The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) signaling pathway is a crucial component of the immune system. It detects abnormal cytosolic double-stranded DNA and promotes the expression of type I interferons and other inflammatory factors, thereby protecting the body from pathogenic infections. In children, an immature immune system or genetic mutations can lead to immune dysregulation, increasing the risk of autoimmune diseases (AID) and autoinflammatory diseases. Recent studies have shown that aberrant activation of the cGAS-STING signaling pathway is associated with the development of AID and autoinflammatory diseases in children. This review summarizes the research progress on the cGAS-STING signaling pathway in childhood AID and autoinflammatory diseases, aiming to provide new directions for clinical diagnosis and treatment.
Humans ; Nucleotidyltransferases/physiology* ; Membrane Proteins/physiology* ; Signal Transduction/physiology* ; Child ; Autoimmune Diseases/immunology* ; Inflammation/etiology*

OBJECTIVES: To elucidate the underlying mechanisms of macrophage-mediated inflammation and tissue injury in diabetic foot ulcer (DFU). METHODS: Skin tissue samples were collected from patients with DFU and with non-DFU. A total of 79 272 high-quality cell transcriptomes were obtained using single-cell RNA sequencing. An unbiased clustering approach was employed to identify cell subpopulations. Seurat functions were used to identify differentially expressed genes between DFU and non-DFU groups, and gene ontology (GO) enrichment analysis was used to reveal gene function. Furthermore, cell-cell communication network construction and ligand-receptor interaction analysis were performed to reveal the mechanisms underlying cellular interactions and signaling regulation in the DFU microenvironment from multiple perspectives. RESULTS: The results revealed a significant expansion of myeloid cells in DFU tissues, alongside a marked reduction in structural cells such as endothelial cells, epithelial cells, and smooth muscle cells. Major cell types underwent functional reprogramming, characterized by immune activation and impaired tissue remodeling. Specifically, macrophages in DFU skin tissues exhibited a shift toward a pro-inflammatory M1 phenotype, with upregulation of genes associated with inflammation and oxidative stress. Cell communication analysis further demonstrated that M1 macrophages served as both primary signal receivers and influencers in the COMPLEMENT pathway mediated communication network, and as key signal senders and mediators in the secreted phosphoprotein 1 (SPP1) pathway mediated communication network, actively shaping the inflammatory microenvironment. Key ligand-receptor interactions driving macrophage signaling were identified, including C3-(ITGAM+ITGB2) and SPP1-CD44. CONCLUSIONS This study establishes a comprehensive single-cell atlas of DFU, revealing the role of macrophage-driven cellular networks in chronic inflammation and impaired healing. These findings may offer potential novel therapeutic targets for DFU treatment.
Humans ; Macrophages/immunology* ; Diabetic Foot/pathology* ; Single-Cell Analysis ; Transcriptome ; Gene Expression Profiling ; Inflammation ; Skin ; Cell Communication ; Signal Transduction ; Cellular Reprogramming

OBJECTIVE: To investigate the molecular alterations of splenocytes associated with anti-factor Ⅷ (FⅧ) immune response and the underlying mechanisms based on hemophilia A (HA) murine model via RNA sequencing (RNA-seq) technology. METHODS: Severe HA mice were immunized with recombinant human factor Ⅷ (rhF8) weekly for 4 weeks to establish an FⅧ inhibitor model. High quality raw data were obtained by using bulk RNA-seq and CASAVA base identification technology, and the differentially expressed genes (DEGs) were identified. The DEGs were statistically classified by gene ontology (GO) annotation to obtain information on the major signaling pathways and biological processes involved in anti-FⅧ immune response in HA mouse splenocytes. The cell clusters, genes, and signaling pathway datasets were comprehensively analyzed by GO, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and single cell RNA-seq (ScRNA-seq) analysis, respectively. Flow cytometry analysis was used to verify the changes in T follicular helper cells (Tfh) and regulatory T cells (Treg). RESULTS: A total of 3731 DEGs was identified, including 2275 genes with up-regulated expression and 1456 genes with down-regulated expression. The DEGs were enriched in helper T cell differentiation, cytokine receptor, T cell receptor signaling pathway, ferroptosis, etc. Uniform Manifold Approximation and Project (UMAP) downscaling and visualization analysis yielded a total number of 11 T/NK cell subsets, visualizing the overall expression distribution of C-X-C chemokine-specific receptor gene cxcr5 among these T/NK cell subsets. Higher expression of cxcr5 was found in activated Tfh from FⅧ inhibitor mice, in comparison to the control group. The visualization using Upset plot R language showed a close interaction between Tfh and Treg. Moreover, the increased frequencies of Tfh and the decreased frequencies of Treg in inhibitor mouse splenocytes were further verified by flow cytometry analysis. CONCLUSION Multiple immune cell subsets, signaling pathways, and characteristic genes may be involved in the process of anti-FⅧ immune response in HA mouse splenocytes. The molecules involved in the regulation of Tfh/Treg may play key roles, which provide potential biological targets and therapeutic strategies for HA patients with inhibitors in the future.
Animals ; Hemophilia A/genetics* ; Mice ; Sequence Analysis, RNA ; Disease Models, Animal ; Spleen/cytology* ; T-Lymphocytes, Regulatory/immunology* ; Humans ; Signal Transduction ; Factor VIII/immunology* ; T-Lymphocytes, Helper-Inducer/immunology*

