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: Pre-transplant exposure to immune checkpoint inhibitors (ICIs) significantly increases the risk of allograft rejection after liver transplantation (LT); however, whether ICI-related rejection leads to increased graft loss remains controversial. Therefore, this study aimed to investigate the association between ICI-related allograft rejection and perioperative graft loss. METHODS: This was a retrospective analysis of adult liver transplant recipients with early biopsy-proven T-cell-mediated rejection (TCMR) at Liver Transplantation Center of Sun Yat-sen Memorial Hospital from June 2019 to September 2024. The pathological features, clinical characteristics, and perioperative graft survival were analyzed. RESULTS: Twenty-eight patients who underwent early TCMR between June 2019 and September 2024 were included. Based on pre-LT ICI exposure, recipients were categorized into ICI-related TCMR (irTCMR, n = 12) and conventional TCMR (cTCMR, n = 16) groups. Recipients with irTCMR had a higher median Banff rejection activity index (RAI) (6 vs . 5, P = 0.012) and more aggressive tissue damage and inflammation. Recipients with irTCMR showed higher proportion of treatment resistance, achieving a complete resolution rate of only 8/12 compared to 16/16 for cTCMR. Graft loss occurred in 5/12 of irTCMR recipients within 90 days after LT, with no graft loss in cTCMRs recipients. Cox analysis demonstrated that irTCMR with an ICI washout period of <30 days was an independent risk factor for perioperative graft loss (hazard ratio [HR], 6.540; 95% confidence interval [CI], 1.067-40.067, P = 0.042). CONCLUSION IrTCMR is associated with severe pathological features, increased resistance to treatment, and higher graft loss in adult liver transplant recipients.
Humans ; Liver Transplantation/adverse effects* ; Male ; Female ; Middle Aged ; Retrospective Studies ; Graft Rejection/immunology* ; Immune Checkpoint Inhibitors/therapeutic use* ; Adult ; T-Lymphocytes/drug effects* ; Graft Survival/immunology* ; Aged

Asthma is a chronic inflammatory disease involving multiple inflammatory cells and cytokines. Its pathogenesis is complex, involving various cells and cytokines. Traditional Chinese medicine(TCM) theory suggests that the pathogenesis of asthma is closely related to the dysfunction of internal organs such as the lungs, spleen, and kidneys. In contrast, modern immunological studies have revealed the central role of T helper 1(Th1)/T helper 2(Th2) and T helper 17(Th17)/regulatory T(Treg) cellular immune imbalance in the pathogenesis of asthma. Th1/Th2 imbalance is manifested as hyperfunction of Th2 cells, which promotes the synthesis of immunoglobulin E(IgE) and the activation of eosinophil granulocytes, leading to airway hyperresponsiveness and inflammation.Meanwhile, Th17/Treg imbalance exacerbates the inflammatory response in the airways, further contributing to asthma pathology.Currently, therapeutic strategies for asthma are actively exploring potential targets for regulating the balance of Th1/Th2 and Th17/Treg immune responses. These targets include cytokines, transcription factors, key proteins, and non-coding RNAs. Precisely regulating the expression and function of these targets can effectively modulate the activation and differentiation of immune cells. In recent years,traditional Chinese medicine active ingredients have shown unique potential and prospects in the field of asthma treatment. Based on this, the present study systematically summarizes the efficacy and specific mechanisms of TCM active ingredients in treating asthma by regulating Th1/Th2 and Th17/Treg immune balance through literature review and analysis. These active ingredients, including flavonoids, terpenoids, polysaccharides, alkaloids, and phenolic acids, exert their effects through various mechanisms, such as inhibiting the activation of inflammatory cells, reducing the release of cytokines, and promoting the normal differentiation of immune cells. This study aims to provide a solid foundation for the widespread application and in-depth development of TCM in asthma treatment and to offer new ideas for clinical research and drug development of asthma.
Asthma/genetics* ; Humans ; Drugs, Chinese Herbal/chemistry* ; Th2 Cells/drug effects* ; Th17 Cells/drug effects* ; T-Lymphocytes, Regulatory/drug effects* ; Th1 Cells/drug effects* ; Animals ; Cytokines/immunology* ; Medicine, Chinese Traditional

