Search Results (515)

Inflammatory bowel disease (IBD) is a chronic immune-mediated condition of the gastrointestinal tract, characterized by dysregulated inflammatory responses throughout the gastrointestinal tract. It includes two major phenotypes, Crohn’s disease (CD) and ulcerative colitis (UC), which present with varying gastrointestinal and systemic symptoms. The pathophysiology of IBD is multifactorial including genetic predisposition, mucosal and epithelial dysfunction, environmental injury, and both innate and adaptive immune response abnormalities. Several predisposing genetic factors have been associated with IBD explaining the strong hereditary risk for both CD and UC. For example, Caspase Recruitment Domain 9 (CARD9) variant rs10781499 increases risk for IBD, while other variants are specific to either CD or UC. CD is related to loss-of-function mutations in the nucleotide oligomerization domain containing the protein 2 (NOD2) gene and Autophagy-Related 16-like 1 (ATG16L1) gene. UC risk is increased particularly in Chinese populations by the A-1661G polymorphism of the Cytotoxic T-lymphocyte antigen 4 (CTLA-4) gene. This abnormal CTLA-4 interferes with B- and T-cell responses causing predisposition to autoimmune conditions. Previous studies suggested that IBD results from breakdown of the adaptive immune system, primarily of T-cells. However, new evidence suggests that a primary breakdown of the innate immune system in both CD and UC increases susceptibility to invasion by viruses and bacteria, with a compensatory overactivation of the adaptive immune system as a result. When this viral and microbial invasion continues, further damage is incurred, resulting in a downward cycle of further cytokine activation and epithelial damage. Released biomarkers also affect the permeability of the epithelial membrane, including lactoferrin, nitric oxide (NO), myeloperoxidase (MPO) and its activation of hypochlorous acid, matrix metalloproteinases (MMPs), especially MMP-9, omentin-1, and others. Increased macrophage and dendritic cell dysfunction, increased neutrophil activity, increased numbers of innate lymphoid cells, increased T-cells with decreased regulatory T-cells (Tregs), and changes in B-cell populations and immunoglobulin (Ig) functions are all associated with IBD. Finally, treatment of IBD has typically consisted of medical management (e.g., aminosalicylates and corticosteroids) and lifestyle modification, and surgical intervention in extreme cases. New classes of medications with more favorable side effect profiles include anti-integrin antibodies, vedolizumab, etrolizumab, and carotegrast methyl. Additionally, fecal microbiota transplant (FMT) is a newer area of research for treatment of IBD along with TNF-blockers, JAK inhibitors, and S1PR modulators. However, expense and long preparation time have limited the usefulness of FMT. Full article

Tumor-infiltrating lymphocytes (TILs) are thought to play important roles in tumor shrinkage and survival prolongation in patients with breast cancer receiving neoadjuvant chemotherapy (NAC). TILs are mononuclear immune cells such as lymphocytes and plasma cells, including CD4+ and CD8+ T cells, natural killer cells, B cells, macrophages, regulatory T cells (Tregs), and myeloid/dendritic cells. The pre-NAC presence of more T cells and fewer Tregs in biopsy samples of primary breast tumors is known to contribute to tumor shrinkage and prolonged survival. This review was conducted to elucidate these roles in patients with breast cancer treated with NAC. Publications selected for inclusion in this review were identified by a PubMed search for articles published in English, performed using the terms “breast cancer”, “neoadjuvant chemotherapy”, “tumor-infiltrating lymphocyte”, “pathological complete response”, and “immune response”. The search was completed in July 2024. The functional roles of TILs in the achievement of these outcomes may vary by tumor subtype; increases and decreases in TIL levels before and after NAC have been shown to have conflicting effects. Biomarkers have been reported to predict local responses in the tumor microenvironment (e.g., immune-related gene signatures) and systemic immune responses (e.g., neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios). Immune gene signatures and immune cell infiltration do not appear to be universally associated with tumor response or outcome in patients with breast cancer treated with NAC. The functional roles of TILs in breast tumor response and breast cancer survival may vary by tumor subtype, and conflicting results for the same subtypes may be due to differences in NAC regimens, immune responses, tumor heterogeneity, sample size, and the technical methods used to evaluate TILs in tumor samples. Full article

