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*

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 ATP synthase inhibitory factor 1 (ATPIF1) on the antitumor activity of chimeric antigen receptor (CAR)-NK92 cells. Methods HER2-targeted CAR-NK92 cells with ATPIF1 overexpression or knockdown were constructed. CAR-positive expression rate was detected by flow cytometry. Cell proliferation capacity was measured using CCK-8 assay. Glycolytic capacity was analyzed by Seahorse metabolic analyzer. Mitochondrial membrane potential levels were detected using JC-1 probe. Target cell lysis rate was evaluated by firefly luciferase reporter assay. Expression levels of CD107a, natural-killer group 2 member D (NKG2D), granzyme B (GzmB), perforin, and interleukin 2 (IL-2) were detected via flow cytometry. Quantitative real-time PCR was used to measure the expression of interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), tumor necrosis factor α (TNF-α), ATPIF1, and hexokinase 1 (HK1). The impact of glycolytic inhibition by 2-Deoxy-D-glucose (2-DG) on CAR-NK92 antitumor capacity was examined. Results Successfully generated HER2-targeting control CAR-NK92 cells, as well as ATPIF1-overexpressing and ATPIF1 knockdown CAR-NK92 cells. The ATPIF1-overexpressing CAR-NK92 cells showed significantly enhanced target cell lysis rate, elevated expression levels of NKG2D and CD107a, increased secretion capacities of Granzyme B (GzmB) and IL-2, and upregulated mRNA expression levels of IFIT1 and TNF-α, while ATPIF1-knockdown cells exhibited opposite effects. ATPIF1 overexpression induced metabolic reprogramming in CAR-NK92 cells, manifested by significantly decreased mitochondrial membrane potential (δpsim), markedly upregulated HK1 mRNA expression, and enhanced basal glycolysis and glycolytic capacity. After glycolysis inhibition with 2-DG (5 μmol/L), both ATPIF1-overexpressing and knockdown CAR-NK92 cells showed no significant differences in NKG2D and CD107a expression levels compared to control cells. Conclusion ATPIF1 regulates the antitumor activity of CAR-NK92 cells through modulating glycolytic metabolism. Overexpression of ATPIF1 can enhance the antitumor efficacy of CAR-NK92 cells.
Humans ; Glycolysis ; Killer Cells, Natural/metabolism* ; Receptors, Chimeric Antigen/immunology* ; Granzymes/genetics* ; Hexokinase/metabolism* ; Cell Line, Tumor ; Interleukin-2/genetics* ; Cell Proliferation ; NK Cell Lectin-Like Receptor Subfamily K/genetics* ; Membrane Potential, Mitochondrial

OBJECTIVE: To explore the effect and mechanism of DNA methyltransferase 1 (DNMT1) knockout on the inhibition of acute myeloid leukemia (AML) by natural killer (NK) cells. METHODS: The peripheral blood NK cells of AML patients and controls were collected, and the mRNA and protein level of DNMT1 were measured by PCR and Western blot, respectively. The <i>DNMT1i> knockout mice were constructed to obtain NK^DNMT1-/- cells. The NK cells were stimulated with interleukin (IL)-12, IL-15, and IL-18 to construct memory NK cells, and then the interferon-γ (IFN-γ) levels were measured by ELISA. After co-culturing with memory NK cells and HL60 cells, the killing effect of NK^DNMT1-/- cells on HL60 cells was detected by LDH assay. Then, the HL60 cell apoptosis and NK cell NKG2D level were measured by flow cytometry. The perforin and granzyme B protein levels of NK cells were measured by Western blot. The AML model mice were constructed by injecting HL60 cells into the tail vein, meanwhile, memory NK cells were also injected, and then the mouse weights, CD33 positive rates, and survival time were detected. RESULTS: The mRNA and protein levels of DNMT1 in NK cells of AML patients were significantly higher than those in the control group (both <i>Pi> < 0.01), while the IFN-γ level induced by interleukin was significantly lower than that in the control group (<i>Pi> < 0.05). Compared with NK^DNMT1+/+ cells, the ability of NK^DNMT1-/- cells to secrete IFN-γ after interleukin stimulation was significantly increased (<i>Pi> < 0.05). The killing and apoptosis-inducing effects of NK^DNMT1-/- cells on HL60 cells were significantly stronger than those of NK^DNMT1+/+ cells (both <i>Pi> < 0.05). The NKG2D level and expression of perforin and granzyme B of NK^DNMT1-/- cells were significantly increased compared with NK^DNMT1+/+ cells (all <i>Pi> < 0.05). Compared with AML mice injected with NK^DNMT1+/+ cells, AML mice injected with NK^DNMT1-/- cells showed significantly increased body weight, decreased CD33 positive rate, and prolonged survival time (all <i>Pi> < 0.05). CONCLUSION Knocking out <i>DNMT1i> can enhance the inhibitory effect of NK cells on AML, which may be related to enhancing NK cell memory function.
Killer Cells, Natural/metabolism* ; Animals ; Leukemia, Myeloid, Acute ; Humans ; DNA (Cytosine-5-)-Methyltransferase 1 ; Mice ; Mice, Knockout ; HL-60 Cells ; Apoptosis ; Interferon-gamma/metabolism* ; Granzymes/metabolism* ; Perforin/metabolism* ; NK Cell Lectin-Like Receptor Subfamily K/metabolism*

