Search Results (432)

Human cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) braziliensis is a complex parasitic disease marked by dynamic host–parasite interactions and immunomodulation. Extracellular vesicles (EV) derived from immune cells have emerged as key mediators of intercellular communication and potential biomarkers in infectious diseases. In this study, we combined a modified lymphocyte proliferation assay with nano-flow cytometry to quantify and phenotype EV released by CD4⁺, CD8⁺, and CD14⁺ cells in PBMC cultures from CL patients at different clinical stages: before treatment (PBT), during treatment (PDT), and post-treatment (PET) with antimonial. Healthy individuals (HI) were included as physiological controls. Upon stimulation with L. (V.) braziliensis antigens, we observed a distinct modulation of EV subsets. In the PBT group, CD4⁺ and CD14⁺ EV were significantly reduced, while CD8⁺ EV remained elevated. During PDT and PET, EV concentrations were restored across all subsets. These findings suggest that L. (V.) braziliensis selectively modulates the release of immune cell–derived EV, possibly as an immune evasion mechanism. The restoration of EV release following antimonial therapy highlights their potential as sensitive biomarkers for disease activity and treatment monitoring. This study offers novel insights into the immunoregulatory roles of EV in CL and underscores their relevance in host–parasite interactions. Full article

Considering the high plasticity of FoxP3⁺ regulatory T (Treg) cells and Interleukin (IL)-17-producing Th17 cells, we hypothesized that a Th17 inflammatory milieu may impair the functional properties of Treg cells in chronic inflammatory arthritides. Therefore, a cross-sectional explorative analysis was set up in patients with psoriatic arthritis (PsoA), rheumatoid arthritis, or spondyloarthritis to investigate the features of Th17 and Treg cells. T cell subpopulation counts, FOXP3 mRNA expression, CpG methylation of the FOXP3 gene, and the suppressive capacity of isolated Treg cells were determined. Ex vivo analysis of PsoA-derived peripheral blood lymphocytes showed a Th17-mediated inflammation. It was accompanied by demethylation of the FOXP3 promotor and Treg-specific demethylated region (TSDR) in Treg cells which, however, resulted neither in elevated FOXP3 mRNA expression nor in increased suppressive Treg cell capacity. To clarify this conundrum, in vitro stimulation of isolated Treg cells with Th17-inducing cytokines (IL-1β, IL-6, IL-23, TGFβ), recombinant IL-17, or the anti-IL-17A antibody secukinumab was performed, demonstrating that cell culture conditions polarizing towards Th17, but not IL-17 itself, impair the suppressive function of Treg cells, accompanied by diminished FOXP3 mRNA expression due to hypermethylation of the FOXP3 promotor and TSDR. This potential causal relationship between Th17 inflammation and impaired Treg cell function requires attention regarding the development of immunomodulatory therapies. Full article

