Evaluation of Regulatory B Cell Subpopulations CD24++CD38++, CD24++CD27+, Plasmablasts and Their Correlation with T Regs CD3+CD4+CD25+FOXP3+ in Dialysis Patients and Early Post-Transplant Rejection-Free Kidney Recipients.

Background: B and T regulatory cells, also known as Bregs and Tregs, are involved in kidney transplantation. The purpose of this study is to monitor changes in the frequency and absolute numbers of Tregs (CD3+CD4+CD25+FoxP3+), transitional Bregs (tBregs) (CD24++CD38++), memory Bregs (mBregs) (CD24++CD27+), and plasmablasts before (T0) and six months (T6) after transplantation. Additionally, we aim to investigate any correlation between Tregs and tBregs, mBregs, or plasmablasts and their relationship with graft function. Methods: Flow cytometry was used to immunophenotype cells from 50 kidney recipients who did not experience rejection. Renal function was assessed using the estimated glomerular filtration rate (eGFR). Results: At T6, there was a significant decrease in the frequency of Tregs, plasmablasts, and tBregs, as well as in the absolute number of tBregs. The frequency of mBregs, however, remained unchanged. Graft function was found to have a positive correlation with the frequency of tBregs and plasmablasts. A significant correlation was observed between the frequency and absolute number of tBregs only when the eGFR was greater than 60 but not at lower values. At an eGFR greater than 60, there was a positive correlation between the absolute numbers of Tregs and mBregs but not between Tregs and tBregs. No correlation was observed for any cell population in dialysis patients. Conclusions: The data show a correlation between the frequency and absolute number of tBregs and the absolute number of Tregs and mBregs with good renal function in the early post-transplant period.

Short-term administration of Qipian®, a mixed bacterial lysate, inhibits airway inflammation in ovalbumin-induced mouse asthma by modulating cellular, humoral and neurogenic immune responses.

AIMS: Qipian® is a commercialized agent composed of extracts of three genera of commensal bacteria, and its mechanism of action on asthma is unclear. This study aimed to examine the impact of Qipian® on airway inflammation and investigate the underlying mechanisms. MATERIALS AND METHODS: Qipian® or dexamethasone (DEX) was administered before OVA challenge in an ovalbumin-induced asthma mouse model, and then asthmatic symptoms were observed and scored. Samples of lung tissues, blood, and bronchoalveolar lavage fluid (BALF) were collected, and eosinophils (Eos), immunoglobins (Igs), and type 1 T helper (Th1)/Th2 cell cytokines were measured. Mucus production in the lung was assessed by periodic acid-Schiff (PAS) staining. The effects of Qipian® on dendritic and T regulatory (Treg) cells were investigated using flow cytometry. KEY FINDINGS: The short-term administration of Qipian® significantly inhibited the cardinal features of allergic asthma, including an elevated asthmatic behaviour score, airway inflammation and immune response. Histological analysis of the lungs showed that Qipian® attenuated airway inflammatory cell infiltration and mucus hyperproduction. Qipian® restored Th1/Th2 imbalance by decreasing interleukin (IL)-4, IL-5, and IL-13 while increasing interferon (IFN)-γ and IL-10. Further investigation revealed that Qipian® treatment induced the upregulation of CD4+CD25+Foxp3+ Treg cells and CD103+ DCs and downregulation of tachykinins neurokinin A (NKA) and NKB in the lung. SIGNIFICANCE: Our findings suggested that short-term treatment with Qipian® could alleviate inflammation in allergic asthma through restoring the Th1/Th2 balance by recruiting Treg cells to airways and inducing the proliferation of CD103+ DCs, which actually provides a new treatment option for asthma.

Leptin Deficiency May Influence the Divergence of Cell-Mediated Immunity Between Lepromatous and Tuberculoid Leprosy Patients.

