BACKGROUND: Cluster of differentiation 8 positive (CD8 + ) T cells play a crucial role in the response against tumors, including hepatocellular carcinoma (HCC), where their dysfunction is commonly observed. While the association between elevated peroxisome proliferator-activated receptor alpha (PPARα) expression in HCC cells and exosomes and unfavorable prognosis in HCC patients is well-established, the underlying biological mechanisms by which PPARα induces CD8 + T cell exhaustion mediated by HCC exosomes remain poorly understood. METHODS: Bioinformatics analyses and dual-luciferase reporter assays were used to investigate the regulation of microRNA-27b-3p ( miR-27b-3p ) and thymocyte selection-associated high mobility group box ( Tox ) by Pparα . In vitro and in vivo experiments were conducted to validate the effects of HCC-derived exosomes, miR-27b-3p overexpression, and Pparα on T cell function. Exosome characterization was confirmed using transmission electron microscopy, Western blotting, and particle size analysis. Exosome tracing was performed using small animal in vivo imaging and confocal microscopy. The expression levels of miR-27b-3p , Pparα , and T cell exhaustion-related molecules ( Tox , Havcr2 , and Pdcd1 ) were detected using quantitative reverse transcription polymerase chain reaction analysis, Western blotting analysis, immunofluorescence staining, and flow cytometry analysis. RESULTS: Pparα expression was significantly increased in HCC and negatively correlated with prognosis. It showed a positive correlation with Tox and a negative correlation with miR-27b-3p . The overexpressed Pparα from HCC cells was delivered to CD8 + T cells via exosomes, which absorbed miR-27b-3p both in vitro and in vivo , acting as "miRNA sponges". Further experiments demonstrated that Pparα can inhibit the negative regulation of Tox mediated by miR-27b-3p through binding to its 3'untranslated regions. CONCLUSIONS HCC-derived exosomes deliver Pparα to T cells and promote CD8 + T cell exhaustion and malignant progression of HCC via the miR-27b-3p /TOX regulatory axis. The mechanisms underlying T-cell exhaustion in HCC can be utilized for the advancement of anticancer therapies.
MicroRNAs/metabolism* ; PPAR alpha/genetics* ; Carcinoma, Hepatocellular/genetics* ; Humans ; Liver Neoplasms/genetics* ; CD8-Positive T-Lymphocytes/immunology* ; Exosomes/metabolism* ; Animals ; Cell Line, Tumor ; Mice ; High Mobility Group Proteins/genetics* ; Male ; T-Cell Exhaustion

Objective Zinc finger protein 335 (Zfp335) plays a crucial role in the early development of thymic T cells and the differentiation of peripheral T cell subpopulations. The objective of this study is to investigate the role and underlying mechanisms of Zfp335 in the regulation of regulatory T cell (Treg) within tumor immunity. Methods The Zfp335 gene was specifically knocked out in Treg using tamoxifen (Zfp335^fl/fl FOXP3^creERT2), and the MC38 tumor model was established. On the 7th day after tumor inoculation, tumor size was observed and measured. Tumor size was monitored and recorded daily starting from day 7 post-inoculation. On day 12, tumors were harvested, and the proportions of CD4⁺ T cells, CD8⁺ T cells, and Treg were analyzed by flow cytometry. Additionally, the mitochondrial function of effector regulatory T cell (eTreg) was assessed. Results From day 10 post-tumor inoculation, tumor volume in the Zfp335^CKO group was significantly reduced compared to that of the wild-type (WT) group. Furthermore, the infiltration of CD4⁺ and CD8⁺ T cells, along with their respective effector cells, was significantly higher in the Zfp335^CKO group than in the WT group. The proportions of CD4⁺ and CD8⁺ T cells producing interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) were also significantly increased in the Zfp335^CKO group compared to that of the WT group. In addition, the percentage of CD8⁺ T cells secreting granzyme B (GzmB) was significantly higher in the Zfp335^CKO group than that in the WT group. In contrast, the proportion of Treg and inducible T cell co-stimulator (ICOS)⁺ Treg in the Zfp335^CKO group was significantly lower than that in the WT group. Finally, the expression level of Mitotracker Deep Red in eTreg from the Zfp335^CKO group was significantly reduced compared to that in the WT group. Conclusion During tumorigenesis, the specific deletion of Zfp335 impairs Treg activation, which is related to decreased mitochondrial function in eTreg. In Zfp335^CKO mice. Tumors exhibit increased infiltration of effector T cells, accompanied by elevated levels of cytotoxic cytokines, ultimately enhancing resistance to tumor progression.
