenesis, and immune exclusion. The expression of the cancer-associated ECM is largely driven by cancer-associated fibroblasts (CAFs), whose molecular diversity has been dissected through single-cell profiling and consolidated in emerging CAF atlases across cancers. By investigating the matrisome composition and CAF heterogeneity, these studies have unraveled the pivotal role of the stroma in shaping tumor biology. Based on these discoveries, ECM proteins and CAFs are now being explored as biomarkers and therapeutic targets. Future integration of multi-omics datasets with clinical outcomes will help to translate these insights into novel biomarkers for patient stratification and stroma-directed therapeutic interventions.

Humans

Radiomics as a spatial context for treatment decision-making in head and neck cancer.

Radiomics has been widely explored as a non-invasive biomarker in head and neck squamous cell carcinoma (HNSCC), yet its clinical role remains unclear. Tissue-based biomarkers differ in their susceptibility to spatial sampling. Biomarkers such as PD-L1 expression, immune-cell infiltration, necrosis, and immune exclusion may exhibit substantial spatial heterogeneity, whereas HPV/p16 status and some genomic alterations are generally more stable across the tumor. Nevertheless, localized sampling may incompletely capture heterogeneity in selected clinical contexts. This mismatch becomes clinically relevant when treatment decisions, particularly for chemoradiotherapy, immunotherapy, or de-escalation, are based on potentially non-representative biopsy findings. In this narrative review, we argue that the role of radiomics is not to outperform established biomarkers, but to contextualize them by capturing spatial heterogeneity related to hypoxia, necrosis, stromal architecture, and immune exclusion. We synthesize current evidence linking radiomic features to these biological processes and map them to specific clinical decision points, including larynx preservation, immunotherapy stratification, and recurrence assessment. Rather than serving as a standalone predictor, radiomics may provide complementary spatial information that helps identify situations in which biopsy-derived biomarkers should be interpreted with caution. Although current evidence is largely retrospective, radiomics offers a pragmatic framework for integrating spatial information into biomarker-guided clinical workflows.

Journal Article

Atopy as a minimal immunodeficiency?

Despite impressive recent advances in the understanding of the chemical and cellular bases of the reaginic response, the pathogenesis of atopic diseases still remains a matter of speculation. The frequent finding of atopic diseases in some primary immunodeficiencies such as selective IgA deficiency and the Wiskott-Aldrich syndrome offers a unique opportunity for studying the immune mechanisms underlying the genesis of atopy. Recent studies in subjects with selective IgA deficiency have challenged the well known hypothesis that atopy is the result of defective "immune exclusion" by the secretory immune system. A number of immunological features found in the primary immunodeficiencies associated with atopic disorders suggest that defective homeostatic mechanisms regulating reaginic responses may play a major role in the pathogenesis of atopy. A thorough analysis of these disease combinations may help to generate new working hypotheses concerning the immune pathogenesis of atopic diseases.

Dysgammaglobulinemia

Spatial Omics in High-Grade Gliomas: Mapping Immune-Tumor Niches for Precision Therapy.

High-grade gliomas (HGGs), particularly glioblastoma (GBM), remain among the most lethal human cancers despite decades of molecular profiling and therapeutic innovation. A primary reason for treatment failure is that HGG biology is spatial: malignant cell states, immune suppression, metabolic stress, and therapeutic resistance are organized into distinct anatomical and functional niches. Spatial omics technologies now enable high-dimensional mapping of gene expression, protein signaling, immune architecture, and metabolic activity within intact tumor tissue. These approaches reveal how proneural and mesenchymal transcriptional states coexist yet localize to distinct regions, alongside hypoxic, invasive, and stem-enriched niches. Spatial analyses show that key clinical determinants, including O6-methylguanine-DNA methyltransferase (MGMT)-associated temozolomide resistance, radiotherapy tolerance in hypoxic regions, and immunotherapy failure driven by myeloid-dominated immune exclusion, are influenced not only by molecular programs but also by cellular location. Beyond biological insight, spatial omics is reshaping clinical paradigms by enabling region-specific patient stratification, early assessment of treatment response, and identification of therapy-resistant reservoirs that seed recurrence. Prior bulk and single-cell studies defined HGG cell states and pathways but often treated resistance as tumor-wide. This review presents a spatially explicit framework that synthesizes spatial transcriptomic and immune-profiling studies to identify tumor-immune niches and spatial bottlenecks that drive therapeutic failure and recurrence.