Leprosy is a disease caused by an intracellular bacillus bacterium called Mycobacterium leprae which lives and multiplies in the hosts' macrophages and Schwann cells. Depending on the degree of the host's cell-mediated immunity (CMI) response to the bacilli, the disease manifests itself in five clinical spectra ranging from polar tuberculoid (TT) to polar lepromatous leprosy (LL). A very high level of T helper 1 (Th1) driven bacilli-specific CMI is seen in the TT form, whereas this response is essentially nonexistent in the LL form. As a result, there is very low or absent bacillary load and localized nodular lesions in TT patients. On the contrary, LL patients presented with high bacillary load and generalized lesions due to low CMI response. The mechanism underlying this divergence of CMI response is not clearly elucidated yet. However, mounting evidence links it to an elevated number of Th1 and Th17 suppressing CD4+ CD25+ FOXP3+ T regulatory cells (Treg cells) which are abundantly found in LL than in TT patients. The predominance of these cells in LL patients is partly attributed to a deficiency of leptin, the cytokine-like peptide hormone, in these patients. Becausea normal level of leptin promotes the proliferation and preferential differentiation of effector T cells (Th1 and Th17) while inhibiting the growth and functional responsiveness of the Treg cells. In contrast, leptin deficiency or neutralization was reported to exert the opposite effect on Treg cells and effector T cells. Other smaller subsets of lymphocytes such as gamma delta (γδ) T cells and B regulatory cells are also modulated by leptin level in the pathogenesis of leprosy. Leptin may therefore regulate the divergence of CMI between TT and LL patients by regulating the homeostasis of effector T cells and Treg cells, and this review will examine the underlying mechanism for this.

The proportion and phenotypic changes of CD4+CD25-Foxp3+ T cells in patients with untreated rheumatoid arthritis.

OBJECTIVE: CD4+CD25+Foxp3+ regulatory T (Treg) cell-mediated immunosuppression is an essential mechanism of rheumatoid arthritis (RA). However, little is known regarding the specific role of CD4+CD25-Foxp3+ Treg cells in RA. This study aimed to investigate the frequency of circulating CD4+CD25-Foxp3+ Treg cells and their role in RA. METHODS: Sixty-one untreated RA patients and 40 healthy controls (HCs) were enrolled in this study. The proportion of CD4+CD25-Foxp3+ T cells and CD4+CD25+Foxp3+ Tregs; the levels of CTLA4, GITR, Helios, and ICOS; and the production of IL-17A, IFN-γ, and IL-10 were assessed by flow cytometry. The correlation of CD4+CD25-Foxp3+ T cells and CD4+CD25+Foxp3+ Tregs with the clinical indicators was conducted by Spearman correlation analysis. RESULTS: The proportion of CD4+CD25-Foxp3+ T cells was elevated in RA and positively correlated with disease activity. CD4+CD25-Foxp3+ T cells expressed less Helios and produced more IFN-γ than conventional Tregs in RA. Additionally, the proportion of CD4+CD25-Foxp3+ T cells was positively correlated with DAS28 score, IgG titer, and anti-CCP titer. CONCLUSIONS: These data indicate that CD4+CD25-Foxp3+ T cells in RA exhibit several different functional properties from conventional Tregs and are correlated with RA disease activity.

Elevated apoptosis and abnormal apoptosis signaling of regulatory T cells in patients with systemic lupus erythematosus.

In systemic lupus erythematosus (SLE), immune tolerance is influenced by defects in naturally occurring T cells (Tregs). To investigate the apoptosis rate of Tregs and their suppressive activity in patients with SLE and then to recognize the genes and signaling pathways that cause Treg apoptosis. FACS was used to assess the frequency and apoptosis rates of Tregs in 48 SLE patients and 28 normal controls (NCs). Coculture of Tregs with CD4+CD25-CD127dim/- T cells was used to assess the suppressive activity of Tregs. Microarray analysis was used to generate unstimulated Tregs gene expression profiles from very high activity patients with SLE and NCs. Real-time PCR was used to confirm differential gene expression. In patients with SLE, the frequency of Tregs was substantially reduced compared to Tregs from NCs. Furthermore, Tregs from SLE patients had an elevated rate of apoptosis and a lower suppressing ability than Tregs from NCs. Tregs apoptosis was negatively associated with the total count of Tregs and positively related to disease activity. Unstimulated Tregs gene expression profiles from patients with recent-onset SLE revealed a biological response that can cause apoptosis, partially triggered by stress, DNA damage, and cytokine stimulation. The discovery of pathway-specific expression signatures is a significant step forward in understanding how Tregs defects contribute to the pathogenesis of SLE. Our findings may contribute to the development of new strategies for treating SLE based on abnormal Tregs apoptosis and restoring immune homeostasis in patients with SLE.

