Recent studies have shown that dengue virus (DENV) infection during pregnancy is linked to adverse pregnancy outcomes, presenting an emerging clinical challenge with poorly understood pathogenic mechanisms. Uterine vascular remodeling, a critical determinant of successful pregnancy, is predominantly regulated by uterine natural killer (uNK) cells. In this study, we explored the effect of uNK cells on uterine injury in a DENV-induced adverse pregnancy mouse model. Transcriptomic analysis revealed significant dysregulation of uterine vascular remodeling and immune response-related gene expression after DENV-2 infection. Histopathological analysis revealed vascular remodeling disorders characterized by the preservation of vascular smooth muscle and a high level of tight junction protein in the vascular wall, accompanied by abnormal dilation of the lumen. These structural abnormalities coincided with a marked increase in uNK cell infiltration in the uterus. Moreover, the depletion of NK cells with anti-Asialo-GM1 mitigated uterine vascular damage and improved pregnancy outcomes. Single-cell RNA sequencing revealed a subpopulation of uNK cells (uNK2) that is characterized by upregulated expression of cytotoxicity-related genes. We further revealed that monocytes/macrophages (Mon_Macro) serve as intermediates in uNK2-mediated neutrophil (NE) recruitment. The SPP1-CD44 signaling axis is the dominant pathway governing uNK2-Mon_Macro crosstalk, and activated Mon_Macro2 can secrete chemokines such as CXCL2 to recruit NE. These findings provide valuable insights into the pathogenesis of DENV-induced uterine injury and facilitate the development of targeted therapeutic interventions for DENV-associated gestational disorders.IMPORTANCEDengue virus (DENV), a globally prevalent mosquito-borne virus, increasingly threatens maternal health because its infection is linked to adverse pregnancy outcomes. However, the mechanisms underlying DENV-induced damage to the uterus remain elusive. This study revealed impaired uterine vascular remodeling and abnormal vascular dilation following DENV-2 infection. Notably, uterine natural killer (uNK) cells are the critical pathological determinants of vascular injury in the uterus. Mechanistically, uNK cells may influence monocytes/macrophages (Mon_Macro) through SPP1-CD44 signaling to drive neutrophil infiltration, leading to uterine damage and adverse pregnancy outcomes. Successful depletion of NK cells reduces vascular damage and improves pregnancy outcomes. These findings provide critical mechanistic insights into DENV-2-induced uterine pathological lesions, fundamentally advancing our understanding of mosquito-borne virus-associated gestational diseases. The identified molecular cascades not only reveal the etiological landscape of pregnancy complications but also establish therapeutic measures for intervention strategies in mosquito-borne viral disorders.
Polycystic ovary syndrome (PCOS), a complex endocrine and metabolic disorder, involves significant dysregulation of the immune system. Natural killer (NK) cells, as key components of innate immunity, demonstrate notable phenotypic and functional alterations in women with PCOS. These changes include not only an elevated proportion in peripheral blood but also dynamic shifts within the local microenvironments of the ovary and endometrium. The increased level of peripheral NK cells correlates with a chronic low-grade inflammatory state, potentially serving as a predictive marker in infertile PCOS patients. Within the endometrium, uterine NK (uNK) cells exhibit reduced numbers and impaired function, accompanied by dysregulation of cytokine networks such as IL-15 and IL-18, which disrupts the immune equilibrium essential for embryo implantation. Abnormal NK cell function further involves alterations in killer immunoglobulin-like receptor (KIR) repertoires and dysregulated secretion of angiogenic factors, thereby compromising endometrial receptivity and vascular remodeling. Hyperandrogenemia modulates the distribution and activity of NK cells in reproductive tissues by influencing their surface activation markers, while insulin resistance promotes the generation of myeloid-feature NK (myNK) cell subsets via the IL-6/Stat3 signaling pathway, collectively exacerbating metabolic inflammation and reproductive dysfunction. Deciphering the role of NK cells in the immunometabolic interplay of PCOS reveals their position as a critical link between. May represent a potential cutoff requiring validation in larger cohorts reproductive impairment and metabolic disturbances, opening new avenues for targeted immunomodulatory interventions. Collectively, NK cells appear to present an important immunometabolic link between reproductive dysfunction and metabolic disturbance in PCOS, highlight their potential relevance as therapeutic targets.
