BACKGROUND: Regulatory dendritic cell (DCreg) subset exhibits a unique capacity for inducing immune tolerance among the variety subsets of dendritic cells (DCs) within gut-associated lymphoid tissues (GALTs). Fms-like tyrosine kinase 3 ligand (FLT3L) is involved in the differentiation of DCregs and the subsequent expansion of regulatory T-cells (Tregs) mediated by DCregs, though the precise mechanism remains poorly understood. This study aimed to explore the expansion mechanism of Treg induced by DCreg and the role of FLT3L in this process. METHODS: DCregs were distinguished from other DC subsets isolated from GALTs of BALB/c mice through a mixed lymphocyte reaction assay. The functions and mechanisms by which FLT3L promoted Treg expansion via DCregs were investigated in vitro through co-culture experiments involving DCregs and either CD4 + CD25 - T-cells or CD4 + CD25 + T-cells. Additionally, an in vivo experiment was conducted using a dextran sulfate sodium (DSS)-induced colitis model in mice. RESULTS: CD103 + CD11b + DC exhibited DCreg-like functionality and was identified as DCreg for subsequent investigation. Analysis of Foxp3 + Treg percentages within a co-culture system of CD4 + CD25 - T-cells and DCregs, with or without FLT3L, demonstrated the involvement of the FLT3/FLT3L axis in driving the differentiation of precursor T-cells into Foxp3 + Tregs induced by DCregs. Cell migration and co-culture assays revealed that the FLT3/FLT3L axis enhanced DCreg migration toward Tregs via the Rho pathway. Additionally, it was observed that DCregs could promote Treg proliferation through the Notch pathway, as inhibition of Notch signaling by DAPT (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester) suppressed Treg expansion within the co-culture system of DCregs and CD4 + T-cells or CD4 + CD25 + T-cells. Furthermore, the FLT3/FLT3L axis influenced JAG1 expression in DCregs, indirectly modulating Treg expansion. In vivo experiments further established that FLT3L promoted DCreg expansion and restored Treg balance in DSS-induced colitis models, thereby ameliorating colitis symptoms in mice. CONCLUSION The FLT3/FLT3L axis is integral to the maintenance of DCreg function in Treg expansion.
Animals ; T-Lymphocytes, Regulatory/immunology* ; Dendritic Cells/immunology* ; Mice ; Mice, Inbred BALB C ; Membrane Proteins/metabolism* ; Receptors, Notch/metabolism* ; Lymphoid Tissue/metabolism* ; Signal Transduction/physiology* ; Coculture Techniques ; Flow Cytometry

Astragalus membranaceus may be a potential therapy for childhood asthma but its driving mechanism remains elusive. The main components of A. membranaceus were identified by HPLC. The children with asthma remission were divided into two combination group (control group, the combination of budesonide and terbutaline) and A. membranaceus group (treatment group, the combination of budesonide, terbutaline and A. membranaceus). The therapeutic results were compared between two groups after 3-month therapy. Porcine peripheral blood mononuclear cells (PBMCs) were isolated from venous blood by using density gradient centrifugation on percoll. The levels of FoxP3, EGF-β, IL-17 and IL-23 from PBMCs and serum IgE were measured. The relative percentage of Treg/Th17 cells was determined using flow cytometry. The main components of A. membranaceus were calycosin-7-O-glucoside, isoquercitrin, ononin, calycosin, quercetin, genistein, kaempferol, isorhamnetin and formononetin, all of which may contribute to asthma therapy. Lung function was significantly improved in the treatment group when compared with a control group (P < 0.05). The efficacy in preventing the occurrence of childhood asthma was higher in the treatment group than the control group (P < 0.05). The levels of IgE, IL-17 and IL-23 were reduced significantly in the treatment group when compared with the control group, while the levels of FoxP3 and TGF-β were increased in the treatment group when compared with the control group (P < 0.05). A. membranaceus increased the percentage of Treg cells and reduced the percentage of Th17 cells. A. membranaceus is potential natural product for improving the therapeutic efficacy of combination therapy of budesonide and terbutaline for the children with asthma remission by modulating the balance of Treg/Th17 cells.
Animals ; Asthma ; drug therapy ; immunology ; Astragalus propinquus ; chemistry ; Budesonide ; administration & dosage ; Cells, Cultured ; Child ; Child, Preschool ; Cytokines ; metabolism ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Female ; Humans ; Immunologic Factors ; administration & dosage ; pharmacology ; Leukocytes, Mononuclear ; drug effects ; metabolism ; Lung ; drug effects ; physiology ; Male ; Swine ; T-Lymphocytes, Regulatory ; cytology ; drug effects ; Terbutaline ; administration & dosage ; Th17 Cells ; cytology ; drug effects ; Treatment Outcome

