Search Results (101)

Background: Ascophyllan, a sulfated polysaccharide extracted from brown seaweed, has shown immunomodulatory and antioxidant effects in preclinical studies, yet human clinical evidence remains scarce. This randomized, double-blind, placebo-controlled pilot trial evaluated the safety and exploratory biological effects of daily ascophyllan supplementation in healthy adults. Methods: Twelve participants were randomized to receive either ascophyllan (n = 6) or placebo (n = 6) for 28 days. Safety was monitored through adverse event reporting and repeated laboratory assessments, including hematology, biochemistry, and inflammatory markers. Immune cell populations were analyzed via serial flow cytometry, serum total antioxidant capacity was measured at multiple time points, and gut microbiome composition was profiled using 16S rRNA gene sequencing. All analyses were exploratory in nature. Results: Ascophyllan supplementation proved well tolerated, with no adverse events observed and stable hematologic, renal, and biochemical parameters throughout the study. Exploratory longitudinal analyses suggested directional modulation of NK-cell-associated phenotypes during ascophyllan supplementation, including directional changes in CD57⁺, NKp46⁺, and NKG2D⁺ NK-cell phenotypes; however, group × time interaction analyses did not remain statistically significant after correction for multiple comparisons. Serum antioxidant capacity showed inter-individual variability with a directional but non-significant increase in the ascophyllan group at intermediate time points. Exploratory microbiome analyses suggested modest directional compositional differences involving members of the Bacteroidaceae and Bifidobacteriaceae families; however, no taxon remained statistically significant after correction for multiple comparisons. Conclusions: These preliminary findings indicate that ascophyllan is safe and well tolerated in healthy adults and may be associated with modulation of innate immune phenotypes, subtle microbiome compositional differences, and directional changes in antioxidant capacity. Larger, adequately powered clinical trials are warranted to confirm these observations and further investigate potential biological and clinical effects. Full article

Melanoma treatment has been transformed by immune checkpoint blockade, yet many patients still experience primary resistance, limited durability of response, or acquired resistance. These limitations underscore the need for additional targets that reflect melanoma biology while enabling new therapeutic strategies, particularly in biologically defined settings of immune escape such as checkpoint-resistant, HLA-low, dedifferentiated, or stress-adapted melanoma. The B7-H6/NKp30 axis has gained attention as a link between tumor cell stress, immune recognition, and therapy-related adaptation. B7-H6 (NCR3LG1), an inducible ligand for NKp30, has been detected in melanoma cell lines and tumor specimens, and soluble B7-H6 has been identified in a subset of patients. Membrane-bound B7-H6 may support NK-cell activation, whereas ligand shedding and accumulation of soluble B7-H6 may reduce effective antitumor recognition and promote immune evasion. Emerging evidence further suggests that B7-H6 expression may be linked to tumor-intrinsic programs relevant to melanoma cell survival, migration, and adaptation to therapeutic stress. However, B7-H6 is not yet a validated predictive biomarker or an established therapeutic target in melanoma, and current evidence remains limited by small melanoma-specific datasets, incomplete information on spatial and temporal heterogeneity, and the absence of melanoma-focused clinical validation. In this review, we examine the role of the B7-H6/NKp30 axis in immune surveillance, tumor escape, biomarker development, and therapeutic targeting, and discuss its translational potential in melanoma as an emerging but incompletely validated pathway that warrants focused investigation in melanoma states where conventional immune control is limited. Full article

