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 DNMT1 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 P < 0.01), while the IFN-γ level induced by interleukin was significantly lower than that in the control group (P < 0.05). Compared with NK^DNMT1+/+ cells, the ability of NK^DNMT1-/- cells to secrete IFN-γ after interleukin stimulation was significantly increased (P < 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 P < 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 P < 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 P < 0.05). CONCLUSION Knocking out DNMT1 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 To explore the effect of formononetin on immunity of mice with transplanted H22 hepatocarcinoma. Methods Male C57BL/6 mice were subcutaneously inoculated with H22 cells (4×10⁵) to establish a tumor-bearing mouse model. The mice were treated with formononetin [10 mg/(kg.d)] or [50 mg/(kg.d)] for 28 days, and then the tumor inhibition rate was calculated. Carrilizumab was used as a positive control drug. The expressions of CD8, granzyme B and forkbox transcription factor 3 (FOXP3) in HCC tissues were analyzed by immunohistochemical staining. The mRNA and protein expression of programmed cell death protein 1 (PD-1) and its ligand 1 (PD-L1) in HCC tissues were detected by real-time PCR or Western blot analysis, respectively. The serum levels of interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) were detected by ELISA. Results Formononetin increased the tumor inhibition rate and the positive rate of CD8 and granzyme B staining in tumor-bearing mice. There was no significant difference in the positive rate of FOXP3 staining in tumor tissues of mice in each group. Formononetin decreased the levels of IL-10 and TGF-β in serum of tumor-bearing mice, and decreased the relative expression of mRNA and protein of PD-1 and PD-L1 in tumor tissue of tumor-bearing mice. Conclusion Formononetin can activate CD8⁺ T cells and reduce the release of immunosuppressive factors in regulatory T cells by blocking PD-1/PD-L1 pathway and play an antitumor role.
Male ; Animals ; Mice ; Carcinoma, Hepatocellular/pathology* ; Liver Neoplasms/genetics* ; Interleukin-10/genetics* ; B7-H1 Antigen ; Granzymes/genetics* ; Programmed Cell Death 1 Receptor/metabolism* ; CD8-Positive T-Lymphocytes/metabolism* ; Mice, Inbred C57BL ; Transforming Growth Factor beta/genetics* ; RNA, Messenger/metabolism* ; Forkhead Transcription Factors/genetics* ; Cell Line, Tumor

Objective This study aims to construct and identify the chimeric antigen receptor NK92 (CAR-NK92) cells targeting NKG2D ligand (NKG2DL) (secreting IL-15Ra-IL-15) and verify the killing activity of NKG2D CAR-NK92 cells against multiple myeloma cells. Methods The extracellular segment of NKG2D was employed to connect 4-1BB and CD3Z, as well as IL-15Ra-IL-15 sequence to obtain a CAR expression framework. The lentivirus was packaged and transduced into NK92 cells to obtain NKG2D CAR-NK92 cells. The proliferation of NKG2D CAR-NK92 cells was detected by CCK-8 assay, IL-15Ra secretion was detected by ELISA and killing efficiency was detected by lactate dehydrogenase (LDH) assay. The molecular markers of NKp30, NKp44, NKp46, the ratio of apoptotic cell population, CD107a, and the secretion level of granzyme B and perforin were detected using flow cytometry. In addition, the cytotoxic mechanism of NKG2D CAR-NK92 cells on the tumor was verified by measuring the degranulation ability. Moreover, after NKG2D antibody inhibited effector cells and histamine inhibited tumor cells, LDH assay was utilized to detect the effect on cell-killing efficiency. Finally, the multiple myeloma tumor xenograft model was constructed to verify its anti-tumor activity in vivo. Results Lentiviral transduction significantly increased NKG2D expression in NK92 cells. Compared with NK92 cells, the proliferation ability of NKG2D CAR-NK92 cells was weaker. The early apoptotic cell population of NKG2D CAR-NK92 cells was less, and NKG2D CAR-NK92 cells had stronger cytotoxicity to multiple myeloma cells. Additionally, IL-15Ra secretion could be detected in its culture supernatant. NKp44 protein expression in NKG2D CAR-NK92 cells was clearly increased, demonstrating an enhanced activation level. Inhibition test revealed that the cytotoxicity of CAR-NK92 cells to MHC-I chain-related protein A (MICA) and MICB-positive tumor cells was more dependent on the interaction between NKG2D CAR and NKG2DL. After stimulating NKG2D CAR-NK92 cells with tumor cells, granzyme B and perforin expression increased, and NK cells obviously upregulated CD107α. Furthermore, multiple myeloma tumor xenograft model revealed that the tumors of mice treated with NKG2D CAR-NK92 cells were significantly reduced, and the cell therapy did not sensibly affect the weight of the mice. Conclusion A type of CAR-NK92 cell targeting NKG2DL (secreting IL-15Ra-IL-15) is successfully constructed, indicating the effective killing of multiple myeloid cells.
Humans ; Mice ; Animals ; Receptors, Chimeric Antigen/genetics* ; Interleukin-15 ; NK Cell Lectin-Like Receptor Subfamily K/metabolism* ; Granzymes ; Cell Line, Tumor ; Multiple Myeloma/therapy* ; Perforin