Radiotherapy employs high-energy X-rays to precisely target tumor tissues while minimizing damage to the surrounding healthy structures. Although its clinical efficacy is well established, the immunomodulatory effects of ionizing radiation remain complex and context-dependent. This study investigated the biological effects of radiotherapeutic doses on immune cells by evaluating lymphocyte viability, phenotypic profiles, and cytokine expression levels. Peripheral blood mononuclear cells (PBMCs) were isolated from six healthy donors and irradiated with 0, 2, or 6 Gy using a 6 MV linear accelerator (LINAC). Dose validation with an ionization chamber demonstrated strong agreement between estimated and measured values (intraclass correlation coefficient = 1, 95% CI). Immune subsets, including T cells (CD3+), helper T cells (CD3+CD4+), cytotoxic T cells (CD3+CD8+), regulatory T cells (CD3+CD4+Foxp3+), and natural killer (CD3-CD56+) cells, along with intracellular cytokines interleukin-12 (IL-12) and interferon-gamma (IFN-γ), were analyzed via flow cytometry at multiple time points. The results showed a significant, dose-dependent decline in overall lymphocyte viability (p < 0.01) compared to control. Cytotoxic T cells were the most radiosensitive, followed by helper and regulatory T cells, while NK cells were the most radioresistant. IL-12 expression initially increased post-irradiation, while IFN-γ levels remained variable. These findings demonstrate that radiation induces distinct alterations in immune phenotypes and cytokine profiles, which may shape the immune response. Immune profiling following irradiation may therefore provide valuable insights for optimizing combination strategies that integrate radiotherapy and immunotherapy in cancer treatment. Full article

Background/Objectives: Biological aging phenotypes in coronary artery disease (CAD) include coronary atherosclerosis, vascular aging, and endothelial dysfunction. The aim of the present study was to investigate the potential links between aging phenotypes, regulatory immune cells, and features of the thymus in patients with CAD. Methods: A single-center, cross-sectional, comparative study was conducted. Patients were stratified according to the severity of coronary atherosclerosis: patients with a Gensini score ≥ 65 points and patients with a Gensini score < 65 points. Peripheral blood and thymus biopsy were obtained. Imaging flow cytometry, ELISA, and immunohistochemical analysis were used for analysis. Results: Thymic morphology ranged from total fatty involution to a preserved structure of the thymus (20–80% area in 31% of obtained samples) but was not associated with the severity of atherosclerosis. Meanwhile, patients with a Gensini score ≥ 65 had impaired thymus cellular composition compared to patients with a Gensini score < 65 points; increased frequency of CD8+ T lymphocytes and NK cells; and decreased frequency of CD4 + CD8+ T lymphocytes. In peripheral blood, the main determinants of a Gensini score ≥ 65 points were low absolute counts of eMDSCs and CD25^low Tregs with FoxP3 nuclear translocation, while advanced vascular aging was associated with elevated eMDSC absolute counts. Advanced coronary atherosclerosis was also associated with decreased numbers of endothelial progenitor cells in circulation. Conclusions: Thymus dysfunction accompanies CAD progression and is manifested in changes in cellular composition rather than morphology. In CAD patients, MDSC and Treg lymphocytes are equally involved in the progression of coronary atherosclerosis, which is aggravated by the decreased regulatory potential of the endothelium. Vascular aging represents a distinct phenotype of biological aging in CAD patients, characterized by the expansion of eMDSCs. Full article

Regulatory T cells (Tregs) are a specialized subset of CD4+ T lymphocytes essential for maintaining immune tolerance and preventing autoimmunity. However, in breast cancer, tumors exploit Tregs to establish an immunosuppressive microenvironment that enables immune evasion, accelerates progression, and contributes to therapeutic resistance. This review synthesizes current evidence on the role of Tregs in invasive breast cancer (IBC), highlighting their prognostic significance across molecular subtypes, mechanisms of immune suppression, and impact on treatment response. We integrated mechanistic and clinical insights to discuss opportunities for Treg-targeted therapeutic strategies, with attention paid to challenges such as autoimmunity, compensatory resistance, and subtype-specific heterogeneity. Finally, we outline future directions, including biomarker-driven precision medicine, novel therapeutic combinations, advanced preclinical models, as well as potential artificial intelligence-assisted approaches that aim to selectively disrupt tumor-promoting Treg functions while preserving the systemic immune balance. Full article

