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.

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.

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.

Regulatory T cells in skin regeneration and wound healing

As the body’s integumentary system,the skin is vulnerable to injuries.The subsequent wound healing processes aim to restore dermal and epidermal integrity and functionality.To this end,multiple tissue-resident cells and recruited immune cells cooperate to efficiently repair the injured tissue.Such temporally-and spatially-coordinated interplay necessitates tight regulation to prevent collateral damage such as overshooting immune responses and excessive inflammation.In this context,regulatory T cells(Tregs)hold a key role in balancing immune homeostasis and mediating cutaneous wound healing.A comprehensive understanding of Tregs’multifaceted field of activity may help decipher wound pathologies and,ultimately,establish new treatment modalities.Herein,we review the role of Tregs in orchestrating the regeneration of skin adnexa and catalyzing healthy wound repair.Further,we discuss how Tregs operate during fibrosis,keloidosis,and scarring.

Differentiation and immunosuppressive function of CD19^(+)CD24^(hi)CD27^(+) regulatory B cells are regulated through the miR-29a-3p/NFAT5 pathway

Background: Regulatory B cells(Bregs) is an indispensable element in inducing immune tolerance after liver transplantation. As one of the microRNAs(miRNAs), mi R-29a-3p also inhibits translation by degrading the target mRNA, and yet the relationship between Bregs and mi R-29a-3p has not yet been fully explored. This study aimed to investigate the impact of miR-29a-3p on the regulation of differentiation and immunosuppressive functions of memory Bregs(m Bregs) and ultimately provide potentially effective therapies in inducing immune tolerance after liver transplantation. Methods: Flow cytometry was employed to determine the levels of Bregs in peripheral blood mononuclear cells. TaqMan low-density array miRNA assays were used to identify the expression of different miRNAs, electroporation transfection was used to induce mi R-29a-3p overexpression and knockdown, and dual luciferase reporter assay was used to verify the target gene of miR-29a-3p. Results: In patients experiencing acute rejection after liver transplantation, the proportions and immunosuppressive function of m Bregs in the circulating blood were significantly impaired. mi R-29a-3p was found to be a regulator of m Bregs differentiation. Inhibition of miR-29a-3p, which targeted nuclear factor of activated T cells 5(NFAT5), resulted in a conspicuous boost in the differentiation and immunosuppressive function of m Bregs. The inhibition of mi R-29a-3p in CD19~+ B cells was capable of raising the expression levels of NFAT5, thereby promoting B cells to differentiate into m Bregs. In addition, the observed enhancement of differentiation and immunosuppressive function of m Bregs upon mi R-29a-3p inhibition was abolished by the knockdown of NFAT5 in B cells. Conclusions: mi R-29a-3p was found to be a crucial regulator for m Bregs differentiation and immunosuppressive function. Silencing mi R-29a-3p could be a potentially effective therapeutic strategy for inducing immune tolerance after liver transplantation.

Regulatory and activated effector T cells in chronic hepatitis C virus: Relation to autoimmunity

AIMTo investigate how Tregs are regulated in chronic hepatitis C virus (HCV) patients via assessment of Tregs markers (granzyme 2, CD69 and FoxP3), Teffs markers [TNFRSF4 (OX40), INFG] and CD4, CD25 genes. METHODSA prospective study was conducted on 120 subjects divided into 4 groups: Group I (n = 30) treatment naïve chronic HCV patients; Group II (n = 30) chronic HCV treated with Peg/Riba; Group III (n = 30) chronic HCV associated with non-organ specific autoantibody and Group IV (n = 30) healthy persons as a control group. Tregs and Teffs markers were assessed in peripheral blood mononuclear cells by quantitative real time reverse transcriptase-polymerase chain reaction. RESULTSChronic HCV patients exhibited significant higher levels of both Teffs and Tregs in comparison to healthy control group. Tregs markers were significantly decreased in Peg/Riba treated HCV patients in comparison to treatment naïve HCV group. In HCV patients with antinuclear antibody (ANA) +ve, Tregs markers were significantly decreased in comparison to all other studied groups. Teffs markers were significantly elevated in all HCV groups in comparison to control and in HCV group with ANA +ve in comparison to treatment naïve HCV group. CONCLUSIONElevated Tregs cells in chronic HCV patients dampen both CD4+ and CD8+ autologous T cell immune response. Interferon-α and ribavirin therapy suppress proliferation of Tregs. More significant suppression of Tregs was observed in HCV patients with autoantibodies favoring pathological autoimmune response.