Humans

Integrative Pan-Cancer Characterization of lncRNA UPK1A-AS1 and Its Role in Hypoxia-Associated Sorafenib Resistance in Hepatocellular Carcinoma.

Long noncoding RNAs (lncRNAs) are emerging as critical regulators of tumor initiation and progression through transcriptional and posttranscriptional mechanisms. UPK1A antisense RNA 1 (UPK1A-AS1), a cancer-associated lncRNA, has been reported to participate in oncogenic processes; however, its overall landscape across human malignancies and its biological role in therapy resistance remain poorly understood. Given the increasing importance of identifying functional lncRNAs with prognostic and therapeutic potential, this study presents a comprehensive multiomics characterization of UPK1A-AS1 and its experimental validation in hepatocellular carcinoma (HCC). We integrated datasets from The Cancer Genome Atlas (TCGA), the Genotype-Tissue Expression Project (GTEx), the cancer immunology data engine (CIDE), and the cBioPortal for cancer genomics (cBioPortal) to systematically assess its expression pattern, genomic alterations, clinical significance, and immunological associations. Our analyses revealed that UPK1A-AS1 is significantly upregulated in multiple tumor types, with copy-number amplification as the predominant genomic alteration driving its overexpression. Elevated UPK1A-AS1 expression was correlated with advanced disease stage, poor differentiation, immune exclusion, and unfavorable prognosis, supporting its potential as a cancer type-dependent biomarker. In parallel, functional studies demonstrated that hypoxia transcriptionally induces UPK1A-AS1 in HCC, where it promotes sorafenib resistance by suppressing apoptosis. Silencing UPK1A-AS1 restored apoptotic and enhanced sorafenib efficacy both in vitro and in vivo. Collectively, our findings suggest that UPK1A-AS1 is a hypoxia-inducible oncogenic lncRNA that plays dual roles in cancer, with cancer type-dependent associations with progression and immune modulation across malignancies and mechanistically mediating hypoxia-associated drug resistance in HCC.

Humans

EGFR-Mutant Non-Small Cell Lung Cancer With Small Cell Transformation: Clinicopathological Features, Treatment Landscape, and Biomarker Profiles.

INTRODUCTION: Transformed small-cell lung cancer (tSCLC) is a clinically important resistance mechanism to EGFR tyrosine kinase inhibitors in EGFR-mutant non-small cell lung cancer. This study characterizes clinical features, treatment outcomes, and biomarker profiles in patients with tSCLC. METHODS: Data from 45 patients with EGFR-mutant NSCLC who developed tSCLC between 2014 and 2023 were analyzed. Demographic characteristics, treatment histories, and delta-like ligand 3 (DLL3) and B7-H3 expression were collected. Objective response rate, progression-free survival (PFS), and posttransformation survival (PTS) were assessed. Spatial transcriptomic profiling was performed in selected cases. RESULTS: Most patients were women (60%) and never-smokers (75.6%). Exon 19 deletion was the predominant EGFR mutation (57.8%). Median PFS and PTS were 3.3 and 9.2 months, respectively. Etoposide plus platinum (EP) was the predominant first-line regimen (69.8%), with 23.2% of the patients receiving EP plus immune checkpoint or tyrosine kinase inhibitors. EP-based combination regimens yielded a numerically higher objective response rate and a significantly longer PFS than EP alone (7.5 versus 2.8 months, p = 0.002). PTS was longer with EP-based regimens than with other regimens (10.4 versus 6.4 months, p = 0.035). DLL3 and B7-H3 were expressed in 87.5% and 66.7% of tumors, respectively, without prognostic significance. Multivariable analysis identified brain metastasis and liver progression at transformation as adverse prognostic factors. Spatial transcriptomic analysis revealed neuroendocrine lineage reprogramming, stromal depletion, and immune exclusion. CONCLUSIONS: tSCLC remains an aggressive resistance phenotype with poor outcomes. EP-based combination strategies may provide clinical benefit, whereas frequent DLL3 expression supports further evaluation of targeted therapies.