Human γδ T cells are a rare but functionally diverse lymphocyte subset critical for tumor surveillance and antimicrobial immunity. Although they express natural killer (NK) cell-associated receptors such as Killer-cell Immunoglobulin-like Receptors (KIRs), the relevance of KIR expression on γδ T cells remains largely unexplored. Using flow cytometry, ATAC-seq and RNA-seq, we identified KIR expression as a marker that distinguished two functionally and molecularly distinct γδ T cell subsets. KIR⁺ γδ T cells exhibited an advanced, memory-like differentiation state characterized by heightened cytotoxicity, stable epigenetic remodeling and a predominant IFNγ-producing profile. In contrast, KIR⁻ γδ T cells maintained a naïve-like phenotype and preferentially produced IL-17 upon polarization. Notably, KIR+ γδ T cells were consistently observed across individuals but were significantly enriched in cytomegalovirus (CMV)-seropositive donors, suggesting that chronic antigenic stimulation could promote the emergence of KIR⁺ effector γδ T cells. These findings reveal a functional dichotomy in human γδ T cells defined by KIR expression, linking IFNγ-driven cytotoxicity with KIR⁺ cells and IL-17 production with KIR⁻ cells. This insight advances our understanding of γδ T cell heterogeneity and has implications for viral immunity, immune memory and the development of γδ T cell-based immunotherapies.
KIR+NKG2A- natural killer (NK) cells can detect and eliminate malignant and infected cells that have downregulated single HLA class I molecules to escape T cell recognition. So far, these KIRonly NK cells cannot be efficiently expanded in vitro without concomitant co-expression of NKG2A, which modulates their specificity. In this context, we recently demonstrated that circulating innate lymphoid cells 1 (cILC1s) have NK cell progenitor potential and can be differentiated into KIRonly NK cells using murine feeder cells. Here, we established an animal-free culture system enabling the generation and expansion of NK cells from cord blood (CB)-derived cILC1s using human mesenchymal stem cells (MSCs) as feeder cells. Compared to the murine niche provided by the OP9-DL1 cell line, human MSCs generally enabled a much more efficient generation of NK cells, resulting in significantly higher yields of KIR+ NK cells. The frequency of KIRonly NK cells could be further increased by addition of the soluble NOTCH ligand DLL1. Furthermore, we utilized the cILC1/MSC platform to study education of KIRonly NK cells by HLA-C-encoded ligands in a human stem cell niche. This effect was strongest for homozygous (C1/C1) compared to heterozygous (C1/C2) donors, suggesting that cognate KIR/KIR ligand interaction mediates a gene-dosage-dependent education effect. Altogether, this optimized culture protocol overcomes previous limitations by enabling efficient generation of KIR-expressing NK cells in an animal-free, GMP-compatible system. The presented approach may facilitate the clinical translation of NK cell-based strategies for cellular immunotherapy and in addition provides a platform for mechanistic studies of NK cell education.
Natural killer (NK) cells are key effector cells involved in tumor immune surveillance, yet their function within the tumor microenvironment (TME) exhibits considerable complexity and plasticity that cannot be adequately explained by the classical CD56/CD16 dichotomy. This functional diversity arises from the phenotypic adaptability and dynamic differentiation of distinct NK cell subsets shaped by the TME. In this review, we systematically examine the defining characteristics and functional roles of recently identified NK cell subsets in the TME; elucidate the molecular mechanisms governing their regulation; and highlight the functional transitions and cooperative interactions among these subsets. Moreover, building on current evidence, we summarize emerging immunotherapeutic approaches targeting specific NK cell subsets. Together, these perspectives offer new insights and strategic directions for deciphering the multifaceted roles of NK cells in antitumor immunity and advancing the development of subset-targeted therapies.
