Imbalance of Circulating Follicular Regulatory and Follicular Helper T Cell Subpopulations Is Associated with Disease Progression and Serum CYFRA 21-1 Levels in Patients with Non-small Cell Lung Cancer

Objective This study aimed to investigate the changes of follicular helper T(TFH)and follicular regulatory T(TFR)cell subpopulations in patients with non-small cell lung cancer(NSCLC)and their significance.Methods Peripheral blood was collected from 58 NSCLC patients at different stages and 38 healthy controls.Flow cytometry was used to detect TFH cell subpopulation based on programmed death 1(PD-1)and inducible co-stimulator(ICOS),and TFR cell subpopulation based on cluster determinant 45RA(CD45RA)and forkhead box protein P3(FoxP3).The levels of interleukin-10(IL-10),interleukin-17a(IL-17a),interleukin-21(IL-21),and transforming growth factor-β(TGF-β)in the plasma were measured,and changes in circulating B cell subsets and plasma IgG levels were also analyzed.The correlation between serum cytokeratin fragment antigen 21-1(CYFRA 21-1)levels and TFH,TFR,or B cell subpopulations was further explored.Results The TFR/TFH ratio increased significantly in NSCLC patients.The CD45RA^(+)FoxP3^(int) TFR subsets were increased,with their proportions increasing in stages Ⅱ to Ⅲ and decreasing in stage IV.PD-1^(+)ICOS+TFH cells showed a downward trend with increasing stages.Plasma IL-21 and TGF-β concentrations were increased in NSCLC patients compared with healthy controls.Plasmablasts,plasma IgG levels,and CD45RA^(+)FoxP3^(int) TFR cells showed similar trends.TFH numbers and plasmablasts were positively correlated with CYFRA 21-1 in stages Ⅰ-Ⅲ and negatively correlated with CYFRA 21-1 in stage IV.Conclusion Circulating TFH and TFR cell subpopulations and plasmablasts dynamically change in different stages of NSCLC,which is associated with serum CYFRA 21-1 levels and reflects disease progression.

Subpopulations of regulatory T cells are associated with subclinical atherosclerotic plaques,levels of LDL,and cardiorespiratory fitness in the elderly

Background:Atherosclerosis forms the pathological basis for the development of cardiovascular disease.Since pathological processes initially develop without clinically relevant symptoms,the identification of early markers in the subclinical stage plays an important role for initiating early interventions.There is evidence that regulatory T cells(Tregs)are involved in the development of atherosclerosis.Therefore,the present study aimed to identify and investigate associations with Tregs and their subsets in a cohort of healthy elderly individuals with and without subclinical atherosclerotic plaques(SAP).In addition,various lifestyle and risk factors,such as cardiorespiratory fitness,were investigated as associated signatures.Methods:A cross-sectional study was performed in 79 participants(male:n=50;age=63.6±3.7 years;body mass index=24.9±3.1 kg/m2;mean±SD)who had no previous diagnosis of chronic disease and were not taking medication.Ultrasound of the carotids to identify SAP,cardiovascular function measurement for vascular assessment and a cardiorespiratory fitness test to determine peak oxygen uptake were performed.Additionally,tests were conducted to assess blood lipids and determine glucose levels.Immunophenotyping of Tregs and their subtypes(resting(rTregs)and effector/memory(mTregs))was performed by 8-chanel flow cytometry.Participants were categorized according to atherosclerotic plaque status.Linear and logistic regression models were used to analyze associations between parameters.Results:SAP was detected in a total of 29 participants.The participants with plaque were older(64.8±3.6 years vs.62.9±3.5 years)and had higher peripheral systolic blood pressure(133.8±14.7 mmHg vs.125.8±10.9 mmHg).The participants with SAP were characterized by a lower percentage of rTregs(28.8%±10.7%vs.34.6%±10.7%)and a higher percentage of mTregs(40.3%±14.7%vs.30.0%±11.9%).Multiple logistic regression identified age(odds ratio(OR)=1.20(95%confidence interval(95%CI):1.011.42))and mTregs(OR=1.05(95%CI:1.021.10))as independent risk factors for SAP.Stepwise linear regression could reveal an association of peak oxygen uptake(β=0.441),low-density lipoprotein(LDL)(β=0.096),and SAP(β=6.733)with mTregs and LDL(β=0.104)with rTregs.Conclusion:While at an early stage of SAP,the total proportion of Tregs gives no indication of vascular changes,this is indicated by a shift in the Treg subgroups.Factors such as serum LDL or cardiopulmonary fitness may be associated with this shift and may also be additional diagnostic indicators.This could be used to initiate lifestyle-based preventive measures at an early stage,which may have a protective effect against disease progression.