Animals ; T-Lymphocytes, Regulatory/metabolism* ; Mice ; CD8-Positive T-Lymphocytes/immunology* ; Neoplasms/genetics* ; Cell Line, Tumor ; Mice, Inbred C57BL ; Mice, Knockout ; DNA-Binding Proteins/genetics* ; Female

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 whether PLCB1 expression leads to gastric adenocarcinoma metastasis and poor prognosis, and to preliminarily analyze its mechanism. Methods 122 gastric adenocarcinoma patients and their adjacent non-cancerous tissues were selected, and tissue microarray technology was used to detect the expression levels of PLCB1, epithelial cadherin(E-cadherin), vimentin and CD8⁺ T cells by immunohistochemistry, and scored by two pathologists. According to the immunohistochemical score of PLCB1, the patients were divided into PLCB1 high expression group (IHC>90) and PLCB1 low expression group (IHC≤90). The clinical pathological characteristics, epithelial mesenchymal transition(EMT)-related proteins and CD8⁺ T cells expression differences between the two groups were compared. The overall survival of the patients was collected, and COX regression analysis and Kaplan-Meier curve were used to evaluate the relationship between PLCB1 expression level and prognosis. Results PLCB1 was highly expressed in 55 cases of gastric adenocarcinoma tissues, while only 12 cases in adjacent non-cancerous tissues. The tumor invasion depth, lymph node metastasis degree and TNM stage of the PLCB1 high expression group were higher than those of the PLCB1 low expression group. Chi-square test showed that PLCB1 expression level was negatively correlated with E-cadherin (r=-0.339), positively correlated with vimentin (r=0.211), and negatively correlated with CD8⁺ T cells (r=-0.343). Kaplan-Meier curve analysis showed that the overall survival and disease-free survival of gastric adenocarcinoma patients with high PLCB1 expression were significantly reduced. Multivariate COX regression analysis showed that except for lymph node metastasis, tumor invasion depth, TNM stage, E-cadherin and vimentin were also independent prognostic factors for gastric adenocarcinoma patients. Conclusion PLCB1 is highly expressed in gastric adenocarcinoma, and is closely related to tumor aggressiveness and prognosis. PLCB1 may induce EMT and inhibit CD8⁺ T cell infiltration to affect gastric adenocarcinoma metastasis and immune response.
Humans ; Stomach Neoplasms/genetics* ; Epithelial-Mesenchymal Transition ; Male ; Female ; Middle Aged ; Prognosis ; Adenocarcinoma/genetics* ; Cadherins/metabolism* ; Aged ; Adult ; CD8-Positive T-Lymphocytes/immunology* ; Vimentin/metabolism* ; Lymphatic Metastasis ; Neoplasm Metastasis

Objectives To investigate interleukin 36γ (IL-36γ) expression, and analyze the influence of IL-36γ to CD8⁺ T cell activity in chronic obstructive pulmonary diseases (COPD) patients with secondary fungal pneumonia. Methods Peripheral blood was collected from 47 COPD patients, 39 COPD patients with secondary fungal pneumonia, and 20 controls. Bronchial alveolar lavage fluid (BALF) was isolated from 27 COPD patients with secondary fungal pneumonia. CD8⁺ T cells were purified. The levels of four IL-36 isoforms in plasma and BALF were measured by enzyme linked immunosorbent assay (ELISA). CD8⁺ T cells were stimulated with recombinant human IL-36γ. The levels of interferon γ(IFN-γ), tumor necrosis factor α(TNF-α), perforin and granzyme B in the cultured supernatants were measured by ELISA. Recombinant human IL-36γ-stimulated CD8⁺ T cells were co-cultured with NCI-H1882 cells in either direct cell-to-cell contact or Transwell^TM manner. The levels of IFN-γ, TNF-α, and lactate dehydrogenase in the cultured supernatants were assessed. The percentage of target cell death was calculated. Results Plasma IL-36α, IL-36β, and IL-36γ levels were significantly elevated in both COPD group and COPD with secondary fungal pneumonia group compared with those