Background/Objectives: Romania remains a tuberculosis (TB) hotspot in the European Union, yet host-derived factors of poor outcomes are poorly characterised. We quantified circulating pro-inflammatory cytokines and examined their interplay with behavioural risk factors, the nutritional status, and the clinical course in adults hospitalised with pulmonary TB. We analysed 80 adults with microbiologically confirmed pulmonary TB and 40 respiratory symptom controls; four TB patients (5%) died during hospitalisation, all within 10 days of admission. Methods: A retrospective analytical case–control study was conducted at the Constanța regional TB referral centre (October 2020—October 2023). Patients with smear- or culture-confirmed TB were frequency-matched by sex, 10-year age band, and BMI class to culture-negative respiratory controls at a 2:1 ratio. The patients’ serum interferon-γ (IFN-γ), interleukin-1α (IL-1α), interleukin-1β (IL-1β), and tumour-necrosis-factor-α (TNF-α) were quantified within 24 h of admission; the neutrophil/lymphocyte ratio (NLR) was extracted from full blood counts. Independent predictors of in-hospital mortality were identified by multivariable logistic regression; factors associated with the length of stay (LOS) were modelled with quasi-Poisson regression. Results: The median TNF-α (24.1 pg mL⁻¹ vs. 16.2 pg mL⁻¹; p = 0.009) and IL-1β (5.34 pg mL⁻¹ vs. 3.67 pg mL⁻¹; p = 0.008) were significantly higher in the TB cases than in controls. TNF-α was strongly correlated with IL-1β (ρ = 0.80; p < 0.001), while NLR showed weak concordance with multiplex cytokine patterns. Among the patients with TB, four early deaths (5%) exhibited a tripling of TNF-α (71.4 pg mL⁻¹) and a doubling of NLR (7.8) compared with the survivors. Each 10 pg mL⁻¹ rise in TNF-α independently increased the odds of in-hospital death by 1.8-fold (95% CI 1.1–3.0; p = 0.02). The LOS (median 29 days) was unrelated to the smoking, alcohol, or comorbidity load, but varied across BMI strata: underweight, 27 days; normal weight, 30 days; overweight, 23 days (Kruskal–Wallis p = 0.03). In a multivariable analysis, under-nutrition (BMI < 18.5 kg m⁻²) prolonged the LOS by 19% (IRR 1.19; 95% CI 1.05–1.34; p = 0.004) independently of the disease severity. Conclusions: A hyper-TNF-α/IL-1β systemic signature correlates with early mortality in Romanian pulmonary TB, while under-nutrition is the dominant modifiable determinant of prolonged hospitalisation. Admission algorithms that pair rapid TNF-α testing with systematic nutritional assessment could enable targeted host-directed therapy trials and optimise bed utilisation in high-burden settings. Full article

The fungal component of microbiota, known as the mycobiome, inhabits different body niches such as the skin and the gastrointestinal, respiratory, and genitourinary tracts. Much information has been gained on the bacterial component of the human microbiota, but the mycobiome has remained somewhat elusive due to its sparsity, variability, susceptibility to environmental factors (e.g., early life colonization, diet, or pharmacological treatments), and the specific in vitro culture challenges. Functionally, the mycobiome is known to play a role in modulating innate and adaptive immune responses by interacting with microorganisms and immune cells. The latter elicits anti-fungal responses via the recognition of specific fungal cell-wall components (e.g., β-1,3-glucan, mannan, and chitin) by immune system receptors. These receptors then regulate the activation and differentiation of many innate and adaptive immune cells including mucocutaneous cell barriers, macrophages, neutrophils, dendritic cells, natural killer cells, innate-like lymphoid cells, and T and B lymphocytes. Mycobiome disruptions have been correlated with various diseases affecting mostly the brain, lungs, liver and pancreas. This work reviews our current knowledge on the mycobiome, focusing on its composition, research challenges, conditioning factors, interactions with the bacteriome and the immune system, and the known mycobiome alterations associated with disease. Full article

CD8+ T lymphocytes (CTLs) act as serial killers of infected or malignant cells by releasing large amounts of interferon-gamma (IFNγ) and granzymes. Although IFNγ is a pleiotropic cytokine with diverse immunomodulatory functions, its precise spatiotemporal regulation and role in CTL-mediated cytotoxicity remain incompletely understood. Using wild-type and granzyme B-mTFP knock-in mice, we employed a combination of in vitro approaches, including T cell isolation and culture, plate-bound anti-CD3e stimulation, degranulation assays, flow cytometry, immunofluorescence, and structured illumination microscopy, to investigate IFNγ dynamics in CTLs. IFNγ expression in CTLs was rapid, transient, and strictly dependent on T cell receptor (TCR) activation. We identified two functionally distinct IFNγ-producing subsets: IFNγ^high (IFNγ^hi) and IFNγ^low (IFNγ^lo) CTLs. IFNγ^hi CTLs exhibited an effector/effector memory phenotype, significantly elevated CD107a surface expression (a marker of lytic granule exocytosis), and higher colocalization with cis-Golgi and granzyme B compared to IFNγ^lo CTLs. Furthermore, CRTAM, an early activation marker, correlated with IFNγ expression in naive CTLs. Our findings establish a link between elevated IFNγ production and enhanced CTL cytotoxicity, implicating CRTAM as a potential regulator of early CTL activation and IFNγ induction. These insights provide a foundation for optimizing T cell-based immunotherapies against infections and cancers. Full article

