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

Programmed death 1 (PD-1) and its ligand (PD-L1) serve as crucial targets in cancer immunotherapy, and their inhibitors have significantly improved the prognosis of many patients with malignant tumors. However, the issues of drug resistance and limited overall response rate associated with monotherapy remain prevalent. As a new generation of immune checkpoints, lymphocyte activation gene 3 (LAG-3) synergistically enhances the suppression of T cells alongside PD-1 in various cancers. Combining the blockade of both PD-1 and LAG-3 yields stronger anti-tumor immune effects compared to blocking either target alone, thereby reversing the immunosuppressive state of the tumor microenvironment and reducing the occurrence of resistance. This review covers the structural characteristics of LAG-3 and unveils its specific interactions with PD-1 across multiple cancers, providing a novel reference for overcoming the limitations of single-agent therapy.
Humans ; Neoplasms/immunology* ; Immunotherapy/methods* ; Programmed Cell Death 1 Receptor/metabolism* ; Lymphocyte Activation Gene 3 Protein ; Antigens, CD/metabolism* ; Animals ; Tumor Microenvironment/immunology* ; Immune Checkpoint Inhibitors/therapeutic use*

Objective To investigate the effects of LBL-007, a novel fully human lymphocyte activation gene 3 (LAG-3) monoclonal antibody, in combination with programmed cell death protein 1 (PD-1) antibody, on the invasion, migration and proliferation of tumor cells, and to elucidate the underlying mechanisms. Methods Human lymphocyte cells Jurkat were co-cultured with A549 and MGC803 tumor cell lines and treated with the isotype control antibody human IgG, LBL-007, anti-PD-1 antibody BE0188, or tumor necrosis factor-alpha (TNF-α, the NF-κB signaling pathway agonist). Tumor cell proliferation was assessed using a colony formation assay; invasion was measured by Transwell^TM assay; migration was evaluated using a wound healing assay. Western blotting was employed to determine the expression levels of NF-κB pathway-related proteins: IκB inhibitor kinase alpha (Ikkα), phosphorylated Ikkα (p-IKKα), NF-κB subunit p65, phosphorylated p65 (p-p65), NF-κB Inhibitor Alpha (IκBα), phosphorylated IκBα (p-IκBα), matrix metalloproteinase 9 (MMP9), and MMP2. Results Compared with the control and IgG isotype groups, LBL-007 and BE0188 significantly reduced tumor cell proliferation, invasion, and migration. They also decreased the phosphorylation of p-IKKα, p-p65 and p-IκBα, and the expression of MMP9 and MMP2 of tumor cells in the co-culture system. The combined treatment of LBL-007 and BE0188 enhanced inhibitory effects. Treatment with the NF-κB signaling pathway agonist TNF-α reversed the suppressive effects of LBL-007 and BE0188 on tumor cell proliferation, invasion, migration, and NF-κB signaling. Conclusion LBL-007 and anti-PD-1 antibody synergistically inhibit the invasion, migration, and proliferation of A549 and MGC803 tumor cells by blocking the NF-κB signaling pathway.
Humans ; Cell Proliferation/drug effects* ; Cell Movement/drug effects* ; Signal Transduction/drug effects* ; NF-kappa B/metabolism* ; Neoplasm Invasiveness ; Antibodies, Monoclonal/pharmacology* ; Programmed Cell Death 1 Receptor/antagonists & inhibitors* ; Cell Line, Tumor ; Antigens, CD/immunology* ; Lymphocyte Activation Gene 3 Protein ; A549 Cells ; I-kappa B Kinase/metabolism* ; Jurkat Cells ; Matrix Metalloproteinase 9/metabolism*