Therapeutic effects of Hirudo medicinalis extract antigens on modulation of CD4+CD25+Foxp3 T cell activity in murine eimeriosis.

Eimeriosis is a common parasitic disease in the chicken industry. The aim of this study was to assess the protective role of Hirudo extract antigens (HEA) against murine eimeriosis induced by Eimeria papillate. The oocyst output, developmental stages, goblet cells and oxidative stress, were investigated. Immunohistochemistry was used to detect anti-apoptotic Bcl2 marker and the number of both CD4+ and CD25+ cells in jejunal tissue, while ELISA was used to quantify TGF-ß, IL-10 and IL-22 in jejunal tissue homogenate. Real-time PCR was also used to detect mRNA expression of mucin 2 (MUC2), inducible nitric oxide synthase (iNOS), IL-1ß, IFN-γ, TNF-α, IL-6, and FoxP3. The most effective dose (5 µg/mice) reduced the oocyst output by 82.95 ± 1.02% (P ˂ 0.001). Similarly, the same dose reduced the jejunal developmental stages by 66.67 ± 0.49% (P ˂ 0.001). Furthermore, HEA therapy increased the number of jejunal goblet cells by 12.8 ± 1 (P ˂ 0.001) and the expression of MUC2 by 0.83 ± 0.06 (P ˂ 0.001). In contrast, TNF-α, IFN-γ, IL-6, iNOS, and IL-1ß expression as well as apoptosis were reduced. The number of CD4+ and CD25+ in the jejunal tissue was increased (14.6 ± 1.2 (P ˂ 0.001), 6.84 ± 1 (P ˂ 0.01), respectively) after HEA therapy. The molecular analysis showed an increased expression of intestinal Foxp3 (3.2 ± 0.13 (P ˂ 0.001), while IL-22 was reduced (124 ± 10 (P ˂ 0.001)) versus an increase in TGF-ß (250 ± 17 (P ˂ 0.01)) and IL-10 (236 ± 16 (P ˂ 0.001)) after HEA treatment in comparison to the non-treated infected group. With respect to the infected group, HEA reduced lipid peroxidation (LPO) (15.7 ± 1.12 (P ˂ 0.001)) and nitric oxide (NO) (13 ± 1.3 (P ˂ 0.001)) but increased reduced glutathione (GSH) (3.7 ± 0.26 (P ˂ 0.001)). In conclusion, HEA therapy protected against intestinal tissue damage by activation of CD4+CD25+Foxp3 cells which showed anti-inflammatory action. Hence, HEA can be recommended as a therapeutic treatment for eimeriosis.

Progesterone modulates CD4+ CD25+ FoxP3+ regulatory T Cells and TGF-ß1 in the maternal-fetal interface of the late pregnant mouse.

OBJECTIVE: Progesterone supplementation is recommended to prevent spontaneous preterm birth (sPTB) in clinical practice. However, the exact mechanism is still unclear. This study aims to better understand the mechanisms that progesterone can prevent PTB. METHODS: Late pregnant mice were given various doses of progesterone receptor antagonist mifepristone, and pregnancy outcomes were observed. Then, non-pregnant and pregnant mice were given a subcutaneous injection of 40 mg/kg progesterone and 5 mg/kg mifepristone, respectively. CD4+ CD25+ FoxP3+ Treg cells in peripheral blood and decidua basalis were detected by FACS. Expressions of FoxP3 and TGF-ß1 in the decidua basalis were detected. RESULTS: Mifepristone induced preterm birth, and an obvious dose-response was found. Proportions of CD4+ CD25+ FoxP3+ Treg cells in the peripheral blood of non-pregnant mice increased significantly after progesterone injection. CD4+ CD25+ FoxP3+ Treg cells in the peripheral blood of pregnant mice increased significantly compared with those of non-pregnant mice. In pregnant mice, mifepristone significantly decreased the proportions of CD4+ CD25+ FoxP3+ Treg cells in peripheral blood, and reduced proportions of Treg cells at the maternal-fetal interface and expressions of FoxP3 and TGF-ß1 in the maternal-fetal interface. Total 40 mg/kg of progesterone did not increase CD4+ CD25+ FoxP3+ Treg in the peripheral blood of pregnant mice, but increased proportions of Treg cells at the maternal-fetal interface and up-regulated FoxP3 and TGF-ß1 expressions in the maternal-fetal interface. CONCLUSION: Progesterone promotes pregnancy immune homeostasis by up-regulating Treg cells and TGF-ß1 expression in the maternal-fetal interface. It may be one of the mechanisms of progesterone in preventing sPTB.