This study was conducted through in vivo and in vitro experiments and aimed to reveal the regulatory effect of water extract of Artemisia annua L. (WEAA) on the antioxidant function of mutton sheep and the underlying mechanism. In the in vivo experiment, 32 Dorper × Han female sheep (3 months old; avg. body weight: 24 ± 0.09 kg) were allocated to four groups (eight lambs/group) and fed a diet containing 0, 500, 1000, and 1500 mg/kg WEAA, respectively. In the in vitro experiments, peripheral blood lymphocytes (PBLs) were cultured with different doses of WEAA (0, 25, 50, 100, 200, 400 µg/mL) to determine the optimal concentration, followed by a 2 × 2 factorial experiment with four treatment groups (six replicates per treatment group): the ML385(−)/WEAA(−) group, the ML385(−)/WEAA(+) group, the ML385(+)/WEAA(−) group, and the ML385(+)/WEAA(+) group. The results showed that WEAA supplementation dose-dependently increased serum, liver and spleen tissue total antioxidant capacity, glutathione peroxidase (GSH-Px), and catalase (CAT) activity while reducing malondialdehyde level (p < 0.05). Moreover, WEAA supplementation significantly upregulated the liver and spleen expression of nuclear factor erythroid 2-related factor 2, superoxide dismutase 2, GSH-Px, CAT and NAD(P)H quinone dehydrogenase 1 (p < 0.05) while significantly downregulating the kelch-like ECH associated protein 1 expression in a dose-dependent manner (p < 0.05), thereby activating the Keap1/Nrf2 pathway with the peak effect observed in the 1000 mg/kg WEAA group. Additionally, supplementation with 100 µg/mL of WEAA had significant antioxidation activity in the culture medium of PBLs. Its action mechanism involved the Keap1/Nrf2 pathway; specifically, WEAA exerted its antioxidant effect by upregulating the gene expression related to the Keap1/Nrf2 pathway. In conclusion, WEAA enhances sheep’s antioxidant capacity by up-regulating Keap1/Nrf2 pathway genes and boosting antioxidant enzyme activity. The results provided experimental support for the potential application of WEAA in intensive mutton sheep farming. Full article

Breast cancer is the most frequently diagnosed cancer among women. In recent years, immunotherapy, a key targeted treatment strategy, has gained prominence in the management of this disease. Immune cells within the tumor microenvironment can significantly affect treatment outcomes. Among immunotherapeutic approaches, or programmed death protein 1(PD-1) and programmed death-ligand 1(PD-L1)-targeted therapies are increasingly recognized for their role in modulating cancer–immune system interactions. This study investigated the impact of PD-1/PD-L1 pathway inhibition on the expression of drug resistance-related proteins in an in vitro breast cancer model incorporating immune cells. MDA-MB-231 and MCF-7 cell lines were used as breast cancer cells, while THP-1 and Jurkat cells represented monocytes and lymphocytes, respectively. The effects of paclitaxel (PTX), doxorubicin (Dox), and PD-1/PD-L1 inhibitors (BMS-1166 and Human PD-L1 Inhibitor IV (PI4)) on cell viability were evaluated using an MTT assay, and the IC₅₀ values were determined. Flow cytometry was used to analyze PD-1/PD-L1 expression and the drug resistance proteins ABCG2 (ATP-binding cassette sub-family G member 2, breast cancer resistance protein), MDR-1 (multidrug resistance protein 1), and MRP-1 (multidrug resistance-associated protein 1) across co-culture models. Based on the results, Dox reduced PD-L1 expression in all groups except for MDA-MB-231:THP-1, while generally lowering drug resistance protein levels, except in MDA-MB-231:Jurkat. BMS-1166 significantly decreased cell viability and enhanced chemotherapy-induced cytotoxicity. Interestingly, in the MDA-MB-231:Jurkat co-culture, both inhibitors reduced PD-L1 but increased drug resistance protein expression. Paclitaxel’s effect on PD-L1 varied depending on the immune context. These findings highlight that PD-1/PD-L1 inhibitors and chemotherapeutic agents differentially affect PD-L1 and drug resistance-related protein expression depending on the immune cell composition within the tumor microenvironment. Full article