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies for which there are few effective biomarkers for diagnosis, prognosis, and treatment monitoring. Given the paucity of data in the literature, this study aimed to evaluate the biomarker potential of selected miRNAs (miR-222-3p, miR-3154, miR-3945, miR-4534, and miR-4742) and their protein targets in the context of PDAC. Methods: The expression levels of miRNA candidates were quantified by real-time quantitative PCR in lymphocyte samples from 46 PDAC patients and 50 healthy controls. In silico analyses were performed to identify potential target genes and proteins. ELISA was used to measure protein expression in both groups. Statistical analyses included ROC curve analysis, linear regression, and correlation analyses. In addition, correlations between miRNA/protein expression and clinicopathologic characteristics, including survival, were investigated. Results: miR-222-3p and miR-3154 were significantly downregulated in PDAC patients compared to controls (p < 0.001). Among the dual miRNA combinations, miR-222-3p and miR-4534 showed the highest discriminatory power (AUC = 0.629, p = 0.022). The miR-222-3p expression was significantly increased in patients with a history of alcohol consumption (p = 0.02). Significant correlations were observed between miR-3154 expression and T-stage (p = 0.01) and between perineural invasion and miR-222-3p levels (p = 0.02). Survival analysis showed that high miR-3945 expression was significantly associated with shorter overall survival (p = 0.001). Elevated levels of ESR1, HCFC1, and EPC1 were significantly associated with lymphatic invasion (p < 0.05), while high KCNA1 expression correlated with shorter survival (p = 0.006), indicating its potential as a negative prognostic biomarker. Linear regression analysis revealed a significant positive correlation between miR-3945 and KCNA1 expression (β = 0.259, p = 0.038), indicating a possible regulatory interaction. A borderline correlation was also found between miR-4742 and EPC1 expression (p = 0.055). Conclusions: This study identifies several miRNAs and associated proteins with diagnostic and prognostic significance in PDAC. The results emphasize the clinical relevance of integrating multi-layered analyses of miRNA–protein interactions. The observed associations highlight the role of these molecular markers in tumor progression and patient survival and offer promising opportunities for future research and clinical application in precision oncology. Full article

Background/Objectives: Macrophages with the M2 phenotype are an immune population with great relevance for tumor development. We have previously demonstrated that mesenchymal stromal cells (MSCs) from cervical cancer (CeCa-MSCs) enhance the immunomodulatory activity of CeCa cells on T lymphocytes; however, the effect of these cells on the ability of tumor cells to polarize macrophages had not been evaluated to date. Methods: To address this, we set out to analyze the effect of normal cervix (NCx) and CeCa-MSCs interacting with CeCa tumor cells (TCs) to polarize macrophages in a coculture system. Results: Our results show that macrophages from TC/NCx-MSC cocultures decreased CD163 expression. In turn, we observed that macrophages from TC/CeCa-MSC cocultures, in contrast to those in the presence of TCs/NCx-MSCs, increased the intracellular production of IDO, IL-4, and IL-10; decreased T lymphocyte proliferation; and increased the presence of soluble IL-10. Interestingly, coculture in the presence of TCs/NCx-MSCs decreased the capacity of macrophages to generate regulatory T lymphocyte populations, as well as their phagocytic capacity, and increased IL-6 secretion, unlike the coculture of macrophages in the presence of TCs/CeCa-MSCs. Our results show that TCs/CeCa-MSCs in cocultures, unlike TCs/NCx-MSCs, have a greater capacity to polarize macrophages to an M2 phenotype and that such macrophages have a greater immunosuppressive potential. Conclusions: This in vitro study suggests that intracellular communication between MSCs and tumor cells in CeCa may promote tumor growth through the polarization of macrophages with increased immunosuppressive activity. Full article

