Immunological Investigations最新文献

Background: Immune homeostasis plays a crucial role in immunology andis dependent on both central and peripheral tolerance. Centraltolerance and peripheral tolerance occur in the thymus and thesecondary lymphoid tissues, respectively. Tolerance breakdown andimmune regulation defects can lead to autoimmune disorders. In thisreview article, we aimed to describe the role of exosomes inregulating central tolerance and provide a summary of their effectson the pathogenesis, diagnosis, and therapeutic potential inmyasthenia gravis (MG).

Methods: Articles for this review wereidentified using the PubMed database.

Results: As the primarylymphoid organ, the thymus is responsible for building an immunecompetent, yet self-tolerant of T-cell population. Thymic statesinclude thymoma, thymic hyperplasia, and thymic atrophy, which canexert a significant influence on the central immune tolerance andrepresent specific characteristics of MG. Previous studies have foundthat exosomes derived from human thymic epithelial cells carryantigen-presenting molecules and a wide range of tissue restrictedantigens, which may indicate a vital role of thymic exosomes in MG.Besides, exosomal miRNAs and lncRNAs may also play a critical role inthe pathophysiology of MG.

Conclusion: This review provides thetherapeutic and diagnostic potential of exosomes in MG patients.

Background: Neurodegenerative diseases (NDs) have caused serious health issues worldwide. A growing body of evidence suggests a correlation between neuroinflammation and abnormal microglial activity with ND symptoms. Microglia survey play crucial roles in CNS during health and the injury. It is proposed that sex affects microglial roles during inflammation, resulting in mouse behavioural changes and expression alterations in key markers related to microglia functions.

Methods: Male and female C57BL/6 mice were injected with a single dose of LPS (5 mg/kg, i.p.) or saline. After 48 h, an open field test was conducted, followed by brain tissues collection for measuring the expression of IGF-1, IL-1β and TREM2 and Immunohistochemistry (IHC) analysis for NLRP3 level.

Results: Males displayed greater depressive-like behaviour in the OFT, with lower levels of IGF-1, IL-1β, and NLRP3 and high TREM2 expression. Female mice did not exhibit this behaviour, in contrast to male mice, they exhibited increased IL-1β and NLRP3 expression.

Discussion: This study revealed that LPS-induced sex-specific changes in genes involved in neuronal cell survival caused behavioural alterations in male mice. Moreover, females had observed inflammatory responses that had no impact on behavioural alterations. Overall, both sexes exhibited sex-specific microglial activation states.

Background: Liver cancer (LC) is a deadly malignancy with limited therapeutic options in recent years. Natural killer cell-derived exosomes (NK-exo), as an important bridge of information transmission between cells, also have a certain killing effect on tumor cells. On this basis, this study investigated the specific regulatory mechanism of NK-exo on LC cells.

Methods: NK-exo was collected by differential centrifugation. The diameter and size distribution were characterized by dynamic light scattering (DLS), respectively. Western Blot (WB) assay detected the expression levels of exosome marker protein, PD-L1, and PI3K-AKT-mTOR signal-related proteins. The effect of NK-exo treatment on LC cell viability was measured by the CCK-8. With the use of CFDA·SE, we assessed the proliferation ability of CD8⁺T cells in direct co-culture with LC cells. The content of cytokines secreted by CD8⁺T cells in each treatment group was determined by enzyme-linked immunosorbent assay (ELISA) kits. We employed flow cytometry to analyze the expression of PD-L1 protein on the surface of LC cells and CD8 level in mice tumor tissues.

Results: CCK-8 assay demonstrated that NK-exo repressed the cell viability of LC cells. WB uncovered that the protein expressions of PD-L1, p-AKT, and p-mTOR in NK-exo treated LC cells were decreased, which was returned to the control level after the addition of PI3K agonist. When NK-exo-treated LC cells were directly co-cultivated with CD8⁺T cells, the proliferation ability and cytokine secretion content of T cells were considerably elevated, and the expression of PD-L1 on LC cell surface was considerably reduced. However, these effects were restored to control levels by PI3K agonists.The in vivo experiments also confirmed that NK-exo could effectively inhibit the progression of LC, and the PI3K agonist could restore this effect to the level of the control group.

Conclusion: This study provided the first evidence that exosomes derived from NK cells inhibited the PI3K-AKT-mTOR signaling pathway in LC cells, and reduced PD-L1 expression, thereby promoting tumor immunity. In comparison to traditional immune checkpoint inhibitors, NK-exo possessed unique mechanisms of action and potential advantages. NK-exo holds the promise of becoming an innovative immunotherapy for the treatment of LC.