Milk fat globule membrane supplementation protects againstβ-lactoglobul-ininduced food allergy in mice via upregulation of regulatory T cells and enhancement of intestinal barrier in a microbiota-derived short-chain fatty acids manner

Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.

Pien Tze Huang alleviates Concanavalin A-induced autoimmune hepatitis by regulating intestinal microbiota and memory regulatory T cells

BACKGROUND Traditional Chinese medicine has used the drug Pien Tze Huang(PTH),a classic prescription,to treat autoimmune hepatitis(AIH).However,the precise mode of action is still unknown.AIM To investigate the mechanism of PTH in an AIH mouse model by determining the changes in gut microbiota structure and memory regulatory T(mTreg)cells functional levels.METHODS Following induction of the AIH mouse model induced by Concanavalin A(Con A),prophylactic administration of PTH was given for 10 d.The levels of mTreg cells were measured by flow cytometry,and intestinal microbiota was analyzed by 16S rRNA analysis,while western blotting was used to identify activation of the toll-like receptor(TLR)2,TLR4/nuclear factor-κB(NF-κB),and CXCL16/CXCR6 signaling pathways.RESULTS In the liver of mice with AIH,PTH relieved the pathological damage and reduced the numbers of T helper type 17 cells and interferon-γ,tumor necrosis factor-alpha,interleukin(IL)-1β,IL-2,IL-6,and IL-21 expression.Simultaneously,PTH stimulated the abundance of helpful bacteria,promoted activation of the TLR2 signal,which may enhance Treg/mTreg cells quantity to produce IL-10,and suppressed activation of the TLR4/NF-κB and CXCL16/CXCR6 signaling pathways.CONCLUSION PTH regulates intestinal microbiota balance and restores mTreg cells to alleviate experimental AIH,which is closely related to the TLR/CXCL16/CXCR6/NF-κB signaling pathway.

Role of Peripheral Regulatory T Lymphocytes in Patients with Thyroid Associated Ophthalmopathy During Systemic Glucocorticoid Treatment:A Prospective Observational Study

Objective Thyroid-associated ophthalmopathy(TAO)is an autoimmune disorder involving the orbital tissue.This study aimed to understand the role of regulatory T cells(Tregs)in TAO during 12-week systemic glucocorticoid(GC)treatment.Methods Thirty-two moderate-severe TAO patients with a clinical activity score(CAS)≥3/7 or with prolonged T2 relaxation time(T2RT)on at least one side of extraocular muscle(EOM)were enrolled.The percentage of the peripheral CD4+CD25(high)CD127(−/low)Tregs was analyzed using flow cytometry before and after the GC treatment.The activity and severity of TAO,T2RT,and the clinical outcomes after the GC treatment were assessed.Their correlation with the peripheral Tregs was investigated.Results There was no significant association between the baseline Treg fraction and the activity and severity of TAO or the treatment response.A significant reduction of Tregs was observed after the GC therapy merely in patients without any clinical improvement.Conclusion Treg reduction after systemic GC therapy is indicative of a poor therapeutic response.Accordingly,dynamic alterations of Tregs could help to evaluate the effectiveness of the GC treatment.