Hepatocellular carcinoma (HCC) poses a formidable therapeutic challenge due to its high heterogeneity, frequent late-stage diagnosis, and chemoresistance. Natural killer (NK) cells are essential for immune surveillance, yet their quantity and function become significantly compromised during HCC progression, thereby promoting tumour immune escape. This review systematically outlines current NK cell-based immunotherapeutic strategies for HCC, including adoptive NK cell transfer, genetic engineering of NK cells, NK cell inhibitory receptor-targeted therapies, reprogramming of the immunosuppressive HCC microenvironment, cytokine-mediated enhancement of NK cell function, and traditional Chinese medicine-augmented NK cell cytotoxicity. Representing a promising immunotherapeutic paradigm, NK cell-based therapy is rapidly advancing from conventional cell infusion toward more precise modalities, including CAR-NK cells and multifunctional antibody engagers. However, the efficacy of these approaches is frequently curtailed by the immunosuppressive tumour microenvironment and tumour heterogeneity. Given the multifactorial nature of NK cell dysfunction, we highlight that rationally designed combination strategies-integrating genetic engineering, TME reprogramming, and checkpoint blockade-represent the most viable path toward durable clinical responses in HCC.
Natural killer (NK) cells play a pivotal role in anti-tumor immunity; however, the prognostic significance of genetic variants in NK cell-related genes in gastric cancer (GC) remains largely uncertain. We systematically evaluated 12,476 single-nucleotide polymorphisms (SNPs) in 151 NK cell-related genes for their associations with overall survival (OS) in 2,211 Chinese GC patients with pathological tumor-node-metastasis (TNM) stage I-III, who were enrolled in the Shanghai genome-wide association study (GWAS). Significant variants were further validated in an independent Jiangsu GWAS cohort comprising 1,049 GC patients with TNM stage I-III. The prognostic value of independent SNPs was evaluated. Bioinformatic annotations were performed through expression QTL, splicing QTL, histone modification QTL, and methylation QTL analyses, as well as transcription factor binding, differential expression, functional enrichment, and immune infiltration analyses. Three independent SNPs (CD160 rs9728526 A>G, MERTK rs114788905 G>A, and IL15 rs140007893 T>A) were significantly associated with GC OS, with adjusted hazard ratios of 1.16 (95% CI = 1.05-1.29, P = 0.006), 0.89 (95% CI = 0.81-0.99, P = 0.033), and 0.77 (95% CI = 0.62-0.97, P = 0.028), respectively. A combined analysis demonstrated a dose-dependent association between the number of unfavorable genotypes and poorer OS. Incorporating these SNPs improved the C-index, time-dependent AUC, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) for OS prediction. Functional annotation indicated that the variant alleles exerted tissue- and immune cell-specific regulatory effects on gene expression, splicing, and transcription factor binding. The expression levels of CD160, MERTK, and IL15 were correlated with immune cell infiltration within the tumor microenvironment in GC. We identified three novel SNPs in NK cell-related genes that independently predict GC survival, providing potential prognostic biomarkers for risk stratification in GC, although further validation is warranted.
6PPD-Quinone (6PPD-Q) is a tire derivative formed by the oxidation of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), a commonly used antioxidant and ozone stabilizer in rubber products, and has emerged as a significant environmental concern in recent years. It is widely present in the atmosphere, surface lakes, and soil. The primary routes of exposure to 6PPD-Q are the digestive tract and respiratory tract. Studies indicate that it is a major factor causing acute mortality in coastal coho salmon (Oncorhynchus kisutch). Reports indicate that 6PPD-Q exhibits greater chemical stability and stronger biological toxicity than 6PPD, demonstrating toxic effects across multiple species. 6PPD-Q has been detected in human urine samples, indicating a need for heightened attention to its potential health risks. 6PPD-Q exhibits multi-organ toxicity in organisms, including intestinal, hepatic, neurotoxic, and reproductive toxicity. Its potential toxic mechanisms are associated with oxidative stress and inflammatory responses, and it can disrupt amino acid metabolism, carbohydrate metabolism, and lipid metabolism while interfering with signal transduction pathways by binding to specific receptors. This paper reviews the environmental contamination of 6PPD-Q, explores its potential toxic effects on organisms and underlying mechanisms, analyzes gaps in the current research and future trends, and contributes to a better understanding of its environmental occurrence and biological hazards.