Taurine promotes the production of CD4+CD25+FOXP3+ Treg cells through regulating IL-35/STAT1 pathway in a mouse allergic rhinitis model.

BACKGROUND: Allergic rhinitis (AR) is one of the most widespread immune conditions worldwide. However, common treatments often present with significant side effects or are cost-prohibitive for much of the population. A plethora of treatments have been used for the treatment of AR including antihistamines, steroids, and immune modulators. Among the treatments which have shown potential for efficacy in treating AR with a minimum of side effects but remains understudied is the conditionally essential amino acid taurine. Taurine has been previously shown to reduce AR symptoms. Here, we examine the role of taurine in modulating T regulatory cells, modulating the cytokine response in AR, and restoring healthy nasal mucosa. METHODS: Blood samples from 20 healthy donors and 20 AR patients were compared for CD4+CD25+FoxP3+ T regulatory (Treg) cell population percentage, cytokine release, and STAT1 signaling with and without taurine treatment or IL-35 neutralization. An OVA-induced AR mouse model was administered vehicle, taurine, or taurine plus an IL-35 neutralizing antibody and assayed for sneezing frequency, inflammatory cytokine response, nasal mucosa goblet cell density, and T regulatory cell percentage. CD4+ cells were further examined for cytokine release, STAT1 phosphorylation, and response to an anti-IL-35 antibody with and without a STAT1 inhibitor. RESULTS: Comparison of blood from normal donors and AR patients showed a reduction in CD4+CD25+FoxP3+ Treg cells in AR patients and a strong correlation between Treg percentage and IL-35 release. A similar pattern of Treg suppression was found in untreated AR mice when compared to normal control mice wherein there was a reduction in Treg percentage and a corresponding decrease in IL-35 release. AR mice also demonstrated increased sneezing frequency, an infiltration of goblet cell in nasal mucosa, and a reduction in IL-35 release from CD4+ cells. Conversely, IL-4, IL-5, and IL-13 secretion from CD4+ cells were increased in AR model mice, as was STAT1 phosphorylation. When AR mice were treated with taurine, sneezing frequency and nasal mucosa goblet cell content were reduced while Treg abundance was increased to that of normal mice. Accordingly, IL-35 release was restored, while IL-4, IL-5, and IL-13 secretion from CD4+ cells were suppressed. Likewise, STAT1 phosphorylation was inhibited with taurine treatment. Taurine-treated mice also given an IL-35 neutralizing antibody exhibited AR pathology including frequent sneezing and high nasal goblet cell content while retaining a restoration of Tregs. Furthermore, murine AR model CD4+ cells exposed to recombinant IL-35 responded with a reduction in inflammatory cytokine release and a decrease in STAT1 phosphorylation, mimicking the effect of taurine treatment. CONCLUSIONS: Taurine induces release of IL-35 in AR; IL-35 promotes the production of CD4+CD25+FoxP3+ Treg cells via a STAT1-dependent pathway. The restoration of Treg populations by taurine normalizes the inflammatory response, reduces AR symptomology, and reduces histopathologic signs of AR.

Extracellular vesicles of Echinococcus granulosus have therapeutic effects in allergic airway inflammation.

BACKGROUND: Previous studies have shown that Echinococcus granulosus cystic fluid can alleviate Th2 allergic airway inflammatory responses by increasing the number of CD4+ CD25+ Foxp3+ T (regulatory T; Treg) cells. Parasite-derived extracellular vesicles (EV) are known to not only promote parasite infection by communicating between parasites but also regulate the inflammatory response by acting as an immunomodulatory agent in the host. METHODS: To evaluate the effect of EV extracted from the cystic fluid of E. granulosus on allergic airway inflammation, gene expression was investigated after administering EV to mouse lung epithelial cells (MLE-12) following 2 h of pretreatment with Aspergillus proteins. An allergic airway inflammation animal model was used to investigate the regulation of the inflammatory response by EV and induced with ovalbumin. RESULTS: EV treatment significantly reduced airway resistance and the number of eosinophils and other immune cells in the bronchoalveolar lavage fluid and Th2- and Th17-related cytokine levels. EV pretreatment decreased the number of IL-4+ CD4+ T cells and increased the number of Treg cells in the lung-draining lymph nodes and spleen. CONCLUSIONS: Echinococcus granulosus cystic fluid derived EV ameliorated Th2 allergic airway inflammatory through Treg cells, similar to whole cystic fluid treatment. Thus, EV may be important immunomodulatory molecules in cystic fluid.