CD4^(+)CD25^(+) regulatory T cells decreased future liver remnant after associating liver partition and portal vein ligation for staged hepatectomy

BACKGROUND Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS)is an innovative surgical approach for the treatment of massive hepatocellular carcinoma(HCC),the key to successful planned stage 2 ALPPS is future liver remnant(FLR)volume growth,but the exact mechanism has not been elucidated.The correlation between regulatory T cells(Tregs)and postoperative FLR regeneration has not been reported.AIM To investigate the effect of CD4^(+)CD25^(+)Tregs on FLR regeneration after ALPPS.METHODS Clinical data and specimens were collected from 37 patients who developed massive HCC treated with ALPPS.Flow cytometry was performed to detect changes in the proportion of CD4^(+)CD25^(+)Tregs to CD4^(+)T cells in peripheral blood before and after ALPPS.To analyze the relationship between peripheral blood CD4^(+)CD25^(+)Treg proportion and clinicopathological information and liver volume.RESULTS The postoperative CD4^(+)CD25^(+)Treg proportion in stage 1 ALPPS was negatively correlated with the amount of proliferation volume,proliferation rate,and kinetic growth rate(KGR)of the FLR after stage 1 ALPPS.Patients with low Treg proportion had significantly higher KGR than those with high Treg proportion(P=0.006);patients with high Treg proportion had more severe postoperative pathological liver fibrosis than those with low Treg proportion(P=0.043).The area under the receiver operating characteristic curve between the percentage of Tregs and proliferation volume,proliferation rate,and KGR were all greater than 0.70.CONCLUSION CD4^(+)CD25^(+)Tregs in the peripheral blood of patients with massive HCC at stage 1 ALPPS were negatively correlated with indicators of FLR regeneration after stage 1 ALPPS and may influence the degree of fibrosis in patients’livers.Treg percentage was highly accurate in predicting the FLR regeneration after stage 1 ALPPS.

Analysis of CD4^+CD25^+ Regulatory T Cells and Foxp3 mRNA in the Peripheral Blood of Patients with Asthma

The changes of CD4^＋CD25^＋ regulatory T cells （CD4^＋CD25^＋ Treg） and Foxp3 mRNA in peripheral blood mononuclear cells （PBMCs） from patients with asthma were investigated in order to elucidate the possible roles of CD4^＋CD25^＋ Treg in the development of asthma. The peripheral blood samples were collected from 29 healthy controls （normal control group） and 78 patients with asthma which included 30 patients in exacerbation group, 25 patients in persistent group, and 23 patients in remission group. By using flow cytometry and RT-PCR, the CD4^＋CD25^＋ Treg ratio and Foxp3 mRNA in PBMCs were detected. The CD4^＋CD25^＋ Treg ratio and Foxp3 mRNA in PBMCs of exacerbation and persistent groups were lower than that of remission and normal control groups （P〈0.05）. Although the CD4^＋CD25^＋ Treg ratio and Foxp3 mRNA of remission group were also lower than that of normal control group, there was no significant difference between them （P〉0.05）. As compared with persistent group, exacerbation group had lower CD4^＋CD25^＋ Treg ratio and Foxp3 mRNA （P〈0.05）. It was indicated that the decrease of CD4^＋CD25^＋ Treg ratio and its function in PBMCs may be responsible for pathogenesis of asthma.

Immunology Mechanism of CD4^＋ CD25^ T Regulatory Cells Acting on Effector T Cells