Objective To investigate the effect of resveratrol on the tumor microenvironment in osteosarcoma. Methods A C57BL/6 xenograft mouse model was established and treated with resveratrol. Single-cell sequencing was performed to analyze changes in the tumor microenvironment. Immunohistochemistry was used to assess immune cell infiltration, while Western blotting was conducted to examine alterations in cellular signaling pathways. Results Resveratrol significantly inhibited the proliferation of LM8 osteosarcoma cells in C57BL/6 mice compared to the control group. Additionally, CD8⁺ T cell recruitment was enhanced. The Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway was notably downregulated in LM8 osteosarcoma cells following resveratrol treatment. Conclusion Resveratrol promotes CD8⁺ T cell infiltration by inhibiting the JAK2/STAT3 signaling pathway, suggesting its potential as a therapeutic agent in osteosarcoma treatment.
Osteosarcoma/genetics* ; STAT3 Transcription Factor/genetics* ; Resveratrol/pharmacology* ; Animals ; Janus Kinase 2/genetics* ; Signal Transduction/drug effects* ; Tumor Microenvironment/immunology* ; Cell Line, Tumor ; Mice, Inbred C57BL ; Mice ; Humans ; Cell Proliferation/drug effects* ; Bone Neoplasms/metabolism* ; CD8-Positive T-Lymphocytes/drug effects* ; Xenograft Model Antitumor Assays

Objective To investigate the therapeutic effects of interleukin 23p19(IL-23p19) monoclonal antibody in the MRL/lpr lupus-like mouse model. Methods A total of 36 female MRL/lpr mice aged 8 weeks were randomly divided into 6 groups: PBS group (blank control), IgG group (isotype IgG), dexamethasone (DEX) group (positive control), and three IL-23p19 monoclonal antibody treatment groups with different dose gradients: low dose (LD, 1 mg/kg), medium dose (MD, 3 mg/kg), and high dose (HD, 10 mg/kg). Drug intervention began at 12 weeks of age via tail vein injection. Urine protein levels were measured using urine protein test strips; serum anti-dsDNA antibody levels were detected by ELISA; serum creatinine and blood urea nitrogen levels were measured using an automatic biochemical analyzer; renal histopathological changes were analyzed by H&E and PAS staining; immunofluorescence was used to assess IgG and C3 immune complex deposition in kidney tissues; flow cytometry was employed to examine the expression of T helper 1(Th1), Th2, Th17, T follicular helper (Tfh), and regulatory T cells(Treg) cell subsets in the spleen; and RT-qPCR was used to detect the expression of related transcription factors in the spleen. Results IL-23p19 monoclonal antibody reduced urine protein levels, alleviated splenomegaly, improved renal function, and decreased anti-dsDNA antibody levels in MRL/lpr mice. It also mitigated glomerulonephritis and reduced renal immune complex deposition. Furthermore, IL-23p19 monoclonal antibody significantly suppressed the proportion of Th1 and Th17 cells while upregulating Treg cell proportion in the spleen. Additionally, it downregulated T-bet and retinoic acid receptor-related orphan receptor γt (RORγt) mRNA levels and upregulated forkhead box P3(FOXP3) mRNA levels in the spleen. Conclusions IL-23p19 monoclonal antibody demonstrates significant therapeutic effects in MRL/lpr mice, likely through modulation of the Th17/Treg cell balance.
Animals ; Female ; Mice, Inbred MRL lpr ; T-Lymphocytes, Regulatory/drug effects* ; Th17 Cells/drug effects* ; Antibodies, Monoclonal/therapeutic use* ; Interleukin-23 Subunit p19/immunology* ; Mice ; Lupus Nephritis/drug therapy* ; Kidney/drug effects* ; Antibodies, Antinuclear/blood*