Background and Objectives: Blood-borne inflammatory ratios have been proposed as inexpensive prognostic tools across a range of diseases, but their role in pulmonary tuberculosis (TB) remains uncertain. In this retrospective case–control analysis, we explored whether composite indices derived from routine haematology—namely the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the systemic immune–inflammation index (SII) and a novel CRP–Fibrinogen Index (CFI)—could enhance risk stratification beyond established cytokine measurements among Romanian adults with culture-confirmed pulmonary T. Materials and Methods: Data were drawn from 80 consecutive TB in-patients and 50 community controls. Full blood counts, C-reactive protein, fibrinogen, and four multiplex cytokines were extracted from electronic records, and composite indices were calculated according to standard formulas. The primary outcomes were in-hospital mortality within 90 days and length of stay (LOS). Results: Among TB patients, the median NLR was 3.70 (IQR 2.54–6.14), PLR was 200 (140–277) and SII was 1.36 × 10⁶ µL⁻¹ (0.74–2.34 × 10⁶), compared with 1.8 (1.4–2.3), 117 (95–140) and 0.46 × 10⁶ µL⁻¹ (0.30–0.60 × 10⁶) in controls. Those with SII above the cohort median exhibited more pronounced acute-phase responses (median CRP 96 vs. 12 mg L⁻¹; fibrinogen 578 vs. 458 mg dL⁻¹), yet median LOS remained virtually identical (29 vs. 28 days) and early mortality was low in both groups (8% vs. 2%). The CFI showed no clear gradient in hospital stay across its quartiles, and composite ratios—while tightly inter-correlated—demonstrated only minimal association with cytokine levels and LOS. Conclusions: Composite cell-count indices were markedly elevated but did not predict early death or prolonged admission. In low-event European cohorts, their chief value may lie in serving as cost-free gatekeepers, flagging those who should proceed to more advanced cytokine or genomic testing. Although routine reporting of NLR and SII may support low-cost surveillance, validation in larger, multicentre cohorts with serial sampling is needed before these indices can be integrated into clinical decision-making. Full article

Gliomas, particularly IDH-wildtype ones, are associated with poor prognosis, yet their immunological landscape remains uncertain. We analyzed RNA sequencing data from 55 glioma patients, estimating immune infiltration with CIBERSORTx and immune cell states via Ecotyper. IDH-wildtype gliomas showed significantly higher immune cell infiltration (p = 0.002), notably of regulatory T cells (Tregs) and macrophages, and a greater proportion of exhausted T cells compared to IDH-mutant gliomas. Clustering based on immune profiles revealed two groups. Cluster A, enriched for IDH-wildtype cases, exhibited heightened immune infiltration but also marked immunosuppression. Cluster B, which included both IDH-wildtype and mutant cases, showed lower levels of immune infiltration. Tumor-infiltrating lymphocyte (TIL) cultured from IDH-wildtype tumors demonstrated limited expansion following anti-PD-1, a CSF1R inhibitor, or a STAT3 inhibitor treatment, without clear cluster-specific differences. Tumor-reactive TILs were mainly observed in cluster A. These findings highlight that IDH-wildtype gliomas have an immunosuppressive and heterogeneous microenvironment, potentially limiting responses to single-agent immunotherapies. A personalized, multi-targeted approach addressing multiple immunosuppressive mechanisms may be essential to improve immunotherapy outcomes in this aggressive glioma subgroup. Full article