Immunoprotective inference of experimental chronic Trichinella spiralis infection on house dust mites induced allergic airway remodeling.

Allergic bronchial asthma is characterized by chronic inflammation of the respiratory airways mediated by T-helper 2 (Th2), Th17 and their cytokines. Although most asthmatic patients suffer from allergic airway remodeling (AAR), aggressive anti-allergic treatment failed to reverse it. The hygiene hypothesis illuminated the counter relationship between allergy and helminthic infections. The immune system is modulated by Trichinella spiralis (T. spiralis) infection to maintain homeostasis. Therefore, this work aimed to investigate the impact of chronic T. spiralis infection on induced AAR in C57BL/6 mice sensitized by house dust mites (HDM) allergens. Forty mice were divided into 3 groups: I (10 healthy mice), IΙ (15 HDM sensitized mice), and ΙΙI (15 T. spiralis chronically infected mice and sensitized with HDM allergens). The assessment aimed to evaluate the effects of regulatory CD4+CD25+FOXP3+ cells (Tregs) and their cytokines comparative to hypersensitivity mediated cytokines. Chronic T. spiralis infection effectively prevented the host's AAR. This result was evidenced by upregulated Tregs in blood by flow cytometric analysis and increased interleukin-10 (IL-10) levels in bronchoalveolar lavage (BAL) by Enzyme linked immunosorbent assay (ELISA) as well as improved lung histopathological changes. Also, serum HDM specific immunoglobulin E (IgE), BAL eosinophils, BAL IL-5 levels, and IL-17 gene expression in lung tissues were significantly reduced in T. spiralis chronically infected mice. In conclusion, the immune response in chronic T. spiralis infection could provide a promising mechanistic tool for protection against AAR, which paves the way for innovative preventive measures of other immunological disorders.

MSCs-released TGFß1 generate CD4+CD25+Foxp3+ in T-reg cells of human SLE PBMC.

BACKGROUND/PURPOSE: Regulatory T-cell (Treg) defects may cause autoreactivity of both T and B cells, leading to autoimmune disease including systemic lupus erythematosus (SLE). The immune response defects in SLE are characterized by the decreased expression of CD4, CD25, and Foxp3, known as inducible Treg (iTreg). Therefore, restoring iTreg expression can reverse autoimmunity states into immune tolerances leading to normal immune responses. Mesenchymal stem cells (MSCs) have immunomodulatory properties to control inflammatory milieu, including in SLE inflammation by releasing TGFß1, IL10, and PGE2, thus MSCs can potentially generate iTreg cells. However, the mechanisms of MSC-released TGFß1 to promote iTreg generation in human SLE remains unclear. This study aims to analyze the role of MSC-released TGFß1 in generating CD4+, CD25+, and Foxp3+ expression in iTreg cells from human SLE peripheral blood mononuclear cells (PBMCs). METHODS: This study used a post-test control group design. MSCs were obtained from human umbilical cord blood and characterized according to their surface antigen expression and multilineage differentiation capacities. PBMCs isolated from SLE patients were divided into five groups, including sham, control, and three treatment groups. The treatment groups were treated by co-culturing MSCs to PBMCs with ratio of 1:1 (T1), 1:25 (T2), and 1:50 (T3) for 72 h incubation. The expression of CD4, CD25, and Foxp3 in Treg was analyzed by flow cytometry assay while TGFß1 level was determined by Cytometric Bead Array (CBA). RESULTS: This study showed that the percentage of CD4+CD25+Foxp3+ iTreg cells was significantly increased in T1 and T2. This finding was aligned with the significant increase of TGFß1 level. CONCLUSION: MSCs promote iTreg cells generation from human SLE PBMCs by releasing TGFß1 to control SLE disease.

CD4+CD25+Foxp3+ regulatory T cells regulate immune balance in unexplained recurrent spontaneous abortion via the Toll-like receptor 4/nuclear factor-κB pathway.

