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 generate and characterize natural killer cell (NK cell)-conditional Cd226 gene knockout mice using Cre-loxP technology, and to explore the role of CD226 on NK cells in alleviating intestinal inflammation in a murine model of ulcerative colitis (UC). Methods NK cell-conditional Cd226 gene knockout mice were generated by crossing loxP-flanked Cd226 mice with Ncr1-Cre mice via the Cre-loxP system. Polymerase chain reaction (PCR) and agarose gel electrophoresis were used for genotyping. A UC model was established by dextran sulfate sodium (DSS) induction. Flow cytometry was performed to analyze CD226 expression levels on NK cells and the infiltration of related immune cells in colon tissues. Hematoxylin-eosin (HE) staining was performed to assess the degree of colonic inflammation. Results DNA gel electrophoresis and flow cytometry confirmed the successful generation of NK cell-specific Cd226 knockout mice. After conditional knockout of Cd226 in NK cells, inflammation in the UC mouse model was alleviated. Flow cytometry results showed a reduced proportion of NK cells in peripheral blood and the colon lamina propria, while HE staining demonstrated attenuated inflammatory responses. Conclusion Specific knockout of Cd226 in NK cells mitigates intestinal inflammation in UC mice by reducing NK cell numbers and inhibiting their pro-inflammatory functions.
Animals ; Colitis, Ulcerative/pathology* ; Killer Cells, Natural/metabolism* ; Mice, Knockout ; T Lineage-Specific Activation Antigen 1 ; Antigens, Differentiation, T-Lymphocyte/genetics* ; Mice ; Disease Models, Animal ; Mice, Inbred C57BL ; Male

Objective To explore the characteristics of the inhibitory effect of Evodiamine on the proliferation of activated T cells. Methods Mononuclear cells from peripheral blood (PBMCs) were obtained from healthy donors through density gradient centrifugation, and T cells were subsequently purified by using immunomagnetic bead separation. T cell activation was induced by employing anti-human CD3 and anti-human CD28 antibodies. T cells were treated with different concentrations of EVO (0.37, 1.11, 3.33, and 10)μmol/L. Flow cytometry was applied to evaluate the proliferation index, apoptosis rate, viability, CD25 expression levels, and cell cycle distribution of T cells. The expression levels of cytokines IL-2, IL-17A, IL-4, and IL-10 were quantified by using ELISA. Results 1.11, 3.33 and 10 μmol/L EVO effectively inhibited the proliferation of activated T cells, with an IC₅₀ of (1.5±0.3)μmol/L. EVO did not induce apoptosis in activated T cells and affect the survival rate of resting T cells. EVO did not affect the expression of CD25 and the secretion of IL-2 in activated T cells. EVO arrested the T cell cycle at the G2/M phase, resulting in an increase in G2/M phase cells, and exhibited a concentration-dependent effect. EVO did not affect the secretion of IL-4, IL-10 by activated T cells, but significantly inhibited the secretion of IL-17A. Conclusion EVO did not significantly affect the activation process of T cells but inhibited T cell proliferation by arresting the cell cycle at the G2/M phase and significantly suppressed the secretion of the pro-inflammatory cytokine IL-17A, which suggests that EVO has the potential to serve as a lead compound for the development of low-toxicity and high-efficiency immunosuppressants and elucidates the mechanisms underlying the anti-inflammatory and immunomodulatory effects of the traditional Chinese medicine Evodia rutaecarpa.
Humans ; Cell Proliferation/drug effects* ; Quinazolines/pharmacology* ; T-Lymphocytes/metabolism* ; Lymphocyte Activation/drug effects* ; Apoptosis/drug effects* ; Interleukin-4/metabolism* ; Interleukin-10/metabolism* ; Interleukin-2 Receptor alpha Subunit/metabolism* ; Interleukin-17/metabolism* ; Interleukin-2/metabolism* ; Cell Cycle/drug effects* ; Cells, Cultured

