BACKGROUND: Increasing evidence indicates that oxidative stress and interferon γ (IFNγ)-driven cellular immune responses are responsible for the pathogenesis of vitiligo. However, the connection between oxidative stress and the local production of IFNγ in early vitiligo remains unexplored. The aim of this study was to identify the mechanism underlying the production of IFNγ by mast cells and its impact on vitiligo pathogenesis. METHODS: Skin specimens from the central, marginal, and perilesional skin areas of active vitiligo lesions were collected to characterize changes of mast cells, CD8 + T cells, and IFNγ-producing cells. Cell supernatants from hydrogen peroxide (H 2 O 2 )-treated keratinocytes (KCs) were harvested to measure levels of soluble stem cell factor (sSCF) and matrix metalloproteinase (MMP)-9. A murine vitiligo model was established using Mas-related G protein-coupled receptor-B2 (MrgB2, mouse ortholog of human MrgX2) conditional knockout (MrgB2 -/- ) mice to investigate IFNγ production and inflammatory cell infiltrations in tail skin following the challenge with tyrosinase-related protein (Tyrp)-2 180 peptide. Potential interactions between the Tyrp-2 180 peptide and MrgX2 were predicted using molecular docking. The siRNAs targeting MrgX2 and the calcineurin inhibitor FK506 were also used to examine the signaling pathways involved in mast cell activation. RESULTS: IFNγ-producing mast cells were closely aligned with the recruitment of CD8 + T cells in the early phase of vitiligo skin. sSCF released by KCs through stress-enhanced MMP9-dependent proteolytic cleavage recruited mast cells into sites of inflamed skin (Perilesion vs . lesion, 13.00 ± 4.00/high-power fields [HPF] vs . 26.60 ± 5.72/HPF, P <0.05). Moreover, IFNγ-producing mast cells were also observed in mouse tail skin following challenge with Tyrp-2 180 (0 h vs . 48 h post-recall, 0/HPF vs . 3.80 ± 1.92/HPF, P <0.05). The IFNγ + mast cell and CD8 + T cell counts were lower in the skin of MrgB2 -/- mice than in those of wild-type mice (WT vs . KO 48 h post-recall, 4.20 ± 0.84/HPF vs . 0.80 ± 0.84/HPF, P <0.05). CONCLUSION Mast cells activated by MrgX2 serve as a local IFNγ producer that bridges between innate and adaptive immune responses against MCs in early vitiligo. Targeting MrgX2-mediated mast cell activation may represent a new strategy for treating vitiligo.
Vitiligo/metabolism* ; Mast Cells/immunology* ; Animals ; Interferon-gamma/metabolism* ; Mice ; Humans ; Melanocytes/metabolism* ; Receptors, G-Protein-Coupled/genetics* ; Mice, Knockout ; Mice, Inbred C57BL ; Male ; Female ; Matrix Metalloproteinase 9/metabolism* ; Stem Cell Factor/metabolism*

This study investigated the functions and regulatory mechanism of Portulacae Herba and its chemical components on the Toll-like receptor 4(TLR4)/myeloid differentiation primary response 88(MyD88)/nuclear factor kappa B(NF-κB) inflammatory signaling pathway in the colon tissue of mice with dextran sodium sulfate(DSS)-induced ulcerative colitis(UC). A total of 35 mice were randomly divided into groups, including a blank group, a model group, a mesalazine group(0. 5 g·kg~(-1)), and low, medium,and high dose alkaloids from Portulacae Herba groups(9, 18, 36 mg·kg~(-1)), and a combination treatment group, with 5 mice in each group. The blank group was given purified water, while the other groups were continuously given a 3% DSS solution for 7 days to induce the UC model. From day 8 onwards, the treatment group received oral gavage according to the prescribed doses for 14 days. The overall condition, body weight, stool characteristics, and presence of blood in the stool were recorded daily. After the experiment, the disease activity index(DAI) was assessed for each group, and colon length was measured. Histopathological changes in colon tissue were examined using hematoxylin-eosin(HE) staining. The levels of pro-inflammatory cytokines, tumor necrosis factor-α(TNF-α),and interleukin-1β( IL-1β) in serum were measured by enzyme-linked immunosorbent assay( ELISA). The protein and m RNA expression of TLR4, MyD88, and NF-κB in colon tissue were measured using Western blot and quantitative real-time PCR(qPCR).Compared to the blank group, the model group showed a significant decrease in body weight, a notable increase in DAI scores, a significant shortening of colon length, and evident histopathological damage. The levels of inflammatory cytokines TNF-α and IL-1β in the serum were significantly elevated, and the protein and m RNA expression of TLR4, MyD88, and NF-κB in colon tissue were significantly up-regulated. In contrast, the alkaloids from Portulacae Herba treatment groups significantly improved symptoms and reduced body weight loss in mice, decreased DAI scores, alleviated colon shortening, lowered serum levels of TNF-α and IL-1β,significantly down-regulated the expression levels of TLR4, MyD88, and NF-κB proteins and genes in colon tissue, as well as reduced histopathological damage. Therefore, the study suggests that alkaloids from Portulacae Herba can alleviate intestinal inflammation damage in DSS-induced UC mice, with its mechanism involving the TLR4/MyD88/NF-κB signaling pathway.