Objective:To detect the inhibiting co-stimulating molecule CTLA4 and cytokines secreted by Treg cells, and explore the immunology mechanism of T regulatory cells acting on effector T cells in co-cultured system(CCS) and separating-cultured system(SCS). Methods: Detecting the percentage of CTLA4 and CD28 expressed on the Treg cells and effector T cells, and then adding Treg cells to mixed lymphocyte reaction(MLR) system in CCS and TransWell Millicell-PCF SCS, at the same time, adding or not adding anti-IL-10 or anti-TGF-β1 to the reacting systems, examining the inhibitory capacity of Treg cells exerting on the MLR. Results: Compared with effector T cells, Treg cells expressed higher level CTLA4 and secreted much more IL-10 and TGF-β1(P<0.01). The inhibitory capacity of Treg cells co-cultured with effector T cells is much stronger than that in separating cultured group(P<0.01). Moreover, the inhibiting rate of Treg cells exerting on effector T cells through secreting IL-10 was more powerful than that through secreting TGF-β1(P<0.01). Conclusion: Both cell-to-cell contact and cytokines secretion mechanisms are involved in CD4 +CD25 + Treg cells operating function. However, the former is more important. Intrestingly, we for the first time point found that IL-10 plays more powerful roles than TGF-β1 in the cytokines secretion mechanism.

Influence of Danshen Injection on airway inflammation and CD4^+ CD25^+ regulatory T cells of asthmatic rats

Objective： To investigate the influence of Danshen Injection on airway inflammation and CD4^＋CD25^＋ regulatory T cells（CD4^＋CD25^＋ Tr） of asthmatic rats, and elucidate the possible mechanism of Danshen Injection in treatment of asthma. Methods： 30 Wister rats were randomly divided into control group, asthma group and Danshen Injection treated group. Bronchoalveolar lavage fluids （BALF） were collected, and cytology studies were conducted. Lung tissues were obtained and pathologic analyses were done with hematoxylin and eosin stain （HE）. Flow cytometry was used to detect the CD4^＋CD25^＋ Tr ratio in peripheral blood mononuclear cells （PBMCs）. Results： Total cell, the percentage of lymphocytes, neutrophils and eosinophils （Eos） in BALF of Danshen Injection-treated group were lower than that in asthma group （P〈0.05, P〈0.01）. Compared with asthma group, less infiltration of inflammatory cells in lung tissues was observed in Danshen Injection-treated group. CD4^＋CD25^＋ Tr of asthma group was lower than that of control and Danshen Injection treated group （P〈0.05）. Conclusion： Danshen Injection can suppress airway inflammation of asthmatic rats, probably by increasing the number of CD4^＋CD25^＋ Tr.

Depletion of CD4^+CD25^+ regulatory T cells can promote local immunity to suppress tumor growth in benzo[a]pyrene-induced forestomach carcinoma

AIM： To elucidate the distribution of CD4^＋CD25^＋ regulatory T cells （Tregs） in different lymphoid tissues and its local enhancement on tumor growth before and after depletion of CD4^＋CD25^＋ Tregs. METHODS： Female ICR mice were garaged with benzo[a]pyrene （BaP） to induce forestomach carcinoma. CD4^＋CD25^＋ Tregs were intraperitoneally depleted with monoclonal antibody PC61. These mice were divided into BaP-only, BaP ＋ IgG, BaP ＋ PC61, and control groups. The forestomach of mice was dissected for histological analysis, and tunnel test was performed for apoptosis of tumor cells. CD4^＋CD25^＋ Tregs were sorted from different lymphoid tissues and expression of Foxp3, IL-10, and chemokine receptors was analyzed by flow cytometry, semi-quantitative and veal-time polymerase chain reaction. RESULTS： The mice gavaged with only BaP showed increased forestomach papilloma and carcinoma at wk 16 and 32. The proportion of CD4^＋CD25^＋ Tregs was significantly higher in peri-stomach regional lymph nodes than in other lymphoid tissues. These CD4^＋CD25^＋ Tregs in regional lymph nodes expressed higher levels of Foxp3 and IL-10, enriched in the CD62L-subset, and CCR1 and CCR5 chemokine receptors. In mice gavaged with BaP ＋ PC61, the number of tumor nodules and tumor volume decreased significantly with massive infiltrating cells and apoptosis of tumor cells. In the draining regional lymph nodes, the number of CD4^＋CD25^＋ Tregs also decreased significantly. CONCLUSION： Inducible and activated CD4^＋CD25^＋ Tregs in the draining regional lymph nodes suppress host local immunity during tumor growth. Depletion of CD4^＋CD25^＋ Tregs can promote host local immunity to suppress tumor growth.