Background: Phospholipase D2 (PLD2) enzymes are expressed on the cytoplasmic membrane of bacteria, fungi, plants, and animals. Recently, extensive research has linked PLD2 to the chronic inflammatory activity of cells. Allergic asthma is a chronic airway inflammation disease. In this context, a recombinant human phospholipase D2 (rhPLD2) was designed and modified from the wild-type PLD2 to study its effects in an ovalbumin (OVA) induced murine model of asthma.

Methods: Hematoxylin and eosin staining was used for lung histopathology. Cytokine concentrations in bronchoalveolar lavage fluid (BALF) were measured using ELISA kits. The ratio of T-bet and GATA-3 expression level in spleen and lymph nodes following rhPLD2 administration was assessed through RT-PCR. Phenotyping analysis of Treg cells from peripheral blood was performed by flow cytometry.

Results: It indicated that OVA-induced mice exhibited elevated pulmonary eosinophilia and allergic inflammation in the airways, along with increased expression of IFN-γ, IL-4 in the lung BALF. Administration of rhPLD2 alleviated lung inflammation and significantly reduce the number of eosinophils in peripheral blood and BALF. RhPLD2 also reversed the IFN-γ/IL-4 ratio at the molecular level in BALF and the T-bet/GATA-3 ratio in lymphocytes of the lung, spleen, lymph nodes at the genetic level. Furthermore, FACS analysis demonstrated that rhPLD2 increased the frequency of both IL-10⁺Treg cells and CD25⁺ Treg cells.

Conclusion: From a therapeutic perspective, rhPLD2 alleviates allergic airway inflammation by balancing Th1/Th2 homeostasis and increasing Treg cells. It has been shown to function in immunoregulatory activities in OVA-induced asthma mice.

Background: Acute respiratory distress syndrome (ARDS) is prominently characterized by uncontrolled inflammation and high mortality. The effect of interleukin-37 (IL-37) on the prognosis of ARDS remains unclear.

Methods: This prospective cohort study detected and analyzed serum IL-37 levels on day 1 (baseline) in 128 patients with ARDS and 40 healthy controls, and on day 7 in patients with ARDS. Clinical and laboratory parameters were assayed. Survival status was tracked within 28-d of enrollment.

Results: BaselineIL-37 concentration was lower in non-survivors (135.00 [87.75, 198.75] pg/mL) than in survivors (250.50 [173.25, 382.75] pg/mL) (p < .05). Non-survivors displayed a greater reduction in IL-37 levels from day 1-7 than survivors (49.87% vs. 40.09%) (p < .05). Baseline IL-37 levels were negatively associated with C-reactive protein, procalcitonin, and IL-6 levels. The area under the receiver operating characteristic curve of the baseline level and percentage decline in IL-37 was 0.755 and 0.809, respectively, for predicting 28-d mortality. Combining IL-37 with the acute physiology and chronic health evaluation II score further improved mortality prediction capability. Patients with ARDS with low IL-37 concentrations (<143.00 pg/mL) or a high percentage decline (≥44.76%) had a poorer survival rate than those with a high concentration or low percentage decline. The baseline IL-37 level and percentage decline independently predicted mortality in a univariate Cox regression model (p < .05).

Conclusions: A low IL-37 level or significantly declining rate predicts higher 28-d mortality in patients with ARDS, indicating that IL-37 may be a promising prognostic biomarker.

Background: Exosomes can be found in the synovial fluid of inflamed knee joints, which play a significant role in osteoarthritis (OA) progression. However, their role - in modulating the cellular environment within the body, particularly monocytes remain unexplored. This study aimed to evaluate the immunomodulatory effect of exosomes on monocytes.

Methods: Exosomes were isolated by ultracentrifugation and characterized using nanoparticle tracking analysis (NTA), scanning electron microscopy (SEM), and Western blot. The effect of exosomes in modulating monocyte phenotypes as well as cytokine secretion were further assessed in a co-culture condition using flow cytometry and ELISA accordingly.

Results: Exosomes were identified as spherical particles with a size distribution ranging from 30 nm to 150 nm. These nanoparticles intensely expressed exosome protein markers including CD9, CD63, CD81, and HSP70. The expression of HLA-DR, CD14, and CD11b on monocytes decreased in the presence of exosomes after 24 h of incubation, regardless of the dose. Exosomes significantly induced the release of anti-inflammatory cytokines IL-1Ra in a time- and dose-dependent manner, while TNF-α secretion remains unchanged regardless of the presence or absence of exosomes.

Conclusion: This study highlights the immunoregulatory role of exosomes on monocytes, emphasizing the need for further studies into the underlying mechanism.

Background: Asthma is the most common chronic pulmonary disease in children. MicroRNAs (miRNAs) play a regulatory role in the occurrence and development of asthma. We aimed to explore the differential expression of miRNAs in the peripheral blood of children with asthma and identify a miRNA that can alleviate asthma inflammation.