(1) Background: Innate lymphoid cells (ILCs) are potent cytokine producers that regulate local immune responses in tissues. Natural killer (NK) cells belong to group 1 ILCs and play an important role in tumor clearance and defense against intracellular pathogens. ILC2 and 3 have been implied in allergic responses and other chronic inflammatory diseases. The role of these cells in the pathogenesis of chronic rhinosinusitis (CRS) is not completely understood. There are changes in the cellular infiltrate in the mucosa of patients with CRS with and without polyps. The aim of this study was to characterize the number and phenotype of NK cells, ILC2s and ILC3s in patients with CRS. (2) Methods: Tissue samples were collected from patients with CRS with and without nasal polyps who were undergoing nasal sinus surgery as well as control patients who were undergoing surgery due to non-inflammatory reasons. Lymphocytes were isolated from the tissues using mechanical and enzymatic dissociation. Peripheral blood lymphocytes were obtained from the same patients. All cells were examined by multicolor flow cytometry. NK cells were analyzed for the distribution of CD56^dimCD16⁺ and CD56^brightCD16⁻ subsets and the expression of IL18Rα, CD16, CD57, GATA3, TCF1 and NKp44. In ILC2s, GATA3 and IL18Rα expression was determined, and ILC3s as well as NKp44⁺ and NKp44⁻ILC3 subsets were analyzed for the expression of IL18Rα. (3) Results: There were significantly fewer NK cells in the nasal polyps compared to the peripheral blood of patients with CRSwNP and tissues from CRSsNP patients, which both showed higher levels of TCF1 expression. Irrespective of the disease condition, NK cells in tissues showed lower CD16 expression and a lower frequency of the CD56^dimCD16⁺ subset compared to the peripheral blood mononuclear cells. Additionally, a smaller percentage of NK cells were terminally matured, as measured by CD16⁺ and CD57⁺ expression, in all examined nasal mucosa tissues. In the tissue ILC3s, we predominantly found cells from the NKp44⁻ subset in all groups. ILC3s from CRSsNP patients showed the highest frequencies of IL18Rα⁺ cells of all examined tissues. ILC2s from the polyps ofCRSwNP patients showed higher levels of GATA3 expression than their peripheral blood counterparts. (4) Conclusions: We found that tissue-resident NK cells in mucosa from the nose and sinuses are a more heterogenous and less mature population than those in peripheral blood. Expression of the examined markers in NK cells was similar among groups. NK cell frequency, both in blood and tissue from CRSsNP patients, was higher than in the other groups, indicating that these cells might play an important role in this phenotype. Changes in the IL18Rα expression of ILC3s suggest a potential role of IL18 signaling in CRS pathogenesis. Full article

Background/Objectives: Adoptive transfer of allogeneic natural killer (NK) cells represents a promising off-the-shelf immunotherapy for cancer, offering advantages in safety and availability over autologous T cell therapies. However, generating therapeutically sufficient NK cell numbers remains challenging due to their low frequency in blood sources. Engineered feeder cell co-cultures have enabled substantial expansions of NK cells to clinically relevant doses. Methods: We evaluated the plasma cell leukemia-derived ARH-77 cell line as a feeder for ex vivo NK cell expansion from healthy donor peripheral blood mononuclear cells (PBMCs). Unmodified ARH-77 was compared to K562, followed by engineering both lines to co-express B7-H6 (NKp30 ligand), CD137L (4-1BBL), IL-15, and IL-15Rα via sequential lentiviral transduction. PBMCs were co-cultured with irradiated feeders in cytokine-supplemented (IL-2, IL-21, and later IL-15) RPMI-1640 or DMEM/F-12 medium for up to 28 days. Expansion (fold change in CD3⁻CD56⁺ cells), purity, surface receptor expression, and cytotoxicity (against K562 targets) were quantified. Results: Unmodified ARH-77 supported significantly greater NK cell expansion than K562 (model-estimated 681-fold vs. 155-fold at week 4 in RPMI; p = 0.0018), with higher purity but comparable cytotoxicity and receptor profiles. Engineered ARH-77 cells achieved robust expansion in RPMI, comparable to that of engineered K562 cells. In optimized DMEM/F-12 medium, engineered ARH-77 drove superior expansion (up to model-estimated 101,241-fold; 95% CI 46,771–219,146 at week 4), significantly outperforming engineered K562 (4.4-fold greater; 95% CI 1.01 to 18.54; p = 0.0479) while maintaining high purity and equivalent cytotoxicity. Substantial inter-donor variability influenced expansion magnitude, though relative feeder performance remained consistent across donors. Conclusions: Genetically modified ARH-77 feeder cells provide a potent platform for large-scale ex vivo expansion of functional NK cells. Full article