OBJECTIVE: It has been reported that the mRNA expression of serine protease 23 (PRSS23) was increased in skin fibroblasts from systemic sclerosis patients (SSc). The purpose of this study is to explore the pathogenetic effect and mechanism of PRSS23 in skin fibrosis of SSc. METHODS: The expression of PRSS23 in skin tissues from the SSc patients and healthy controls was detected by immunohisto-chemistry. Fibroblasts isolated from fresh skin tissue were used to detect the expression of PRSS23 by real-time quantitative PCR (RT-qPCR) and Western blot. Overexprssion of PRSS23 in BJ, the fibroblasts cell line of skin, was constructed by lentivirus. After stimulation with 400 μmol/L hydrogen peroxide for 12 h, Annexin V/7-AAD staining was used to detect apoptosis of fibroblasts; flow cytometry and Western blot were used to detect the expression of apoptosis-related protein cleaved Caspase-3. The expression of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in fibroblasts was detected by RT-qPCR and enzyme linked immunosorbent assay (ELISA). RESULTS: Compared with the healthy controls, the expression of PRSS23 in skin tissues of the SSc patients was significantly increased [4.952 (3.806-5.439) <i>vsi>. 0.806 (0.395-1.173), <i>Pi> < 0.001], and fibroblast was the main cell that expressed PRSS23. The mRNA [27.59 (25.02-30.00) <i>vsi>. 1.00, <i>Pi> < 0.001] and protein [0.675 (0.587-0.837) <i>vsi>. 0.451 (0.342-0.502), <i>Pi>=0.029] of PRSS23 in skin fibroblasts isolated from the SSc patients were significantly up-regulated. Compared with the control group, the anti-apoptotic ability of skin fibroblasts overexpressing PRSS23 was enhanced, and the proportion of apoptotic cells was significantly reduced after hydrogen peroxide induction [(5.043±1.097)% <i>vsi>. (17.480±3.212)%, <i>Pi>=0.022], the expression of apoptosis-related protein cleaved Caspase-3 was also markedly reduced [(0.718±0.022) <i>vsi>. (1.422±0.105), <i>Pi>=0.003]. In addition, the mRNA [(99.780±1.796) <i>vsi>. (1.000±0.004), <i>Pi> < 0.001] and protein [(211.600±2.431) ng/L <i>vsi>. (65.930±1.768) ng/L, <i>Pi> < 0.001] of IL-6 in the fibroblasts overexpressing PRSS23 were significantly up-regulated; the mRNA[(3.555±0.555) <i>vsi>. (1.000±0.004), <i>Pi> < 0.001] and protein levels [(41.190±0.949) ng/L <i>vsi>. (31.150±0.360) ng/L, <i>Pi> < 0.001] of TNF-α in the fibroblasts overexpressing PRSS23 were also significantly up-regulated. CONCLUSION The expression of PRSS23 is increased in skin fibroblasts of SSc patients. PRSS23 can inhibit cell apoptosis, promote the secretion of inflammatory factors such as IL-6 and TNF-α, and regulate the process that skin fibroblasts transform into pro-inflammatory type. So, PRSS23 is associated with the development of skin fibrosis.
Humans ; Scleroderma, Systemic/enzymology* ; Fibroblasts/pathology* ; Apoptosis ; Skin/metabolism* ; Fibrosis ; Interleukin-6/metabolism* ; Caspase 3/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Male ; Female ; Cells, Cultured ; RNA, Messenger/metabolism* ; Middle Aged ; Adult ; Serine Endopeptidases/genetics*