OBJECTIVES: To investigate the therapeutic effects of cimifugin on Crohn's disease (CD)-like colitis in mice and its possible mechanism. METHODS: Thirty adult male C57BL/6 mice were randomized equally into control group, 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced CD-like colitis model group, and cimifugin treatment (daily gavage at 12.5 mg/kg) group. The therapeutic effect of cimifugin was evaluated by observing changes in body weight, disease activity index (DAI) scores, colon length, histopathological inflammation scores, and inflammatory cytokine levels in the colonic mucosa. Intestinal barrier integrity in the mice was assessed using immunofluorescence assay and Western blotting for claudin-1 and ZO-1; T-helper (Th) cell subset ratios in the mesenteric lymph nodes were analyzed with flow cytometry. Network pharmacology, KEGG enrichment analysis and molecular docking were used to predict the targets of cimifugin and analyze the key pathways and cimifugin-MAPK protein interactions, which were validated by Western blotting in the mouse models. RESULTS: In mice with TNBS-induced colitis, cimifugin treatment significantly attenuated body weight loss and colon shortening, lowered DAI and histopathological scores, decreased IFN-γ and IL-17 levels, and increased IL-4 and IL-10 levels in the colonic mucosa. Cimifugin treatment also significantly improved TNBS-induced claudin-1 dislocation and reduction of goblet cells, upregulated claudin-1 and ZO-1 expressions, reduced Th1 and Th17 cell percentages, and increased Th2 and Treg cell percentages in the colonic mucosa of the mice. KEGG analysis suggested a possible connection between the effect of cimifugin and MAPK signaling, and molecular docking showed strong binding affinity between cimifugin and MAPK core proteins. Western blotting demonstrated significantly decreased phosphorylation levels of JNK, ERK, and p38 in the colonic mucosa of cimifugin-treated mouse models. CONCLUSIONS Cimifugin alleviates TNBS-induced CD-like colitis by repairing intestinal barrier damage and restoring Th1/Th2 and Th17/Treg balance via suppressing MAPK pathway activation.
Animals ; Mice, Inbred C57BL ; Male ; Mice ; Crohn Disease/immunology* ; Colitis/immunology* ; MAP Kinase Signaling System/drug effects* ; Trinitrobenzenesulfonic Acid ; T-Lymphocytes, Helper-Inducer/drug effects* ; Intestinal Mucosa ; Disease Models, Animal

Xiaohuang Qudan decoction (XHQDD) is a classical traditional Chinese medicine (TCM) formula widely used in the treatment of cholestatic liver injury. Despite its widespread use, the protective mechanism of XHQDD against cholestatic liver injury remains incompletely understood. The aim of this study was to investigate whether XHQDD mediates its beneficial effects by inhibiting the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway and regulating TH17/Treg balance. To this end, the researchers used Sprague-Dawley (SD) rats and established a cholestatic liver injury model by oral administration of alpha-naphthylisothiocyanate (ANIT). The experimental group was divided into six groups: Control (CON), ANIT, ursodeoxycholic acid (UDCA), XHQDD-low dose (XHQDD-L) group, XHQDD-medium dose (XHQDD-M) group, and XHQDD-high dose (XHQDD-H) groups. Then, after 7 d of treatment, various tests were performed to verify the results. Firstly, XHQDD and its drug-containing serum were analyzed by ultra-high performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS), and 14 blood-entry components were identified. Then, bile flow was monitored and found to be significantly reduced in the model group, which was significantly reversed in the UDCA and XHQDD groups. To further assess ANIT-induced liver injury, hematoxylin and eosin (H&E) and Sirius red staining, alongside transmission electron microscopy (TEM), were employed to observe liver tissues, revealing hepatocellular injury, cholestasis, and hepatic fibrotic changes. Serum inflammatory factors and liver injury indicators were assessed using enzyme-linked immunosorbent assay (ELISA), indicating an inflammatory state in ANIT-induced liver injury rats. The expression levels of JAK2/STAT3-related genes and proteins in liver and intestinal tissues were measured via quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunohistochemistry, immunofluorescence (IF) staining, and Western blottting (WB) assays. These studies revealed that the inflammatory state of liver-injured rats was inextricably linked to the inflammatory cascade associated with the JAK2/STAT3 pathway and that XHQDD may exert anti-inflammatory efficacy by inhibiting the JAK2/STAT3 pathway. Flow cytometry was used to determine the percentage of T helper 17 (Th17)/regulatory T (Treg) cells in serum and hepatocytes, and it was further found that XHQDD was able to regulate Th17/Treg immune homeostasis in liver-injured rats. The findings suggest that XHQDD markedly alleviates inflammation in ANIT rats, potentially treating cholestasis and liver injury through JAK2/STAT3 inhibition and Th17/Treg balance regulation.
Animals ; STAT3 Transcription Factor/immunology* ; Janus Kinase 2/immunology* ; Drugs, Chinese Herbal/pharmacology* ; Rats, Sprague-Dawley ; 1-Naphthylisothiocyanate/adverse effects* ; Male ; Rats ; Th17 Cells/immunology* ; Cholestasis/immunology* ; Signal Transduction/drug effects* ; T-Lymphocytes, Regulatory/immunology* ; Chemical and Drug Induced Liver Injury/immunology* ; Liver/drug effects*