Despite the groundbreaking advances in cancer immunotherapy achieved by immune checkpoint inhibitors (ICIs), their efficacy remains limited by the immunosuppressive tumor microenvironment (TME). Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), key effectors of the Hippo signaling pathway, play pivotal roles in tumor immune evasion. They directly regulate the expression of immune checkpoints, mediate the formation of an immunosuppressive microenvironment, inhibit T cell function, and interact with other signaling pathways to promote immune escape. Diverse strategies targeting YAP/TAZ have been developed, including direct inhibition, modulation of upstream regulators, and suppression of downstream target genes. Preclinical studies have demonstrated that combining YAP/TAZ inhibition with ICIs significantly enhances therapeutic efficacy across various tumor models. This review summarizes recent advances in understanding the role of YAP/TAZ in immune evasion within the TME and explores the potential of targeting this pathway to improve immunotherapy outcomes. Furthermore, it discusses the translational value of combination therapies based on YAP/TAZ inhibition, providing a theoretical framework and practical guidance for the development of innovative immunotherapeutic strategies and precision medicine approaches.
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Humans ; Immunotherapy/methods* ; Neoplasms/metabolism* ; Signal Transduction/drug effects* ; Adaptor Proteins, Signal Transducing/immunology* ; Animals ; Transcriptional Coactivator with PDZ-Binding Motif Proteins ; Transcription Factors/immunology* ; YAP-Signaling Proteins ; Tumor Microenvironment

Immune thrombocytopenia (ITP) is a hemorrhagic autoimmune disease characterized by antibody-mediated platelet injury. ITP has complicated immunopathological mechanisms that need further elucidation. It is well known that the costimulatory molecules OX40 ligand (OX40L) and OX40 play essential roles in the immunological mechanisms of autoimmune diseases. Previously, we discovered that the expression of OX40L and OX40 is significantly increased in the peripheral blood mononuclear cells (PBMCs) of ITP patients. In our present study, OX40L-induced follicular helper T (Tfh) cells exhibited an activated phenotype with elevated expression of inducible T-cell costimulator (ICOS), programmed cell death protein-1 (PD-1), and cluster of differentiation 40 ligand (CD40L) in vitro. Moreover, aberrant OX40L‒OX40 expression might promote the Tfh1-to-Tfh2 shift in vivo, inducing the generation of autoantibodies by enhancing the helper function of Tfh cells for B lymphocytes in a mouse model, which might accelerate the progression of ITP. Additionally, signal transduction through the OX40L‒OX40 axis might be related to the activation of tumor necrosis factor receptor-associated factor (TRAF)‒nuclear factor-κB (NF-κB) and Janus kinase (JAK)‒signal transducer and activator of transcription (STAT) signaling pathways. Overall, OX40L‒OX40 signaling is proposed as a potential novel therapeutic target for ITP.
Animals ; OX40 Ligand/physiology* ; Purpura, Thrombocytopenic, Idiopathic/immunology* ; Cell Differentiation ; Mice ; T-Lymphocytes, Helper-Inducer/cytology* ; T Follicular Helper Cells/cytology* ; Signal Transduction ; Receptors, OX40 ; Mice, Inbred C57BL ; Humans ; Female