Isolation and identification of CD4^+CD25^+ regulatory T cells in rat

Objective： To establish a stable and high efficient method for collection of CD4^＋CD25^＋ regulatory T cells from rats in vitro. Methods： CD4^＋CD25^＋ regulatory T cells were isolated from the rat splenic cells through two steps by magic cell sorting （MACS） system. The first step was negative selection of CD4^＋T cells by cocktail antibodies and anti-IgG magic microbeads, and the second step was positive selection of CD25^＋T cells by anti-CD25 PE and anti-PE magic microbeads. The purity and viability of separated cells were measured by flow cytometry （FACS） and Trypan blue staining. The suppressive ability of seperated cells on the proliferation of CD4^＋CD25^- T cells was assessed by cell proliferation assay. Results： The purity of negatively enriched CD4^＋ T cells was 79%-87% （83.6%±2.5% ） , and the purity of positively enriched CD4^＋CD25^＋ T cells was 86%- 93% （ 90.2±1.8% ） with the viability of 92%～95% （92.8% ± 3.4% ）. The enriched cells significantly suppressed the proliferation of CD4^＋CD25^- T cells in mixed lymphocyte culture （P 〈 0.05）. Conclusion： An effective method can be established for enrichment of CD4^＋CD25^＋ regulatory T cells in two steps by MACS, with satisfied cell purity, viability and function.

Combination of tumor-associated regulatory T cell deletion and PD-1/PD-L1 blockade: A promising immunotherapy for hepatocellular carcinoma?

During the past decades,the treatment of hepatocellular carcinoma(HCC)has been limited to surgical resection and liver transplantation,but the prognosis is still poor.Recently,tumor immunotherapy,particularly immune checkpoints programmed cell death-1/programmed cell death ligand-1(PD-1/PD-L1)blockade,brings a breakthrough for HCC[1,2].However,anti-PD-1/PD-L1 immunotherapy is not satisfactory and the response rates were between 20%and 30%[3].How to improve the efficacy of PD-1/PD-L1blockade is the main issue.

Effect of CD4^+CD25^+ regulatory T cells in the development of anterior chamber-associated immune deviation

AIM: To investigate whether CD4(+)CD25(+) regulatory T (Treg) cells play a role in the development of anterior chamber-associated immune deviation (ACAID). METHODS: The dynamic changes in the frequency of CD4(+)D25(+) T cells, CD4(+)D25(+) FoxP3(+) T cells and CD4(+)CD25(+) PD-1(+) T cells from spleens of mice with ACAID were analyzed by flow cytometry. Foxp3 mRNA expression in purified CD4(+)CD25(+) T cells was analyzed using real-time PCR. The suppressive effect of purified CD4(+)CD25(+) T cells on the proliferation of CD4(+)CD25(-) T cells was evaluated by [H-3] thymidine incorporation. A blocking experiment was performed to further address the role of CD4(+)CD25(+) T cells in ACAID. The expression of IL-10 in purified CD4(+)CD25(+) T cells was evaluated by ELISA. RESULTS: Increased frequencies of CD4(+)CD25(+) T cells, CD4(+)CD25(+) Foxp3(+) T cells and CD4(+)CD25(+) PD-1(+) T cells were observed in ACAID. The CD4(+)CD25(+) T cells from mice with ACAID showed enhanced suppressive effect on the proliferation of CD4(+)CD25(-) T cells. Treatment of BALB/c mice with anti-CD25 antibody after injection of OVA into the anterior chamber significantly inhibited the induction of ACAID. Furthermore, purified CD4(+)CD25(+) T cells from ACAID mice secreted IL-10. CONCLUSION: Our results demonstrate that Treg cells are induced in the mice undergoing ACAID. These Treg cells may play a role in the development of ACAID.