Exposure to arsenic, a known environmental and occupational genotoxicant, poses significant health risks. Identifying agents capable of mitigating its effects is crucial for public health. This study evaluates the protective potential of Argovit™ silver nanoparticles (AgNPs) against cytotoxic and genotoxic damage induced by sodium arsenite in ex vivo cultured human lymphocytes obtained from the whole blood of healthy donors. Lymphocytes were exposed to sodium arsenite (3.7 × 10⁻³ µg/mL) and Argovit™ AgNPs (3.6 × 10⁻³ µg/mL). The cytokinesis-block micronucleus (CBMN) assay was performed using a modified 144 h protocol to assess delayed effects across two cell cycles. Four groups were analyzed: untreated control, sodium arsenite only, AgNPs only, and sodium arsenite followed by AgNPs. Arsenite exposure increased cytotoxic and genotoxic biomarkers. In contrast, post-treatment with AgNPs significantly reduced these effects. All treatments were performed in duplicate, and data were analyzed using the Kruskal–Wallis test with Dunn’s post hoc comparison (p < 0.05). Statistical analysis confirmed the antigenotoxic and cytoprotective properties of Argovit™. These findings support its potential application as a mitigating agent in scenarios of environmental or occupational exposure to genotoxic compounds. Full article

The lymphocyte-specific transcription factor interferon regulatory factor 4 (IRF4) is a key player in immune evasion in cancers, with the complex mechanism(s) being barely understood. In this study, we have focused on the role of IRF4 in regulating T cell functions through its transcriptional regulation of programmed death 1 (PD1) and its ligand PD1 ligand 1 (PD-L1), which were identified as IRF4 transcriptional targets in multi-omics analysis. We have shown that IRF4 transcriptionally regulates both PD1 and PD-L1, promoting immune suppression in the context of Epstein–Barr virus (EBV) infection. Co-culturing EBV+ JiJoye lymphoma cells with CD4+ T cells or with peripheral blood mononuclear cells (PBMCs) downregulates CD4+ T cell functions, but the depletion of IRF4 in EBV+ JiJoye lymphoma cells reduces PD1 and PD-L1 expression, and partially restores CD4+ T cell functions. Moreover, CD4+ T cell depletion from PBMCs enhances EBV transformation, and EBV has a greater efficiency in transforming PBMCs from HIV patients with impaired CD4+ T cell functions. These findings support the role of IRF4 in immune evasion by upregulating PD1/PD-L1 during EBV transformation, and that functional CD4+ T cells are essential for limiting EBV transformation. 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

Bacillus Calmette–Guerin (BCG) central nervous system (CNS) infections are one of the rarest complications following BCG exposure. A 77-year-old male, with bladder cancer previously treated with BCG instillation, presented with fever, confusion, and brain magnetic resonance imaging (MRI) consistent with encephalitis one month after the last BCG instillation. Cerebrospinal fluid (CSF) showed marked hypoglycorrhachia, hyperproteinorrachia, and lymphocytic pleocytosis. Despite CSF culture negativity, the presentation was considered suggestive of BCG-related encephalitis, and the empirical standard antitubercular treatment (rifampin, isoniazid and ethambutol), plus dexamethasone, was initiated. Following initial improvement, gait ataxia and hemiplegia were observed at the 4-month follow-up. MRI revealed an excluded enlarged left lateral ventricle with signs of ventriculitis, requiring surgical drainage. CSF collected during neurosurgery resulted positive on PCR for M. tuberculosis complex. Adjunctive linezolid was initiated, replaced by levofloxacin due to adverse events after 2 weeks. The patient was discharged following a normal CSF analysis. Oral antitubercular therapy was prescribed for 14 months and there were no signs of relapse at the 24-month follow-up. Previously, 16 cases of CNS BCGitis have been reported, without any cases of clinical relapse during antitubercular treatment. Furthermore, our study reports the use of linezolid as a 4th antitubercular drug for CNS BCGitis. Full article