Mechanism of T cell hyporesponsiveness to HBcAg is associated with regulatory T cells in chronic hepatitis B

AIM： To study the mechanisms of hyporesponsiveness of HBV-specific CD4^＋ T cells by testing TH1 and TH2 commitment and regulatory T cells. METHODS： Nine patients with chronic hepatitis B were enrolled. Peripheral blood mononuclear cells were stimulated with HBcAg or HBsAg to evaluate their potential to commit to TH1 and TH2 differentiation. HBcAg-specific activity of regulatory T cells was evaluated by staining with antibodies to CD4, CD25, CTLA-4 and interleukin-10. The role of regulatory T cells was further assessed by treatment with anti-interleukin-10 antibody and depletion of CD4^＋CD25^＋ cells. RESULTS： Level of mRNAs for T-bet, IL-12R β2 and IL-4 was significantly lower in the patients than in healthy subjects with HBcAg stimulation. Although populations of CD4^＋CD25^highCTLA-4^＋ T cells were not different between the patients and healthy subjects, IL-10 secreting cells were found in CD4^＋ cells and CD4^＋CD25^＋ cells in the patients in response to HBcAg, and they were not found in cells which were stimulated with HBsAg. Addition of anti-IL-10 antibody recovered the amount of HBcAgspecific TH1 antibody compared with control antibody （P 〈 0.01, 0.34% ± 0.12% vs 0.15% ± 0.04%）. Deletion of CD4^＋CD25^＋ T cells increased the amount of HBcAgspecific TH1 antibody when compared with lymphoo/tes reconstituted using regulatory T cells （P 〈 0.01, 0.03% ± 0.02% vs 0.18% ± 0.05%）.CONCLUSION： The results indicate that the mechanism of T cell hyporesponsiveness to HBcAg includes activation of HBcAg-induced regulatory T cells in contrast to an increase in TH2-committed cells in response to HBsAg.

Gastric cancer cells induce human CD4^+ Foxp3^+ regulatory T cells through the production of TGF-β1

AIM: To elucidate the molecular and cellular features responsible for the increase of regulatory T cells (Tregs) in gastric cancer. METHODS: The frequencies of CD4 + Foxp3 + Tregs and the level of transforming growth factor-β1 (TGF-β1) were analyzed from 56 patients with gastric cancer byflow cytometry and enzyme-linked immunosorbent assay respectively. Foxp3 gene expression was analyzed by real-time polymerase chain reaction. The gastric cancer microenvironment was modeled by establishing the coculture of gastric cancer cell line, MGC-803, with sorting CD4 + T cells. The normal gastric mucosa cell line, GES-1, was used as the control. The production of TGF-β1 was detected in supernatant of MGC and GES-1. The carboxyfluorescein diacetatesuccinimidyl ester (CFSE) dilution assay was performed to evaluate the proliferation characteristics of induced Tregs. Neutralizing anti-TGF-β1 antibody was added to the co-culture system for neutralization experiments. RESULTS: The level of serum TGF-β1 in gastric cancer patients (15.1 ± 5.5 ng/mL) was significantly higher than that of the genderand age-matched healthy controls (10.3 ± 3.4 ng/mL) (P < 0.05). Furthermore, the higher TGF-β1 level correlated with the increased population of CD4 + Foxp3 + Tregs in advanced gastric cancer (r = 0.576, P < 0.05). A significant higher frequency of CD4 + Foxp3 + Tregs was observed in PBMCs cultured with the supernatant of MGC than GES-1 (10.6% ± 0.6% vs 8.7% ± 0.7%, P < 0.05). Moreover, using the purified CD4 + CD25 T cells, we confirmed that the increased Tregs were mainly induced from the conversation of CD4 + CD25 naive T cells, and induced Tregs were functional and able to suppress the proliferation of effector T cells. Finally, we demonstrated that gastric cancer cells induced the increased CD4 + Foxp3 + Tregs via producing TGF-β1. Gastric cancer cells upregulated the production of TGF-β1 and blockade of TGF-β1 partly abrogated Tregs phenotype. CONCLUSION: Gastric cancer cell can induce Tregs development via producing TGF-β1, by which the existence of cross-talk between the tumor and immune cells might regulate anti-tumor immune responses.