Animals ; Colitis, Ulcerative/immunology* ; Toll-Like Receptor 4/immunology* ; Myeloid Differentiation Factor 88/metabolism* ; Mice ; NF-kappa B/metabolism* ; Signal Transduction/drug effects* ; Male ; Alkaloids/administration & dosage* ; Drugs, Chinese Herbal/administration & dosage* ; Humans ; Female ; Colon/metabolism* ; Disease Models, Animal

This study aims to investigate the protective effects and mechanisms of polysaccharide extract PCP1 from Polygonatum cyrtonema in ameliorating cerebral ischemia-reperfusion(I/R) injury in rats through modulation of the Toll-like receptor 4(TLR4)/NOD-like receptor protein 3(NLRP3) signaling pathway. In vivo, SD rats were randomly divided into the sham group, model group, PCP1 group, nimodipine(NMDP) group, and TLR4 signaling inhibitor(TAK-242) group. A middle cerebral artery occlusion/reperfusion(MCAO/R) model was established, and neurological deficit scores and infarct size were evaluated 24 hours after reperfusion. Hematoxylin-eosin(HE) and Nissl staining were used to observe pathological changes in ischemic brain tissue. Transmission electron microscopy(TEM) assessed ultrastructural damage in cortical neurons. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of interleukin-1β(IL-1β), interleukin-6(IL-6), interleukin-18(IL-18), tumor necrosis factor-α(TNF-α), interleukin-10(IL-10), and nitric oxide(NO) in serum. Immunofluorescence was used to analyze the expression of TLR4 and NLRP3 proteins. In vitro, a BV2 microglial cell oxygen-glucose deprivation/reperfusion(OGD/R) model was established, and cells were divided into the control, OGD/R, PCP1, TAK-242, and PCP1 + TLR4 activator lipopolysaccharide(LPS) groups. The CCK-8 assay evaluated BV2 cell viability, and ELISA determined NO release. Western blot was used to analyze the expression of TLR4, NLRP3, and downstream pathway-related proteins. The results indicated that, compared with the model group, PCP1 significantly reduced neurological deficit scores, infarct size, ischemic tissue pathology, cortical cell damage, and the levels of inflammatory factors IL-1β, IL-6, IL-18, TNF-α, and NO(P<0.01). It also elevated IL-10 levels(P<0.01) and decreased the expression of TLR4 and NLRP3 proteins(P<0.05, P<0.01). Moreover, in vitro results showed that, compared with the OGD/R group, PCP1 significantly improved BV2 cell viability(P<0.05, P<0.01), reduced cell NO levels induced by OGD/R(P<0.01), and inhibited the expression of TLR4-related inflammatory pathway proteins, including TLR4, myeloid differentiation factor 88(MyD88), tumor necrosis factor receptor-associated factor 6(TRAF6), phosphorylated nuclear factor-kappaB dimer RelA(p-p65)/nuclear factor-kappaB dimer RelA(p65), NLRP3, cleaved-caspase-1, apoptosis-associated speck-like protein(ASC), GSDMD-N, IL-1β, and IL-18(P<0.05, P<0.01). The protective effects of PCP1 were reversed by LPS stimulation. In conclusion, PCP1 ameliorates cerebral I/R injury by modulating the TLR4/NLRP3 signaling pathway, exerting anti-inflammatory and anti-pyroptotic effects.