Endotoxins are common exogenous pyrogens. Excessive endotoxins in medical devices and injections can lead to serious consequences such as sepsis, septic shock, and even death. Therefore, endotoxin detection plays a crucial role in medical, pharmaceutical, and food sectors. The wide application of <i>Limulusi> amebocyte lysate (LAL) has led to a sharp decline in the number of horseshoe crabs. Moreover, the LAL assay has limitations such as interbatch variations and difficulty in quantification. The recombinant factor C (rFC) assay is stable between batches, highly sensitive, and capable of quantitation, and thus it can be used as an alternative for the LAL assay. However, the high cost and complex procedures involved in producing recombinant factor C have limited the widespread application of this method. In order to simplify the preparation and reduce the production cost of recombinant factor C, this study focuses on the production of recombinant factor C based on the baculovirus expression system. Multiple measures such as a high-yield and anti-apoptotic vector qBac-IIIG, the optimal signal peptide, and the optimized codon were used to reach the goal of endotoxin detection with cell supernatant. This method simplifies the steps of protein purification. The sensitivity of the supernatant reached 0.05 EU/mL in a 1-L fermentation system, and 500 000 detecting reactions can be supported per liter of fermentation broth. This study increases the yield and activity of recombinant factor C, simplifies the procedures of protein purification, and reduces the cost, laying a foundation for the promotion and application of recombinant factor C in endotoxin detection.
Animals ; Recombinant Proteins/genetics* ; Horseshoe Crabs/chemistry* ; Baculoviridae/metabolism* ; Endotoxins/analysis* ; Protein C/biosynthesis* ; Genetic Vectors/genetics* ; Arthropod Proteins/genetics* ; Enzyme Precursors ; Serine Endopeptidases

The study aims to investigate the impacts of prolyl oligopeptidase (POP) on the replication of foot-and-mouth disease virus (FMDV) in BHK-21 cells. Firstly, the effects of FMDV replication on POP expression in BHK-21 cells were analyzed by Western blotting and Real-time reverse transcription polymerase chain reaction (RT-qPCR). Secondly, a eukaryotic expression plasmid for POP was constructed, and the effects of POP overexpression on the replication of two different serotypes of FMDV were assessed by Western blotting, RT-qPCR, and virus titer assays. Thirdly, specific small interfering RNAs (siRNAs) targeting <i>POPi> were synthesized, and their efficiency in interfering with endogenous POP expression was identified by RT-qPCR. The impacts of downregulating endogenous POP expression on FMDV replication were further evaluated by Western blotting, RT-qPCR, and virus titer assays. The results indicated that FMDV infection did not significantly affect POP expression in BHK-21 cells. Overexpression of POP dose-dependently enhanced the replication of both FMDV/O and FMDV/A serotypes. Conversely, siRNA-mediated downregulation of endogenous POP expression markedly suppressed FMDV/O replication. This study is the first to demonstrated that the role of the host POP protein in promoting FMDV replication in BHK-21 cells, thereby providing a critical theoretical foundation and potential molecular targets for developing efficient candidate cell strains for foot-and-mouth disease inactivated vaccines.
Foot-and-Mouth Disease Virus/genetics* ; Virus Replication/genetics* ; Prolyl Oligopeptidases ; Serine Endopeptidases/physiology* ; Animals ; Cell Line ; RNA, Small Interfering/genetics* ; Foot-and-Mouth Disease/virology* ; Cricetinae