OBJECTIVETo study the relationship between the expression of peripheral blood HLA-DR, CD4CD25 regulatory T cells, IL-17 and IL-27 with liver damage in children with human cytomegalovirus (HCMV) infection.

METHODSTwenty-one HCMV children with liver damage and twenty-one HCMV children without liver damage were enrolled in this study. The expression of peripheral blood HLA-DR and CD4CD25 regulatory T cells was detected by flow cytometry. Plasma levels of IL-17 and IL-27 were measured using ELISA.

RESULTSThe plasma levels of IL-17 and IL-27 in children with liver damage were significantly higher than in those without liver damage, while the expression of peripheral blood CD4CD25 regulatory T cells was lower than in those without liver damage (P<0.05). Plasma IL-17 and IL-27 levels were negatively correlated with the expression of peripheral blood CD4CD25 regulatory T cells (P<0.01).

CONCLUSIONSImmune imbalance mediated by CD4CD25 regulatory T cells and over-expression of IL-17 and IL-27 may be involved in the pathogenesis of liver damage in children with HCMV infection.

CD4 Antigens ; immunology ; Cytomegalovirus ; physiology ; Cytomegalovirus Infections ; blood ; complications ; genetics ; Female ; Flow Cytometry ; HLA-DR Antigens ; genetics ; immunology ; Humans ; Infant ; Interleukin-17 ; blood ; genetics ; Interleukin-2 Receptor alpha Subunit ; immunology ; Interleukins ; blood ; genetics ; Liver ; injuries ; metabolism ; Liver Diseases ; blood ; etiology ; immunology ; Male ; T-Lymphocytes, Regulatory ; immunology

Transforming growth factor (TGF)-β regulates a wide variety of cellular responses, including cell growth arrest, apoptosis, cell differentiation, motility, invasion, extracellular matrix production, tissue fibrosis, angiogenesis, and immune function. Although tumor-suppressive roles of TGF-β have been extensively studied and well-characterized in many cancers, especially at early stages, accumulating evidence has revealed the critical roles of TGF-β as a pro-tumorigenic factor in various types of cancer. This review will focus on recent findings regarding epithelial-mesenchymal transition (EMT) induced by TGF-β, in relation to crosstalk with some other signaling pathways, and the roles of TGF-β in lung and pancreatic cancers, in which TGF-β has been shown to be involved in cancer progression. Recent findings also strongly suggested that targeting TGF-β signaling using specific inhibitors may be useful for the treatment of some cancers. TGF-β plays a pivotal role in the differentiation and function of regulatory T cells (Tregs). TGF-β is produced as latent high molecular weight complexes, and the latent TGF-β complex expressed on the surface of Tregs contains glycoprotein A repetitions predominant (GARP, also known as leucine-rich repeat containing 32 or LRRC32). Inhibition of the TGF-β activities through regulation of the latent TGF-β complex activation will be discussed.
Drug Discovery ; Humans ; Lung Neoplasms ; drug therapy ; immunology ; metabolism ; Membrane Proteins ; metabolism ; Pancreatic Neoplasms ; drug therapy ; immunology ; metabolism ; Signal Transduction ; drug effects ; physiology ; T-Lymphocytes, Regulatory ; metabolism ; Transforming Growth Factor beta ; antagonists & inhibitors ; immunology ; metabolism

BACKGROUNDPostresuscitation immune dysfunction contributes to the low survival rate after successful resuscitation, but its mechanism remains poorly understood. The purpose of this study was to investigate whether splenic regulatory T-cell (Treg) apoptosis was involved in the postresuscitation immune dysfunction.

