Search Results (195)

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

Human cytomegalovirus (HCMV) establishes lifelong latency following primary infection, residing within myeloid progenitor cells and monocytes. To achieve this, the virus employs multiple immune evasion strategies. It suppresses innate immune signaling by inhibiting Toll-like receptor and cGAS-STING pathways. In addition, the virus suppresses major histocompatibility complex (MHC)-dependent antigen presentation to evade T cell recognition. As the downregulation of MHC molecules may trigger NK cell activation, the virus compensates for this by expressing proteins such as UL40 and IL-10, which engage inhibitory NK cell receptors and block activating signals, thereby suppressing NK cell immune surveillance. Viral proteins like UL36 and UL37 block host cell apoptosis and necroptosis, allowing HCMV to persist undetected and avoid clearance. In settings of profound immunosuppression, such as after allogeneic hematopoietic stem cell transplantation (allo-HSCT) or solid organ transplantation, slow immune reconstitution creates a window for viral reactivation. Likewise, immunosenescence and chronic low-grade inflammation during aging increases the risk of reactivation. Once reactivated, HCMV triggers programmed cell death, releasing viral PAMPs (pathogen-associated molecular patterns) and host-derived DAMPs (damage-associated molecular patterns). This release fuels a potent inflammatory response, promoting further viral reactivation and exacerbating tissue damage, creating a vicious cycle. This cycle of inflammation and reactivation contributes to both transplant-related complications and the decline of antiviral immunity in the elderly. Therefore, understanding the immune regulatory mechanisms that govern the switch from latency to reactivation is critical, especially within the unique immune landscapes of transplantation and aging. Elucidating these pathways is essential for developing strategies to prevent and treat HCMV-related disease in these high-risk populations. 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

Neutrophils are among the first cells to be recruited to the lungs during Chlamydia pneumoniae infection in mouse models; however, their regulatory functions are not yet fully understood. This study examined the mechanisms and significance of IL-10-producing neutrophils throughout C. pneumoniae pulmonary infection in C57BL/6 mice. Our findings revealed that infection with C. pneumoniae induces IL-10 secretion in bone marrow-derived neutrophils, depending on Toll-like receptor 2 (TLR2) activation. This process involves TLR2-dependent mitochondrial reactive oxygen species (ROS) production, which triggers the endoplasmic reticulum (ER) stress pathway, including IRE1α and subsequent Xbp1 splicing. Inhibition of this pathway or depletion of neutrophils (using the 1A8 monoclonal antibody) significantly reduces IL-10 levels in bronchoalveolar lavage fluid (BALF) in vivo. Conversely, the absence of IL-10-producing neutrophils, whether through depletion or TLR2 deficiency, leads to increased IL-12p70 and IFN-γ-positive NK cells, along with decreased regulatory T cells and M2-like macrophages. This results in a lower bacterial burden in the lungs but causes more severe pulmonary damage and decreased survival rates. These findings highlight that IL-10 produced by neutrophils via the TLR2-mitochondrial ROS–ER stress pathway is essential for modulating pulmonary immune responses and maintaining immune homeostasis during C. pneumoniae infection, thereby preventing excessive inflammation and tissue damage. Full article

Therapy resistance is a major obstacle to cancer treatment, and transforming growth factor-beta (TGF-β) signaling has emerged as a major instigator across many cancer types and therapeutic regimens. Solid tumors overexpress TGF-β ligands, and canonical and non-canonical TGF-β signaling pathways drive molecular changes in most cell types within the tumor to hijack therapeutic responses. Cancer therapies further stimulate TGF-β release to potentiate this problem. Molecular mechanisms of TGF-β action supporting resistance include upregulation of drug efflux pumps, enhanced DNA Damage Repair, elaboration of stiffened extracellular matrix, and decreased neoantigen presentation. TGF-β also activates pro-survival pathways, such as epidermal growth factor receptor, B-cell lymphoma-2 expression, and AKT-mTOR signaling. TGF-β-induced epithelial-to-mesenchymal transformation leads to tumor heterogeneity and acquisition of stem-like states. In the tumor microenvironment, TGF-β induces extracellular matrix production, contractility, and secretion of immunosuppressive cytokines by cancer-associated fibroblasts that contribute to drug resistance. TGF-β also blunts cytotoxic T and NK cell activities and stimulates recruitment and differentiation of immunosuppressive cells, including T-regulatory cells, M2 macrophages, and myeloid-derived suppressor cells. The importance of TGF-β signaling in development of drug resistance cannot be understated and should be further explored mechanistically to identify novel molecular approaches and combinatorial drug dosing strategies to prevent drug-resistance. Full article