Immune suppression in the tumor microenvironment (TME) is closely related to abnormal glycolysis. Tumor cells gain metabolic advantages and suppress immune responses through the "Warburg effect". Traditional Chinese medicine (TCM) has been shown to regulate key glycolysis enzymes (such as HK2 and PKM2), metabolic signaling pathways (such as PI3K/AKT/mTOR, HIF-1α) and non-coding RNAs at multiple targets, thus synergistically inhibiting lactate accumulation, improving vascular abnormalities, and relieving metabolic inhibition of immune cells. Studies have shown that TCM monomers and formulas can promote immune cell infiltration and functions, improve metabolic microenvironment, and with the assistance by the nano-delivery system, enhance the precision of treatment. However, the dynamic mechanism of the interaction between TCM-regulated glycolysis and TME has not been fully elucidated, for which single-cell sequencing and other technologies provide important technical support to facilitate in-depth analysis and clinical translational research. Future studies should be focused on the synergistic strategy of "metabolic reprogramming-immune activation" to provide new insights into the mechanisms of tumor immunotherapy.
Humans ; Tumor Microenvironment/immunology* ; Glycolysis/drug effects* ; Neoplasms/drug therapy* ; Medicine, Chinese Traditional ; Signal Transduction ; Drugs, Chinese Herbal/pharmacology*

OBJECTIVE: To observe the effect of heat-sensitive moxibustion at "Feishu" (BL13) on immunoinflammatory response in rats with allergic rhinitis (AR) based on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, so as to explore its underlying mechanism. METHODS: Thirty-two male SD rats were randomly divided into a blank group (6 rats) and a modeling group (26 rats). In the modeling group, AR model was prepared using systemic and local attack sensitization method with ovalbumin. The successfully-modeled rats were randomized into a model group (6 rats), a medication group (6 rats) and a moxibustion group (14 rats). In the moxibustion group, the suspending moxibustion was operated at bilateral "Feishu" (BL13), 40 min each time, once daily, for 21 consecutive days; during which, the temperature of the body and tail was recorded. During intervention, if the temperature of the body and tail increased by >1 ℃, the heat-sensitive reaction at the point was determined in the rats of the moxibustion group, and these rats were collected in a heat-sensitive moxibustion group (8 rats involved and 6 rats of them were randomly collected to ensure the sample-size consistency); and those without heat-sensitive moxibustion reaction were assigned to a traditional moxibustion group (6 rats). In the medication group, fluticasone propionate nasal spray was applied, 8 μL on each side, once daily and for 21 days. The behavioral score for AR symptoms after modeling and intervention, and the content of serum immunoglobulin E (IgE) after modeling were observed. After intervention, the histological morphology of the nasal mucosa was observed using HE staining, the positive expression of thymic stromal lymphopoietin (TSLP) in the nasal mucosa was detected using immunohistochemistry, the levels of IgE, interleukin (IL)-4, IL-5, IL-13 and interferon-γ (IFN-γ) were detected by ELISA, and the protein expression of the member 4 of tumor necrosis factor receptor superfamily (OX40), phosphorylated protein kinase B (p-AKT), phosphorylated phosphatidylinositol 3-kinase (p-PI3K) in nasal mucosa was detected by Western blotting. RESULTS: After modeling, the behavioral score of AR symptoms and serum IgE level in the modeling group were higher than those of the blank group (P<0.01), suggesting the success of AR modeling. After intervention, compared with the blank group, the behavioral score of AR symptoms was increased (P<0.01)；the nasal mucosa structure was disordered, the inflammatory infiltration was severe; the positive expression of TSLP in the nasal mucosa increased (P<0.01), the levels of serum IgE, IL-4, IL-5, and IL-13 elevated (P<0.01), and the level of IFN-γ decreased (P<0.01); and the protein expression of OX40, p-AKT, and p-PI3K in the nasal mucosa increased (P<0.05) in the model group. Compared with the model group, the behavioral score of AR symptoms was reduced (P<0.01); the nasal mucosa structure, inflammatory infiltration, and vascular dilation were ameliorated to varying degrees; the positive expression of TSLP in the nasal mucosa decreased (P<0.01); the content of serum IgE, IL-4, IL-5, and IL-13 decreased (P<0.05), and that of IFN-γ increased (P<0.05) in the medication, traditional moxibustion, and heat-sensitive moxibustion groups. Compared with the model group, the protein expression of p-AKT was reduced in the medication and traditional moxibustion groups (P<0.05), the protein expression of OX40, p-AKT, and p-PI3K in the nasal mucosa decreased in the heat-sensitive moxibustion group (P<0.05). When compared with the medication group, the positive expression of TSLP in the nasal mucosa was reduced (P<0.05) in the heat-sensitive moxibustion group. In comparison with the traditional moxibustion group, the content of serum IL-13 was reduced and the content of IFN-γ elevated in the heat-sensitive moxibustion and the medication groups (P<0.05), the protein expression of p-PI3K reduced in the medication group (P<0.05), and the positive expression of TSLP and the protein expression of OX40 and p-PI3K in the nasal mucosa were reduced in the heat-sensitive moxibustion group (P<0.05). CONCLUSION Heat-sensitive moxibustion at "Feishu" (BL13) can alleviate the symptoms of AR rats, ameliorate the inflammatory infiltration and telangiectasia of nasal mucosa, and inhibit immunoinflammatory response, which may be obtained by regulating PI3K/AKT signal pathway.
Animals ; Moxibustion ; Male ; Rats ; Signal Transduction ; Rats, Sprague-Dawley ; Rhinitis, Allergic/genetics* ; Proto-Oncogene Proteins c-akt/immunology* ; Acupuncture Points ; Humans ; Phosphatidylinositol 3-Kinases/immunology* ; Phosphatidylinositol 3-Kinase/immunology*