Methods: We used high-throughput sequencing to analyze differences in peripheral blood miRNA between children with acute asthma and healthy children, followed by target gene prediction and functional enrichment analysis. We inhibited miR-142-3p's expression in asthmatic mice to observe asthma symptoms. Inflammatory changes in lung tissue were assessed using hematoxylin and eosin staining and ELISA. Subsequently, the target gene of miR-142-3p was identified through a dual-luciferase reporter assay, and PTEN and AKT expression levels in mice lung tissue were determined using qPCR and western blot.

Results: Fifty one differentially expressed miRNAs were identified. Inhibition of miR-142-3p expression in asthmatic mice reversed the downregulation of PTEN and activation of AKT in lung tissue, while also significantly alleviating symptoms and pulmonary inflammation in the asthmatic mice.

Conclusion: miRNAs were differentially expressed in the peripheral blood of children with asthma. miR-142-3p regulates airway inflammation via the PTEN/AKT pathway.

Background: In this review article, we aimed to discuss the pathogenesis of sensorineural hearing loss (SNHL) in patients with different forms of chronic rhinosinusitis (CRS), with special reference to the connection of the immune response of the nasal and middle ear mucosa and inner ear structures.

Methods: Articles for this review were identified using PubMed and Google© Scholar databases.

Results: Different phenotypes of CRS may be associated with impaired function of the inner and outer cells of the organ of Corti. This is primarily due to the secondary CRS, which occurs within systemic diseases, such as granulomatosis with polyangiitis (GPA) and eosinophilic granulomatosis with polyangiitis (EGPA). Also, the tetrad, which includes CRS with nasal polyps, non-allergic asthma, hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs), and so-called eosinophilic otitis media can lead to SNHL.

Conclusion: Previous studies suggest that disrupted harmony between the immune response in the nasal and middle ear mucosa and inner ear structures may contribute to developing SNHL in CRS patients. This especially applies to CRS as part of NSAID-exacerbated respiratory disease and systemic necrotizing vasculitis, including GPA and EGPA. However, the exact mechanisms of development of SNHL in different forms of CRS have not been sufficiently investigated and new studies are necessary soon. Apart from the pathophysiological basis of SNHL, different therapeutic approaches in the clinical phenotypes of CRS have also been discussed.

Background: The aim of this study was to evaluate the possible role of lipopolysaccharide-binding protein (LBP) and interleukin 6 (IL-6) in the development of digital ulcers (DUs) in Systemic sclerosis (SSc).

Methods: 60 SSc patients were enrolled and tested for serum levels of LBP and IL-6. The development of DUs was assessed in a 12-month follow-up period.

Results: Median LBP and IL-6 were 107.445 ng/mL and 10.8 pg/mL whilst 33.3% patients had LBP ≥ 11995 ng/mL and 51.7% patients had IL-6 ≥ 12.5 pg/mL. DUs history were present in 41.7% SSc patients and at follow-up 23.3% patients developed new DUs. Baseline LBP (14105 ng/mL vs 10355 ng/mL, p < .001) and IL-6 (195 pg/mL vs 9.4 ng/mL, p < .001) were higher in SSc patients with new DUs. The ROC curves showed a good diagnostic accuracy for a cut-off of LBP ≥ 11995 ng/mL [AUC = 0.804 (95% CI = 0.656-0.951), p < .001] and for a cut-off of IL-6 ≥ 12.5 pg/mL [AUC = 0.897 (95% CI = 0.783-1.000), p < .001]. Free survival from new DUs was shorter in SSc patients with increased LBP (p < .001) or IL-6 (p = .003).

Conclusions: LPB or IL-6 could play a role in digital microvascular damage of SSc patients.

Background: The discovery of interleukin-2 (IL-2) and its receptor (IL-2R) almost 50 years ago revolutionized immunology, marking a pivotal moment in understanding T cell biology and immune regulation. Initially identified as a T cell growth factor, IL-2 unveiled critical insights into cytokine-mediated immune cell proliferation and differentiation.

Methods: This review highlighted the characterization of IL-2R as a multi-chain receptor complex set a precedent for decoding cytokine receptor signaling. The unique interplay between IL-2 and its high-affinity receptor component, IL-2Rα, epitomizes the principle of specificity and efficiency in cytokine signaling, enabling precise immune modulation. Regulatory T cells (Tregs) exploit IL-2Rα high affinity to outcompete effector T cells for IL-2, ensuring immune tolerance and preventing autoimmunity.

Results: Despite its foundational role in immune homeostasis, leveraging IL-2 for therapeutic purposes has proven challenging.

Conclusion: IL-2-based therapies hold transformative potential in autoimmunity, cancer immunology, and transplantation, yet they remain elusive due to the complex balance between immunostimulatory and immunosuppressive effects. This review explores the milestones in IL-2 biology, its dualistic functions, and the ongoing quest to harness its therapeutic promise.