Skin cancer is the most common cancer worldwide. The incidence of skin cancer has been increasing worldwide. Nearly 75% of all skin cancers are basal cell carcinomas (BCC), cutaneous squamous cell carcinoma (cSCC) represents approximately 20%, and those remaining are melanomas (4%) or other rare tumors (1%). Given the high cure rates and the ability to histologically confirm tumor clearance, surgical therapy is the gold standard for the treatment of skin cancer. Conventional surgery is the most employed technique for the removal of non-melanoma skin cancer (NMSCs). Mohs Micrographic Surgery (MMS) is the most precise surgical method for the treatment of non-melanoma skin cancer, allowing for 100% margin evaluation, being the gold-standard method for surgical treatment of non-melanoma skin cancer. Whenever it is possible to obtain wide margins (4 to 6 mm), cure rates vary from 70% to 99%. Imiquimod, a synthetic imidazoquinolinone amine, is a topical immune response modifier approved by the U.S. Food and Drug Administration (FDA) for the treatment of external anogenital warts, actinic keratosis (AK), and superficial basal cell carcinoma (sBCC). The efficacy of imiquimod is primarily attributed to its ability to modulate both innate and adaptive immune responses, as well as its direct effects on cancer cells. Imiquimod exerts its immunomodulatory effects by activating Toll-like receptors 7 and 8 (TLR7/8) on various immune cells, including dendritic cells, macrophages, and natural killer (NK) cells. Upon binding to these receptors, imiquimod triggers the MyD88-dependent signaling pathway, leading to the activation of nuclear factor kappa B (NF-κB) and interferon regulatory factors (IRFs). This cascade leads to the production of pro-inflammatory cytokines, including interferon-alpha (IFN-α), tumor necrosis factor-alpha (TNF-α), interleukin-12 (IL-12), and interleukin-6 (IL-6). These cytokines enhance local inflammation, recruit additional immune cells to the tumor site, and stimulate antigen presentation, thereby promoting an anti-tumor immune response. Radiation therapy (RTh) may be employed as a primary treatment to BCC. It may also be employed as an adjuvant treatment to surgery for SCC and aggressive subtypes of BCC. RTh triggers both direct and indirect DNA damage on cancer cells and generates reactive oxygen species (ROS) within cells. ROS trigger oxidative damage to DNA, proteins, and lipids, exacerbating the cellular stress and contributing to tumor cell death. Recently, immunotherapy emerged as a revolutionary treatment for all stages of SCC. Cemiplimab is a human programmed cell death 1 (PD-1)-blocking antibody that triggers a response to over 50% of patients with locally advanced and metastatic SCC. A randomized clinical trial (RCT) published in 2022 revealed that cemiplimab was highly effective in the neoadjuvant treatment of large SCCs. The drug promoted a significant tumor size decrease, enabling organ-sparing operations and a much better cosmetic effect. A few months ago, a RCT of cemiplimab on adjuvant therapy for locally aggressive SCC was published. Interestingly, cemiplimab was administered to patients with local or regional cutaneous squamous cell carcinoma after surgical resection and postoperative radiotherapy, at high risk for recurrence owing to nodal features, revealed that cemiplimab led to much lower risks both of locoregional recurrence and distant recurrence. Full article