Delta-like ligand 3

Loss of tumor-infiltrating lymphocytes and poor response to immunotherapy in IDH GOF mutant melanoma.

Recent innovations in melanoma treatment with immune checkpoint blockade (ICB) have improved overall outcomes for patients; however, over 50% of patients still develop resistance to treatment. These patients either have intrinsic resistance and never respond to therapy or develop acquired resistance months or years into treatment. The mechanisms underlying ICB resistance remain poorly understood. Our data show that patients with isocitrate dehydrogenase gain-of-function (IDH GOF) mutant melanoma have a worse response to anti-PD1 immunotherapy. IDH mutations have been found to be oncogenic and associated with differential methylation in multiple cancers but are not yet characterized in human melanoma. Here, we investigate the clinical, immune, and transcriptional phenotypes of IDH GOF melanomas through analyses of clinical response, single-cell RNA-seq, bulk RNA-seq, and DNA methylation data. Single-cell data analysis showed decreased immune infiltrate and activity in the IDH GOF tumors. Bulk sequencing data demonstrated the association among IDH mutation, immune exclusion, and disruptions in global DNA methylation. The melanoma-derived genomic data presented support previously described resistance mechanisms of IDH mutation in other cancer types and is the first demonstration to our knowledge of the role of IDH GOF in the human melanoma tumor microenvironment.

Humans

Genetic and nutritional variations in antigen handling and disease.

Low function (deficiency), within the 'normal range', of each of five immunity functions is associated with immunopathological disease, and/or defective antigen handling. These are probably genetically determined, either polygenic or single gene, but environmental factors such as diet influence them greatly, and the vulnerability may be especially great in the newborn period. The relevant systems are those involved in the immune elimination of antigen (antibody and macrophages) and those possibly involved in the immune exclusion of antigen (IgA, the alternative pathway of complement, and cilial action). The gut has an especially complicated role in antigen-handling, and feeding influences its capacity to do so. Eczema was prevented by a regimen of neonatal antigen avoidance, which was largely breast-feeding, and it is likely that other immunopathological diseases result from antigen contact during periods of malnutrition. The mechanisms of such effects are likely to be complicated, but adjustment of the environment to suit the genetically vulnerable, particularly in the newborn period, can lead to the prevention of disease.

Adult

Immunologic and genetic factors predisposing to allergy.

Allergy often begins with a subtle and/or transient T cell defect. This defect is first responsible for an IgA deficiency. The normal function of IgA is immune exclusion. In its absence, allergens can pass through the mucosa and stimulate the immunocompetent cells. The T cell defect may also be implied by the synthesis of IgE directed against the allergens which passed through. Clinical, biological and immunological findings (T cell defect in allergic disease, low range of IgA in the early life of atopics) are in agreement. The genetic factor for pollinosis and house dust allergy are segregated. In ragweed allergy there is an Ir gene coding for antigen-specific Ig of different classes and a group of non-linked major histocompatibility complex alleles coding for non antigen-specific IgE. There are some links with HLA. In house dust allergy the Ir gene is very common and almost everyone can produce an allergy under some conditions (T cell defect). Whatever the immunologic and genetic factors are, they need allergens and environmental factors to induce allergy. Allergy is a complex state in which several mechanisms, often associated and sometimes unclear, are involved. Some of them may be an abnormality of the autonomic nervous system, and/or an increase in the mucous membrane permeability, and/or a subtle immunodeficiency. All these mechanisms are regulated by genetic factors and modulated by environmental ones.