Objective To prepare mouse anti-human lymphocyte activation gene 3 (LAG3) monoclonal antibody (mAb) and perform immunological identification of the antibody. Methods BALB/c mice were immunized with LAG3-mLumin-3T3 cells, which stably express the extracellular and transmembrane regions of human LAG3 in mouse 3T3 cells. The secretion of anti-human LAG3 antibodies in mouse serum was assessed using flow cytometry and immunofluorescence. SP2/0 cells were injected subcutaneously into the mice to elicit solid myelomas, and mouse myeloma cells were subsequently isolated. Spleen cells from the immunized mice were fused with the myeloma cells to establish hybridomas, which were then separated using the limiting dilution method. Flow cytometry was used to detect LAG3 mAbs in the hybridoma culture medium. To map the epitopes recognized by these mAbs, 3T3 cells expressing individual extracellular domains of LAG3(LAG3 domains 1/-2/-3/-4-3T3) were used. Flow cytometry was also applied to analyze LAG3 expression on activated human peripheral blood mononuclear cells (PBMC) before and after co-culture with the LAG3 mAbs. Results Mice immunized with the recombinant eukaryotic cell antigen produced anti-LAG3 antibodies. The generated hybridomas secreted mouse anti-human LAG3 mAbs, with each hybridoma line recognizing different LAG3 antigenic domains. Conclusion Mouse anti-human LAG3 mAbs were successfully generated, with different hybridoma clones secreting antibodies that recognize distinct LAG3 epitopes. These findings lay the groundwork for further studies into the biological properties of LAG3 and the development of diagnostic reagents and therapeutic blocking antibodies for cancer treatment.
Animals ; Humans ; Mice ; Lymphocyte Activation Gene 3 Protein ; Antibodies, Monoclonal/immunology* ; Mice, Inbred BALB C ; Hybridomas/immunology* ; Antigens, CD/genetics* ; Immunization ; Recombinant Proteins/immunology* ; Female ; Eukaryotic Cells/immunology* ; Flow Cytometry ; Epitopes/immunology*

Nucleolar complex associated 4 homolog (NOC4L) is a key factor in ribosome biogenesis, and this study aims to investigate its roles in activated T cells from the perspective of translation regulation. Firstly, flow cytometry was employed to determine the expression levels of NOC4L in the CD4⁺ T cells under different conditions in the transgenic reporter mice expressing Noc4l^mCherry. Subsequently, the expression of NOC4L along with cell proliferation was examined under Th1 and Th17 polarization conditions. Finally, in vitro experiments were conducted to identify the proteins interacting with NOC4L during the activation of Th1 and Th17 cells, on the basis of which the potential mechanisms of NOC4L were explored. The results showed that the expression level of NOC4L increased in activated CD4⁺ T cells, and the expression of NOC4L was closely associated with the proliferation and division of activated T cells. The in vitro experiments revealed interactions between NOC4L and proteins involved in ribosome assembly and cell proliferation during T cell activation. These findings lay a foundation for probing into the post-transcriptional regulation in helper T cells and hold profound significance for understanding the activation and regulatory mechanisms of T cells.
Animals ; Mice ; Lymphocyte Activation ; Cell Proliferation ; Mice, Transgenic ; Nuclear Proteins/genetics* ; Th1 Cells/immunology* ; Th17 Cells/metabolism* ; CD4-Positive T-Lymphocytes/immunology* ; Ribosomes/metabolism*

BACKGROUND: Asbestos fibers possess tumorigenicity and are thought to cause mesothelioma. We have previously reported that exposure to asbestos fibers causes a reduction in antitumor immunity. Asbestos exposure in the mixed lymphocyte reaction (MLR) showed suppressed induction of cytotoxic T lymphocytes (CTLs), accompanied by a decrease in proliferation of CD8 METHODS: For MLR, human peripheral blood mononuclear cells (PBMCs) were cultured with irradiated allogenic PBMCs upon exposure to chrysotile B asbestos at 5 μg/ml for 7 days. After 2 days of culture, IL-15 was added at 1 ng/ml. After 7 days of MLR, PBMCs were collected and analyzed for phenotypic and functional markers of CD8 RESULTS: IL-15 addition partially reversed the decrease in CD3 CONCLUSION These findings indicate that CTLs induced upon exposure to asbestos possess dysfunctional machinery that can be partly compensated by IL-15 supplementation, and that IL-15 is more effective in the recovery of proliferation and granzyme B levels from asbestos-induced suppression of CTL induction compared with IL-2.
Asbestos/adverse effects* ; CD8-Positive T-Lymphocytes/metabolism* ; Humans ; Interleukin-15/pharmacology* ; Lymphocyte Activation/immunology* ; T-Lymphocytes, Cytotoxic/metabolism*