Objective To clarify the mechanism that HIV infection mediates mitochondrial damage of CD4⁺ T lymphocytes (CD4⁺ T cells) through mitogen-activated protein kinase (MAPK) pathway. Methods From October 1st, 2022 to March 31st, 2023, 47 HIV-infected people who received antiretroviral therapy (ART) for 4 years were recruited, including 22 immune non-responders (INR) and 25 responders (IR); and 26 sex and age-matched control participants (HC) who were negative for HCV, HBV, and HIV infections. The immune parameters were analyzed by flow cytometry. Finally, peripheral blood mononuclear cells (PBMCs) from HC or HIV patients were treated with MAPK pathway inhibitor SB203580, and the changes of mitochondrial function of CD4⁺ T cells were observed. Results Compared with HC group, the proportion of CD4⁺ T cells in PBMCs in INR group and IR group was significantly lower, and the proportion of CD4⁺ T cells in PBMCs in INR group was significantly lower than that in IR group. In addition, the proportion of naive (CD45RA⁺CD27⁺)T cells in PBMCs in INR group was significantly lower than that in HC group and IR group. Compared with HC group and IR group, the proportions of CD4⁺PD-1⁺, CD4⁺Av⁺ and CD4⁺MO⁺ in PBMCs in INR group and the proportions of CD45RA⁺CD27⁺PD-1⁺, CD45RA⁺CD27⁺Av⁺, CD45RA⁺CD27⁺MO⁺ in CD4⁺ T cell subsets increased significant. Compared with HC-con group, the basal respiration, maximal respiration and adenosine triphosphate(ATP) production of CD4⁺ T cells in HIV-con group decreased significantly, and JC-1 (green/red) in CD4⁺ T cells increased significantly. Compared with HIV-con group, the basal respiration, maximal respiration, ATP production and respiratory potential of CD4⁺ T cells in HIV-SB203580 group increased significantly, and the JC-1 (green/red) in CD4⁺ T cells decreased significantly. Conclusion Abnormal activation of the MAPK signaling pathway is observed in HIV patients receiving ART treatment, especially in CD4⁺ T cells of INR patients, which may lead to impaired mitochondrial function and abnormal CD4⁺ T cell homeostasis.
Humans ; HIV Infections/immunology* ; Male ; Mitochondria/drug effects* ; Female ; CD4-Positive T-Lymphocytes/metabolism* ; Adult ; Middle Aged ; MAP Kinase Signaling System/drug effects* ; Pyridines/pharmacology* ; Imidazoles/pharmacology* ; Leukocytes, Mononuclear/immunology*

The activation mechanism of chimeric antigen receptor (CAR)-engineered T cells may differ substantially from T cells carrying native T cell receptor, but this difference remains poorly understood. We present the first comprehensive portrait of single-cell level transcriptional and cytokine signatures of anti-CD19/4-1BB/CD28/CD3ζ CAR-T cells upon antigen-specific stimulation. Both CD4 helper T (T) cells and CD8 cytotoxic CAR-T cells are equally effective in directly killing target tumor cells and their cytotoxic activity is associated with the elevation of a range of T1 and T2 signature cytokines, e.g., interferon γ, tumor necrotic factor α, interleukin 5 (IL5), and IL13, as confirmed by the expression of master transcription factor genes TBX21 and GATA3. However, rather than conforming to stringent T1 or T2 subtypes, single-cell analysis reveals that the predominant response is a highly mixed T1/T2 function in the same cell. The regulatory T cell activity, although observed in a small fraction of activated cells, emerges from this hybrid T1/T2 population. Granulocyte-macrophage colony stimulating factor (GM-CSF) is produced from the majority of cells regardless of the polarization states, further contrasting CAR-T to classic T cells. Surprisingly, the cytokine response is minimally associated with differentiation status, although all major differentiation subsets such as naïve, central memory, effector memory, and effector are detected. All these suggest that the activation of CAR-engineered T cells is a canonical process that leads to a highly mixed response combining both type 1 and type 2 cytokines together with GM-CSF, supporting the notion that polyfunctional CAR-T cells correlate with objective response of patients in clinical trials. This work provides new insights into the mechanism of CAR activation and implies the necessity for cellular function assays to characterize the quality of CAR-T infusion products and monitor therapeutic responses in patients.
Antigens ; metabolism ; CTLA-4 Antigen ; metabolism ; Cell Differentiation ; drug effects ; Cell Line ; Cytokines ; metabolism ; Cytotoxicity, Immunologic ; drug effects ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Lymphocyte Activation ; drug effects ; immunology ; Lymphocyte Subsets ; drug effects ; metabolism ; Phenotype ; Proteomics ; Receptors, Chimeric Antigen ; metabolism ; Single-Cell Analysis ; methods ; T-Lymphocytes, Regulatory ; drug effects ; metabolism ; Th1 Cells ; cytology ; drug effects ; Th2 Cells ; cytology ; drug effects ; Transcription, Genetic ; drug effects ; Up-Regulation ; drug effects