Background/Objectives: Celiac disease (CD) is a T-cell-mediated autoimmune condition, triggered by gluten ingestion. Duodenal biopsy is the gold-standard diagnosis for CD, which is often limited by interobserver variability between pathologists. Immunohistochemistry (IHC) is a powerful technique for detecting biomarkers with potential diagnostic significance. This study aims to investigate five candidate biomarkers, BTNL8, NKp46, TdT, THEMIS, and TCRδ, that might improve the reproducibility of the diagnosis of CD. Methods: Formalin-fixed paraffin-embedded material, surplus to diagnostic requirements, was obtained from 46 subjects (untreated CD: n = 21, CD treated with gluten-free diet: n = 5; controls: n = 20) and immunostained for BTNL8, NKp46, TdT, THEMIS and TCRδ. BTNL8 staining was scored on a 0–3 semi-quantitative scale. NKp46, TdT, THEMIS, and TCR delta-positive intra-epithelial lymphocytes (IELs) were quantified as mean counts per 100 epithelial cells (ECs). Results: TCRδ-positive IELs were markedly elevated in CD biopsies (median 9.4 IELs/100 ECs) compared to healthy controls (median 0.5 IELs/100 ECs; p < 0.001), with a threshold of >2.1 TCRδ-positive IELs per 100 ECs yielding an AUC of 0.94 and interobserver agreement of 0.82. NKp46 expression was also increased in CD (median 13.8 IELs/100 ECs) versus controls (median 9.6; p < 0.001), with >12.8 NKp46-positive IELs per 100 ECs achieving an AUC of 0.86 and interobserver agreement of 0.82. Immunostaining for the other biomarkers demonstrated less clear differences between CD and healthy controls. Conclusions: Corroborating several recent publications, TCRδ immunostaining provides high diagnostic accuracy and good interobserver agreement in the diagnosis of CD on duodenal biopsy, even for patients on a gluten-free diet. Full article

Background/Objectives: Natural killer (NK) cells are key innate lymphoid cells that restrict tumour progression by secreting proinflammatory cytokines and directly lysing malignant cells, with their activity tightly regulated by a balance of activating and inhibitory surface receptors. The natural cytotoxicity receptor NKp44 is induced on NK cells following stimulation with IL-2 or IL-15 and recognizes platelet-derived growth factor D (PDGF-DD) as a ligand. Mechanistic interpretation of NKp44 signalling upon PDGF-DD engagement is confounded by the existence of three distinct NKp44 isoforms (NKp44-1, -2, and -3), each capable of initiating divergent intracellular signalling cascades. Unlike NKp44-2 and -3, NKp44-1 encodes a cytoplasmic tyrosine residue (Y238) that conforms to a putative immunoreceptor tyrosine-based inhibition motif (ITIM) and has been reported to suppress NK cell effector functions in some contexts. However, it remains unclear whether the NKp44 isoforms are translated and expressed in NK cells, and formal evidence defining NKp44-1 signalling in response to engagement by PDGF-DD is lacking. Methods: In this study, we used C-terminal targeting monoclonal antibodies (mAbs) and a NFAT-GFP reporter system to define the expression and signalling properties of NKp44 isoforms in response to PDGF-DD. Results: We demonstrate protein expression of NKp44-1 and NKp44-2-/3 receptors in IL-2 expanded NK cells. We further show that NKp44-1 transduces activating rather than inhibitory signals when engaged by PDGF-DD ligand, albeit weaker than NKp44-3. Intriguingly, we find that Y238 is dispensable for NKp44-1 activating signalling and instead functions as a YXXΦ internalisation motif. Conclusions: Collectively, these findings provide the first evidence that the NKp44-1 and NKp44-2/3 isoforms are expressed in NK cells and establish that PDGF-DD activates signalling through NKp44-1 independently of Y238. This work lays the foundations for future studies investigating how PDGF-DD sensing by the different NKp44 isoforms shapes immune functions in different physiological and pathological contexts. Full article