METHODSThirty-eight pigs were randomly divided into sham-operated group (SHAM group, n = 8), 12 h post return of spontaneous circulation (ROSC) group, 24 h post-ROSC group, and 48 h post-ROSC group (n = 10 per group). A Wuzhishan miniature porcine model of 8-min ventricular fibrillation cardiac arrest (CA) was established. The apoptosis rates of Treg in the spleen were tested by flow cytometry; the expressions of forkhead/winged helix transcription factor (Foxp3) of Treg in the spleen were detected by real-time polymerase chain reaction; and the levels of interleukin-4 (IL-4), IL-10, and interferon gamma (IFN-γ) of Treg in the spleen were detected by enzyme-linked immunosorbent assay.

RESULTSThe apoptosis rates of Treg in all post-ROSC groups were significantly lower than that of SHAM group (7.7% ± 1.9%, 7.1% ± 1.8%, 6.2% ± 0.4% vs. 13.1% ± 1.6%; P < 0.05); the expression levels of Foxp3 and IL-10 were also decreased with the increase of apoptosis rates of Treg. Helper T-cells CD4+ lymphocyte subsets were significantly lower in the post-ROSC groups compared with SHAM group (29.1% ± 2.2%, 24.3% ± 2.2%, 24.1% ± 2.5% vs. 43.8% ± 4.5%; P < 0.01) at 12, 24, and 48 h after ROSC. Compared with SHAM group, the levels of IFN-γ (161.0 ± 12.9, 167.7 ± 10.5, 191.2 ± 7.7 vs. 7.6 ± 0.9 ng/L) and IL-4 (27.7 ± 6.2, 35.9 ± 3.5, 50.6 ± 6.1 vs. 13.3 ± 2.3 ng/L) and the ratio of IFN-γ/IL-4 (8.6 ± 2.3, 4.9 ± 0.4, 4.5 ± 0.9 vs. 0.8 ± 0.2) were all greatly elevated in all post-ROSC groups (P < 0.05).

CONCLUSIONSApoptosis rate of Treg was significantly decreased after CA, and thus the proportion of Treg was increased and the inhibitory effects were enhanced, which further led to the decrease of the amount of CD4+ T-cells. In addition, the T helper type 2/T helper type 1 (Th2/Th1) cell drift of Treg in the spleen caused postresuscitation immune dysfunction.

Animals ; Apoptosis ; physiology ; Cardiopulmonary Resuscitation ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Forkhead Transcription Factors ; metabolism ; Heart Arrest ; immunology ; metabolism ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Random Allocation ; Spleen ; cytology ; Swine ; Swine, Miniature ; T-Lymphocytes, Regulatory ; cytology ; metabolism ; physiology ; Ventricular Fibrillation ; complications ; metabolism

The defectiveness of bone marrow mesenchymal stem cells (BM-MSCs) in acquired aplastic anemia (AA) has been a frequent research topic in recent years. This review summarizes the defectiveness of BM-MSCs which is responsible for the mechanism of acquired AA and the prospective application of BM-MSCs in the treatment of acquired AA. An increasingly number of laboratory statistics has demonstrated that the defectiveness of BM-MSCs is more likely to play an important role in the pathogenesis of AA, namely, the apparently different biological characteristics and gene expression profiles, the decreased ability of supporting hematopoiesis as well as self-renewal and differentiation, and the exhaustion of regulating immune response of hematopoietic environment. Those abnormalities continuously prompt AA to become irreversible bone marrow failure along with the imbalanced immunity. With deepening research on MSCs, infusion of MSCs for the primary purpose of recovering hematopoietic microenvironment may become a new approach for the treatment of AA.
Anemia, Aplastic ; etiology ; immunology ; therapy ; Bone Marrow ; Cell Differentiation ; Cell Proliferation ; Cytokines ; analysis ; Humans ; Lymphocyte Activation ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; physiology ; T-Lymphocytes, Regulatory ; immunology