Homeostasis must be maintained for the healthy living of an organism. In addition to physiological and anatomical homeostasis, the maintenance of the immune system, called immune homeostasis or immunohomeostasis, is critical for overall well-being and general homeostasis. CD8⁺ cytotoxic T cells/lymphocytes (CTLs) are crucial components of the adaptive immune systems of all vertebrates with a thymus. Hence, the thymus is an essential primary lymphoid organ (PLO) for developing T cell-mediated immunity (TCMI) that comprises CD4⁺ helper T cells (Th) cells and their subtypes, such as Th0 (naïve helper T cells), Th1 (pro-inflammatory Th cells that secrete IFN-γ), Th2 (secrete type 2 cytokines, such as IL-4, IL-5, IL-6, IL-10, and IL-13), Th9 (secrete IL-9), Th17 (secrete IL-17), Th22 (secrete IL-22), follicular Th cells (T_fhs, secrete IL-21), regulatory T cells (T_regs), and CD8⁺CTLs. The current article explores the critical role of CD8⁺CTLs in the maintenance of immune homeostasis. The role of the thymus (PLO) in generating and regulating CD8⁺CTLs, as well as mobilizing them to distant lymph nodes (LNs) and the spleen, which are referred to as secondary lymphoid organs (SLOs) and target organs, is discussed in section two of the article. The subsequent third section discusses the role of CD8⁺CTLs’ cytotoxic and immunoregulatory action to maintain immune homeostasis during infection and other inflammatory conditions. Moreover, they mask themselves to different cell types, like Th cells, such as Tc2s, Tc9s, Tc17s, and Tc22s, to maintain immune homeostasis. CD8⁺CTLs also behave as T_regs to exert their immunoregulatory functions. In addition to conventional CD8⁺CTLs, granzyme K (GzmK)⁺CD8⁺CTLs and CD4⁺CTLs with their cytotoxic action to maintain immune homeostasis have also been discussed. The next section discusses cell–cell (APC–CD8⁺CTL) interactions that not only increase the cytotoxic functions of CD8⁺CTLs but also program APCs to support their cytotoxic functions. These CD8⁺CTLs secrete different cytokines (IFN-γ and IL-10) and cytotoxic molecules (perforin and Gzms), which exert immunoregulatory actions to maintain immune homeostasis. The article concludes with a future perspective and a conclusion section, highlighting the critical need to understand CD8⁺CTLs’ cytotoxic and immunoregulatory functions in maintaining immune homeostasis across various diseases, including those with newly identified roles for CD8⁺CTLs. Full article

Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer (BC), comprising approximately 20% of newly diagnosed BC cases. The poor prognosis, high recurrence rates, and inefficacy of hormone-based therapies make TNBC one of the greatest challenges in contemporary oncology. The unique immunological features of TNBC, including relatively high tumor mutational burden, abundance of tumor-infiltrating lymphocytes, and elevated PD-L1 expression, offer a wide range of opportunities for immunotherapeutic approaches, of which the most progressive and promising are neoantigen-driven ones. This review examines the current landscape of neoantigen-based therapeutic approaches in TNBC treatment, spanning from discovery methodologies to clinical applications. We provide a critical analysis of the tumor microenvironment (TME) in TNBC, highlighting the balance between its immunoactivating (CD8+ T-cells, dendritic cells) and immunosuppressive (regulatory T-cells, M2 macrophages) components as the key determinant of therapeutic success, as well as reviewing the emerging approaches to TME reprogramming and recruiting in favor of better outcomes. We also present state-of the-art methods in neoantigen identification and prioritization, covering the landscape of technological platforms and prediction algorithms, addressing the existing accuracy limitations along with emerging computational solutions, and comprehensively discussing the TNBC neoantigen spectrum. Our analysis shows the strong domination of patient-specific (“private”) neoantigens over shared variants in the TNBC, with TP53 as the only gene with recurrent variants. Finally, we extensively cover neoantigen-recruiting therapeutic modalities including adoptive cell therapies, personalized vaccine platforms (peptide-based, mRNA/DNA vaccines, dendritic cell vaccines), and oncolytic viruses-based approaches. Our study of current clinical trials demonstrates the substantial gap between early proof-of-concept experiments and further applicability of neoantigen-driven therapies. The major challenges hampering the success of such methods include neoantigen prediction inaccuracy rates, high manufacturing costs, and time consumption. Promising ways to overcome these difficulties include the development of combinational strategies, TME modeling and modifying, and improvement of the therapy delivery properties, along with the optimization of production workflows and cost-effectiveness of vaccine development. Full article

Chronic lymphocytic leukemia (CLL) is associated with immune dysfunction, but how disease-intrinsic mechanisms in treatment-naive patients influence the coordination of adaptive responses to novel antigens remains unclear. Here, we assessed SARS-CoV-2-specific antibody and T cell immunity in 38 treatment-naive CLL patients and 13 healthy controls (HCs) following vaccination. Despite significantly reduced total immunoglobulin levels compared to HCs, 94.7% of CLL patients developed SARS-CoV-2-specific IgG, and 89.5% mounted IgA responses, with serum titers comparable to those of HCs. Virus-specific T cell responses, measured by IFN-γ release following antigen stimulation, were detected in 78.9% of patients. CLL patients had significantly more circulating CD4⁺ T follicular helper (Tfh) and T follicular regulatory (Tfr) cells than HCs. These expansions correlated with B cell abundance, which, in untreated CLL, predominantly reflects malignant B cells. Notably, Tfh cell frequencies and absolute counts were highest in patients lacking a SARS-CoV-2-specific T cell response, indicating a decoupling between Tfh expansion and functional antiviral immunity. Overall, these findings demonstrate that while SARS-CoV-2-specific immune responses are largely preserved in treatment-naive CLL patients, disease-driven alterations in T cell composition may compromise the coordination and quality of antigen-specific T cell-mediated immunity. Full article