Breeding wheat varieties that are resilient to arid climates, which impart a complex combination of stresses, including excessive Ca, high pH, nutrient deficiency, and aridity, is important. Afghan landrace wheat is assumed to have evolved with a specific prototypical pattern of traits to adapt to its challenging, composite stress environment. Here, a useful semi-hydroponic double cup screen aiding proteomic analysis was exploited to reconstruct the combined excessive Ca²⁺ (100 ppm) and extreme pH (11.0) of the soils and to dissect specific morpho-physiological characteristics and adaptation strategies in Kihara Afghan wheat landrace (KAWLR). When compared to other cultivars and growth habits, several winter-type KAWLR showed lower unused N-K-P and greater rhizosphere pH stability in the bottom cup and higher tolerance in terms of greater root allocation shift, and most of their above ground traits (shoot biomass, chlorophyll content, and stomatal conductance) were strongly correlated with root length and biomass under stress conditions. Quantitative proteomics on the roots of a tolerant winter-type KAWLR, Herat-740 (KU-7449), showed a strong decreasing trend in changed proteins (12 increased/816 decreased). The proteins (such as mitochondrial phosphate carrier protein, cytoskeleton-related α-, and β-tubulin) that increased in abundance were associated with energy transport and cell growth. A metabolism overview revealed that most proteins that were mapped to glycolysis, fermentation, and the TCA cycle decreased in abundance. However, proteins related to cell wall and lipid metabolism pathways remained unchanged. Our results suggest that winter-type KAWLR adopts a homeostatic stress adaptation strategy that globally downshifts metabolic activity, while selectively maintaining root growth machinery. Root allocation shift, rhizosphere pH stabilization (nutrient solubilization), and a selective proteome response maintaining the root growth machinery in winter-type KAWLR could be breeding selection markers for early-stage screening in calcareous-alkaline arid land. Full article

Background/Objectives: While previous studies have explored the relationship between periampullary diverticulum (PAD) and conventional endoscopic retrograde cholangiopancreatography (ERCP) success, data on advanced cannulation techniques like needle-knife papillotomy (NKP) remain limited. This study aimed to assess NKP outcomes in PAD patients with difficult biliary cannulation. Methods: A retrospective study was conducted on 122 PAD patients who underwent NKP in a single center. Patient characteristics, ERCP indications, common bile duct diameter, PAD type, diverticular size, major duodenal papilla (MDP) morphology, and post-ERCP adverse events were assessed. We also analyzed factors associated with the outcomes of NKP in patients with PAD. Results: Of the 122 patients, NKP was successful in 82 (67.2%) and failed in 40 (32.8%), with diverticular diameter being significantly larger in the failure group. By PAD type, the diverticular median diameters were 1.2 cm (type I), 0.9 cm (type II), and 0.5 cm (type III) (p < 0.001), with NKP success rates of 50%, 66.3%, and 75%, respectively (p = 0.391). By MDP morphology, the success rates were 73.7% (type I), 38.2% (type II), 92.9% (type III), and 82.4% (type IV) (p = 0.059). The overall adverse event rate was 16.4%, with pancreatitis (6.6%), bleeding (5.7%), and cholangitis (4.1%) showing no significant differences between the success and failure groups. Multivariate analysis identified MDP morphology (type II vs. I, OR: 0.256, p = 0.011) and active bleeding during NKP (OR: 0.117, p < 0.001) as independent predictors of failure. Conclusions: MDP morphology and intraprocedural bleeding are significant independent predictors of NKP failure in PAD patients with difficult biliary cannulation, whereas PAD type has no significant impact on NKP outcomes. Full article