OBJECTIVETo study the roles of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) and IL-33 in the pathogenesis of asthma in children.

METHODSFlow cytometry was used to detect peripheral blood CD4(+)CD25(+)Foxp3(+)Treg proportion in CD4(+)T lymphocytes in.45 children with asthma, 50 children with wheezing caused by respiratory syncytial virus infection and 40 healthy children. Serum levels of IFN-γ, IL-4, IL-5 and IL-33 were measured using ELISA.

RESULTSThe level of peripheral blood CD4(+)CD25(+)Foxp3(+)Treg in the asthma group was significantly lower than in the wheezing and control groups (P<0.05). In contrast, serum levels of IL-33 in the asthma group was significantly higher than in the wheezing and control groups (P<0.05). Peripheral blood CD4(+)CD25(+)Foxp3(+)Treg level was negatively correlated with serum IL-33 level in the asthma group(r=-0.156, P<0.01).

CONCLUSIONSCD4(+)CD25(+)Foxp3(+)Treg may interact with IL-33 in the pathogenesis of childhood asthma.

Asthma ; etiology ; immunology ; Child ; Child, Preschool ; Female ; Forkhead Transcription Factors ; analysis ; Humans ; Infant ; Interleukin-2 Receptor alpha Subunit ; immunology ; Interleukin-33 ; Interleukins ; physiology ; Male ; T-Lymphocytes, Regulatory ; physiology

Different functions have been attributed to CD4+CD25+Foxp3+ regulatory T-cells (Tregs) during malaria infection. Herein, we describe the disparity in Treg response and pro- and anti-inflammatory cytokines during infection with Plasmodium berghei ANKA between young (3-week-old) and middle-aged (8-month-old) C57BL/6 mice. Young mice were susceptible to cerebral malaria (CM), while the middle-aged mice were resistant to CM and succumbed to hyperparasitemia and severe anemia. The levels of pro-inflammatory cytokines, such as TNF-alpha, in young CM-susceptible mice were markedly higher than in middle-aged CM-resistant mice. An increased absolute number of Tregs 3-5 days post-inoculation, co-occurring with elevated IL-10 levels, was observed in middle-aged CM-resistant mice but not in young CM-susceptible mice. Our findings suggest that Treg proliferation might be associated with the suppression of excessive pro-inflammatory Th1 response during early malaria infection, leading to resistance to CM in the middle-aged mice, possibly in an IL-10-dependent manner.
Aging/*immunology ; Animals ; Cytokines/genetics/metabolism ; Female ; Gene Expression Regulation ; Malaria/*immunology/*parasitology ; Mice ; Plasmodium berghei/*classification ; T-Lymphocytes, Regulatory/classification/*physiology

OBJECTIVETo study the effects of early intervention on CD4+CD25+ regulatory T cells and TLR4 expression with Mycobacterium phlei F.U.36 in asthmatic mice.

METHODSThirty female BALB/c mice were randomly divided into three groups: control, asthma model and Mycobacterium phlei F.U.36 treated asthma groups. Asthma was induced by sensitization and challenges with ovalbumin (OVA) in the later two groups. Mycobacterium phlei F.U.36 was intraperitoneally injected 2 weeks before the first sensitization (0.57 μg/time, once every other day for three times) in the intervention group. After 24 hrs of the last challenge, the mice were sacrificed and the left lung tissues were obtained for the observation of lung pathological changes. Splenic mononuclear cells were isolated. The percentage of CD4+CD25+ regulatory T cells in CD4+ T cells and the mean fluorescence intensity of TLR4 on CD4+ CD25+ T cells were detected by flow cytometry.

