Search Results (1,789)

Chlamydia trachomatis infection causes pelvic inflammatory disease and infertility, but how host immune factors control pathogen clearance or pathology is not fully understood. Using a mouse model of genital tract infection with Chlamydia muridarum, we examined the role of CD1d-restricted Natural killer T (NKT) cells. Invariant NKT cell-deficient mice (Jα18^−/−) showed prolonged vaginal shedding of infectious elementary bodies (EBs), delayed clearance, and decreased early cytokine production compared to wild-type (WT) controls. Conversely, CD1d^−/− mice, which lack both invariant and diverse NKT cells, did not show significant differences in vaginal shedding compared to WT mice. Surprisingly, both NKT-deficient mice (Jα18^−/− and CD1d^−/−) produced higher levels of inflammatory cytokines in the oviduct at day 35 post-infection (p.i.) and experienced more frequent upper genital tract pathology (hydrosalpinx) at day 80 p.i. However, no infectious EBs were recovered from the oviducts or uterine horns of NKT-deficient mice after day 35 p.i. Cortisone acetate reactivated infectious shedding in chronically infected NKT-deficient mice at day 100 p.i. These findings highlight distinct roles for NKT cell subsets: invariant NKT cells promote early clearance via rapid cytokine production, while the broader NKT population helps limit tissue damage. Targeting NKT pathways could help prevent chronic infection and infertility. Full article

Background: Oropharyngeal squamous cell carcinoma (OPSCC) is a major subtype of head and neck cancer, with prognosis increasingly influenced by the tumour immune microenvironment. Although immune checkpoint inhibitors have improved outcomes for some patients, reliable predictive biomarkers remain limited. Methods: This study aimed to investigate the prognostic relevance and epigenetic regulation of natural killer T (NKT)-cell-related gene signatures in OPSCC. Clinicopathological and transcriptomic data from 81 OPSCC patients were analysed using single-sample gene set enrichment analysis (ssGSEA) to evaluate immune-related gene set enrichment scores. Associations with overall survival and clinical features were assessed, and candidate prognostic genes were further explored through expression, methylation, and network analyses. Results: High NKT cell differentiation enrichment scores were significantly associated with improved survival and favourable clinical features. Gene-level analyses identified ITK, ZNF683, and ATF2 as key prognostic markers linked to T-cell signalling and epigenetic regulation. Methylation profiling revealed hypermethylation of ITK and hypomethylation of ZNF683 in tumour tissues, suggesting an epigenetic basis for altered gene expression. Conclusions: These findings highlight NKT cell differentiation as a strong prognostic indicator in OPSCC and support further exploration of epigenetic–immunologic interactions as potential therapeutic targets. Full article

Killer-cell immunoglobulin-like receptors (KIRs) play a crucial role in the cytotoxic activity of natural killer (NK) cells, encompassing both inhibitory and activating types. A higher ratio of cytotoxic to inhibitory receptors may harm successful pregnancies by disrupting the uterine environment. Ongoing debates surround the impact of KIR gene variations on recurrent pregnancy loss (RPL) and infertility across populations. This study aimed to explore KIR gene polymorphisms in RPL and infertility among the Venezuelan admixed population. The Venezuelan population exhibits a genetic mix of Caucasian, African, and local Amerindian ancestry, distinguishing it from other Latin American admixed populations. This study included 100 controls and 86 patients: 73 women with idiopathic RPL (53 primary and 20 secondary) and 13 infertile patients (4 primary and 9 secondary). The frequency of activating receptors KIR2DS2 and KIR2DS3 was significantly lower (p < 0.05) in the whole patient group compared to controls. However, when analyzing the haplotypes and genotypes, the significance between patients and controls was lost. When comparing RPL and infertile patients, KIR2DS2, KIR2DL3, 2DL5, and 3DL1 were significantly less frequent in infertile women. In infertile women, KIR2DS3 frequency was increased compared to controls and RPL. The results suggest that the frequency of inhibitory receptors may differentiate patients with RPL and infertility. Further studies should ascertain the expression and function of KIRs in uterine NK cells in patients with RPL and infertility. Full article