Background/Objectives: The present study evaluated the diagnostic utility of underutilized parameters derived from complete blood count (CBC) analysis in identifying late-onset neonatal sepsis (LOS). The parameters evaluated included the nucleated red blood cell count (NRBC), neutrophil-to-lymphocyte ratio (NLR), red cell distribution width (RDW), plateletcrit (PCT), and platelet-to-lymphocyte ratio (PLR). Methods: This was a retrospective, single-center, case-control study in a tertiary neonatal intensive care unit. The study included 38 neonates diagnosed with LOS, and 22 healthy control subjects. The data collected encompassed demographic characteristics, clinical findings, and laboratory values, including complete blood count (CBC)-derived parameters, C-reactive protein (CRP) levels, and blood cultures. Statistical analyses were performed to assess differences between groups and the diagnostic performance of key parameters via receiver operating characteristic (ROC) curves. Results: The results of the study are as follows: A set of notable discrepancies were identified in a number of parameters when comparing the LOS and control groups. Elevated levels of C-reactive protein (CRP), platelet count, platelet-to-lymphocyte ratio (PLR), lymphocyte percentage, and neutrophil-to-lymphocyte ratio (NLR) were found to be associated with LOS. Concurrently, decreased hemoglobin, hematocrit, neutrophil percentage, NRBC percentage, and NLR were also associated with LOS. PLR exhibited the most robust diagnostic efficacy, with a cutoff value of 45.24 attaining 81.6% sensitivity, 61.9% specificity, and an area under the curve (AUC) of 0.787 (95% CI: 0.671–0.903). The application of a logistic regression analysis indicated that the PLR emerged as the most salient independent predictor of LOS (odds ratio [OR]: 1.071; 95% confidence interval [CI]: 1.009–1.135; p = 0.023). Conclusions: CBC-derived parameters, particularly the PLR, have been shown to offer promising diagnostic value for LOS. These findings support the incorporation of these accessible and cost-effective biomarkers into clinical practice for the early diagnosis and management of LOS, warranting further validation in larger, multicenter studies. Full article

Background: Allergic rhinitis (AR) is triggered by immunoglobulin E (IgE)-mediated immune responses to airborne allergens. Recent studies highlight the pivotal role of T follicular helper 2 (Tfh2) cells in IgE production. Interleukin-37 (IL-37) has emerged as an intrinsic modulator of innate immunity and inflammatory processes. We aimed to investigate the regulatory effect of IL-37 on Tfh2 cells in the pathogenesis of AR. Methods: Blood samples were collected from AR patients and controls. The IL-37 levels and the frequency of Tfh2 cells were detected by enzyme-linked immunosorbent assay (ELISA) and flow cytometry, respectively. The isolated Tfh2 cells were cultured or cocultured with naive B cells. The regulatory effects of IL-37 on Tfh2/B cells were assessed using ELISA, quantitative real-time polymerase chain reaction (qRT-PCR). Mouse models of ovalbumin (OVA)-induced AR were established to explore the effect of IL-37 in vivo. Results: IL-37 suppressed the production of IL-4 and IL-21 by Tfh2 cells and downregulated C-X-C chemokine receptor type 5 (CXCR5) and B-cell lymphoma 6 protein (Bcl6) mRNA expression while upregulating B lymphocyte-induced maturation protein 1 (Blimp1) and signal transducers and activators of transduction5 (STAT5) mRNA. IL-37 decreased IgE production by B cells significantly, and the addition of anti-IL-18 receptor α alleviated this effect. In mouse models, IL-37 reduced nasal rubbing, sneezing, eosinophil counts, OVA-specific IgE, and Tfh2 proportions. Conclusions: IL-37 plays a crucial role in modulating Tfh2 cell responses in AR, suggesting a potential therapeutic target for this condition. Full article