BACKGROUND: T cell dysfunction, which includes exhaustion, anergy, and senescence, is a distinct T cell differentiation state that occurs after antigen exposure. Although T cell dysfunction has been a cornerstone of cancer immunotherapy, its potential in transplant research, while not yet as extensively explored, is attracting growing interest. Interferon regulatory factor 4 (IRF4) has been shown to play a pivotal role in inducing T cell dysfunction. METHODS: A novel ultra-low-dose combination of Trametinib and Rapamycin, targeting IRF4 inhibition, was employed to investigate T cell proliferation, apoptosis, cytokine secretion, expression of T-cell dysfunction-associated molecules, effects of mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways, and allograft survival in both in vitro and BALB/c to C57BL/6 mouse cardiac transplantation models. RESULTS: In vitro , blockade of IRF4 in T cells effectively inhibited T cell proliferation, increased apoptosis, and significantly upregulated the expression of programmed cell death protein 1 (PD-1), Helios, CD160, and cytotoxic T lymphocyte-associated antigen (CTLA-4), markers of T cell dysfunction. Furthermore, it suppressed the secretion of pro-inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17. Combining ultra-low-dose Trametinib (0.1 mg·kg -1 ·day -1 ) and Rapamycin (0.1 mg·kg -1 ·day -1 ) demonstrably extended graft survival, with 4 out of 5 mice exceeding 100 days post-transplantation. Moreover, analysis of grafts at day 7 confirmed sustained IFN regulatory factor 4 (IRF4) inhibition, enhanced PD-1 expression, and suppressed IFN-γ secretion, reinforcing the in vivo efficacy of this IRF4-targeting approach. The combination of Trametinib and Rapamycin synergistically inhibited the MAPK and mTOR signaling network, leading to a more pronounced suppression of IRF4 expression. CONCLUSIONS Targeting IRF4, a key regulator of T cell dysfunction, presents a promising avenue for inducing transplant immune tolerance. In this study, we demonstrate that a novel ultra-low-dose combination of Trametinib and Rapamycin synergistically suppresses the MAPK and mTOR signaling network, leading to profound IRF4 inhibition, promoting allograft acceptance, and offering a potential new therapeutic strategy for improved transplant outcomes. However, further research is necessary to elucidate the underlying pharmacological mechanisms and facilitate translation to clinical practice.
Animals ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Interferon Regulatory Factors/metabolism* ; Heart Transplantation/methods* ; T-Lymphocytes/immunology* ; Sirolimus/therapeutic use* ; Pyridones/therapeutic use* ; Graft Survival/drug effects* ; Pyrimidinones/therapeutic use* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Male ; Signal Transduction/drug effects*