CD4^+CD25^(high) Regulatory Cells in Peripheral Blood of NSCLC Patients

The proportion and changes of CD4^＋CD25^high regulatory T cells （Trs） in peripheral blood of non-small cell lung cancer （NSCLC） patients were analyzed and their clinical significance explored. The peripheral blood was collected from 61 patients with NSCLC and 15 healthy controls. By using monoclonal antibodies, the blood samples were evaluated with the flow cytometry for lymphocyte subsets （CD3^＋, CD4^＋ and CD8^＋） and CD4^＋CD25^high Tr cells. The results showed that the proportion of CD4^＋CD25^high Tr cells in NSCLC group was significantly higher than in control group [（4.36 ±2.07） % vs （2.04±1.03） %, P〈0.01]. The proportion of CD4^＋CD25^ high Tr cells in late stage was higher than that in early stage [stages Ⅰ ＋Ⅱ （2.264±0.6） %; stage Ⅲ（3.284± 1.38） %; stage IV （6.06 4±4.08） %] （P〈0.05）. Kaplan-Meier survival analysis revealed that the prognosis of the patients who had higher proportion of CD4^＋CD25^high Tr cells in peripheral blood was worse （P=0.0026）. In conclusion, the relative increase in CD4^＋CD25^high Tr cells in peripheral blood may be related to im- munosuppression and tumor progression in patients with NSCLC. This finding suggests that CD4^＋CD25^high Tr cells in peripheral blood of NSCLC may be positive for prognosis analysis. The use of depletion of the CD4^＋CD25^high Tr cell therapy to treat NSCLC patients may be an effective strategy.

INVESTIGATION OF REGULATORY T CELLS IN PATIENTS WITH NON-SMALL CELL LUNG CANCER

Objective To evaluate the prevalence of CD4 ^＋ CD25^high regulatory T cells （ Treg cells） in the peripheral blood mononuclear cells （PBMC） and tumor-infiltrating lymphocytes （TIL） of patients with non-small cell lung cancer （NSCLC） and to investigate immunosuppression to the progression of cancer. Methods Peripheral blood and tumor tissues were collected from 20 patients with NSCLC at the time of surgery. None of the patients received surgery, radiotherapy, chemotherapy, or other medical interventions before this study. Cancer stages of the patients were Ⅰ-Ⅲ A. Venous blood samples were obtained from 20 health donors. PBMC were isolated from blood samples by differential centrifugation over Ficoll-Hypaque. TILs were isolated from tumors by differential centrifugation over Ficoll-Hypaque and Percoll. Percentage of CD4^＋ CD25^highTr/CD4＋T in PBMC and TIL was assessed by the flow cytometry. Results The percentage of CD4^ ＋ CD25high Tr/ CD4 ^＋T in PBMC [ （4. 87 ± 1.22 ） % ] of NSCLC patients was significantly higher than that in healthy donors [ （ 2.36 ± 0. 72 ） % ] （ P 〈 0.01 ）. The percentage of CD4^＋ CD25^highTr/ CD4^＋ T in PBMC [ （5.40 ± 1.20） % ] of NSCLC patients in stage Ⅱ-Ⅲ A was significantly higher than that in stage Ⅰ [ （3. 87 ± 0. 22 ） % ] （ P 〈 0. 01 ）. The percentage of CD4 ＋ CD25hiShTr/ CD4 ＋ T in TIL[ （ 8. 66 ±0. 76） % ] of NSCLC patients in stage Ⅱ-Ⅲ A was significantly higher than that in stage Ⅰ [ （ 7. 04 ± 0. 80） % ] （ P 〈 0. 01 ）. Conclusion The prevalence of CD4 ^＋ CD25^highTreg cells in PBMC and TIL of NSCLC patients was significantly higher than that in healthy donors. These Treg cells may be preventing appropriate antitumor immune responses. The population of CD4^ ＋ CD25^highTreg cells in PBMC and TILs of NSCLC patients with Ⅱ-Ⅲ A stage was significantly higher than that of NSCLC patients with Ⅰ stage. These Treg cells may facilitate development of tumors.