Cesarean scar pregnancy (CSP), a condition characterised by inflammation, occurs in 0.2% of women with a history of cesarean section(s), and is clinically categorised by type 1 and type 2 according to the ultrasound findings. Recent studies reported that systemic inflammation indices derived from routine whole-blood tests may serve as additional clinical predictive markers for early CSP detection, with lymphocyte counts showing a reduction. However, the specific lymphocyte populations contributing to this reduction remain unclear. This study included 72 women diagnosed with CSP and 50 gestation-matched controls. The subsets of peripheral lymphocytes, including CD45 lymphocytes/monocytes, CD3 T cells, CD4 T helper cells, CD8 cytotoxic T cells, CD19 B cells, total NK cells and NKT-like cells, were measured. We found a significant reduction in peripheral total NK cells and CD8 cytotoxic T cells in CSP women compared to controls. However, there were no differences in peripheral immune cell profiles between type 1 and type 2 CSP. Using total NK cell counts with a cut-off value of 210/µl, the area under the curve (AUC) was 0.698, with a sensitivity of 64%. Our findings suggest that the reduction in peripheral total NK cells and CD8 T cytotoxic cells may play a role in the development of CSP. Additionally, peripheral total NK cell counts, derived from routine whole-blood tests, could serve as a predictive marker for early CSP diagnosis.
Hepatocellular carcinoma (HCC) is a major global health problem, ranking as the sixth most frequently diagnosed cancer and the third leading cause of cancer-related mortality worldwide. Although the incidence of viral infection-mediated HCC has decreased in recent years, the incidence of alcohol- and metabolic dysfunction-associated HCC has increased, driven by changes in lifestyle and diet. Excessive alcohol consumption contributes to advanced liver diseases, including liver fibrosis, cirrhosis and HCC. Despite the clinical relevance of alcohol-associated HCC, there are no suitable animal models that adequately reflect the pathophysiological features of alcohol-associated HCC in humans. Here, to address this limitation, we established a mouse model of alcohol-associated HCC through the combined administration of N-diethylnitrosamine and carbon tetrachloride (CCl4), followed by administration of an alcohol-containing Lieber-DeCarli diet. The results indicated that chronic alcohol exposure in the presence of N-diethylnitrosamine and CCl4 substantially accelerated HCC development, which was characterized by increased oxidative stress, inflammation and severe fibrosis. Furthermore, we found that chronic ethanol consumption disrupted hepatic immunity, characterized by natural killer/natural killer T cell depletion, increased PD1+CD8+ cells, reduced cytotoxicity and elevated inflammation. We also observed marked alterations in the gut microbiome following chronic alcohol administration. These immunological and microbiome alterations fostered an immunosuppressive microenvironment that accelerated HCC progression. Our newly developed mouse model induced liver tumorigenesis within a relatively short timeframe and recapitulated the clinical and pathological features of alcohol-associated HCC. The model therefore represents a valuable tool for studying the mechanisms underlying alcohol-associated HCC and related chronic liver diseases.
Mitochondrial dysfunction resulting in mitochondrial DNA (mtDNA) leakage is one of the main triggers of immune responses in systemic lupus erythematosus (SLE). In contrast, mitochondrial RNA (mtRNA) leakage and its role in SLE remains poorly understood. Interferon-alpha (IFN-α) and immune complexes (ICs) are both pathogenic contributors to SLE. Following the detection of increased mtRNA in the serum of patients with SLE, we explored the mechanisms of mtRNA leakage. Exposure to IFN-α at 100 U/ml, a pathophysiological concentration detected in SLE patients with mild to moderate disease activity, resulted in mitochondrial permeability transition pore (mPTP) opening and voltage dependent anion channel 1 (VDAC1) oligomerization, leading to mtRNA leakage and downstream inflammatory pathway activation in bone marrow-derived macrophages (BMDMs) of mice. However, we did not observe the activation of BCL2 antagonist/killer 1 (BAK) and BAK/BCL2-associated X (BAX) (BAX/BAK) pores and mitophagy does not play roles in these effects. Overloaded mitochondrial calcium released from the endoplasmic reticulum is likely responsible for mitochondrial pore opening. Similar effects were observed with ICs treatment. Several commonly recognized events contributing to mitochondrial pore opening such as cell death, apoptosis and changes of mitochondrial membrane potential were not detected and a pan-caspase inhibitor Z-VAD-FMK could not block IFN-α and ICs-induced mtRNA release. Our studies demonstrated an unexpected phenomenon that a pathophysiological concentration of IFN-α and ICs can selectively induce mitochondrial pore opening leading to mtRNA release in primary macrophages.
