Immunological Investigations最新文献

Background: Phagocytosis is an important function of macrophages. However, when it's dysregulated, it could compromise homeostasis. Thus, this study aimed to assess the inhibitory activity of pterocarpanquinone LQB 118 on murine macrophage phagocytosis.

Methods: We used peritoneal macrophages isolated from mice to evaluate the impact of LQB 118 (5 μM) on the modulation of phagocytic activity and possible action mechanism related: IL-12 (by ELISA), NO (by Griess reaction),ROS production (by flow cytometry), and intracellular signaling proteins (iNOS, P-Akt, P-mTOR, NF-κB, and P-NF-κB) (by flow cytometry).The macrophages were stimulated with zymosan to assess both phagocytic activity and flow cytometry assays.

Results: Treatment with LQB 118 resulted in a reduction in the phagocytosis of zymosan particles by macrophages. This effect could potentially be attributed to LQB's inhibition of IL-12 production and mTOR/NF-κB signaling. Furthermore, LQB 118 decreased the levels of ROS and NO without interfering with iNOS and Akt activation.

Conclusion: These findings show the anti-phagocytic activity of LQB 118 on macrophage, highlighting the potential of this compound as a candidate for modulating macrophage-driven inflammation.

Introduction: Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder with limited reliable diagnostic biomarkers. This study evaluates the utility of DEAD-box helicase 5 (DDX5) as a diagnostic and differential marker for SLE and assesses the performance of a capture bead-based flow cytometry (CBFCM) method for detecting serum proteins.

Method: Serum samples were collected from 52 patients with SLE, 38 patients with rheumatoid arthritis (RA), 49 patients with lung cancer (LC), and 50 healthy controls (HCs). Levels of DDX5, anti-DDX5, anti-dsDNA, and anti-Sm were quantified using enzyme-linked immunosorbent assay (ELISA) and CBFCM.

Results: Serum DDX5 levels were significantly elevated in patients with SLE compared to patients with RA and HCs, correlating with the SLE activity. DDX5 demonstrated strong discriminatory power between SLE and RA. Combining DDX5, anti-dsDNA, and anti-Sm as biomarkers yielded an area under the curve (AUC) of 0.976 for SLE diagnosis. Decision curve analysis indicated a high clinical benefit from the combined biomarkers. The sensitivity and specificity of DDX5 were 66.11% and 88.89% for ELISA, and 72% and 91.3% for CBFCM.

Discussion: DDX5 shows promise as a novel serological biomarker for SLE diagnosis and differential diagnosis. Additionally, CBFCM outperforms ELISA in detecting soluble serum proteins.

Background: Tissue-resident memory T (TRM) cells possess unique abilities to migrate, establish themselves in tissues, and monitor peripheral tissues without circulating. They are crucial in providing long-lasting and local immune protection against surface infections. TRMs demonstrate distinct phenotypic and functional characteristics compared to central memory T (Tcm) cells and effector memory T (Tem) cells.

Methods: We reviewed a large number of literature to explore the physiological and functional roles of tissue-resident memory T cells, as well as the link between TRM cells and the development and prognosis of digestive tract tumors. We also investigated the association between TRM cells, intestinal flora, and metabolites.

Results: Recent studies have implicated TRMs in the immune response against tumors, making them a potential target for cancer therapy. However, research specifically focused on gastrointestinal tumors is limited.

Conclusion: This review aims to compile and assess the most recent data on the role of TRM cells in gastrointestinal tumor immunity. Additionally, it explores recent advancements in immunotherapy and investigates how TRMs may influence intestinal flora and metabolites.

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: 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: 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.