OBJECTIVE: The present study aimed to evaluate the effects of cluster of differentiation (CD)4+CD25+ forkhead box p3 (Foxp3)+ regulatory T cells (Tregs) on unexplained recurrent spontaneous abortion (URSA) and the associated mechanisms. METHODS: The proportion of CD4+CD25+Foxp3+ Tregs and inflammatory cytokine concentrations in the peripheral blood of women with URSA were measured by flow cytometry and enzyme-linked immunosorbent assay, respectively. CBA/JxDBA/2J mating was used to establish an abortion-prone mouse model and the model mice were treated with the Toll-like receptor 4 (TLR4) antagonist E5564 and the TLR4 agonist lipopolysaccharide. RESULTS: The proportion of CD4+CD25+Foxp3+ Tregs was decreased and the inflammatory response was increased in women with URSA. In the abortion-prone mouse model, E5564 significantly increased the proportion of CD4+CD25+Foxp3+ Tregs, decreased the inflammatory response, and increased Foxp3 mRNA and protein expression. Lipopolysaccharide had adverse effects on the abortion-prone model. CONCLUSIONS: These data suggest that CD4+CD25+Foxp3+ Tregs regulate immune homeostasis in URSA via the TLR4/nuclear factor-κB pathway, and that the TLR4 antagonist E5564 may be a novel and potential drug for treating URSA.

Regulatory T cells do not suppress rather activate human basophils by IL-3 and STAT5-dependent mechanisms.

Basophils play an important role in orienting Th2 immune response, and in the pathogenesis of allergic and inflammatory disorders. However, the mechanism by which basophils are kept in check remains unclear and hence we explored the role of regulatory T cells (Treg cells) in this process. We demonstrate that human Treg cells do not suppress rather induce activation of basophils, and promote Th2 responses by IL-3 and STAT5-dependent mechanism.

Dysfunction of regulatory T cells mediated by AKT-FOXO1 signaling pathway occurs during the development of psoriasis.

Psoriasis is an immune-mediated skin disease with abnormal T cells. Regulatory T cells (Treg) are a kind of cell group with immunosuppressive effects. This study aimed to explore the role of Treg cells in the pathogenesis of psoriasis and its possible mechanism. Imiquimod induced psoriasis mice model was conducted. The skin lesions were evaluated according to the psoriasis area and severity index (PASI). Skin biopsies were taken for HE staining and immunohistochemical staining of IL-23, IL-17, IL-33 and TNF-α. CD4+CD25+ Treg cells were isolated. The proportions of Treg cells, cell proliferation, and immunosuppressive activity were analyzed by flow cytometry. The expression of AKT, Foxo1, pAKT, pFoxo1 protein, and the localization of Foxo1 protein in Treg cells were detected by western blot and immunofluorescence. The results showed that the psoriasis mice model was established successfully. There was no significant difference in the proportion of Treg cells between the two groups (P > 0.05). The cell proliferation abilities were decreased, and the immunosuppressive functions of Treg cells were weakened in the psoriatic group (P < 0.05). Western blot showed that pAKT and pFoxo1 levels of Treg cells were significantly increased in the psoriatic group (P < 0.05). Immunofluorescence showed that Foxo1 was mainly expressed in the nucleus of Treg cells in the control group, whereas expressed in the cytoplasm in the psoriasis group. Therefore, we concluded that the cell proliferation and immunosuppressive dysfunction of Treg cells mediated by AKT-FOXO1 signaling pathway may occurs during the development of psoriasis.

Ginsenoside Rg3 Alleviates Complete Freund's Adjuvant-Induced Rheumatoid Arthritis in Mice by Regulating CD4+CD25+Foxp3+Treg Cells.

Ginsenoside Rg3 (GRg3) is one of the major bioactive ingredients of ginseng, which is not only used as a herbal medicine but also used as a functional food to support body functions. In this study, the beneficial effects of GRg3 on rheumatoid arthritis (RA) mice was evaluated from anti-inflammatory and immunosuppressive aspects. The footpad swelling rate, pathological changes of the ankle joint, and levels of tumor necrosis factor α, interleukin 6, interleukin 10, and tumor necrosis factor ß were used to assess the anti-inflammatory effect of GRg3 on RA mice. Flow cytometric analysis of CD4+CD25+Foxp3+Treg cell percentage and metabolomic analysis based on gas chromatography-tandem mass spectrometry were used to assess the immunosuppressive effect and underlying mechanisms. GRg3 exhibited anti-inflammatory and immunosuppressive effects on RA mice. The potential mechanisms were related to regulate the pathways of oxidative phosphorylation and enhance the function of CD4+CD25+Foxp3+Treg cells to maintain peripheral immune tolerance of RA mice. These findings can provide a preliminary experimental basis to exploit GRg3 as a functional food or an effective complementary for the adjuvant therapy of RA.