The immune response to SARS-CoV-2 infection involves significant alterations in the phenotype and function of natural killer (NK) cells. This study aimed to investigate the dynamic changes in NK cell subsets during COVID-19 by analyzing their activation and inhibitory markers [CD3, CD14, CD16, CD19, CD25, CD45, CD56, CD57, CD69, CD159a (NKG2A), CD159c (NKG2C), CD314 (NKG2D), CD335 (NKp46)], cytotoxic potential (perforin, interferon-gamma, granzyme B), and direct cytotoxicity against a newly genetically modified K562 cell line. Peripheral blood samples were collected from COVID-19 patients on days 3–5 and day 30 post-symptom onset and were compared to healthy controls. 16-color flow cytometry analysis revealed distinct shifts in NK cell subpopulations, characterized by increased expression of the inhibitory receptor NKG2A and the activating receptors NKG2D and NKG2C, particularly in the CD56⁺CD16⁻ subset. Elevated IFN-γ production on day 30 suggested a recovery-phase immune response, while the persistent upregulation of NKG2A indicated an ongoing regulatory mechanism. The CD16⁺CD56⁻ subpopulation exhibited increased expression of the markers CD69 and CD25 over time; however, its cytotoxic potential, assessed through granzyme B levels and direct cytotoxicity assays, remained lower than that of healthy controls. Significant correlations were observed between CD57 and CD69 expression, as well as NKp46 and IFN-γ production, highlighting a coordinated balance between activation and regulatory mechanisms. These findings suggest that NK cells undergo functional adaptation during COVID-19, displaying signs of partial exhaustion while retaining antiviral potential. Understanding the interplay between NK cell activation and suppression may provide valuable insights into immune dysregulation in COVID-19 and inform potential therapeutic interventions. Full article

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive malignancy characterized by complex interactions within the tumor microenvironment (TME) that facilitate immune evasion and tumor progression. The TME consists of diverse cellular components, including cancer-associated fibroblasts, immune and endothelial cells, and extracellular matrix elements, that collectively modulate tumor growth, metastasis, and resistance to therapy. Immune evasion in HNSCC is orchestrated through multiple mechanisms, including the suppression of cytotoxic T lymphocytes, recruitment of immunosuppressive cells, such as regulatory T and myeloid-derived suppressor cells, and upregulation of immune checkpoint molecules (e.g., PD-1/PD-L1 and CTLA-4). Natural killer (NK) cells, which play a crucial role in anti-tumor immunity, are often dysfunctional within the HNSCC TME due to inhibitory signaling and metabolic constraints. Additionally, endothelial cells contribute to tumor angiogenesis and immune suppression, further exacerbating disease progression. Recent advancements in immunotherapy, particularly immune checkpoint inhibitors and NK cell-based strategies, have shown promise in restoring anti-tumor immunity. Moreover, TP53 mutations, frequently observed in HNSCC, influence tumor behavior and therapeutic responses, highlighting the need for personalized treatment approaches. This review provides a comprehensive analysis of the molecular and cellular mechanisms governing immune evasion in HNSCC with a focus on novel therapeutic strategies aimed at improving patient outcomes. Full article

Background: Soft tissue sarcomas (STSs) are a rare and heterogeneous group of mesenchymal tumors with limited response to current therapies, particularly in advanced stages. STS tumors were traditionally considered “cold” tumors, characterized by limited immune infiltration and low immunogenicity. However, emerging evidence is challenging this perception, highlighting a potentially critical role for the immune system in STS biology. Objective: Building on our previous findings suggesting impaired natural killer (NK) cell activity in STS patients, we aimed to perform an in-depth characterization of peripheral NK cells in STS. Methods: Peripheral blood samples from STS patients and sex- and age-matched healthy donors were analyzed to assess NK cell degranulation, IFNγ production, and receptor repertoire. Results: Functional assays revealed a notable reduction in both degranulation and IFNγ production in NK cells from STS patients. STS patients also exhibited dysregulated expression of activating and inhibitory NK cell receptors. Principal component analysis (PCA) identified CD27 and NKp44 as critical markers for distinguishing STS patients from healthy donors. Increased CD27 expression represents a shift towards a more regulatory NK cell phenotype, and we found that CD27 expression was negatively correlated with NK cell degranulation and IFNγ production. ROC curve analysis demonstrated strong potential to distinguish between the groups for both CD27 (AUC = 0.85) and NKp44 (AUC = 0.94). Conclusion: In conclusion, STS patients exhibited impaired NK cell function, altered receptor repertoire, and a shift towards a less cytotoxic and more regulatory phenotype. Full article