INTRODUCTION: Pleural infections are a significant cause of mortality. Intrapleural fibrinolytic therapy (IPFT) utilising alteplase and dornase is a treatment option for patients unsuitable for surgery. The optimal dose of alteplase is unknown, and factors affecting treatment success in an Asian population are unclear. We sought to determine the factors affecting treatment success in Tan Tock Seng Hospital, Singapore and evaluate the efficacy of lower doses of IPFT. METHOD: A retrospective analysis of patients with pleural infections treated with IPFT between July 2016 and November 2023 was performed. Treatment success was defined as survival without surgery at 3 months. Data, including patient demographics; comorbidities; RAPID (renal, age, purulence, infection source and dietary factor) scores; and radiological characteristics, were extracted from medical records and analysed. Linear mixed effects model and logistic regression were performed to determine factors affecting treatment success. RESULTS: A total of 131 cases were analysed. Of these, 51 (38.9%) reported positive pleural fluid culture, and the most common organism was <i>Streptoccocus anginosusi>. Mean age was 65 years (standard deviation [SD] 15.5). Mean time from chest tube insertion to first dose of IPFT was 10.2 days (SD 11.5). Median starting dose of alteplase was 5 mg. Treatment success was reported in 112 cases (85.5%). There were no significant differences between the alteplase dose and radiological clearance. Patient age (odds ratio [OR] 0.94, confidence interval [CI] 0.89-0.98) and interval between chest tube insertion to first dose (OR 0.95, CI 0.91-0.99) were statistically significant variables for the treatment success. CONCLUSION Lower starting doses of alteplase remain effective in the treatment of pleural infection. Early IPFT may result in better outcomes.
Humans ; Tissue Plasminogen Activator/therapeutic use* ; Retrospective Studies ; Aged ; Fibrinolytic Agents/therapeutic use* ; Male ; Female ; Middle Aged ; Thrombolytic Therapy/methods* ; Treatment Outcome ; Singapore ; Pleural Effusion/drug therapy* ; Pleural Diseases/drug therapy* ; Cohort Studies ; Chest Tubes ; Deoxyribonuclease I ; Recombinant Proteins

OBJECTIVE: To investigate the safety and effectiveness of balloon occlusion and intra-sac thrombin injection in the endovascular repair of ruptured abdominal aortic aneurysm. METHODS: From October 2019 to October 2022, the clinical data of 16 patients with rAAA treated with balloon occlusion technique and intra-sac thrombin injection combined with EVAR were retrospectively analyzed, including 13 males and 3 females, aged 42-85 years, with a median age of 70.5 years. The time of preoperative first aid (from hospital arrival to operation start), average operation time, stay in intensive care unit (ICU), average hospitalization time, success rate of surgical treatment, perioperative (30 d) mortality rate, incidence of complications, the maximum diameter and volume change of the aneurysm were observed and recorded. RESULTS: Among the 16 patients with ruptured abdominal aortic aneurysm, the technical success rate was 100.0% (16/16). One patient died of multiple organ dysfunction 6 hours after operation. The success rate of surgical treatment was 93.8% (15/16). The preoperative first aid time was (53.3±6.2) min, the average operation time was (89.9±17.1) min, the stay in the intensive care unit (ICU) was (1.7±0.8) d, and the average hospitalization time was (7.8±1.3) d. The intraoperative balloon occlusion time was (32.4±4.1) min. The postoperative renal function of all the patients had no significant deterioration compared with that preoperative. Abdominal compartment syndrome (ACS) occurred in 1 patient after operation, which improved after CT puncture and drainage. The median follow-up time was 36 months. During the follow-up period, 1 patient died of acute myocardial infarction 2 years after operation, and the remaining 14 patients survived. Among the 14 follow-up patients, 1 type Ⅱ endoleak occurred, and no other types of endoleak occurred. By the end of the follow-up, the maximum diameter of the aneurysm sac in 14 patients was significantly lower than that before operation [(44.6±8.0) mm <i>vs.i>(66.0±15.5) mm, <i>Pi> < 0.001], and in 12 patients with CTA, the volume of the aneurysm sac was significantly shrunk than that before operation [(311.7±170.3) mm³ <i>vsi>. (168.6±68.1) mm³, <i>Pi> < 0.05]. CONCLUSION Balloon occlusion during endovascular repair is safe and effective in the treatment of ruptured abdominal aortic aneurysm; intraoperative thrombin injection of the aneurysm sac can significantly reduce the incidence of intraoperative and postoperative abdominal compartment syndrome and endoleak and, to a certain extent, improve the success rate of treatment.
Humans ; Male ; Female ; Aged ; Balloon Occlusion/methods* ; Aortic Aneurysm, Abdominal/surgery* ; Thrombin/administration & dosage* ; Retrospective Studies ; Aged, 80 and over ; Middle Aged ; Aortic Rupture ; Endovascular Procedures/methods* ; Adult ; Treatment Outcome ; Operative Time