Astragalus polysaccharide attenuates rat experimental colitis by inducing regulatory T cells in intestinal Peyer's patches

AIM: To explore probable mechanism underlying the therapeutic effect of Astragalus polysaccharide(APS) against experimental colitis.METHODS: Thirty-two Sprague-Dawley rats were randomly divided into four groups. Colitis was induced with 2, 4, 6-trinitrobenzene sulfonic acid(TNBS). The rats with colitis were treated with 400 mg/kg of APS for 7 d. The therapeutic effect was evaluated by colonic weight, weight index of the colon, colonic length, and macroscopic and histological scores. The levels of regulatory T(Treg) cells in Peyer's patches were measured by flow cytometry, and cytokines in colonic tissue homogenates were analyzed using enzyme-linked immunosorbent assay. The expression of related orphan receptor-gt(ROR-gt), IL-23 and STAT-5a was measured by Western blot.RESULTS: After 7-d treatment with APS, the weight index of the colon, colonic weight, macroscopical and histological scores were decreased, while the colonic length was increased compared with the model group. The expression of interleukin(IL)-2, IL-6, IL-17, IL-23 and ROR-gt in the colonic tissues was down-regulated, but Treg cells in Peyer's patches, TGF-β and STAT5 a in the colonic tissues were up-regulated.CONCLUSION: APS effectively ameliorates TNBSinduced experimental colitis in rats, probably through restoring the number of Treg cells, and inhibiting IL-17 levels in Peyer's patches.

Immunomodulation by mesenchymal stem cells:Interplay between mesenchymal stem cells and regulatory lymphocytes

Mesenchymal stem cells(MSCs) possess immunomodulatory properties, which confer enormous potential for clinical application. Considerable evidence revealed their efficacy on various animal models of autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus and uveitis. MSCs elicit their immunomodulatory effects by inhibiting lymphocyte activation and proliferation, forbidding the secretion of proinflammatory cytokines, limiting the function of antigen presenting cells, and inducing regulatory T(Treg) and B(Breg) cells. The induction of Treg and Breg cells is of particular interest since Treg and Breg cells have significant roles in maintaining immune tolerance. Several mechanisms have been proposed regarding to the MSCs-mediated induction of Treg and Breg cells. Accordingly, MSCs induce regulatory lymphocytes through secretion of multiple pleiotropic cytokines, cell-to-cell contact with target cells and modulation of antigen-presenting cells. Here, we summarized how MSCs induce Treg and Breg cells to provoke immunosuppression.

Curcumin improves regulatory T cells in gut-associated lymphoid tissue of colitis mice

AIM: To explore the probable pathway by which curcumin(Cur) regulates the function of Treg cells by observing the expression of costimulatory molecules of dendritic cells(DCs).METHODS: Experimental colitis was induced by administering 2, 4, 6-trinitrobenzene sulfonic acid(TNBS)/ethanol solution. Forty male C57BL/6 mice were randomly divided into four groups: normal, TNBS + Cur, TNBS + mesalazine(Mes) and TNBS groups. The mice in the TNBS + Cur and TNBS +Mes groups were treated with Cur and Mes, respectively, while those in the TNBS group were treated with physiological saline for 7 d. After treatment, the curative effect of Cur was evaluated by colonic weight, colonic length, weight index of the colon, and histological observation and score. The levels of CD4+CD25+Foxp3+ T cells(Treg cells) and costimulatory molecules of DCs were measured by flow cytometry. Also, related cytokines were analyzed by enzyme-linked immunosorbent assay. RESULTS: Cur alleviated inflammatory injury of the colonic mucosa, decreased colonic weigh and histological score, and restored colonic length. The number of Treg cells was increased, while the secretion of TNF-α, IL-2, IL-6, IL-12 p40, IL-17 and IL-21 and the expression of costimulatory molecules(CD205, CD54 [ICAM-1], TLR4, CD252[OX40 L], CD256 [RANK] and CD254 [RANK L]) of DCs were notably inhibited in colitis mice treated with Cur.CONCLUSION: Cur potentially modulates activation of DCs to enhance the suppressive functions of Treg cells and promote the recovery of damaged colonic mucosa in inflammatory bowel disease.