Natural products demonstrate potent immunomodulatory properties through checkpoint modulation, macrophage polarization, and T cell/natural killer (NK) cell activation. While cancer organoid-immune co-culture platforms enable physiologically relevant modeling of tumor–immune interactions, systematic investigation of natural product immunomodulation in these systems remains entirely unexplored. We conducted a comprehensive literature analysis examining natural products tested in cancer organoids, immunomodulatory mechanisms from traditional models, technical advances in organoid-immune co-cultures, and standardization requirements for clinical translation. Our analysis reveals a critical research gap: no published studies have investigated natural product-mediated immunomodulation using organoid-immune co-culture systems. Even though compounds like curcumin, resveratrol, and medicinal mushroom polysaccharides show extensive immunomodulatory effects in two-dimensional (2D) cultures, and organoid technology achieves high clinical correlation for drug response prediction, all existing organoid studies focus exclusively on direct cytotoxicity. Technical challenges include compound stability, limited matrix penetration requiring substantially higher concentrations than 2D cultures, and maintaining functional immune populations in three-dimensional (3D) systems. The convergence of validated organoid-immune co-culture platforms, Food and Drug Administration (FDA) regulatory support through the Modernization Act 2.0, and extensive natural product knowledge creates unprecedented opportunities. Priority research directions include systematic screening of immunomodulatory natural products in organoid-immune co-cultures, development of 3D-optimized delivery systems, and clinical validation trials. Success requires moving beyond cytotoxicity-focused studies to investigate immunomodulatory mechanisms in physiologically relevant 3D systems, potentially unlocking new precision cancer immunotherapy approaches. Full article

Background: Diabetic foot ulcers (DFUs) are a severe complication of diabetes and are characterized by impaired wound healing and a high amputation risk. Exosomes—which are nanovesicles carrying proteins, RNAs, and lipids—mediate intercellular communication in wound microenvironments, yet their biomarker potential in DFUs remains underexplored. Methods: We analyzed transcriptomic data from GSE134431 (13 DFU vs. 8 controls) as a training set and validated findings in GSE80178 (6 DFU vs. 3 controls). A sum of 7901 differentially expressed genes (DEGs) of DFUs were detected and intersected with 125 literature-curated exosome-related genes (ERGs) to yield 51 candidates. This was followed by GO/KEGG analyses and a PPI network construction. Support vector machine–recursive feature elimination (SVM-RFE) and the Boruta random forest algorithm distilled five biomarkers (DIS3L, EXOSC7, SDC1, STX11, SYT17). Expression trends were confirmed in both datasets. Analyses included nomogram construction, functional and correlation analyses, immune infiltration, GSEA, gene co-expression and regulatory network construction, drug prediction, molecular docking, and RT-qPCR validation in clinical samples. Results: A nomogram combining these markers achieved an acceptable calibration (Hosmer–Lemeshow p = 0.0718, MAE = 0.044). Immune cell infiltration (CIBERSORT) revealed associations between biomarker levels and NK cell and neutrophil subsets. Gene set enrichment analysis (GSEA) implicated IL-17 signaling, proteasome function, and microbial infection pathways. A GeneMANIA network highlighted RNA processing and vesicle trafficking. Transcription factor and miRNA predictions uncovered regulatory circuits, and DGIdb-driven drug repurposing followed by molecular docking identified Indatuximab ravtansine and heparin as high-affinity SDC1 binders. Finally, RT-qPCR validation in clinical DFU tissues (n = 5) recapitulated the bioinformatic expression patterns. Conclusions: We present five exosome-associated genes as novel DFU biomarkers with diagnostic potential and mechanistic links to immune modulation and vesicular transport. These findings lay the groundwork for exosome-based diagnostics and therapeutic targeting in DFU management. Full article

Due to the complexity of modeling tumor-host interactions within the tumor microenvironment in vitro, we developed a 3D heterotypic cellular breast cancer (BC) model. We generated spheroid models using MCF7, MDA-MB-231, and SK-BR-3 cell lines alongside cancer-associated (BrC4f) and normal (BN120f) fibroblasts in ultra-low attachment plates. Stromal spheroids (3Df) were formed using a liquid overlay technique (graphical abstract). The YT cell line and peripheral blood NK (PB-NK) cells were used as immune components in our 3D model. In this study, we showed that stromal cells promoted tumor cell aggregation into spheroids, regardless of the initial proliferation rates, with NK cells accumulating in fibroblast-rich regions. The presence of CAFs within the model induced alterations in the expression levels of MICA/B and PD-L1 by tumor cells within the 3D-2 model. The feasibility of utilizing a 3D cell BC model in combination with cytokines and PB-NKs was evaluated. We observed that IL-15 and IL-2 enhanced NK cell activity within spheroids, whereas TGFβ had varying effects on proliferation depending on the cell type. Stimulation with IL-2 and IL-15 or TGFβ1 altered PB-NK markers and stimulated their differentiation into ILC1-like cells in 3D models. These findings underscore the regulatory function of CAFs in shaping the response of the tumor microenvironment to immunotherapeutic interventions. Full article