Sepsis is a life-threatening syndrome caused by a dysregulated host response to infection. It follows a dynamic course in which early hyperinflammation coexists and overlaps with progressive immune suppression, a process best described as immunodynamic disruption. Key mechanisms include extensive lymphocyte death, expansion of regulatory T cells, impaired antigen presentation, and persistent activation of inhibitory checkpoints such as programmed cell death protein 1 (PD-1) and cytotoxic T lymphocyte–associated protein 4 (CTLA-4). These changes reduce immune competence and increase vulnerability to secondary infections. Clinically, reduced expression of Human Leukocyte Antigen–DR (HLA-DR) on monocytes and persistent lymphopenia have emerged as robust biomarkers for patient stratification and timing of immunomodulatory therapies. Beyond the acute phase, many survivors do not achieve full immune recovery but instead develop a Persistent Immune Remnant, defined as long-lasting immune, metabolic, and endothelial dysfunction despite apparent clinical resolution. Recognizing PIR emphasizes the need for long-term monitoring and biomarker-guided interventions to restore immune balance. To integrate these observations, we propose the SIMMP–Sepsis model (Sepsis-Associated Persistent Multiorgan Immunometabolic Syndrome), which links molecular dysfunction to clinical trajectories and provides a framework for developing precision immunotherapies. This perspective reframes sepsis not only as an acute crisis but also as a chronic immunometabolic syndrome, where survival marks the beginning of active immune restoration. Full article

Background: Type 1 diabetes (T1D) is an autoimmune disorder characterized by destruction of insulin-producing β-cells. While conventional insulin therapy manages hyperglycemia, it fails to halt autoimmunity. Oral immunotherapy targeting autoantigens like GAD65 offers potential for antigen-specific tolerance; however, its efficacy is limited by gastrointestinal degradation and poor mucosal uptake. Lactococcus lactis (L. lactis), a food-grade delivery vector, enables sustained antigen release and intestinal tract immune modulation, yet the differential transcriptomic mechanisms underlying mucosal versus systemic immune responses remain uncharacterized. Methods: Non-obese diabetic (NOD) mice were randomized into control and GAD65 groups, receiving oral PBS or the GAD65 recombinant L. lactis vaccine, respectively. Fasting blood glucose was monitored weekly. GAD65-specific IgA and IgG, along with immune tolerance-related factors, were quantified using ELISA. Lymphocyte subsets were analyzed by flow cytometry, alongside RNA sequencing and transcriptional profiling. Results: The study demonstrated that the orally administered GAD65-L. lactis vaccine could significantly induce GAD65-specific IgA antibody and TGF-β cytokine and alleviate hyperglycemia and diabetes symptoms in NOD mice. Our study facilitated the induction of GAD65-specific regulatory T cells within both intestinal lamina propria lymphocytes (LPLs) and splenic lymphocytes. Notably, antigen-specific tolerance was mainly observed in intestinal LPLs. Crucially, the immune responses elicited by the vaccine demonstrated significant disparities between intestinal LPLs and splenic lymphocytes, with intestinal LPLs exhibiting unique local immune tolerance transcriptomic profiles. Conclusions: Our findings have enhanced the comprehension of the mechanisms by which oral vaccines influence the interplay between mucosal and systemic immune responses, thereby establishing a foundational framework for the design of oral vaccines. This understanding is instrumental in advancing antigen-specific immune tolerance strategies for autoimmune diseases such as Type 1 Diabetes (T1D). Full article