Immunosuppressive effects of rat mesenchymal stem cells:involvement of CD4^+ CD25^+ regulatory T cells

BACKGROUND: Recent studies show that mesenchymal stem cells (MSCs) have immunomodulatory properties. They suppress the immune response to alloantigen and modify the proliferation of T cells. CD4(+)CD25(+) regulatory T cells have strong immunomodulatory potential. However, little is known about the effects of rat MSCs (rMSCs) on the development of regulatory T cells. METHODS: MSCs were obtained from bone marrow of male Sprague-Dawley rats, and co-cultured with CD3(+) T cells from allogeneic spleen cells. The proportion of CD4(+)CD25(+) regulatory T cells was analyzed by flow cytometry. To further confirm the immunosuppressive activity of rMSCs, we used MTT assay and flow cytometry of CD3(+) T cells to investigate the proliferative responses of CD3(+) T cells to mitogenic stimuli. Enzyme-linked immunosorbent assay was performed to detect alterations of the cytokines TNF-alpha, TGF-beta and IL-10. RESULTS: The proliferation of CD3(+) T cells decreased when co-cultured with rMSCs, and the degree of inhibition was concentration-dependent. The percentage of CD4(+)CD25(+) regulatory T cells increased when CD3(+) T cells were co-cultured with different concentrations of rMSCs. The levels of pro-inflammatory cytokine (TNF-alpha) decreased while anti-inflammatory JGF-beta, IL-10) cytokines increased in mixed lymphocyte reaction. CONCLUSIONS: rMSCs inhibit allogeneic T cell proliferation in mixed cell cultures. This immunosuppressive effect seems to be mediated by inducing the generation of CD4(+)CD25(+) regulatory T cells and soluble factors.

Analysis of circulating regulatory T cells （CD4 ＋CD25 ＋CD 127-）after cryosurgery in prostate cancer

This study was performed to assess the response of regulatory T cells （Tregs） following cryosurgery in prostate cancer （PCa） patients by measuring their frequency and immune function. Blood was collected prior to and at 4 and 8 weeks after treatment in 30 patients with high-risk PCa who underwent cryosurgery and from 15 healthy volunteers. Circulating CD4＋CD25＋CD127- Tregs were isolated. Their frequency was detected by flow cytometry, and immune suppressive function was evaluated by measuring the proliferation of CD4＋CD25- T cells cocultured with Tregs. The results showed that the percentage of circulating CD4＋CD25＋CD127- Tregs was increased in PCa patients compared to healthy volunteers （7.6%±0.73% vs. 5.8%±0.54%, P〈0.001）. The frequency of circulating CD4＋CD25＋CD127- Tregs was reduced 4 weeks after cryosurgery compared to before surgery （6.3%__.0.58% vs. 7.6%±0.73%, P〈0.001）, and the decrease persisted for 8 weeks. However, the suppressive function of Tregs was increased in eight of 12 patients, which might contribute to cancer recurrence. Then the response of circulating Tregs is complicated after cryosurgery for PCa, and further studies are warranted.

Regulatory T cells in viral hepatitis

The pathogenesis and outcome of viral infections are significantly influenced by the host immune response. The immune system is able to eliminate many viruses in the acute phase of infection. However, some viruses, like hepatitis C virus (HCV) and hepatitis B virus (HBV), can evade the host immune responses and establish a persistent infection. HCV and HBV persistence is caused by various mechanisms, like subversion of innate immune responses by viral factors, the emergence of T cell escape mutations, or T cell dysfunction and suppression. Recently, it has become evident that regulatory T cells may contribute to the pathogenesis and outcome of viral infections by suppressing antiviral immune responses. Indeed, the control of HCV and HBV specific immune responses mediated by regulatory T cells may be one mechanism that favors viral persistence, but it may also prevent the host from overwhelming T cell activity and liver damage. This review will focus on the role of regulatory T cells in viral hepatitis.

Regulatory T cells in patients with inflammatory bowel diseases treated with adacolumn granulocytapheresis

AIM: To investigate if the clinical efficacy of granulocytes and monocytes by adsorption (GMA) is associated with an increased frequency of peripheral regulatory T cells (Tregs), as these cells have proven to be successful in suppressing inflammatory bowel disease (IBD) in animal models. METHODS: We report four cases of corticosteroid- dependent ulcerative colitis (UC) and two Crohn’s disease (CD) cases with severe cutaneous lesions who received GMA therapy. The frequency of CD4+ CD25high (Tregs) in peripheral blood was analyzed by flow cytometry and the expression of FoxP3 and TGF beta in purified CD4+ T cells was determined by real time PCR prior to and one month after the last apheresis session, and at the time of endoscopic and clinical assessing. RESULTS: Increased expression of Fox P3 mRNA was found in all five patients who responded to cytapheresis with remission of clinical symptoms, mucosal inflammation and cutaneous lesions, and an increased frequency of circulating Tregs was found in four patients. These changes were not observed in the patient with UC who did no respond to GMA. Variations in TGF-β (mRNA) did not parallel that of FoxP3 mRNA. CONCLUSION: The clinical efficacy of GMA on IBD and related extra intestinal manifestations was associated with an expansion of circulating CD4+ CD25+ Tregs and higher expression of FoxP3 in CD4+ T cells. Accordingly, an elevated CD4+ CD25+ FoxP3 may be a valuable index of remission in patients with IBD and other chronic relapsing-remitting inflammatory conditions during treatment with GMA.