OBJECTIVE: To analyze the Epstein-Barr virus (EBV) load in different lymphocyte subsets, as well as clinical characteristics and outcomes in patients with hematologic malignancies experiencing EBV reactivation. METHODS: Peripheral blood samples from patients were collected. B, T, and NK cells were isolated sorting with magnetic beads by flow cytometry. The EBV load in each subset was quantitated by real-time quantitative polymerase chain reaction (RT-qPCR). Clinical data were colleted from electronic medical records. Survival status was followed up through outpatient visits and telephone calls. Statistical analyses were performed using SPSS 25.0. RESULTS: A total of 39 patients with hematologic malignancies were included, among whom 35 patients had undergone allogeneic hematopoietic stem cell transplantation (allo-HSCT). The median time to EBV reactivation was 4.8 months (range: 1.7-57.1 months) after allo-HSCT. EBV was detected in B, T, and NK cells in 20 patients, in B and T cells in 11 patients, and only in B cells in 4 patients. In the 35 patients, the median EBV load in B cells was 2.19×10⁴ copies/ml, significantly higher than that in T cells (4.00×10³ copies/ml, P <0.01) and NK cells (2.85×10² copies/ml, P <0.01). Rituximab (RTX) was administered for 32 patients, resulting in EBV negativity in 32 patients with a median time of 8 days (range: 2-39 days). Post-treatment analysis of 13 patients showed EBV were all negative in B, T, and NK cells. In the four non-transplant patients, the median time to EBV reactivation was 35 days (range: 1-328 days) after diagnosis of the primary disease. EBV was detected in one or two subsets of B, T, or NK cells, but not simultaneously in all three subsets. These patients received a combination chemotherapy targeting at the primary disease, with 3 patients achieving EBV negativity, and the median time to be negative was 40 days (range: 13-75 days). CONCLUSION In hematologic malignancy patients after allo-HSCT, EBV reactivation commonly involves B, T, and NK cells, with a significantly higher viral load in B cells compared to T and NK cells. Rituximab is effective for EBV clearance. In non-transplant patients, EBV reactivation is restricted to one or two lymphocyte subsets, and clearance is slower, highlighting the need for prompt anti-tumor therapy.
Humans ; Hematologic Neoplasms/virology* ; Herpesvirus 4, Human/physiology* ; Epstein-Barr Virus Infections ; Hematopoietic Stem Cell Transplantation ; Virus Activation ; Lymphocyte Subsets/virology* ; Flow Cytometry ; Killer Cells, Natural/virology* ; Male ; Female ; B-Lymphocytes/virology* ; Viral Load ; Adult ; T-Lymphocytes/virology* ; Middle Aged

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

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*

OBJECTIVE: To explore the effect of human bone marrow mesenchymal stem cells (MSCs) with ectopic high OCT4 expression on T-cell proliferation, activation and secretion in vitro. METHODS: Peripheral blood mononuclear cells were isolated from healthy children. Anti-CD3 and anti-CD28 monoclonal antibodies were used to activate T lymphocytes, which were stimulated by interleukin (IL)-2 for one week in vitro. Then MSCs with ectopic high OCT4 expression (MSC-OCT4) were co-cultured with activated T lymphocytes. After one week of co-culture, the supernatant was collected and the levels of Th1/Th2 cytokines [IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α and interferon (IFN)-γ] were determined by flow cytometry. The lymphocytes after one week of co-culture were collected and counted by Countstar software. After the proportions of activated/inactivated T cell subsets were determined by flow cytometry, the absolute lymphocyte counts were calculated and expressed as mean ± standard deviation. RESULTS: Compared with control T cell alone culture group, the proliferation of CD3⁺ T cells, CD3⁺CD4⁺ T cells, and CD3⁺CD8⁺ T cells were significantly inhibited in MSC group and MSC-OCT4 group. Compared with MSC, MSC-OCT4 could inhibit CD3⁺CD8⁺ T cell proliferation better (P =0.049), and mainly inhibited early T cell activation. Compared with control T cell alone culture group, the levels of IL-2 and INF-γ were significantly down-regulated both in MSC group and MSC-OCT4 group.After co-culture with T cells for one week, the level of IL-6 significantly increased in MSC group and MSC-OCT4 group compared with that before co-culture. Compared with control MSC group, MSC-OCT4 group had higher viable cell numbers after 1 week of co-culture (P =0.019), and could resist the inhibition of proliferation by higher concentration of mitomycin C. CONCLUSION Both MSC and MSC-OCT4 can inhibit the proliferation and activation of IL-2-stimulated T cells in vitro. After overexpression of OCT4, MSC has better proliferation ability in vitro and can inhibit the proliferation of CD3⁺CD8⁺ T cells more effectively, which may have a better and more lasting immunosuppressive ability to regulate the balance of Th1/Th2.
Child ; Humans ; Bone Marrow Cells ; CD8-Positive T-Lymphocytes/metabolism* ; Cell Proliferation ; Cells, Cultured ; Interleukin-2 ; Interleukin-6/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Lymphocyte Activation ; Mesenchymal Stem Cells ; Tumor Necrosis Factor-alpha/metabolism*