RESULTSThe percentage of CD4+CD25+ regulatory T cells in the asthma model group was significantly lower than that in the control group (P<0.01), but the mean fluorescence intensity of TLR4 on CD4+CD25+ regulatory T cells was not significantly different from the control group. The percentage of CD4+CD25+ regulatory T cells and the mean fluorescence intensity of TLR4 on CD4+CD25+ regulatory T cells increased significantly in asthmatic mice receiving Mycobacterium phlei F.U.36 treatment compared with the asthma group (P<0.01).

CONCLUSIONSEarly intervention with Mycobacterium phlei F.U.36 can increase TLR4 expression on CD4+CD25+ cells and the number of CD4+CD25+ regulatory T cells, and thus provides therapeutic effects in asthmatic mice.

Animals ; Asthma ; immunology ; pathology ; Female ; Lung ; pathology ; Mice ; Mice, Inbred BALB C ; Mycobacterium phlei ; T-Lymphocytes, Regulatory ; immunology ; Toll-Like Receptor 4 ; physiology

OBJECTIVETo study the roles of CD4(+)CD25(+) regulatory T cells and Foxp3 mRNA in peripheral blood as well as serum total immunoglobulin E (IgE) in the pathogenesis of bronchiolitis caused by respiratory syncytial virus (RSV).

METHODSThe proportion of CD4(+)CD25(+) regulatory T cells and expression of Foxp3 mRNA in peripheral blood, and total serum IgE level were tested by flow cytometry, RT-PCR and ELISA respectively in 57 children with RSV bronchiolitis (26 atopic patients and 31 nonatopic patients). Twenty five healthy children were used as the control group.

RESULTSThe proportion of CD4(+)CD25(+) regulatory T cells in peripheral blood in children with bronchiolitis, either in the atopic (7.7+/- 1.6%)or the nonatopic group (8.8+/- 2.1%), was significantly lower than that in the control group (10.5+/- 1.6%) (P< 0.01). Foxp3 mRNA expression in peripheral blood was significantly lower in both atopic and nonatopic children with bronchiolitis than that in the control group (P< 0.01). Significantly increased total serum IgE level was noted in both atopic (241.2+/- 102.5 IU/mL) and nonatopic children (125.5+/- 63.2 IU/mL) with bronchiolitis compared with that in the control group (27.2+/- 10.5 IU/ml) (P< 0.01). There were significant differences in the proportion of CD4(+)CD25(+) regulatory T cells and Foxp3 mRNA expression in peripheral blood (P< 0.05) as well as total serum IgE level (P< 0.01) between the atopic and the nonatopic group. The proportion of CD4(+)CD25(+) regulatory T cells (r=-0.70, P< 0.01) and Foxp3 mRNA expression in peripheral blood (r=-0.79, P< 0.01) were closely negatively correlated to total serum IgE level.

CONCLUSIONSBoth the proportion of CD4(+)CD25(+) regulatory T cells and Foxp3 mRNA expression in peripheral blood were reduced, in contrast, the total serum IgE level increased in children with RSV bronchiolitis. This suggested that CD4(+)CD25(+) regulatory T cells and Foxp3 mRNA together with IgE participated in the pathogenesis of RSV bronchiolitis.

Bronchiolitis ; etiology ; immunology ; CD4-Positive T-Lymphocytes ; immunology ; Female ; Forkhead Transcription Factors ; genetics ; Humans ; Immunoglobulin E ; blood ; Infant ; Male ; RNA, Messenger ; blood ; Respiratory Syncytial Virus Infections ; etiology ; immunology ; T-Lymphocytes, Regulatory ; physiology