Animals ; Toll-Like Receptor 4/genetics* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Rats, Sprague-Dawley ; Rats ; Reperfusion Injury/genetics* ; Male ; Signal Transduction/drug effects* ; Polysaccharides/isolation & purification* ; Polygonatum/chemistry* ; Brain Ischemia/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Humans

Necrotizing enterocolitis (NEC) is an intestinal inflammatory and necrotic disease seen in premature infants, and remains the leading cause of death resulted from gastrointestinal diseases in premature infants. The specific pathogenesis of NEC is still unclear. In recent years, a lot of studies have reported that Toll-like receptor 4 (TLR4) plays a key role in the pathogenesis of NEC. TLR4, which is abundantly expressed in intestinal epithelial cells of premature infants, binds to bacterial lipopolysaccharide (LPS) to activate downstream signaling pathways, leading to disruption of intestinal epithelial integrity and bacterial translocation, resulting in intestinal ischemic necrosis and inflammatory responses, which may rapidly progress to severe sepsis, multiple organ dysfunction, and death. This paper reviews the mechanism of TLR4-related signaling pathways in intestinal epithelial injury and inflammatory responses in newborns with NEC, providing a reference to study new therapeutic targets for NEC.
Enterocolitis, Necrotizing/pathology* ; Toll-Like Receptor 4/metabolism* ; Humans ; Infant, Newborn ; Signal Transduction ; Inflammation/metabolism* ; Animals ; Intestines/immunology* ; Intestinal Mucosa/pathology* ; Infant, Premature

B and T lymphocyte attenuator (BTLA) is an inhibitory immune checkpoint, which typically interacts with herpesvirus entry mediator (HVEM) and plays a crucial role in regulating immune balance. BTLA interacts with its ligand HVEM in a cis manner on the surface of the same immune cell to maintain immune tolerance, while trans interactions on the surface of different immune cells mediate immunosuppressive effects. Dysregulation of the BTLA/HVEM axis can impair the functions of immune cells, particularly T lymphocytes, promoting immune escape of tumor cells and ultimately leading to tumor progression. Researchers have found that BTLA and HVEM are abnormally expressed in various tumors and are associated with prognosis, suggesting that they may be potential targets for tumor immunotherapy. This review summarizes the molecular structures of BTLA and HVEM, immunomodulatory mechanisms, recent advances in hematologic malignancies, potential inhibitors of BTLA/HVEM interaction, and their applications in immunotherapy for hematologic malignancies.