OBJECTIVE: To investigate the effect of miR-125b on T cell activation in patients with aplastic anemia (AA) and its molecular mechanism. METHODS: A total of 30 AA patients were enrolled in department of hematology, Binzhou Medical University Hospital from January 2018 to October 2021, as well as 15 healthy individuals as healthy control (HC) group. Peripheral blood mononuclear cells (PBMCs) were isolated, in which the levels of miR-125b and B7-H4 mRNA were detected by RT-qPCR. Immunomagnetic beads were used to separate naive T cells and non-naive T cells from AA patients and healthy people to detect the levels of miR-125b and B7-H4 mRNA. Lentivirus LV-NC inhibitor and LV-miR-125b inhibitor were transfected into cells, and T cell activation was detected by flow cytometry. The dual-luciferase reporter gene assay was used to detect the targetting relationship between miR-125b and B7-H4. RT-qPCR and Western blot were used to detect the levels of miR-125b, CD40L, ICOS, IL-10 mRNA and B7-H4 protein. RESULTS: Compared with HC group, the expression of miR-125b was up-regulated but B7-H4 mRNA was down-regulated in PBMCs of AA patients (P <0.05), and the proportions of CD4⁺CD69⁺ T cells and CD8⁺CD69⁺ T cells in PBMCs of AA patients were higher (P <0.05). The expression of miR-125b was significantly up-regulated but B7-H4 mRNA was down-regulated in both naive T cells and non-naive T cells of AA patients (P <0.05), and non-naive T cells was more significant than naive T cells (P <0.05). Compared with NC inhibitor group, the expression of miR-125b was significantly decreased, the expression level of CD69 on CD4⁺ and CD8⁺ T cells in PBMCs was also significantly decreased, while the luciferase activity was significantly increased after co-transfection of miR-125b inhibitor and B7-H4-3'UTR-WT in the miR-125b inhibitor group (P <0.05). Compared with NC inhibitor group, the mRNA and protein levels of B7-H4 were significantly increased in the miR-125b inhibitor group (P <0.05). Compared with miR-125b inhibitor+shRNA group, the expression levels of CD69 on CD4⁺ and CD8⁺ T cells were significantly increased, and the levels of CD40L, ICOS and IL-10 mRNA were also significantly increased in the miR-125b inhibitor+sh-B7-H4 group (P <0.05). CONCLUSION MiR-125b may promote T cell activation by targetting B7-H4 in AA patients.
Humans ; Anemia, Aplastic/genetics* ; CD40 Ligand/metabolism* ; Interleukin-10 ; Leukocytes, Mononuclear/metabolism* ; Luciferases ; MicroRNAs/genetics* ; RNA, Messenger/metabolism* ; Lymphocyte Activation ; T-Lymphocytes/metabolism*