in control group. However, only plasma IL-36γ level was higher in COPD with secondary fungal pneumonia group than that in COPD group [(200.11±99.95)pg/mL vs (53.03±87.18)pg/mL, P=0.023]. There was no remarkable difference in plasma IL-36 receptor antagonist level among three groups. IL-36γ level in BALF from infectious site was higher than that from non-infectious site in COPD with secondary fungal pneumonia group [(305.82±59.60)pg/mL vs (251.93±76.01)pg/mL, P=0.011]. IL-36γ stimulation enhanced IFN-γ, TNF-α, perforin and granzyme B secreted by CD8⁺ T cells. When IL-36γ-stimulated CD8⁺ T cells were directly mixed with NCI-H1882 cells for co-culture, the percentage of cell death was increased [(16.06±3.67)% vs (11.47±2.36)%, P=0.002]. When using Transwell^TM plate for non-contact co-culture, IL-36γ-stimulated CD8⁺ T cell-mediated death of NCI-H1882 cells showed no significant difference compared to that without stimulation [(4.77±0.78)% vs (4.99±0.92)%, P=0.554]. Conclusion IL-36γ level in plasma and infectious site is elevated in COPD patients with secondary fungal pneumonia, which enhances the cytotoxicity of CD8⁺ T cells in peripheral blood and infectious microenviroment.
Humans ; Pulmonary Disease, Chronic Obstructive/complications* ; CD8-Positive T-Lymphocytes/metabolism* ; Male ; Female ; Aged ; Middle Aged ; Interferon-gamma/metabolism* ; Interleukin-1/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Lung Diseases, Fungal/complications* ; Bronchoalveolar Lavage Fluid/chemistry* ; Perforin/metabolism* ; Pneumonia/immunology* ; Granzymes/metabolism*

Objective To investigate the differences of type 2 innate lymphocytes (ILC2) and interlukin 9 (IL-9) between chronic lymphocytic leukemia (CLL) patients and healthy controls, and to understand the effects of ILC2 on the function of regulatory T cells (Tregs), CD8⁺ T cells and CLL cells through IL-9. Methods Flow cytometry was used to detect the levels of ILC2 and Tregs in the peripheral blood of 45 newly diagnosed CLL patients and 24 healthy controls, and the expressions of granzyme B and perforin in CD8⁺ T cells in the peripheral blood of 28 patients and 15 healthy controls; ELISA was used to detect the level of IL-9 in the serum. ILC2 of patients and healthy controls was sorted by immunomagnetic beads and cultured separately, and the level of IL-9 in the culture supernatant was measured by ELISA. ILC2 sorted from CLL patients and healthy control-derived peripheral blood mononuclear cells(PBMCs) were co-cultured with the B cell leukemia MEC-1 cells, one group was supplemented with IL-9 antibody and the other group was not. After 72 hours of culture, the ratio of Tregs, programmed death 1 (PD-1), T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), cytotoxic T lymphocyte antigen 4 (CTLA-4) on Tregs, granzyme B and perforin in CD8⁺ T cells were measured by flow cytometry, IL-9 level of the culture supernatant was measured by ELISA, the apoptosis of MEC-1 cells was measured by Annexin V-PI. Results Compared with the healthy control group, the levels of ILC2, Tregs and IL-9 in the CLL group increased significantly. The levels of granzyme B and perforin in CD8⁺ T cells were positively correlated in the peripheral blood of CLL patients. Compared with the healthy control group, IL-9 levels in the supernatant of sorted ILC2 from CLL patients increased. In the anti-IL9 antibody group, the level of PD-1 and TIGIT on Tregs decreased, and the level of granzyme B in CD8⁺ T cells increased significantly. The level of IL-9 in the anti-IL9 antibody group decreased statistically. And MEC-1 cells showed increased early apoptotic rate in the anti-IL9 antibody group statistically. Conclusion In CLL, ILC2 affects CD8⁺ T cells and Tregs through IL-9, which weakens the anti-tumor effect of CD8⁺ T cells, enhances the immunosuppressive effect of Tregs, and plays a role in the occurrence and development of CLL disease.
Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/immunology* ; CD8-Positive T-Lymphocytes/immunology* ; T-Lymphocytes, Regulatory/immunology* ; Middle Aged ; Male ; Female ; Interleukin-9/blood* ; Aged ; Granzymes/metabolism* ; Perforin/metabolism* ; Immunity, Innate ; Adult ; Lymphocytes/immunology*

OBJECTIVE: To investigate the effect of iron overload on the expression of programmed death-1 (PD-1) on the surface of T lymphocyte in mice, in order to analyze the mechanism of iron overload inhibiting T cell function. METHODS: Flow cytometry was used to detect the labile iron pool (LIP), reactive oxygen species (ROS), and the expression of PD-1 in peripheral blood T cells in mice with iron overload. RESULTS: The mean fluorescence intensity of calcein in T cells of mice in iron overload group was 2 492±311.1, which was significantly lower than 3 136±537.3 in the control group ( P <0.01), suggesting that increased LIP in iron overload group. Compared with the control group, the ratio of CD4/CD8 of peripheral blood T cells was normal or increased in iron overload group. The level of ROS in T cells was 2 452±393.3 in iron overload group, which was significantly increased compared to 1 874±121.8 in the control group ( P <0.001). The expression of PD-1 on the surface of T cells was significantly increased. The percentage of PD-1⁺ cells in CD8⁺T cells was (12.97±6.92)% and (6.18±2.95)% in iron overload group and control group, respectively ( P <0.05), and that in CD8^-T cells was (33.55±15.69)% and (12.51±4.11)% ( P <0.001). CONCLUSION The expression of PD-1 on peripheral blood T cells in mice with iron overload is significantly increased, which may be involved in inhibiting T cell effector function.
Animals ; Mice ; Programmed Cell Death 1 Receptor/metabolism* ; Iron Overload/metabolism* ; Reactive Oxygen Species/metabolism* ; T-Lymphocytes/metabolism* ; Flow Cytometry ; Iron ; CD8-Positive T-Lymphocytes/metabolism*

OBJECTIVE: To investigate the correlation between platelet alloantibodies and CD8⁺ T cell with platelet desialylation and apoptosis in platelet transfusion refractoriness(PTR). METHODS: The expression of RCA-1, CD62P and Neu1 on platelets were detected in 135 PTR patients and 260 healthy controls. The ability of PTR patients' sera with anti-HLA antibody, anti-CD36 antibody and antibody-negative groups to induce platelet desialylation and apoptosis, and the potential effect of FcγR inhibitors on desialylation and apoptosis were evaluated. Additionally, the association between CD8⁺ T cells and platelet desialylation in patients was analyzed. RESULTS: The expression of RCA-1 and Neu1 on platelets in PTR patients were significantly higher than those in healthy donors（P < 0.05）, but were not related to platelet alloantibody (P >0.05). The sera of PTR patients generally induced platelet desialylation in vitro （P < 0.05）, with no significant differences among the groups（P >0.05）. However, the sera with anti-CD36 antibodies could induce platelet apoptosis significantly higher than that in the anti-HLA antibody group and antibody-negative group in vitro (P < 0.05). In PTR patients with anti-CD36 antibodies, platelet apoptosis was dependent on FcγR signaling, while desialylation is not. Moreover, CD8⁺ T cells in PTR patients were significantly associated with platelet desialylation (P < 0.05). CONCLUSION Platelet desialylation is a common pathological phenomenon in PTR patients， which involves the participation of CD8⁺ T cell, but isn't associated with platelet alloantibody; while anti-CD36 antibodies have potential clinical significance in predicting platelet apoptosis in PTR patients.