Monocyte-derived dendritic cells (moDCs) are widely used in cancer immunotherapy due to their accessibility and their ability to initiate potent T cell responses. However, the immunosuppressive tumor microenvironment often compromises the therapeutic efficacy of these treatments. Temozolomide (TMZ), an alkylating chemotherapeutic agent widely used in the treatment of glioblastoma, has been proposed to exert additional immunomodulatory effects beyond its cytotoxic role. This study was designed to evaluate the influence of TMZ on the phenotype and functional characteristics of human moDCs. Flow cytometry analysis revealed that TMZ treatment increased HLA-DR expression, whereas CD11c and CD86 expression did not change significantly. Gene expression analysis revealed a notable increase in interleukin (IL)-12 and tumor necrosis factor-alpha (TNF-α) transcripts, consistent with an enhanced immunostimulatory potential. TMZ also downregulates indoleamine 2,3-dioxygenase (IDO) and transforming growth factor-beta (TGF-β), both of which are associated with immunoregulatory pathways. The observed profile suggests that TMZ alone can modulate DC-associated immune mediators in a manner consistent with enhanced immunostimulatory features under controlled in vitro conditions. However, the translational relevance of these findings remains limited due to the absence of functional DC-T cell/natural killer (NK) cell assays and the lack of clinically relevant co-exposures, such as dexamethasone. While TMZ appears compatible with DC-based vaccine strategies, further functional studies are needed to clarify its net effect on T cell responses and to optimize its integration into combined immunotherapy regimens.
Natural killer (NK) cells undergo stepwise differentiation from multipotent progenitors within secondary lymphoid tissues. Despite the central importance of the tissue microenvironment in their development, little is known about cell-cell interactions that regulate human NK cell trafficking and maturation. Here, we identify the chemokine receptor CXCR4 and its lig- and CXCL12 as regulators of stromal-NK cell interactions required for NK cell maturation. We demonstrate that CXCR4 is expressed throughout human NK cell development in peripheral blood and tonsil, and CXCL12 is enriched in stromal niches containing developing NK cells. Pharmacologic blockade or genetic disruption of CXCR4 resulted in diminished adhesion to integrin ligands and high-resolution imaging demonstrated crosstalk between CXCR4 and integrins, providing a mechanistic basis for chemokine-dependent modulation of adhesion. Further, CXCR4 blockade resulted in altered contact-dependent motility on stromal cells and integrin ligands, with decreased stable stromal engagement and increased cell speed. Consistent with a requirement for these interactions, treatment with the CXCR4 antagonist plerixafor (AMD3100) impaired NK cell generation from CD34 + precursors. Analysis of NK cells from WHIM syndrome patients with CXCR4 gain-of-function mutations treated with plerixafor revealed similar defects in migration and adhesion, supporting the in-vivo relevance CXCR4-dependent regulation of NK cell adhesion and motility.