BACKGROUND: G protein-coupled receptor kinase 2 (GRK2) could participate in the regulation of diverse cells via interacting with non-G-protein-coupled receptors. In the present work, we explored how paroxetine, a GRK2 inhibitor, modulates the differentiation and activation of immune cells in rheumatoid arthritis (RA). METHODS: The blood samples of healthy individuals and RA patients were collected between July 2021 and March 2022 from the First Affiliated Hospital of Anhui Medical University. C57BL/6 mice were used to induce the collagen-induced arthritis (CIA) model. Flow cytometry analysis was used to characterize the differentiation and function of dendritic cells (DCs)/T cells. Co-immunoprecipitation was used to explore the specific molecular mechanism. RESULTS: In patients with RA, high expression of GRK2 in peripheral blood lymphocytes, accompanied by the increases of phosphatidylinositol 3 kinase (PI3K), protein kinase B (AKT), and mammalian target of rapamycin (mTOR). In animal model, a decrease in regulatory T cells (T regs ), an increase in the cluster of differentiation 8 positive (CD8 + ) T cells, and maturation of DCs were observed. Paroxetine, when used in vitro and in CIA mice, restrained the maturation of DCs and the differentiation of CD8 + T cells, and induced the proportion of T regs . Paroxetine inhibited the secretion of pro-inflammatory cytokines, the expression of C-C motif chemokine receptor 7 in DCs and T cells. Simultaneously, paroxetine upregulated the expression of programmed death ligand 1, and anti-inflammatory cytokines. Additionally, paroxetine inhibited the PI3K-AKT-mTOR metabolic pathway in both DCs and T cells. This was associated with a reduction in mitochondrial membrane potential and changes in the utilization of glucose and lipids, particularly in DCs. Paroxetine reversed PI3K-AKT pathway activation induced by 740 Y-P (a PI3K agonist) through inhibiting the interaction between GRK2 and PI3K in DCs and T cells. CONCLUSION Paroxetine exerts an immunosuppressive effect by targeting GRK2, which subsequently inhibits the metabolism-related PI3K-AKT-mTOR pathway of DCs and T cells in RA.
G-Protein-Coupled Receptor Kinase 2/metabolism* ; Arthritis, Rheumatoid/immunology* ; Animals ; Dendritic Cells/metabolism* ; Paroxetine/therapeutic use* ; Proto-Oncogene Proteins c-akt/metabolism* ; Mice ; Humans ; Mice, Inbred C57BL ; Signal Transduction/drug effects* ; Male ; Phosphatidylinositol 3-Kinases/metabolism* ; Lymphocyte Activation/drug effects* ; Female ; T-Lymphocytes/metabolism* ; Middle Aged

BACKGROUND: Regulatory dendritic cell (DCreg) subset exhibits a unique capacity for inducing immune tolerance among the variety subsets of dendritic cells (DCs) within gut-associated lymphoid tissues (GALTs). Fms-like tyrosine kinase 3 ligand (FLT3L) is involved in the differentiation of DCregs and the subsequent expansion of regulatory T-cells (Tregs) mediated by DCregs, though the precise mechanism remains poorly understood. This study aimed to explore the expansion mechanism of Treg induced by DCreg and the role of FLT3L in this process. METHODS: DCregs were distinguished from other DC subsets isolated from GALTs of BALB/c mice through a mixed lymphocyte reaction assay. The functions and mechanisms by which FLT3L promoted Treg expansion via DCregs were investigated in vitro through co-culture experiments involving DCregs and either CD4 + CD25 - T-cells or CD4 + CD25 + T-cells. Additionally, an in vivo experiment was conducted using a dextran sulfate sodium (DSS)-induced colitis model in mice. RESULTS: CD103 + CD11b + DC exhibited DCreg-like functionality and was identified as DCreg for subsequent investigation. Analysis of Foxp3 + Treg percentages within a co-culture system of CD4 + CD25 - T-cells and DCregs, with or without FLT3L, demonstrated the involvement of the FLT3/FLT3L axis in driving the differentiation of precursor T-cells into Foxp3 + Tregs induced by DCregs. Cell migration and co-culture assays revealed that the FLT3/FLT3L axis enhanced DCreg migration toward Tregs via the Rho pathway. Additionally, it was observed that DCregs could promote Treg proliferation through the Notch pathway, as inhibition of Notch signaling by DAPT (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester) suppressed Treg expansion within the co-culture system of DCregs and CD4 + T-cells or CD4 + CD25 + T-cells. Furthermore, the FLT3/FLT3L axis influenced JAG1 expression in DCregs, indirectly modulating Treg expansion. In vivo experiments further established that FLT3L promoted DCreg expansion and restored Treg balance in DSS-induced colitis models, thereby ameliorating colitis symptoms in mice. CONCLUSION The FLT3/FLT3L axis is integral to the maintenance of DCreg function in Treg expansion.
Animals ; T-Lymphocytes, Regulatory/immunology* ; Dendritic Cells/immunology* ; Mice ; Mice, Inbred BALB C ; Membrane Proteins/metabolism* ; Receptors, Notch/metabolism* ; Lymphoid Tissue/metabolism* ; Signal Transduction/physiology* ; Coculture Techniques ; Flow Cytometry