Infiltration and activation of peripheral immune cells are critical in the progression of multiple sclerosis and its experimental animal model, experimental autoimmune encephalomyelitis (EAE). This study investigates the role of high mobility group box 1 (HMGB1) in oligodendrocyte precursor cells (OPCs) in modulating pathogenic T cells infiltrating the central nervous system through the blood-brain barrier (BBB) by using OPC-specific HMGB1 knockout (KO) mice. We found that HMGB1 released from OPCs promotes BBB disruption, subsequently allowing increased immune cell infiltration. The migration of CD4+ T cells isolated from EAE-induced mice was enhanced when co-cultured with OPCs compared to oligodendrocytes (OLs). OPC-specific HMGB1 KO mice exhibited lower BBB permeability and reduced immune cell infiltration into the CNS, leading to less damage to the myelin sheath and mitigated EAE progression. CD4+ T cell migration was also reduced when co-cultured with HMGB1 knock-out OPCs. Our findings reveal that HMGB1 secretion from OPCs is crucial for regulating immune cell infiltration and provides insights into the immunomodulatory function of OPCs in autoimmune diseases.
Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; HMGB1 Protein/deficiency* ; Mice, Knockout ; Oligodendrocyte Precursor Cells/immunology* ; Mice, Inbred C57BL ; CD4-Positive T-Lymphocytes/immunology* ; Cell Movement ; Blood-Brain Barrier/immunology* ; Mice ; Myelin Sheath/pathology* ; Disease Models, Animal ; Coculture Techniques ; Oligodendroglia/metabolism* ; Female ; Cells, Cultured

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

Cytotoxic CD4⁺ T cells (CD4⁺ CTLs) represent a novel subset of T cells with cytotoxic effects. They recognize target cells in an antigen-specific manner, relying on class II major histocompatibility complex (MHC-II) interactions. CD4⁺ CTLs exert cytotoxic effects on target cells by secreting cytotoxic molecules such as granzymes, perforin, and granulysin. Recent studies have revealed their significant roles in various autoimmune diseases. This review focuses on the differentiation, phenotypic characteristics, and roles of CD4⁺ CTLs in different types of autoimmune disorders, aiming to provide new insights for the prevention and treatment of these diseases.
Humans ; Autoimmune Diseases/immunology* ; CD4-Positive T-Lymphocytes/immunology* ; Animals ; T-Lymphocytes, Cytotoxic/immunology* ; Perforin/immunology* ; Granzymes/immunology*

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 This study aimed to analyze the characteristics and clinical significance of peripheral lymphocytic subsets and cytokine levels, including interleukin 1β(IL-1β), IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12P70, IL-17A, tumor necrosis factor α(TNF-α), interferon γ(IFN-γ) and IFN-α, in patients with primary biliary cholangitis (PBC), to provide some novel insights into the pathogenesis of PBC. Methods We retrospectively collected clinical features and laboratory data from hospitalized patients who were primarily diagnosed with PBC and from healthy physical examinees at the Third People's Hospital of Changzhou between January 1, 2023, and June 30, 2024. Results A total of 152 PBC patients and 96 healthy controls who met the inclusion and exclusion criteria were enrolled. Significant differences were observed in baseline characteristics and laboratory data between the two groups. After the propensity score matching (PSM) analysis, 61 PBC patients and 61 healthy controls were successfully matched, ensuring that the general characteristics (age and gender) of the two groups were balanced and comparable. Compared to the control group, the proportion of peripheral lymphocytes was significantly higher in the PBC group (31.9% vs. 17.8%), primarily due to an increase in CD4⁺ T cells (46.77% vs. 41.19%), while CD8⁺T cells were significantly decreased (19.73% vs. 22.07%). Notably, the proportions of CD4⁺ programmed cell death 1 (PD-1)⁺ T and CD8⁺PD-1⁺ T cells were elevated, with CD8⁺PD-1⁺ T cells showing a significant positive correlation with the severity of liver inflammation (r=0.41). Furthermore, the mitochondrial mass (MM) of CD4⁺ T cells was significantly increased in PBC patients, whereas no significant changes were observed in the MM of CD8⁺ T cells or the mitochondrial membrane potential (MMP) of CD3⁺ T cells. Additionally, the plasma levels of cytokines, such as IL-4, IL-8, IL-10 and IFN-α, were abnormally elevated. The plasma levels of IL-5 and IL-1β were negatively correlated with the stage of liver fibrosis in patients with PBC (r=-0.52). Conclusion The overactivation and proliferation of CD4⁺ T cells, along with the suppression of CD8⁺ T cell function and increased PD-1 expression leads to T cell exhaustion, indicating significant immunological alterations in PBC patients. These changes are closely associated with the disease progression. Additionally, cytokines are likely involved in the immune regulation process of PBC and may influence the pathogenic mechanisms of the disease. Regular monitoring of lymphocyte subsets and cytokine levels can help assess the immune status and disease activity in patients with PBC, thereby guiding the individualized treatment strategies.
Humans ; Male ; Female ; Middle Aged ; Liver Cirrhosis, Biliary/blood* ; Retrospective Studies ; T-Lymphocyte Subsets/immunology* ; Aged ; Cytokines/blood* ; Adult ; CD8-Positive T-Lymphocytes/immunology*

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

Hepatitis B virus (HBV)-specific CD8⁺ T cells play a central role in controlling HBV infection; however, their function is impaired during chronic HBV infection, manifesting as a state of dysfunction. Recent studies have revealed that CD8⁺ T cell dysfunction in chronic HBV infection differs from the classical exhaustion observed in other viral infections or tumors. In 2024, several pivotal studies further elucidated novel mechanisms underlying CD8⁺ T cell dysfunction in chronic HBV infection and identified new therapeutic targets, including 4-1BB and transforming growth factor-beta (TGF-β). This review, while elucidating the dysfunction of CD8⁺ T cells in chronic HBV infection and its underlying mechanisms, focuses on summarizing the key findings from these latest studies and explores their translational value and clinical significance.
Humans ; Hepatitis B, Chronic/virology* ; CD8-Positive T-Lymphocytes/immunology* ; Hepatitis B virus/physiology* ; Animals ; Transforming Growth Factor beta/immunology*

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*