Humans ; Receptors, Tumor Necrosis Factor, Member 14/chemistry* ; Receptors, Immunologic/immunology* ; Hematologic Neoplasms/genetics* ; Immunotherapy/methods* ; Animals

Objective To explore the effect of Evodiamine (Evo) on the immune function of allergic rhinitis (AR) rats and the regulatory mechanism on C-C motif chemokine ligand 2 (CCL2)/ C-C motif chemokine receptor 2 (CCR2) pathway. Methods The related targets of Evo-AR-immune function were screened by network pharmacology, and the protein interaction network diagram of intersecting targets was constructed. The AR rat model was established by ovalbumin (OVA) combined with aluminium hydroxide, and the rats were divided into six groups: a normal control (NC) group, a model group, a Loratadine (LOR) group, an Evodiamine low dose (Evo-L) group, a Evodiamine high dose (Evo-H) groups, and an Evo-H combined with CCL2 group. After the last administration, the symptoms of rats in each group were scored; ELISA was applied to detect the levels of histamine, immunoglobulin E (IgE), interleukin 4 (IL-4), IL-13 and interferon γ (IFN-γ); Diff-Quick staining solution was applied to detecte the number of cells in the nasal lavage fluid (NALF); hematoxylin eosin (HE) staining was applied to observe the pathological changes of nasal mucosa tissue; real-time quantitative PCR was applied to detect the levels of CCL2 and CCR2 mRNA in tissue; Western blot was applied to detect the expression levels of CCL2, CCR2 and CXC motif chemokine ligand 8 (CXCL8) proteins in nasal mucosa. Results There were eight intersection targets of EVo-AR-immune function, and protein interaction network diagram showed that CXCL8 was the core target. Compared with the NC group, the score of nasal symptoms, the levels of histamine, IgE, IL-4 and IL-13, the numbers of eosinophil, macrophages, neutrophils, lymphocytes and total cells, the mRNA and protein expression levels of CCL2 and CCR2, and the expression of CXCL8 protein in the model group were increased, while the level of IFN-γ was decreased. Compared with the model group, the score of nasal symptoms, the levels of histamine, IgE, IL-4 and IL-13, the numbers of eosinophil, macrophages, neutrophils, lymphocytes and total cells, the mRNA and protein expression levels of CCL2 and CCR2, and the expression of CXCL8 protein in LOR and Evo groups were decreased, while the level of IFN-γ was increased. Further use of CCL2 recombinant protein for compensatory experiments revealed that the improvement effect of Evo on immune function in AR rats was reversed by CCL2. Conclusion Evo can improve the immune function of AR rats, and its mechanism may be related to the inhibition of the CCL2/CCR2 pathway.
Animals ; Receptors, CCR2/immunology* ; Signal Transduction/drug effects* ; Chemokine CCL2/immunology* ; Rats ; Rhinitis, Allergic/metabolism* ; Immunoglobulin E/blood* ; Quinazolines/pharmacology* ; Male ; Interferon-gamma ; Rats, Sprague-Dawley ; Interleukin-13 ; Histamine ; Interleukin-4/immunology* ; Disease Models, Animal

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 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: To screen anti-tumor drugs that improve antigen processing and presentation in acute myeloid leukemia (AML) cells. METHODS: A TCR-like or TCR mimic antibody that can specifically recognize HLA-A*0201:WT1_126-134 ( <i>RMFPNAPYLi>) complex (hereafter referred to as HLA-A2:WT1) was synthesized to evaluate the function of antigen processing and presentation machinery (APM) in AML cells. AML cell line THP1 was incubated with increasing concentrations of IFN-γ, hypomethylating agents (HMA), immunomodulatory drugs (IMiD), proteasome inhibitors (PI) and γ-secretase inhibitors (GSI), followed by measuring of HLA-ABC, HLA-A2 and HLA-A2:WT1 levels by flow cytometry at consecutive time points. RESULTS: The TCR-like antibody we generated only binds to HLA-A*0201⁺WT1⁺ cells, indicating the specificity of the antibody. HLA-A2:WT1 level of THP-1 cells detected with the TCR-like antibody was increased significantly after co-incubation with IFN-γ, showing that the HLA-A2:WT1 TCR like antibody could evaluate the function of APM. Among the anti-tumor agents screened in this study, GSI (LY-411575) and HMA (decitabine and azacitidine) could significantly increase the HLA-A2:WT1 level. The IMiD lenalidomide and pomalidomide could aslo upregulate the expression of HLA-A2:WT1 complex under certain concentrations of the drugs and incubation time. As proteasome inhibitors, carfilzomib could significantly decreased the expression of HLA-A2:WT1, while bortezomib had no significant effect on HLA-A2:WT1 expression. CONCLUSION HLA-A2:WT1 TCR-like antibody can effectively reflect the APM function. Some of the anti-tumor drugs can affect the APM function and immunogenicity of tumor cells.
Humans ; Leukemia, Myeloid, Acute/immunology* ; Antineoplastic Agents/pharmacology* ; Antigen Presentation/drug effects* ; HLA-A2 Antigen/immunology* ; Receptors, Antigen, T-Cell/immunology* ; Cell Line, Tumor ; Interferon-gamma