Humans ; Apoptosis ; CD8-Positive T-Lymphocytes/immunology* ; Blood Platelets/metabolism* ; Platelet Transfusion ; Isoantibodies ; Male ; Female ; Middle Aged

Extensive epigenetic reprogramming involves in memory CD8+ T-cell differentiation. The elaborate epigenetic rewiring underlying the heterogeneous functional states of CD8+ T cells remains hidden. Here, we profile single-cell chromatin accessibility and map enhancer-promoter interactomes to characterize the differentiation trajectory of memory CD8+ T cells. We reveal that under distinct epigenetic regulations, the early activated CD8+ T cells divergently originated for short-lived effector and memory precursor effector cells. We also uncover a defined epigenetic rewiring leading to the conversion from effector memory to central memory cells during memory formation. Additionally, we illustrate chromatin regulatory mechanisms underlying long-lasting versus transient transcription regulation during memory differentiation. Finally, we confirm the essential roles of Sox4 and Nrf2 in developing memory precursor effector and effector memory cells, respectively, and validate cell state-specific enhancers in regulating Il7r using CRISPR-Cas9. Our data pave the way for understanding the mechanism underlying epigenetic memory formation in CD8+ T-cell differentiation.
CD8-Positive T-Lymphocytes/metabolism* ; Cell Differentiation ; Chromatin/immunology* ; Animals ; Mice ; Immunologic Memory ; Epigenesis, Genetic ; SOXC Transcription Factors/immunology* ; NF-E2-Related Factor 2/immunology* ; Mice, Inbred C57BL ; Gene Regulatory Networks ; Enhancer Elements, Genetic

BACKGROUND: One of the most important treatment modalities for non-small cell lung cancer (NSCLC) is immune checkpoint inhibitor. Nevertheless, a small percentage of patients do not respond well to these therapies, highlighting the significance of identifying important CD8+ T cell subsets for immunotherapy and creating trustworthy biomarkers. The purpose of this study is to assess the potential utility of TIM3+CD8+ T cells as new biomarkers by examining their expressions in various areas of the NSCLC tumor microenvironment. METHODS: Based on biopsy techniques, tumor tissue samples were obtained from patients with NSCLC and categorized into tumor central and non-central regions. Using flow cytometry, the infiltration of TIM3+CD8+ T cells and the surface expression of programmed cell death 1 (PD-1) on these cells were examined, and their correlations with the effectiveness of immunotherapy were assessed. RESULTS: The non-central region of tumor tissues had considerably larger infiltration of TIM3+CD8+ T lymphocytes compared to the non-central region (P<0.0001). This pattern was found in both subgroups with tumor diameters ≥3 cm or <3 cm (P<0.01). In comparison to TIM3-CD8+ T cells, TIM3+CD8+ T cells showed higher levels of PD-1 (P<0.001), with more PD-1+TIM3+CD8+ T cells invading the non-central region (P<0.01). Clinical responders to immunotherapy had considerably lower infiltration levels of TIM3+CD8+ T cells in the tumor non-central region compared to non-responders, with lower levels correlated with better clinical outcomes (P<0.01), while no correlation was identified in the tumor central region (P>0.05). According to reciever operating characteristic (ROC) curve analysis, TIM3+CD8+ T cells in the tumor non-central region had an area under the curve (AUC) of 0.9375 for predicting the effectiveness of immunotherapy, which was considerably higher than that of TIM3+CD8+ T cells in the tumor central region and programmed cell death ligand 1 (PD-L1) [tumor proportion score (TPS)]. CONCLUSIONS In the tumor microenvironment of NSCLC, TIM3+CD8+ T cells show regional distribution patterns. The expression of this cell population in the non-central region of the tumor microenvironment may be a biomarker for predicting the effectiveness of immunotherapy.
Humans ; Carcinoma, Non-Small-Cell Lung/metabolism* ; Lung Neoplasms/metabolism* ; Hepatitis A Virus Cellular Receptor 2/immunology* ; Tumor Microenvironment/immunology* ; CD8-Positive T-Lymphocytes/metabolism* ; Male ; Female ; Middle Aged ; Aged ; Adult ; Programmed Cell Death 1 Receptor/metabolism* ; Immunotherapy ; Clinical Relevance