Systemic lupus erythematosus is a multifactorial autoimmune disease characterized by the dysregulation of both innate and adaptive immunity, resulting in chronic inflammation, autoantibody production, and multi-organ damage. Innate immune dysfunction involves macrophages, neutrophils, plasmacytoid dendritic cells, natural killer cells, and the complement system, which collectively amplify autoimmunity through defective clearance of apoptotic cells, overproduction of pro-inflammatory cytokines, and abnormal type I interferon signaling. Adaptive immune abnormalities, including skewed T-cell subsets, impaired regulatory T and B cells, and autoreactive B-cell hyperactivity, further perpetuate pathogenic autoantibody generation. Gut microbiota dysbiosis contributes to SLE pathogenesis via Th17 activation, loss of mucosal tolerance, and molecular mimicry mechanisms. This review synthesizes current knowledge on the immunopathogenesis of SLE, emphasizing the interplay between innate and adaptive immunity and integrating evidence from both human and experimental murine models to provide a comprehensive understanding of disease mechanisms. Full article

Background: Acute respiratory infections (ARIs) pose a significant clinical challenge in paediatric populations, especially in children with comorbidities who may exhibit underlying immune dysregulation. Inosine pranobex (IP) is an immunomodulatory agent that enhances T-lymphocyte and Natural Killer (NK) cell function, offering a targeted therapeutic rationale for such cases. Objective: This study aimed to retrospectively describe the clinical characteristics, immunological profiles, and outcomes of paediatric patients with complex, PCR-confirmed viral ARIs and significant comorbidities, for whom adjunctive therapy with IP was initiated based on clinical judgment. Methods: This retrospective case series analysed data from 14 paediatric patients hospitalised at a specialised centre (National Institute of Paediatric Tuberculosis and Respiratory Diseases in Dolny Smokovec, Slovakia). Cases were selected based on PCR-confirmed viral ARI, a history of recurrent infections, significant comorbidities, and initiation of IP therapy. The indication for IP was guided by the treating physician in cases of severe, prolonged, or recurrent disease course, where immune dysregulation was suspected, often supported by prior immunophenotyping. Results: A frequent observation in this cohort was the presence of baseline cellular immune alterations with a frequent observation of baseline cellular immune alterations, most notably the depletion of natural killer (NK) cells. NK cell depletion was identified in half of the patients (7/14). Following the initiation of treatment regimens that included adjunctive IP, clinical stabilisation or improvement was observed in all 14 patients included in the study. The therapy was well tolerated, with no reported adverse events attributable to IP. Conclusions: This case series highlights the common presence of cellular immune alterations in children with complex ARIs. While the observational nature of this study precludes any conclusions about causality, the favourable clinical course, safety profile, and strong immunological rationale support the need for prospective controlled trials to evaluate the role of IP in this specific high-risk paediatric population. Full article

Chronic hepatitis B virus (HBV) infection is a major health problem that leads to approximately one million deaths every year worldwide. Mother-to-child transmission (MTCT) is the major cause of chronic HBV infection. HBV e antigen (HBeAg) is a secretory viral protein and modulates the immunological landscape of the newborn to promote HBV persistence. HBeAg actively reprograms innate and adaptive immunity. Mechanistically, HBeAg regulates macrophage polarization, suppresses dendritic cell and natural killer (NK) cell activities, impairs T cell and B cell functions, and promotes the expansion of myeloid-derived suppressor cells (MDSCs). These multifaceted effects contribute to immune tolerance and persistent HBV infection in the offspring of carrier mothers. Clinically, HBeAg status is a critical determinant for MTCT risk stratification and intervention, particularly in resource-limited settings. Despite advances in neonatal immunoprophylaxis and maternal antiviral therapy, residual transmission of HBV persists. Emerging approaches targeting HBeAg directly or restoring antiviral immunity offer promising avenues for breaking immune tolerance and achieving HBV elimination. This review summarizes current understanding of HBeAg-mediated immune modulation and highlights strategies that are being used to disrupt MTCT and treat HBV patients. Full article

Alphavirus chikungunya (CHIKV) is an arthropod-borne alphavirus of the Togaviridae family, transmitted primarily by Aedes aegypti and Ae. albopictus mosquitoes. CHIKV infection often results in debilitating manifestations that compromise quality of life and generate significant socioeconomic impacts. Recurrent epidemics in tropical and subtropical regions underscore the urgent need to better understand the host immune responses and their contribution to disease outcome. CHIKV establishes infection by overcoming the host’s initial immunological barriers. Innate immune cells, including fibroblasts, dendritic cells, macrophages, monocytes, neutrophils and natural killer (NK) cells, are among the first to respond to infection, ensuring a rapid antiviral defense and supporting the development of adaptive immune responses. However, excessive release of inflammatory mediators and prolonged infiltration of innate cells into joint tissues contribute to disease chronicity and the persistence of arthralgia. In this review, we provide a comprehensive synthesis of current evidence on innate cells that serve as targets for CHIKV infection, highlighting mechanisms that promote effective antiviral defense as well as those responsible for pathological inflammation and chronic disease and identifying key gaps that remain to be addressed. Full article