The Tumor Microenvironment (TME) exerts a pivotal regulatory effect on the initiation, progression, and therapeutic response of Head and Neck Squamous Cell Carcinoma (HNSCC). Serine Palmitoyltransferase Small Subunit A (SPTSSA) is a TME-associated gene with well-characterized roles in multiple malignancies, yet its biological function and clinical significance in HNSCC remain largely elusive. This study aimed to systematically investigate the clinical value of SPTSSA in HNSCC and explore its potential as a novel prognostic biomarker and therapeutic target for this disease. The expression of SPTSSA between Head and Neck Squamous Cell Carcinoma (HNSCC) tissues and non-tumoral tissues was compared using gene expression data. Associations with clinicopathologic features and patient outcomes were also analyzed. In vitro assays in HNSCC cell lines were used to test the effects of SPTSSA on malignant phenotypes. Multiplex immunofluorescence histochemistry was applied to assess SPTSSA protein levels in the TME and their relationship with immune markers and clinical factors. Circulating SPTSSA protein levels were measured in the blood of HNSCC patients to evaluate diagnostic value. SPTSSA expression was significantly higher in HNSCC tissues than in non‑tumoral tissues. Overexpression of SPTSSA enhanced HNSCC cell proliferation in vitro, supporting a pro‑tumorigenic function. Elevated SPTSSA protein levels in patient blood suggested potential diagnostic utility. In tumor tissues, SPTSSA protein expression correlated with CD4+ T cells, CD8+ T cells, and CD56+ natural killer cells, indicating a link with immune remodeling in the TME. High SPTSSA expression and advanced TNM stage independently predicted poor clinical outcomes. The study's findings establish SPTSSA as a critical oncogenic driver in HNSCC, with its upregulation closely linked to TME immune remodeling and poor patient prognosis. These results expand the oncogenic landscape of HNSCC and align with SPTSSA's pro-tumorigenic roles in other malignancies. Elevated circulating SPTSSA offers a non-invasive diagnostic tool for early detection, while its correlation with immune cell infiltration positions SPTSSA as a promising molecular target for HNSCC immunotherapy. SPTSSA is an oncogenic gene that drives HNSCC progression and is closely associated with an unfavorable patient prognosis. Its aberrant expression in both tumor tissues and peripheral blood may facilitate risk stratification and early clinical detection of HNSCC. Furthermore, the correlation between SPTSSA and immune cell infiltration in the TME highlights its potential as a promising molecular target for gene- and cell-based immunotherapeutic strategies in HNSCC.
Natural killer (NK) cell-derived exosomes have demonstrated anti-cancer activity against various cancers, but the role in regulating ferroptosis in lung cancer remains unclear. This study investigates whether exosomes derived from NK-92 cells (NK92-exo) can trigger ferroptosis in A549 cells and elucidates the underlying mechanisms, providing a novel strategy for lung cancer treatment. NK92-exo were isolated via ultracentrifugation and density-gradient ultracentrifugation and characterized. The changes related to ferroptosis were determined using specific detection kits and transmission electron microscopy (TEM). Predict miR-663a and SLC11A2 associated with ferroptosis in A549 cells through bioinformatics analysis and validated. Lentivirus infection was used to overexpress SLC11A2 in A549 cells, and the expression levels of GPX4, NRF2, and PTGS2 were analyzed. NK92-exo were successfully isolated and characterized. Co-culturing NK92-exo with A549 cells significantly increased ferroptosis-related changes, such as elevated MDA, ROS, and Fe2+ levels, decreased GSH level and mitochondrial membrane potential, and observed shrunken mitochondria and mitochondrial rupture. The expression level of miR-663a was significantly downregulated by NK92-exo treatment, resulting in evident upregulation of its potential target SLC11A2 in A549 cells. Additionally, SLC11A2 overexpression significantly enhanced ferroptosis in A549 cells, an effect that was further enhanced by NK92-exo treatment. NK92-exo decreased intracellular miR-663a abundance and increased SLC11A2 expression, thereby promoting ferroptosis in A549 cells. These findings suggest that NK92-exo may serve as a novel therapeutic bioproduct for lung cancer treatment.
Natural killer (NK) cells are critical for early antiviral immunity, yet their metabolic regulation during acute human viral infection remains incompletely understood. We analyzed NK cell activation and metabolic reprogramming in 47 vaccinated individuals with mild breakthrough SARS-CoV-2 infection and 20 matched healthy control subjects. COVID-19 patients exhibited elevated plasma interferon α and NK cell activation markers (CD69, CD38), alongside increased basal STAT5 phosphorylation, consistent with IL-15-mediated signaling. Functionally, NK cells from infected subjects displayed heightened cytotoxicity. Metabolic profiling at the single-cell level revealed increased cell size, translational activity, amino acid and glucose uptake, and mitochondrial membrane potential, indicating a globally activated metabolic state specific to NK cells. Using newly developed spectral cytometry panels targeting metabolic regulators, we identified CPT1a as the most discriminative marker between patient and control NK cells, with elevated expression in both CD56bright and CD56dim subsets. CPT1a levels correlated with CD38 expression and with uptake of the fluorescent palmitate analog BODIPY-FL C16, reflecting enhanced long-chain fatty acid oxidation. These changes were absent in B and T lymphocytes. Our findings support that during SARS-CoV-2 infection, human NK cells undergo coordinated cytokine-driven activation and metabolic remodeling, integrating glycolysis and lipid oxidation to support amplified effector function.