A Praziquantel Treatment Study of Immune and Transcriptome Profiles in Schistosoma haematobium-Infected Gabonese Schoolchildren.

BACKGROUND: Although Schistosoma haematobium infection has been reported to be associated with alterations in immune function, in particular immune hyporesponsiveness, there have been only few studies that have used the approach of removing infection by drug treatment to establish this and to understand the underlying molecular mechanisms. METHODS: Schistosoma haematobium-infected schoolchildren were studied before and after praziquantel treatment and compared with uninfected controls. Cellular responses were characterized by cytokine production and flow cytometry, and in a subset of children RNA sequencing (RNA-Seq) transcriptome profiling was performed. RESULTS: Removal of S haematobium infection resulted in increased schistosome-specific cytokine responses that were negatively associated with CD4+CD25+FOXP3+ T-cells and accompanied by increased frequency of effector memory T-cells. Innate responses to Toll like receptor (TLR) ligation decreased with treatment and showed positive association with CD4+CD25+FOXP3+ T-cells. At the transcriptome level, schistosome infection was associated with enrichment in cell adhesion, whereas parasite removal was associated with a more quiescent profile. Further analysis indicated that alteration in cellular energy metabolism was associated with S haematobium infection and that the early growth response genes 2 and 3 (EGR 2 and EGR3), transcription factors that negatively regulate T-cell activation, may play a role in adaptive immune hyporesponsiveness. CONCLUSIONS: Using a longitudinal study design, we found contrasting effects of schistosome infection on innate and adaptive immune responses. Whereas the innate immune system appears more activated, the adaptive immunity is in a hyporesponsive state reflected in alterations in CD4+CD25+FOXP3+ T-cells, cellular metabolism, and transcription factors involved in anergy.

Alloactivation of Naïve CD4+CD8-CD25+T Regulatory Cells: Expression of CD8α Identifies Potent Suppressor Cells That Can Promote Transplant Tolerance Induction.

Therapy with alloantigen-specific CD4+CD25+ T regulatory cells (Treg) for induction of transplant tolerance is desirable, as naïve thymic Treg (tTreg) are not alloantigen-specific and are weak suppressor cells. Naïve tTreg from DA rats cultured with fully allogeneic PVG stimulator cells in the presence of rIL-2 express IFN-gamma receptor (IFNGR) and IL-12 receptor beta2 (IL-12Rß2) and are more potent alloantigen-specific regulators that we call Ts1 cells. This study examined additional markers that could identify the activated alloantigen-specific Treg as a subpopulation within the CD4+CD25+Foxp3+Treg. After culture of naïve DA CD4+CD8-CD25+T cells with rIL-2 and PVG alloantigen, or rIL-2 without alloantigen, CD8α was expressed on 10-20% and CD8ß on <5% of these cells. These cells expressed ifngr and Il12rb2. CD8α+ cells had increased Ifngr that characterizes Ts1 cells as well was Irf4, a transcription factor induced by TCR activation. Proliferation induced by re-culture with rIL-12 and alloantigen was greater with CD4+CD8α+CD25+Treg consistent with the CD8α+ cells expressing IL-12R. In MLC, the CD8α+ fraction suppressed responses against allogeneic stimulators more than the mixed Ts1 population, whereas the CD4+CD8-CD25+T cells were less potent. In an adoptive transfer assay, rIL-2 and alloantigen activated Treg suppress rejection at a ratio of 1:10 with naïve effector cells, whereas alloantigen and rIL-2 activated tTreg depleted of the CD8α+ cells were much less effective. This study demonstrated that expression of CD8α by rIL-2 and alloantigen activation of CD4+CD8-CD25+Foxp3+T cells was a marker of activated and potent Treg that included alloantigen-specific Treg.

[Inhibition of Toxoplasma gondii excretory - secretory antigens on growth of murine Lewis lung carcinoma].