Background/Objectives: Chimeric antigen receptor T-cell (CAR-T) therapy is a novel form of adoptive cellular immunotherapy that involves modifying autologous T cells to recognize and target tumor-associated antigens (TAAs) on malignant cells, independent of major histocompatibility complex (MHC) restriction. Although CAR-T therapy has shown remarkable success in treating hematologic malignancies, its efficacy in solid tumors remains limited, largely due to the lack of tumor-specific antigens and the complexity of the tumor microenvironment. This review aims to explore the rationale for continuing the development of adoptive cellular therapies in head and neck cancer (HNC), offering insights into the diagnostic and therapeutic challenges associated with this heterogeneous group of malignancies. Methods: We conducted a comprehensive literature review using the PubMed database to identify relevant studies on the application of CAR-T cell therapy in the management of HNC. Results: HNC presented numerous barriers to CAR-T cell infiltration, primarily due to the unique characteristics of its tumor microenvironment (TME). The TME in HNC is notably immunosuppressive, with a lymphocytic infiltrate predominantly composed of regulatory T cells (Tregs) and natural killer (NK) cells. These immune cells typically exhibit low expression of the CD16 receptor, which plays a crucial role in mediating antibody-dependent cellular cytotoxicity (ADCC), thereby limiting the effectiveness of CAR-T cell therapy. Conclusions: This comprehensive review suggests a potential clinical applicability of CAR-T therapy in HNC management. Full article

Preeclampsia (PE) is one of the main causes of obstetric complications and leads to both maternal and neonatal mortality. The maternal innate immune system plays an important role throughout pregnancy by providing protection against pathogens, while simultaneously inducing tolerance to a semi-allogenic developing fetus and placental development. Background/Objectives: To conduct a comparative study of immunological markers in the blood and placenta in preeclampsia. Methods: A total of 35 pregnant women were enrolled in a comparative study with preeclampsia (7) and with physiological pregnancy (28). A study of the immune status in peripheral blood and placenta was conducted with an examination of the subpopulation of lymphocytes profile and intracellular cytokines production by flow cytometry. Results: In the blood of pregnant women with PE, there was a decrease in CD14+ monocytes, as well as a significant increase of natural killers CD16+, CD56+ and activation markers HLA-DR+ and CD95+, as well as a significant rise in production of IL-10, TNF, Perforin, GM-CSF, and IGF. At the same time, in placental tissue in patients with preeclampsia, on the contrary, a significant decrease in regulatory cells CD4+, CD8+, CD14+, CD56+, CD59+, activation markers CD95+, as well as anti-inflammatory cytokine IL-10, growth factors VEGFR and IGF was detected. Conclusions: The maternal–fetal immune profile is crucial for successful fetal development and dysregulation of T-, B-, and NK cells can contribute to inflammation, oxidative stress, and the development of preeclampsia. Full article

Cell therapy is promising for heart failure treatment, with growing interest in cardiovascular progenitor cells (CPCs) from pluripotent stem cells. A major challenge is managing the immune response, due to their allogeneic source. Regulatory T cells (Treg) offer an alternative to pharmacological immunosuppression by inducing immune tolerance. This study assesses whether Treg therapy can mitigate the xeno-immune response, improving cardiac outcomes in a mouse model of human CPC intramyocardial transplantation. CPCs stimulated immune responses in allogeneic and xenogeneic settings, causing proliferation in T cell subsets. Tregs showed immunosuppressive effects on T lymphocyte populations when co-cultured with CPCs. Post infarction, CPCs were transplanted intramyocardially into an immune-competent mouse model 3 weeks after myocardial infarction. Human or murine Tregs were intravenously administered on transplantation day and three days later. Control groups received CPCs without Tregs or saline (PBS). CPCs with Tregs improved LV systolic function in three weeks, linked to reduced myocardial fibrosis and enhanced angiogenesis. This was accompanied by decreased splenocyte NK cell populations and pro-inflammatory cytokine levels in cardiac tissue. Treg therapy with CPC transplantation enhances cardiac functional and structural outcomes in mice. Though it does not directly avert graft rejection, it primarily affects NKG2D+ cytotoxic cells, indicating systemic immune modulation and remote heart repair benefits. Full article