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.

Association of T regulatory cells with natural course and response to treatment with interferon-α in patients with chronic hepatitis B infection

Background Regulatory T cell populations, particularly CD4＋CD25＋ T regulatory cells, have been implicated in the persistence of hepatitis B virus （HBV） infection. However, no clear relationship has been established between the frequency of CD4~CD25~ T regulatory cells in the peripheral blood and either the disease phases in the natural history of chronic HBV infection or in the response to interferon-a therapy. Methods In the present study, three different common markers of CD4＋CD25＋ T regulatory cells were used to determine the numbers of T regulatory cells in healthy controls and in patients with chronic HBV infection. Results No significant difference was found when samples were gated for CD25hi and CD25＋FoxP3＋ T cells. A significant correlation was found between the number of CD4＋ Treg cells that gated with CD25＋FoxP3＋ and CD25＋CD127low/- in healthy controls and in patients with chronic hepatitis B （CHB） （r=0.67, 0.59; P 〈0.01）. The percentages of Treg cells were （8.56±2.01）% in asymptomatic carriers （Asc）, （8.74±3.04）% in inactive HBsAg carriers, （10.7±2.93）% in CHB and （7.42±1.28）% in healthy controls （F=-11.1, P 〈0.001）. The percentage of Treg cells in patients with CHB was higher than in asymptomatic HBV patients, inactive HBsAg carriers, or healthy controls （P 〈0.01）. The proportion of CD4＋CD25＋CD127 low/T cells in patients who responded to interferon-（] was （11.9±3.3）%, （9.1±2.4）% and （9.0±2.9）% at baseline, week 12 and week 24 after treatment, respectively （Z=2.42, P〈0.05; Z=2.67, P〈0.01）. Conclusions These results suggest that the proportion of the CD4＋CD25＋ regulatory T cells might be affected by the application of different markers in process to detect T regulatory cells. The frequency of Treg cells was increased in patients with CHB, which might be associated with the disease activity of these patients and contribute to prevention of extensive liver damage. A decline in Treg cells at week 12 of treatment might be associated with a better response to treatment with interferon-α.

Regulatory T cells in inflammatory bowel diseases and colorectal cancer

Regulatory T cells(T regs) are key elements in immunological self-tolerance.The number of T regs may alter in both peripheral blood and in colonic mucosa during pathological circumstances.The local cellular,microbiological and cytokine milieu affect immunophenotype and function of T regs.Forkhead box P3+ T regs function shows altered properties in inflammatory bowel diseases(IBDs).This alteration of T regs function can furthermore be observed between Crohn's disease and ulcerative colitis,which may have both clinical and therapeutical consequences.Chronic mucosal inflammation may also influence T regs function,which together with the intestinal bacterial flora seem to have a supporting role in colitis-associated colorectal carcinogenesis.T regs have a crucial role in the immunoevasion of cancer cells in sporadic colorectal cancer.Furthermore,their number and phenotype correlate closely with the clinical outcome of the disease,even if their contribution to carcinogenesis has previously been controversial.Despite knowledge of the clinical relationship between IBD and colitis-associated colon cancer,and the growing number of immunological aspects encompassing sporadic colorectal carcinogenesis,the molecular and cellular links amongst T regs,regulation of the inflammation,and cancer development are still not well understood.In this paper,we aimed to review the current data surrounding the role of T regs in the pathogenesis of IBD,colitis-associated colon cancer and sporadic colorectal cancer.