OBJECTIVE: To investigate the effect of Toxoplasma gondii excretory-secretory antigens (ESA) on CD4+ CD25+ Foxp3+ T (Treg) cells in mice carrying Lewis lung carcinoma, and examine the inhibitory effect of T. gondii ESA on tumor growth. METHODS: C57BL/6 mice were randomly assigned into the PBS group (n = 14) and the Lewis group (n = 34). Mice in the Lewis group were subcutaneously injected with 2 × 105 Lewis lung carcinoma cells in the right axilla, while animals in the PBS group were injected with the same volume of sterile PBS. On day 7 post-injection (D7), mice in the PBS group were further divided into the PBS2 group and the PBS2 + ESA group, of 7 mice in each group, and mice in the Lewis group were further divided into the Lewis2 group and the Lewis2 + ESA group, of 17 mice in each group. Then, mice in the PBS2 + ESA group and the Lewis2 + ESA group were intraperitoneally injected with 100 µL of ESA. The mouse spleen coefficient was calculated in each group 7 days post-injection with ESA, and the changes of Treg cell counts and the long-term tumor growth were measured in tumor-bearing mice. RESULTS: The spleen coefficient was significantly greater in the PBS2 + ESA group and the Lewis2 + ESA group than in the PBS2 (0.66% ± 0.09% vs. 0.30% ± 0.02%, P < 0.05) and Lewis2 groups (0.69% ± 0.07% vs. 0.33% ± 0.03%, P < 0.05) 7 days post-treatment with ESA, respectively, and the percentage of splenic Treg cells in splenocytes was significantly lower in the PBS2 + ESA group and the Lewis2 + ESA group than in the PBS2 (1.28% ± 0.14% vs. 2.06% ± 0.07%, P < 0.05) and Lewis2 groups (1.58% ± 0.14% vs. 2.44% ± 0.23%, P < 0.05), respectively. T. gondii ESA treatment caused a delay in tumor growth, and the tumor size was significantly smaller in the Lewis2 + ESA group than in the Lewis2 group (P < 0.05). CONCLUSIONS: T. gondii ESA may reduce the proportion of splenic Treg cells in splenocytes and inhibit tumor growth in mice carrying Lewis lung carcinoma.

Acceleratory effects of ambient fine particulate matter on the development and progression of atherosclerosis in apolipoprotein E knockout mice by down-regulating CD4+CD25+Foxp3+ regulatory T cells.

OBJECTIVE: Atherosclerosis is an autoimmune inflammatory disease that is closely associated with long-term exposure to fine particulate matter (PM2.5). CD4+CD25+Foxp3+ regulatory T cells (Tregs) play a critical role in the regulation of T cell-mediated immune responses, and the depletion of CD4+CD25+Foxp3+ Tregs has been thought to play a prominent role in atherosclerosis. Therefore, we investigated the association between the CD4+CD25+Foxp3+ Tregs population and atherosclerotic development in ApoE-/- mice exposed to PM2.5. METHODS: We employed a real-world system to subject 40 ApoE-/- mice to ambient inhalation of PM2.5 (PM2.5 group, n = 20) or filtered air (FA group, n = 20) for 12 weeks. PM2.5 source apportionment, atherosclerotic lesions within aorta, lipid deposition and plaque accumulation in whole artery, serum level of inflammatory factors and lipid profiles, CD4+CD25+Foxp3+ Tregs population in splenocytes, Foxp3 protein and mRNA expressions in descending aorta and spleen were quantified, respectively. RESULTS: The daily average concentration of PM2.5 was 57.4 ± 25.6 µg/m3. Atherosclerotic lesions within aorta, lipid deposition and plaque accumulation in whole artery, serum levels of IL-6, TNF-α, TC and LDL-C in the PM2.5 group increased significantly compared to the FA group. Whereas, serum levels of IL-10 and TGF-ß, CD4+CD25+Foxp3+ Tregs population in splenocytes, Foxp3 protein and mRNA expressions in descending aorta and spleen in the PM2.5 group decreased significantly compared to the FA group. CONCLUSION: These results suggest that PM2.5 could accelerate the development of atherosclerosis in ApoE-/- mice, which is related to CD4+CD25+Foxp3+ Tregs down-regulation, as well as lipid deposition and systemic inflammation.