Cannabinoid receptor 1 (CB1) has been implicated in multiple inflammatory diseases by regulating pro-inflammatory mediators or altering immune cell polarization. However, the expression and direct functional role of CB1 in T cells remain largely unexplored. Here, we demonstrate that primary murine T cells express CB1 and that its novel agonist, BI-5756, directly increases the frequencies of regulatory T cells (Tregs) in primary murine pan T cells after activation. In addition, BI-5756 exhibits an in vivo protective effect against graft-versus-host disease (GvHD), an allogeneic T cell-mediated inflammatory complication after allogeneic hematopoietic cell transplantation (allo-HCT), resulting in an improved overall survival with enhanced platelet recovery and reconstitution of bone marrow-derived B and T cells. BI-5756 also directly suppresses tumor cell growth and upregulates MHC I, MHC II, and CD80 on tumor cells, which may subsequently enhance T cell-mediated anti-tumor responses in mixed lymphocyte reaction with A20 cells. The ability of BI-5756 to increase Tregs was significantly abrogated by rimonabant, a potent and selective CB1 antagonist, suggesting that the immunomodulatory effect of BI-5756 is mediated via CB1. In summary, BI-5756, a potent CB1 agonist, increases Tregs while preserving anti-tumor responses in vitro and effectively reduces GvHD in vivo. Full article

Background: T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of immature T cells, driven by dysregulated transcriptional networks and oncogenic signaling pathways. Here, we present the first comprehensive analysis of the expression and regulation of TSPAN32, a tetraspanin implicated in lymphocyte homeostasis, in T-ALL. Methods: Transcriptomic data from the Leukemia MILE study (GSE13159) were analyzed to assess TSPAN32 expression across leukemic subtypes. Gene Set Enrichment Analysis (GSEA) was performed to explore biological pathways associated with TSPAN32-correlated genes. For mechanistic validation, HPB-ALL cells were used as a model, with NOTCH signaling inhibited by γ-secretase inhibitor (GSI) treatment and TAL1–LMO1 overexpression induced through doxycycline-inducible lentiviral vectors. Gene expression changes were quantified by RT-qPCR. Results: TSPAN32 was frequently downregulated in T-ALL compared to healthy bone marrow, although expression was retained in a subset of cases. GSEA revealed that TSPAN32-correlated genes were inversely associated with cell cycle–related programs, consistent with its established role as a negative regulator of T cell proliferation. Mechanistically, TAL1–LMO1 overexpression strongly induced TSPAN32, while GSI-mediated NOTCH inhibition partially reactivated its expression. Interestingly, GSI treatment also increased TAL1 levels despite downregulating LMO1. Conversely, TAL1–LMO1 overexpression suppressed NOTCH1 and NOTCH3, highlighting a reciprocal regulatory interplay between NOTCH and TAL1/LMO1 oncogenic circuits that shapes TSPAN32 expression dynamics in T-ALL. Conclusions: This study identifies TSPAN32 as a novel transcriptional target under the influence of key leukemogenic pathways and suggests its potential role as a modulator of leukemic T cell proliferation, with implications for therapeutic strategies targeting TAL1 and NOTCH signaling. Full article

Background: Enterotoxigenic Bacteroides fragilis (ETBF) carries the bft toxin gene, which influences the host immune response and inflammatory pathways and promotes colorectal cancer (CRC). This study investigated the potential role of ETBF in CRC liver metastasis. Methods: We reviewed the records of 226 consecutive patients who underwent curative-intent (R0) resection of CRC liver metastases. ETBF DNA in fresh-frozen metastasis specimens was quantified using droplet digital PCR (ddPCR). Patients were grouped into very-low (≤80%; N = 178), low (80–90%; N = 24), and high (>90%; N = 24) ETBF-DNA groups. Three tissue cores per specimen were stained for CD8, CD4, CD20, FOXP3, CD68, and CD163, and immune-cell densities were measured digitally (cells/mm²). Results: ETBF DNA was detected in 219 of 226 lesions (96.9%). The densities of cytotoxic CD8⁺ T-cells, effector CD4⁺ T-cells, CD20⁺ B-cells, and CD163⁺ macrophages did not differ significantly by ETBF-DNA group (P_trend all > 0.12). FOXP3⁺ regulatory T-cells (Tregs) decreased (P_trend = 0.010), and CD68⁺ macrophages increased (P_trend = 0.020) as ETBF-DNA levels increased. ETBF-DNA levels in CRC liver metastases were not associated with disease-free survival or overall survival or serum C-reactive protein levels. Conclusions: ETBF was present in almost all CRC liver metastases. Higher ETBF levels were associated with a tumor-immune microenvironment enriched in CD68⁺ macrophages and deficient in FOXP3⁺ Tregs, suggesting that ETBF facilitates immune evasion without loss of effector lymphocytes. Although ETBF-DNA levels did not predict survival in this single-center cohort, the potential role of ETBF in immune remodeling and as a candidate biomarker and therapeutic target in metastatic CRC warrants further study. Full article