Cryptococcus neoformans is an encapsulated opportunistic yeast widely distributed in the environment and classified as critical-priority fungal pathogen by the World Health Organisation due to its high mortality and limited access to timely diagnosis and effective treatment. Infection is typically acquired via inhalation, with the primary pulmonary focus often remaining asymptomatic. Particularly in individuals with impaired cell-mediated immunity, it may disseminate hematogenously to central nervous system (CNS), skin and other organs. Cutaneous cryptococcosis is a rare clinical manifestation and in most cases, represents secondary involvement of disseminated disease. Its clinical presentation is highly variable and may mimic cellulitis, abscesses, ulcers or necrotizing soft-tissue infections, posing significant diagnostic challenges. Ruxolitinib is a Janus-kinase inhibitor used to treat myelofibrosis and polycythemia vera. By suppressing interferon-γ and interleukin-12-mediated immune responses, it impairs macrophage activation, reduces T-helper-1 cell responses, suppresses natural-killer cell function, and regulates hematopoietic activity. However, these immunomodulatory effects predispose patients to invasive opportunistic infections, particularly fungal infections. In the literature, cryptococcal infections associated with ruxolitinib have been reported in a limited number of case reports, most commonly involving the pulmonary and/or central nervous system. Cutaneous involvement is exceedingly rare, and to date, no cases from Türkiye have been reported. In this case report, a 67-year-old woman with myelofibrosis who had been receiving ruxolitinib therapy for three-years and developed cutaneous cryptococcosis infection mimicking necrotizing fasciitis, accompanied by asymptomatic pulmonary involvement was presented. Despite broad-spectrum antibacterials, a small papule on the medial thigh rapidly progressed over 25 days, with severe disproportionate pain raising suspicion of necrotizing fasciitis. On admission, physical examination revealed an 8×8 cm ulcerative tissue defect on the left thigh, with surrounding erythema, ecchymosis, desquamation and hemopurulent discharge. Magnetic resonance imaging demonstrated findings suggestive of necrotising soft-tissue infection, prompting urgent surgical intervention. Intraoperatively, diffuse inflammation and patchy necrotic areas were observed and surgical debridement followed by vacuum-assisted wound closure was performed. Microbiological cultures of deep-tissue specimens yielded C.neoformans and the pathogen was confirmed by matrix-assisted laser desorption/ ionisation-time-of-flight-mass spectrometry (MALDI-TOF-MS). Antifungal susceptibility testing showed minimum inhibitory concentrations of 0.5 µg/mL for amphotericin B and 4 µg/mL for fluconazole. Histopathological examination demonstrated yeast cells within a background of suppurative inflammation and focal necrosis. Although the patient had no respiratory symptoms, chest computed tomography revealed a cavitary pulmonary nodule consistent with fungal infection. Bronchoalveolar lavage cultures showed no microbial growth. Evaluation for central nervous system involvement resulted negative for India-ink staining and cerebrospinal fluid multiplex polymerase chain reaction (PCR) test. These findings were considered consistent with systemic cryptococcosis involving the skin and lungs. Antibacterials were discontinued and intravenous liposomal amphotericin-B plus fluconazole was initiated. After central netvous system involvement was excluded, sequential therapy with fluconazole was planned. Ruxolitinib dose was adjusted by haematology. Significant clinical improvement was observed in the early phase of treatment and pain however, the patient died due to acute pulmonary embolism. This case highlights a rare cutaneous presentation of ruxolitinib-associated cryptococcosis and emphasizes the importance of clinical awareness for opportunistic fungal infections in immunosuppressed patients.