Environment

Decoding spatiotemporal fibrotic and cellular immunosuppression of therapeutic T cells in live pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDA) is profoundly immunosuppressive. To help define this behavior, we present integrated experimental and computational frameworks to elucidate therapeutic T cell dynamics. Through the development of TME-CARTographer (TME-CART), a computational pipeline integrating high-dimensional data, graph theory, behavior analysis, and deep learning (DL), we present quantitative insights on 4D T cell-TME interactions in live PDA tumors. Mapping physical immunosuppression demonstrates that collagen fiber architectures direct migration while concomitantly limiting off-axis movement, creating immune exclusion zones. Expanding these findings, we establish that the collagen matrix harbors and spatially organizes immunosuppressive myeloid cells to serve as cooperative co-modulators of T cell behaviors, including migration, sampling, repulsion, and sequestration. Consistent with these findings, DL defines both linear and nonlinear collagen matrix and cellular neighborhood interactions as drivers of T cell behavior. The TME-CART DL framework also accurately predicts shifts in immunosuppression following depletion of myeloid cells. Overall, we identify synergistic barriers impeding anti-tumor T cell behaviors and present TME-CART as a discovery platform for interpreting complex 4D data to enhance the understanding and design of immunotherapies.

Journal Article

[On the production of anti-human-lymphocyte serum (ALS) by means of combined local and intravenous immunization in swine].

Lymphocytes of donors' peripheral blood were used for the study of pig antihuman ALS preparation by means of local and intravenous immunization. The results were compared with those obtained with exclusively local application of the same antigen. Antisera were tested from the aspect of activity (lymphoagglutination, lymphocytotoxicity, the rosette inhibition test) and for the presence of unwanted antibodies (haemagglutinins, thromboagglutinins, precipitins to serum proteins). Of all alternatives tested the following scheme proved to be optimal: subcutaneous application of 2 X 10(9) lymphocytes with adjuvans on day 0, followed by intravenous application of the same dosage on day 13, and serum harvesting on day 20. Antisera thus obtained displayed titres 1: 32 000 to 1 : 130 000 in the RIT - this being maximum level reached by exclusively local immunization only in some animals. Therefore, favourable immunosuppressive effect in vivo can be expected. Even more profound difference was observed in the level of unwanted antibodies that were found to be on markedly lower level after combined immunization. There is a good reason to suppose that with the help of further techniques, more likely absorption, these can be lowered to acceptable level. It is apparent from the results that with the help of a suitable immunization procedure not only highly active ALS can be obtained but also formation of nondesirable antibodies can be suppressed and, despite their thrombocyte contamination peripheral blood lymphocytes can successfully be used.

Animals

Novel immunotherapeutic strategies for colorectal cancer treatment: Advances, challenges, and future directions.

Immunotherapy has reshaped the treatment landscape of colorectal cancer (CRC), with the clearest and most durable benefit established in mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) disease. However, framing CRC immunotherapy simply as "MSI-H responsive versus microsatellite stable (MSS) resistant" is no longer sufficient. Recent studies indicate that a subset of proficient mismatch repair (pMMR) colon cancers, particularly in the neoadjuvant setting, can mount clinically meaningful responses to immune checkpoint blockade, suggesting that disease stage, local immune organization, and treatment timing critically influence immunotherapy sensitivity. In parallel, emerging evidence has expanded the relevant immune landscape beyond the tumor bed itself, showing that spatially organized stromal and adipose niches can actively divert tumor-reactive lymphocytes and promote immune escape. These advances shift the central challenge in CRC immunotherapy from simply identifying new agents to defining when and in whom immune resistance is reversible, and which biological bottlenecks-such as vascular dysfunction, myeloid suppression, and spatial immune exclusion-must be overcome. In this context, alternative checkpoint inhibitors, bispecific antibodies, cellular therapies, vaccines, nanotechnology-enabled platforms, and microbiome-targeted approaches remain important, but their translational maturity and evidentiary support differ substantially. Biomarker development is likewise evolving from static genomic classification toward dynamic and mechanism-informed stratification incorporating circulating tumor DNA (ctDNA), chromosomal instability, immune architecture, and treatment-induced response trajectories. This review synthesizes recent advances in CRC immunotherapy while emphasizing evidence hierarchy, biomarker-guided patient selection, and the mechanistic basis of combination strategies. We argue that the next phase of CRC immunotherapy will depend less on the indiscriminate addition of novel agents and more on the rational deployment of immunotherapy across molecularly, spatially, and temporally defined disease states.

Humans

Pan-cancer multi-omics machine learning defines a lactylation-associated immune-excluded tumor state with proteomic and experimental corroboration.