Primary central nervous system lymphoma of T-cell origin (T-PCNSL) is rare, and its clinicopathological features remain unclear. Peripheral T-cell lymphoma of γδ T-cell origin is an aggressive lymphoma mainly involving extranodal sites. Here, we report a case of γδ T-PCNSL involving the intramedullary spinal cord and presenting with paraplegia. A 75-year-old Korean woman visited the hospital complaining of back pain and lower extremity weakness. Magnetic resonance imaging revealed multifocal enhancing intramedullary nodular lesions in the thoracic and lumbar spinal cord. An enhancing nodular lesion was observed in the periventricular white matter of the lateral ventricle in the brain. There were no other abnormalities in systemic organs or skin. Laminectomy and tumor removal were performed. The tumor consisted of monomorphic, medium-to-large atypical lymphocytes with pale-to-eosinophilic cytoplasm. Immunohistochemically, the tumor cells were CD3(+), TCRβF1(-), TCRγ(+), CD30(-), CD4(-), CD8(-), CD56(+), TIA1(+), granzyme B(+), and CD103(+). Epstein-Barr virus in situ was negative. This case represents a unique T-PCNSL of γδ T-cell origin involving the spinal cord.
Aged ; Back Pain ; Brain ; Central Nervous System ; Cytoplasm ; Female ; Granzymes ; Herpesvirus 4, Human ; Humans ; Laminectomy ; Lateral Ventricles ; Lower Extremity ; Lymphocytes ; Lymphoma ; Lymphoma, T-Cell ; Lymphoma, T-Cell, Peripheral ; Magnetic Resonance Imaging ; Paraplegia ; Skin ; Spinal Cord Diseases ; Spinal Cord ; T-Lymphocytes ; White Matter

Peripheral T cell lymphoma, unspecified (PTCL-U) comprises a heterogenous group of mature T-cell lymphomas that do not match with any defined T-cell entities in the current classification system. A 68-year-old man presented with extensive erythematous to brownish ulcerative tumors with yellowish discharge on the neck, trunk, and both upper extremities that had persisted for the past 7 months. Histological findings showed medium- to large-sized pleomorphic lymphocytes with cellular atypia infiltrating the deep dermis and subcutis. Immunohistochemical analysis of specimens from this patient revealed positive staining for CD2, CD45, and granzyme B and mildly positive staining for CD3, CD4, CD30, and CD79a. Based on these clinico-pathological findings, the patient was finally diagnosed with PTCL-U. We report herein a rare case of PTCL-U presenting as multiple ulcerative tumors.
Aged ; Classification ; Dermis ; Granzymes ; Humans ; Lymphocytes ; Lymphoma, T-Cell ; Lymphoma, T-Cell, Peripheral ; Neck ; T-Lymphocytes ; Ulcer ; Upper Extremity

PURPOSE: The tumor microenvironment is known to be associated with the metabolic activity of cancer cells and local immune reactions. We hypothesized that glucose metabolism measured by 2-deoxy-2-(¹⁸F)fluoro-D-glucose (¹⁸F-FDG) positron emission tomography (PET)-computed tomography (CT) (¹⁸F-FDG PET-CT) would be associated with local immune responses evaluated according to the presence of tumor infiltrating lymphocytes (TILs). MATERIALS AND METHODS: We retrospectively reviewed 56 patients who underwent ¹⁸F-FDG PET-CT prior to gastrectomy. In resected tumor specimens, TIL subsets, including cluster of differentiation (CD) 3, CD4, CD8, Forkhead box P3 (Foxp3), and granzyme B, were subjected to immunohistochemical analysis. The prognostic nutritional index (PNI) was calculated as: (10×serum albumin value)+(0.005×peripheral lymphocyte counts). Additionally, the maximum standard uptake value (SUVmax) was calculated to evaluate the metabolic activity of cancer cells. RESULTS: The SUVmax was positively correlated with larger tumor size (R=0.293; P=0.029) and negatively correlated with PNI (R=−0.407; P=0.002). A higher SUVmax showed a marginal association with higher CD3 (+) T lymphocyte counts (R=0.227; P=0.092) and a significant association with higher Foxp3 (+) T lymphocyte counts (R=0.431; P=0.009). No other clinicopathological characteristics were associated with SUVmax or TILs. Survival analysis, however, indicated that neither SUVmax nor Foxp3 held prognostic significance. CONCLUSIONS: FDG uptake on PET-CT could be associated with TILs, especially regulatory T cells, in gastric cancer. This finding may suggest that PET-CT could be of use as a non-invasive tool for monitoring the tumor microenvironment in patients with gastric cancer.
Fluorodeoxyglucose F18 ; Gastrectomy ; Glucose ; Granzymes ; Humans ; Lymphocyte Count ; Lymphocytes ; Lymphocytes, Tumor-Infiltrating ; Metabolism ; Nutrition Assessment ; Positron-Emission Tomography ; Retrospective Studies ; Stomach Neoplasms ; T-Lymphocytes, Regulatory ; Tumor Microenvironment