Osteoarthritis (OA) is widely recognized as the most prevalent degenerative disorder affecting the joints, representing a major contributor to chronic pain and disability. Despite its high burden, the molecular mechanisms underlying OA pathogenesis remain poorly understood, particularly in the context of immune microenvironment modulation. This study explores the immune-related OA progression mechanisms and investigates potential biomarkers to aid diagnosis and therapeutic intervention. Gene expression data from the GEO database were analyzed, differentially expressed genes (DEGs) and OA-associated gene modules were identified using the LIMMA package in combination with weighted gene co-expression network analysis (WGCNA). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted on intersecting genes, which were analyzed using the protein-protein interaction network, XGBoost, and Random Forest, identifying core genes. Subsequently, immune cell infiltration was determined through immune cell infiltration analysis and single-cell sequencing analysis. Next, core genes were validated using Mendelian randomization (MR) and Western blotting (WB). Finally, in vitro validation confirmed key findings. A total of 1,171 upregulated DEGs were identified. WGCNA analysis delineated 25 co-expression modules, and the turquoise module emerged as the most strongly related to OA. The PPI network, XGBoost, and Random Forest analysis pinpointed three hub genes: protein tyrosine phosphatase receptor type C (PTPRC), C-X3-C Motif Chemokine Receptor 1 (CX3CR1) and Integrin Subunit Beta 2 (ITGB2). Immune cell infiltration analysis indicates that these key genes exhibit significant associations with immune cells, while single-cell sequencing and GSEA enrichment analysis further suggested their involvement in inflammatory pathways and immune activation. In vitro experiments demonstrate that one of the hub genes-PTPRC-alleviates the deterioration of OA through three levels. Virtual knockout in Natural Killer (NK) cells further confirms that PTPRC influences OA by regulating the immune microenvironment. This study identified three promising biomarkers in OA and certificated that PTPRC plays a pivotal role in alleviating OA progression through immunomodulation, offering a novel intervention pathway for tissue engineering combined with immunomodulatory therapy in OA.
Tuberculosis remains the biggest global killer from infectious causes, with an estimated 1.25 million deaths per year. The quadruple drug regimen of rifampicin, isoniazid, pyrazinamide, and ethambutol has been standard therapy for 40 years, with good outcomes in patients with drug susceptible tuberculosis who are able to tolerate the drug regimen. However, the frequency of adverse drug reactions and emergence of drug resistant tuberculosis has created demand for new treatment strategies: there is now a surge in novel tuberculosis agents and regimens entering human trials. For decades, drug resistant tuberculosis required at least 18 months of second line and third line combination treatments that included injectable agents. In 2022, in response to a growing body of trial evidence, the World Health Organization (WHO) introduced six month and nine month all oral regimens for pulmonary drug resistant tuberculosis in specific settings. These encompass agents in the bedaquiline-pretomanid-linezolid/moxifloxacin regimen, as well as repurposed and novel agents such as clofazimine and delamanid. In addition, a large number of novel antimicrobial and host directed treatments are progressing to late stage clinical trials for tuberculosis, raising the prospect of shorter, more efficacious, and better tolerated treatments. This review summarises the agents and regimens recommended in the latest consolidated WHO treatment guidelines for tuberculosis (2025), including a synopsis of the evidence base for their safety, efficacy, and cost effectiveness. It also outlines the antimicrobial and host directed treatments that have entered phase 2-4 clinical trials for pulmonary tuberculosis in adults.
Celiac disease (CeD) is an autoimmune disorder triggered by dietary gluten. While HLA-DQ2/8-mediated presentation of gliadin peptides is required for disease, the mechanisms that underlie the loss of oral tolerance to gluten remain incompletely understood. Long-noncoding RNAs (lncRNAs) have been increasingly recognized as regulators of immune function, yet their role in oral tolerance has not been previously explored. Here, using a screen designed to identify lncRNAs responsive to T cell activation and enriched for CeD-associated GWAS variants, we identified lnc13 as a top candidate. In HLA-DQ8 transgenic mice lacking lnc13, unmanipulated gluten ingestion led to molecular signatures resembling human CeD and hallmark features of loss of oral tolerance to gluten: increased IFN-γ+ lymphocytes, IL-12+ myeloid cells, cytotoxic intraepithelial immune cells and crypt hyperplasia in the small intestine. Mechanistically, lnc13 binds specific DNA regulatory regions and limits immune cell responsiveness to proinflammatory signals. In particular, lnc13 restrains IL-15-driven differentiation of CD8+ natural killer-like lymphokine-activated killer cells (an IL-15-dependent pathway strongly implicated in CeD). These findings establish lnc13 as a critical noncoding modulator of oral gluten tolerance.