Background: Infertility is a multifactorial condition that causes significant emotional distress and financial burden for couples. Despite advances in assisted reproductive technologies (ARTs), many patients experience recurrent implantation failure (RIF) or pregnancy loss. Intralipid, an intravenous lipid emulsion, has been proposed as an adjunctive therapy due to its immune-modulatory effects, particularly in reducing elevated natural killer (NK) cell activity, which may be associated with poor reproductive outcomes. This study evaluated the effect of intralipid infusion on pregnancy rates and miscarriage rates in women with recurrent implantation failure undergoing in vitro fertilization (IVF). Materials and Methods: This was a retrospective study of women who had suffered from recurrent implantation failure and underwent IVF between September 2023 and September 2024. A comparative group undergoing IVF but who did not have recurrent implantation failure matched for age was selected. Outcomes of clinical pregnancy, miscarriage and livebirth rates were compared in both groups. Results: A total of 113 women undergoing IVF were identified and 51 received intralipid. Intralipid was initiated at varying stages of the IVF process, a day before embryo transfer (ET) (18 or 35.3%), on the day of ET (20 or 39.2%) and after ET (13 or 25.5%). The clinical pregnancy rate was 44.2% in the treatment group compared to 29% in the comparator group (p < 0.05) while the miscarriage rates were 13.7% versus 11.3% (p > 0.05). Elevated NK cells were present in 65.4% of the patients who received intralipid, but the correlation between NK cell levels and pregnancy outcomes was weak (Spearman ρ = 0.032). No adverse effects were reported in any of the women. Conclusions: Intralipid infusion increased the successful pregnancy rates in women who had recurrent implantation failure during IVF. The successful pregnancy rate was significantly higher than that in those undergoing ART who had not suffered from RIF. These findings support several studies on the potential benefit and safety of intralipids in women undergoing ART, but the numbers remain small and more prospective studies are needed to confirm these findings 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

This study presents a comparative analysis of tumor growth models based on logistic, exponential, and Gompertz formulations. Their response to therapeutic intervention is examined to identify which model shows better behavior with minimal decline of immune cells. The framework incorporates three main cell populations as follows: natural killer cells, cytotoxic T cells, and tumor cells, along with treatment effects. Dynamical properties such as positive invariance, existence, boundedness, and equilibrium stability are investigated. Numerical simulations indicate that the logistic model gives more favorable treatment outcomes compared to the exponential and Gompertz models. The results also show a faster decline of immune cell populations in the exponential and Gompertz models than in the logistic model under varying drug flux. Full article

Recent studies propose that nanomaterials, either independently or coupled with biomolecular conjugates, have the ability to influence immune activity directly, creating new opportunities for advancing immunotherapies targeting infections and cancer. This review highlights current findings on how functionalized carbon nanotubes (f-CNTs), graphene, and carbon nanohorns interact with immune cells. Among these, f-CNTs have been the most thoroughly explored, though research interest in graphene has been rising steadily. Analysis of published work shows that macrophages are the most frequently studied immune cells (56%), followed by lymphocytes (30%), particularly T cells (22%). Investigations into monocytes and dendritic cells represent 7%, mixed populations such as peripheral blood mononuclear cells make up 6%, and studies on B cells and natural killer (NK) cells remain minimal (1%). Much of the available research has focused on assessing cytotoxicity and compatibility rather than uncovering precise mechanisms of immune modulation. Nonetheless, recent large-scale gene expression profiling has revealed novel immunomodulatory properties of f-CNTs, including stimulation of certain inflammatory signaling pathways. Research on graphene’s immune interactions is still developing. Overall, this review consolidates evidence on the immunological potential of biocompatible f-CNTs and graphene, offering groundwork for their future application in immunology and medicine. Full article