Background/Objectives: Juzentaihoto (JTT), a traditional Kampo formula composed of ten medicinal herbs, is widely prescribed in Japan for immune enhancement and general health maintenance. This exploratory, open-label pilot study aimed to evaluate the feasibility and immunomodulatory effects of JTT in cancer patients and to explore its potential mechanisms of action. Methods: Ten cancer patients received oral JTT (7.5 g/day) for 14 days, while healthy volunteers served as a reference group. Peripheral natural killer (NK) cell phenotypes and CD95 expression were analyzed by flow cytometry, and serum Fas ligand (FasL) concentrations were measured by ELISA. Complementary in vitro assays using PBS-extracted, autoclaved JTT were conducted to assess Fas/FasL-mediated apoptosis in Jurkat and primary T cells by flow cytometry and Western blotting for cleaved caspase-8 and -3. Additional experiments with staurosporine (intrinsic apoptosis) and TRAIL in OSC-19 carcinoma cells were performed to determine pathway specificity. Results: In patients, most NK-cell markers showed no statistically significant within-subject changes, although a trend-level increase in NKp46 and a significant reduction in NK-cell CD95 expression (paired p = 0.014) were observed. Between-group differences primarily reflected baseline disparities between cancer patients and healthy controls. In vitro, JTT (50–100 µg/mL) partially attenuated FasL-induced apoptosis and reduced cleaved caspase-3 without affecting cleaved caspase-8, suggesting selective downstream modulation of the extrinsic pathway. Conclusions: Within the limitations of a small, non-randomized cohort without placebo, these findings are hypothesis-generating and indicate that JTT selectively modulates Fas-mediated lymphocyte apoptosis without promoting tumor immune evasion. Further randomized trials and mechanistic studies incorporating co-culture or 3D tumor–immune models are warranted to confirm these observations and identify active constituents. Full article

Neuroendocrine neoplasms (NENs) represent a small and heterogeneous group of tumors that share a common phenotype, originating from cells within the endocrine and nervous systems. Metallodrugs have had a significant impact on the treatment of NENs, as platinum-based chemotherapy is the first-line therapy approved for managing these types of tumors. Currently, medicinal inorganic chemistry is investigating new metal-based drugs to mitigate the side effects of existing agents, including cisplatin and its derivative compounds. Among the emerging alternatives to platinum-based drugs, ruthenium-based complexes garnered attention as potential chemotherapeutics due to their notable antineoplastic and antimetastatic activity. This review focuses on the promising antitumor effects of certain Ru compounds in NEN therapy, emphasizing their potential in NEN treatment through interaction with new potential targets. Among these, IT-139 (also known as KP-1339 or NKP-1339), which has already entered clinical trials, and other new Ru compounds are highlighted. Full article

Chimeric antigen receptor (CAR) T-cell therapy directed to CD19 and B-cell maturation antigen has revolutionized treatment of B-cell leukemia and lymphoma, and multiple myeloma. However, identifying suitable targets for acute myeloid leukemia (AML) remains challenging due to concurrent expression of potential target antigens on normal hematopoietic stem cells or tissues. As the stress-induced B7H6 molecule is rarely found on normal tissues but expressed on many cancers including AML and melanoma, the NKp30-ligand B7H6 emerges as a promising target for NKp30-based CAR T therapy for these tumors. In this study, we report a comprehensive B7H6 expression analysis on primary AML and melanoma as well as on different tumor cell-lines examined by RT-qPCR and flow cytometry, and efficient anti-tumor reactivity of NKp30-CAR T cells to AML and melanoma. To overcome limitations of autologous CAR T-cell fitness-dependent efficacy and patient-tailored production, we generated CRISPR/Cas9-mediated TCR-knockout (TCR^KO) NKp30-CAR T cells as an off-the-shelf approach for CAR T therapy. Functional studies comparing NKp30-CD28 CAR or NKp30-CD137 CAR TCR⁺ and TCR^KO T lymphocytes revealed superior anti-tumoral immunity of NKp30-CD28 CAR TCR^KO T cells to AML and melanoma cell lines in vitro, and effective control of tumor burden in an NSG melanoma-xenograft mouse model. In conclusion, these findings highlight the therapeutic potential of NKp30 CAR TCR^KO T cells for adoptive T-cell therapy to B7H6-expressing cancers, including melanoma and AML. 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