BACKGROUND: Histone lactylation links lactate metabolism to chromatin regulation, but whether lactylation-program-associated transcriptional patterns delineate recurrent pan-cancer tumor states remains unclear. METHODS: We integrated mRNA, lncRNA, and miRNA profiles from 9712 TCGA tumors across 33 cancer types with GTEx references, six GEO cohorts, IMvigor210, and an institutional clear-cell renal cell carcinoma (ccRCC) cohort used for exploratory DIA-NN proteomic corroboration. Random-effects co-expression meta-analysis, multi-omics consensus clustering, regulon inference, immune deconvolution, TIDE, oncoPredict, and SHAP-based machine learning were applied. hsa-miR-431-5p was functionally evaluated as a proof-of-concept CS2-associated miRNA in bladder cancer models. RESULTS: LacCoEx-Atlas comprised 398,491 lactylation-related co-expression pairs across 24,667 RNA features under a random-effects framework (median I² = 88.6%). Consensus clustering identified two subtypes: CS2 showed glycolytic-mesenchymal-immune-excluded features, M2 macrophage enrichment, CD8⁺ T-cell depletion, elevated HDAC4/NSD3/KDM6B activity, and worse survival, whereas CS1 showed oxidative, sirtuin-active programs. CS2 had fewer predicted ICI responders (18.3% vs. 52.0%) and a lower observed ORR in IMvigor210 (15.3% vs. 24.0%). oncoPredict identified NU7441 as a hypothesis-generating CS2-associated sensitivity signal (Hedges' g = 1.17). DIA-NN proteomics in 50 ccRCC specimens provided exploratory support for CS2-associated hypoxia, ECM degradation, and metastasis programs. The 10-feature mRNA LARItools model achieved an apparent AUC of 0.9413, while a separate multi-omics model achieved 0.971; neither was independently validated. LARItools reproduced prognostic separation across six GEO cohorts. miR-431-5p promoted malignant phenotypes and EMT in bladder cancer cells, with concordant CMU4h expression findings. CONCLUSIONS: Lactylation-program-associated transcriptional patterns delineate a recurrent immune-excluded pan-cancer tumor state associated with adverse prognosis, reduced predicted immunotherapy responsiveness, exploratory single-cancer protein-level support, and testable DNA damage response-targeting hypotheses. LacCoEx-Atlas and LARItools provide open resources for lactylation-program-associated tumor-state stratification and future translational research.

Humans

Secreted protein circuits in the gastrointestinal tumour microenvironment: determinants of immunotherapy response and resistance.

Immune checkpoint blockade has transformed treatment in selected gastrointestinal (GI) cancers, yet primary resistance, incomplete responses and acquired resistance remain common. This heterogeneity is not explained by tumour-cell genomics alone; extracellular signalling programmes within the tumour microenvironment can determine immune recruitment, access and adaptation to therapy. The tumour secretome-including cytokines, chemokines, growth factors, complement components, matricellular proteins, soluble checkpoint molecules and extracellular-vesicle-associated cargo-regulates immune-cell recruitment, exclusion, suppression, tertiary lymphoid structure formation and exhaustion across anatomical and molecular contexts. Across gastric and esophageal cancers, colorectal cancer, pancreatic ductal adenocarcinoma, hepatocellular carcinoma and biliary tract cancers, recurrent suppressive circuits include TGF-β, VEGF, CXCL12-CXCR4, CXCL8/IL-8-CXCR1/2, CCL2-CCR2, CSF1-CSF1R, IL-6-family cytokines, SPP1/osteopontin, periostin, galectins, DKK1, MIF, complement and soluble or vesicular PD-L1. Conversely, CXCL9/10/11-CXCR3 signalling and CXCL13-associated tertiary lymphoid structures characterise immune-permissive states that can support checkpoint responsiveness. We organise these circuits into four overlapping functional modules-myeloid-enriched, fibroblast-driven exclusion, angiogenic-immunosuppressive and immune-permissive-and apply a four-level evidence hierarchy that separates clinical validation from mechanistic inference. Clinically useful secretome biomarkers will therefore need to integrate cellular source, spatial localisation, receptor context, temporal dynamics and linkage to actionable immune-state transitions.

Humans