The term extracellular vesicles (EVs) includes a variety of anucleated, non-self-replicative particles released by cells, whose cargo content is compartmentalized by a lipidic bilayer membrane and includes proteins, DNA, and RNA (both coding and non-coding) molecules. MicroRNAs (miRs) are small non-coding RNA involved in gene expression regulation that functionally participate in inter-cellular communication as EV cargo. Natural Killer (NK) cells are innate immunity lymphocytes specialized in the killing of cancer cells and virally infected cells. Increasing evidence shows that NK cell-derived EVs contribute to the anti-tumoral activity of NK cells and that such effects are, at least in part, mediated by the miR cargo of these EVs. Conversely, cancer cells release EVs whose cargo includes proteins and miRs that impair NK cell function. These interactions highlight a central role for EV miRs both in the NK-mediated cytotoxicity and as a major immune-escape mechanism for cancer cells, ultimately contributing to the overall success or failure of NK cells in eliciting their anti-tumoral activity. Full article

Signaling Lymphocyte Activation Molecule Family member 7 (SLAMF7) represents a potential target for CAR T-cell therapy in the treatment of multiple myeloma (MM), and it is a promising alternative to classic BCMA-CAR therapy. The receptor is expressed on immune cells, particularly natural killer cells and T cells, that can trigger both activating and inhibitory signals. It is highly expressed in MM cells at all disease stages, playing a crucial role in cell adhesion and communication between immune cells, and being involved in the development and progression of the disease. The target has a proven clinical success with Elotuzumab (anti-SLAMF7 antibody); it works by activating immune cells to kill myeloma cells, and limited expression on normal tissues, with, potentially, few side effects. SLAMF7’s combination of specificity, stability, and clinical validation makes it an excellent target for current and future MM therapies. However, ‘fratricide death’, a phenomenon where the engineered CAR-T cells attack and kill each other, is a critical issue that requires safe engineering solutions. In this work, we will provide an overview on the field with a specific focus on SLAMF7 as an emerging CAR-T cell target in MM. Full article

In animal models, elimination of the senescent cells in the hematopoietic stem cells (HSCs) compartment leads to the rejuvenation of hematopoiesis. Whether this treatment principle can be applied to the human system remains controversial. The identification of senescent cells in human bone marrow poses another major challenge. To address these questions, we have studied hematopoietic stem and progenitor cells (HSPCs, CD34⁺) from the bone marrow of 15 healthy human subjects (age range: 19–74 years). Single-cell RNA sequencing, functional transcriptome analysis, and development trajectory studies were performed. In a previous report, we demonstrated the accumulation of a senescent population in the aging HSC compartment. The present study focuses on the differences with age downstream in the lymphoid trajectory. While a reduction in B progenitors in the early lymphoid compartment can be confirmed, the accumulation of a lymphoid cluster downstream upon aging is novel and remarkable. This cluster comprises cells with a significant deficiency in B differentiation markers, as well as 9.4% cells with transcriptome signatures of memory-like natural killer (NK) progenitors. Applying our analysis algorithm to other human bone marrow datasets from the literature, we are able to validate the presence of this unique cluster in aged lymphoid progenitors. The accumulation of a population comprising cells defective in B differentiation potential, as well as cells with transcriptome features of memory-like NK progenitors represents a novel hallmark for senescence in the late development trajectory of human lymphoid compartment. Full article

This review is focused on understanding the reasons why basal cell carcinoma (BCC), the most common, increasingly prevalent cancer, is classified as an “immune excluded” malignancy. It is, despite manifesting one of the highest tumor mutational burdens of any solid human malignancy, considered to be a biomarker of enhanced tumor immunogenicity and efficacy of tumor-targeted immunotherapy. Following a brief clinical overview, the balance of the review addresses important translational issues based on recent insights into the mechanisms underpinning immune exclusion/evasion in BCC. These include, firstly, the role of infectious agents and non-infectious potential causes of predisposition for and/or exacerbation of disease development and progression. Secondly, an overview of existing and emerging novel therapeutic strategies to ameliorate immune exclusion in BCC based on targeting several key immunosuppressive mechanisms. These are (i) inappropriate activation of the hedgehog signaling pathway (HHSP) due to formation of key driver mutations; (ii) interference with the presentation of tumor-specific antigens/neoantigens to cytotoxic T-cells; (iii) attenuation of the influx of anti-tumor natural killer cells; (iv) the recruitment and activation of immune suppressive regulatory T-cells; and (v) localized and systemic immune dysfunction achieved via elevated levels of soluble co-inhibitory immune checkpoint proteins (ICPs). The final section is focused on current and emerging pharmacologic and immune-based therapies. Full article