Establishment of Nasal Tolerance to Heat Shock Protein-60 Alleviates Atherosclerosis by Inducing TGF-β-dependent Regulatory T Cells

Mounting evidence supports that a newly identified regulatory T cell (Treg),CD4+LAP+ Treg,is associated with oral tolerance induction and following inhibition of atherosclerosis,but little is described about whether nasal tolerance to antigen likewise induces the novel Tregs production and the relevant antiatherosclerotic benefit.We investigated the effect of nasal administration of heat shock protein-60 (HSP60) on atherogenesis.HSP60 or phosphate buffer solution (PBS) was nasally adminis-tered to six-week-old male ApoE-/-mice.At the 10th week after the nasal administration,there was a significant decrease in atherosclerotic plaque areas of aortic roots in the HSP60-treated mice as com-pared with those in the PBS-treated mice.Atherosclerosis suppression was accompanied with a signifi-cant increase in CD4+LAP+ and CD4+CD25+Foxp3+ Tregs and a concurrently increased production of TGF-β in the HSP60-treated mice.The protective effect of HSP60 was offset by injection of anti-TGF-βantibody.It is concluded that nasal administration of HSP60 can inhibit atherosclerotic formation through immune tolerance which is established by Tregs depending on the induction of anti-inflammatory cytokine TGF-β.Immune tolerance induced by nasal administration of HSP60 may provide an alternative therapeutic method for atherosclerosis.

Rapamycin ameliorates experimental autoimmune uveoretinitis by inhibiting Th1/Th2/Th17 cells and upregulating CD4+CD25+ Foxp3 regulatory T cells

· AIM: To determine the effects of rapamycin on experimental autoimmune uveoretinitis(EAU) and investigate of role of rapamycin on T cell subsets in the disease.·METHODS: EAU was induced in rats using peptides1169 to 1191 of the interphotoreceptor binding protein(IRBP). Rapamycin(0.2 mg/kg/d) was administrated by intraperitoneal injection for a consecutive 7d after immunization. Th1/Th2/Th17 cytokines, TGF-β1, and IL-6produced by lymphocyteswere measured by ELISA, while Th17 cells and CD4 +CD25 + regulatory T cells(Tregs)from rat spleen were detected by flow cytometry.·RESULTS: Intraperitoneal treatment immediately after immunization dramatically ameliorated the clinical course of EAU. Clinical responses were associated with reduced retinal inflammatory cell infiltration and tissue destruction. Rapamycin induced suppression of Th1/Th2/Th17 cytokines, including IFN-γ, IL-2, IL-17, IL-4, and IL-10 release from T lymphocytes of EAU rats, in vitro.Rapamycin also significantly increased TGF-β1production but had no effect on IL-6 productionof T lymphocytes from EAU rats in vitro. Furthermore,rapamycin decreased the ratio of Th17 cells/CD4 +T cells and upregulated Tregs in EAU, as detected by flow cytometry.·CONCLUSION: Rapamycin effectively interferes with T cell mediated autoimmune uveitis by inhibiting antigen-specific T cell functions and enhancing Tregs in EAU.Rapamycin is a promising new alternative as an adjunct corticosteroid-sparing agent for treating uveitis.

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.

Changes of CD4^+ CD25^+ Regulatory T Cells in Peripheral Blood in Patients with Hepatocellular Carcinoma Before and after TACE

This study investigated the changes of CD4＋ CD25＋ regulatory T cells （Tregs） in periph-eral blood of patients with hepatocellular carcinoma before and after transcatheter arterial chemoem-bolization （TACE）. The proportion of CD4＋ CD25＋ Tregs among CD4＋ T lymphocytes in peripheral blood of 33 patients with hepatocellular carcinoma was determined by flow cytometry before, 1 week and 1 month after TACE. And 25 healthy volunteers served as control. One month after TACE, the patients were divided into two groups： 22 in group A, who were in stable condition or getting better; and 10 in group B, who were deteriorating. One patient died and was excluded. The results showed that the percentage of CD4＋CD25＋ Tregs among CD4＋ T lymphocytes did not significantly change in the 33 patients 1 week after TACE as compared with that before TACE, however, the difference was significant （P〈0.01） between the patients with hepatocellular carcinoma and the healthy subjects. The percentage of CD4＋ CD25＋ Tregs among CD4＋ T lymphocytes in group A 1 month after TACE was decreased significantly in comparison with that before and 1 week after TACE （P〈0.01）, whereas, that in group B was increased significantly 1 month after TACE （P〈0.01）. It was concluded that patients with hepatocellular carcinoma had a higher proportion of CD4＋CD25＋ Tregs in peripheral blood. TACE did not significantly affect the level of CD4＋ CD25＋ Tregs within short time （such as 1 week）. The proportion of CD4＋CD25＋ Tregs in peripheral blood 1 month after TACE was related to the prognosis of hepatocellular carcinoma.