Disrupted regulatory T cell homeostasis in inflammatorybowel diseases

In the gut, where billions of non-self-antigens from the food and the microbiota are present, the immune response must be tightly regulated to ensure both host protection against pathogenic microorganisms and the absence of immune-related pathologies. It has been well documented that regulatory T cells(Tregs) play a pivotal role in this context. Indeed, Tregs are able to prevent excessive inflammation, which can lead to the rupture of intestinal homeostasis observed in inflammatory bowel diseases(IBDs). Both the worldwide incidence and prevalence of such diseases have increased throughout the latter part of the 20^(th) century. Therefore, it is crucial to understand how Tregs suppress the colitogenic immune cells to establish new treatments for patients suffering from IBDs. In this review, we will first summarize the results obtained in animal model studies that highlight the importance of Tregs in maintaining intestinal homeostasis and describe the specific suppressive mechanisms involved. Next, our current knowledge about Tregs contribution to human IBDs will be reviewed, as well as the current therapeutic perspective on using Tregs for clinical IBD treatment and the challenges that remain to be resolved to ensure both the safety and effectiveness of these therapies in targeting this critical immune-regulatory cell population.

Effects of estrogen on CD4^+ CD25^+ regulatory T cell in peripheral blood during pregnancy

Objective To investigate the effects of estrogen(E_2)level on regulatory T cells(Treg)in peripheral blood during pregnancy.Methods:A total of 30 healthy non-pregnant women were selected as control group,90 pregnant women of early,middle and late pregnancy and 30 postpartum women at 1 month after parturition were selected as experimental groups including early pregnancy group,middle pregnancy group and late pregnancy group;the proportions of CD4^+CD25^+Treg and CD4^+CD25^+CD127^-Treg among CD4 T cells were detected by flow cytometry;the serum estrogen content in peripheral blood was detected by electrochemical immune luminescence method.Results:E_2 level was coincident with the change of Tregs number during pregnancy.The estrogen content in peripheral blood increased gradually from early pregnancy to late pregnancy,then decreased significantly after parturition,and the level at 1 month after parturition down to the level in non-pregnancy group(P>0.05);the level of E_2 in pregnancy groups were significantly higher than those in non-pregnancy group(P<0.01);and there were significant differences among early pregnancy group,middle pregnancy group and late pregnancy group(P<0.05).The proportions of CD4^+CD25^+Treg and CD4^+CD25^+CD127^-Treg in pregnancy groups were significantly higher than those in non-pregnancy group(P<0.05),but decreased significantly after parturition,and there was no significant difference between non-pregnancy group and postpartum women group(P>0.05):the proportions in middle and late pregnancy groups were significantly higher than those in early pregnancy group(P<0.05).but decreased slightly in late pregnancy group,there was no significant difference between late pregnancy group and middle pregnancy group(P>0.05).There was correlation between Tregs number with estrogen level during pregnancy.The proportion of CD4^+CD25^+Treg and CD4^+CD25^+CD 127^-Treg were positively correlated with estrogen level.Conclusions:High proportion of CD4^+CD25^+Trcg and CD4^+CD25^+CD127^-Treg is closely related to the high level of E,during pregnancy.It suggested that high level of estrogen may induce an increase of CD4^+CD25^+Treg in peripheral blood.and then influence the immune function of pregnant women.The results of this experiment might play an important role of estrogen in immune-modulation during pregnancy.