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

Cytokine-activated T cells (CATs) can be easily expanded and are widely applied to cancer immunotherapy. However, the good efficacy of CATs is rarely reported in clinical applications because CATs have no or very low antigen specificity. The low-efficacy problem can be resolved using T cell antigen receptor-engineered CAT (TCR-CAT). Herein, we demonstrate that NY-ESO-1 HLA-A*02:01-specific high-affinity TCR (HAT)-transduced CATs can specifically kill cancer cells with good efficacy. With low micromolar range dissociation equilibrium constants, HAT-transduced CATs showed good specificity with no off-target killing. Furthermore, the high-affinity TCR-CATs delivered significantly better activation and cytotoxicity than the equivalent TCR-engineered T cells (TCR-Ts) in terms of interferon-γ and granzyme B production and in vitro cancer cell killing ability. TCR-CAT may be a very good alternative to the expensive TCR-T, which is considered an effective personalized cyto-immunotherapy.
Cell Line, Tumor ; Cytokines ; metabolism ; Cytotoxicity, Immunologic ; Genetic Engineering ; HLA-A2 Antigen ; metabolism ; Humans ; Immunotherapy, Adoptive ; methods ; Lymphocyte Activation ; Receptors, Antigen, T-Cell ; genetics ; immunology ; T-Lymphocytes ; immunology

Novel biologics that redirect cytotoxic T lymphocytes (CTLs) to kill tumor cells bearing a tumor associated antigen hold great promise in the clinic. However, the ability to safely and potently target CD3 on CTL toward tumor associated antigens (TAA) expressed on tumor cells remains a challenge of both technology and biology. Herein we describe the use of a Half DVD-Ig format that can redirect CTL to kill tumor cells. Notably, Half DVD-Ig molecules that are monovalent for each specificity demonstrated reduced non-specific CTL activation and conditional CTL activation upon binding to TAA compared to intact tetravalent DVD-Ig molecules that are bivalent for each specificity, while maintaining good drug like properties and appropriate PK properties.
Animals ; Antibodies, Bispecific ; immunology ; Antibodies, Monoclonal ; immunology ; pharmacokinetics ; CD3 Complex ; metabolism ; Cell Line, Tumor ; Cytotoxicity, Immunologic ; ErbB Receptors ; metabolism ; Female ; Humans ; Lymphocyte Activation ; immunology ; Mice, SCID ; Neoplasms ; immunology ; pathology ; Rats, Sprague-Dawley ; T-Lymphocytes, Cytotoxic ; immunology

Chimeric antigen receptor (CAR) T cell therapy is a promising cancer treatment that has recently been undergoing rapid development. However, there are still some major challenges, including precise tumor targeting to avoid off-target or "on-target/off-tumor" toxicity, adequate T cell infiltration and migration to solid tumors and T cell proliferation and persistence across the physical and biochemical barriers of solid tumors. In this review, we focus on the primary challenges and strategies to design safe and effective CAR T cells, including using novel cutting-edge technologies for CAR and vector designs to increase both the safety and efficacy, further T cell modification to overcome the tumor-associated immune suppression, and using gene editing technologies to generate universal CAR T cells. All these efforts promote the development and evolution of CAR T cell therapy and move toward our ultimate goal-curing cancer with high safety, high efficacy, and low cost.
Cell Movement ; immunology ; Cell Proliferation ; Gene Expression ; Genetic Vectors ; chemistry ; metabolism ; Humans ; Immunotherapy, Adoptive ; methods ; Lymphocyte Activation ; Lymphocytes, Tumor-Infiltrating ; cytology ; immunology ; transplantation ; Neoplasms ; genetics ; immunology ; pathology ; therapy ; Patient Safety ; Receptors, Antigen, T-Cell ; chemistry ; genetics ; immunology ; Recombinant Fusion Proteins ; chemistry ; genetics ; immunology ; Signal Transduction ; Single-Chain Antibodies ; chemistry ; genetics ; T-Lymphocytes ; cytology ; immunology ; transplantation ; Treatment Outcome