Natural killer (NK) cells are promising candidates for adoptive immunotherapy, but their clinical application requires standardized expansion protocols that yield functional cells in sufficient numbers. This study examined how initial seeding density and donor-intrinsic variability affect NK cell proliferation and receptor phenotype during in vitro expansion in a G-Rex^® 24-well plate under IL-2 stimulation. NK cells from healthy donors were analyzed longitudinally by flow cytometry, and targeted SNP sequencing of selected receptor genes (IL2RA, IL2RB, FCGR3A, NCR1, KLRK1, and ICAM-1) was performed to assess potential genetic contributions. A seeding density of 2.0 × 10⁶ cells/cm² promoted high expansion rates and favorable expression of activating receptors including CD16a, NKp46, and NKG2D. Nonetheless, marked inter-donor differences were observed. Some donors exhibited impaired proliferation and aberrant receptor expression, possibly associated with high-priority SNPs and distinct haplotype structures. Others showed robust proliferation despite the absence of identifiable genetic drivers, suggesting the involvement of variants in other genes or non-genetic mechanisms such as epigenetic priming or adaptive NK-cell differentiation. These results highlight the influence of both culture conditions and donor-intrinsic factors on NK-cell expansion outcomes. Integrating phenotypic and genetic analyses may improve the reproducibility and personalization of NK-cell-based manufacturing protocols for therapeutic use. 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

Background: The STING (Stimulator of Interferon Genes) pathway plays a vital role in the body’s innate immune defense system, primarily involved in DNA sensing and type I interferon production. While STING is well-established in various immune cells, its role in natural killer (NK) cells, particularly within the context of liver fibrosis, remains inadequately explored. Aim: The current study investigates the relationship between STING expression, NK cell activity, and insulin receptor (IR) signaling in patients with metabolic dysfunction-associated steatohepatitis (MASH). Methods: Peripheral NK cells were isolated from healthy controls and MASH patients with varying stages of liver fibrosis (early: F1/F2; advanced: F3/F4). The expressions of STING, IR, NK cell activation markers (CD107a, NKp46), and NK cell inhibitory markers (LAIR-1, Siglec-7) were assessed using flow cytometry. NK cell cytotoxicity against primary hepatic stellate cells (pHSCs) was evaluated through apoptosis assays. STING agonists (2′3′-cGAMP and DMXAA) were used to stimulate NK cells, and their effects on STING expression, NK cell activation, and cytotoxicity were measured. Additionally, the impact of insulin signaling on STING expression and NK cell function was examined. Results: Our results demonstrate that STING expression in NK cells correlates with disease severity in liver fibrosis. NK cells from MASH patients with advanced fibrosis (F3/F4) showed inhibited STING protein levels that were statistically comparable to healthy NK cells and accompanied by impaired cytotoxicity and decreased IFN-γ production. In contrast, NK cells from early fibrosis (F1/F2) exhibited higher STING expression and better functional activity. STING agonist treatment (2′3′-cGAMP) restored STING expression and enhanced NK cell activity across all fibrosis stages. Furthermore, insulin treatment and combined insulin and 2′3′-cGAMP treatment synergistically upregulated both IR and STING expressions, leading to improved NK cell function and increased cytotoxicity, particularly in advanced fibrosis. Conclusion: Our results highlight the potential of targeting STING and insulin signaling pathways as a therapeutic approach in restoring NK cell function and enhance immune surveillance in liver fibrosis. Full article