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.

An Association between Immunosenescence and CD4^+CD25^+ Regulatory T Cells: A Systematic Review

Objective Age-related increment of the prevalence of CD4^＋CD25^＋ regulatory T （Treg） cells were described controversially, and whether such changes explain immune dysfunction in the elderly is still unclear. The aim of this systematic review is to evaluate the role of the Tregs in immunosenescence. Methods Medline and manual searches were performed to identify all published epidemiological and animal studies investigating the efficacy of the association between immunosenescence and Treg cells. Results It was founded that the frequency, phenotypic characteristics, and number/function of Tregs were altered significantly with aging. Medical conditions in individuals with advanced ageas well as apoptosis intensity of Treg cells had an impact on the accumulation of Tregs which in turn could deteriorate cytotoxic activity of CD8＋ T and NK cells and production of IL-2. The range of immune cells that could be suppressed by Treg cells was quite wide and covered CD4^＋CD25^＋ T cells, NK cells, dendritic cells and even monocytes. These changes were observed both in humans and experimental animals. Besides, it was believed that frequency of Tregs increased with age and was accompanied by intensified suppressive activity for Tregs in patients, for example, with Alzheimer disease （AD） and Parkinson disease （PD）. The impaired condition of CD4＋ T cells, so-called immunosenescence, rendered transplant recipients less responsive to an allogeneic kidney graft, an effect that was limited to transplant recipients who were aged over 60 years. Conclusions Treg cells are associated with immunosenescence. All these changes contribute to the aging-related decline of immune responses and lead to the higher risk of immune-mediated diseases, cancer or infections in aged individuals.

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 Patients with Acute Coronary Syndrome and the Effects of Atorvastatin

The function of CD4＋CD25＋ regulatory T lymphocytes （Treg） in patients with acute coronary syndrome （ACS） and the effects of atorvastatin were investigated. Forty-eight patients with ACS were randomly divided into two groups： group C receiving conventional therapy （n=24）, and group C＋A receiving conventional therapy＋atorvastatin （10 mg/day, n=24）. T lymphocytes from ACS patients （before and 2 weeks after the treatment） or 18 healthy subjects were separated and the flow cytometry was used to measure the percentage of Treg. The inhibitory ability of Treg on effector T cells was determined by mixed lymphocyte reaction （MLR）. ELISA was used to measure the serum levels of cytokines （IL-10, TGF-β1 and IFN-γ） before and after treatment. The results showed that as compared with normal control group, Treg percentage was decreased significantly （P〈0.01）, the inhibitory ability of Treg on the T lymphocytes proliferation was reduced （P〈0.01）, IFN-γ levels were increased and IL-10 and TGF-β1 levels were lowered in ACS patients. After treatment with atorvastatin, Treg percentage and the inhibitory ability of Treg on T lymphocytes proliferation were significantly increased in ACS patients. Serum IFN-γ was decreased significantly, while IL-10 and TGF-β1 were elevated significantly as compared with the non-atorvastatin group. The number of Treg was positively correlated with serum TGF-β1, but negatively with serum IFN-γ and CRP. It was concluded that ACS was associated with decreased number and defected function of Treg, which may play an important role in initiating immune-inflammatory response in ACS. The inhibitory effects of atorvastatin on inflammation in ACS may be due to its beneficial effects on Treg and restoration of immune homeostasis.

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.

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.

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.

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.

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.

Increase of CD4^+CD25^+ T cells in Smad3^(-/-) mice

AIM： To investigate the changes of lymphocyte subpopulations, especially CD4^＋CD25^ T regulatory cells in Smad3^-/- mice. METHODS： Hematological changes and changes of lymphocyte subpopulations were detected in Smad3＂/- mice using cell counter and flow cytometry, respectively, and compared to their littermate controls. RESULTS： The numbers of neutrophils and lymphocytes in peripheral blood were significantly increased in Smad3^-/- mice compared to littermate controls. CD19^＋ expressing cells in blood and spleen, and CD8^＋ T cells in thymus were all markedly decreased in Smad3^-/- mice. More important, Smad3^-/- mice had an increased population of CD4^＋CD25^＋ T cells in peripheral lymphoid tissues, including thymus, spleen, and lymph nodes. CONCLUSION： These observations suggest that the changes of lymphocyte subpopulations might play a role in susceptibility to inflammation of Smad3^-/- mice.

乌司他丁对脓毒症患者CD^(4+)CD^(25+)调节性T细胞变化的影响及其与预后的关系

目的探讨乌司他丁对脓毒症患者CD^(4+)CD^(25+)调节性T细胞(Treg)的影响及其与预后的关系。方法脓毒症患者随机分为乌司他丁治疗组和对照组,对照组给予常规的脓毒症治疗,乌司他丁治疗组在对照组的基础上加用乌司他丁治疗。分别于确诊后第1天、第3天、第5天比较两组间CD^(4+)CD^(25+)细胞/CD^(4+)细胞比例、白介素(IL-10)水平以及28 d死亡率。结果乌司他丁治疗组患者的病死率和ICU住院时间均低于对照组,差异均有统计学意义(χ~2=4.21,t=3.12,P均<0.05)。乌司他丁治疗组患者的CD^(4+)CD^(25+)细胞/CD^(4+)细胞比例和血清IL-10值在第1、3、5天组内比较,差异均有统计学意义(Hc分别=114.58、45.93,P均<0.05);乌司他丁治疗组第3天CD^(4+)CD^(25+)细胞/CD^(4+)细胞比例和IL-10值均高于第1天,第5天比例较第3天明显下降,差异均有统计学意义(t分别=10.57、6.43、3.73、5.08,P均<0.05)。在第3天,乌司他丁治疗组CD^(4+)CD^(25+)细胞/CD^(4+)细胞比例低于对照组,在第5天CD^(4+)CD^(25+)细胞/CD^(4+)细胞比例和IL-10值明显低于对照组,差异均有统计学意义(t分别=2.38、7.97、5.79,P均<0.05)。结论乌司他丁能抑制脓毒症患者CD^(4+)CD^(25+)Treg及IL-10的持续上升,避免出现免疫麻痹,降低病死率。

自身免疫性糖尿病患者CD_4^+CD_(25)^+T细胞的变化

目的通过观察自身免疫性糖尿病患者外周血CD4+CD25+T细胞的变化,探讨其在发病中的可能作用。方法流式细胞仪检测20例LADA、20例T1DM、20例T2DM及21例正常对照外周血CD4+CD25+、CD3+CD8+T细胞。结果①LADA、T1DM组外周血CD4+CD25+T细胞低于T2DM、正常对照组(p均<0.05)。②LADA、T1DM患者外周血CD3+CD8+T细胞较T2DM、正常对照组增高(LADAvs正常对照p<0.01,其余p<0.05)。结论自身免疫性糖尿病患者免疫调节性CD4+CD25+T细胞减少,不能有效维持对胰岛自身抗原的耐受;外周细胞毒性CD3+CD8+T细胞增多进而破坏胰岛β细胞,导致自身免疫性糖尿病的发生和发展。

Prognostic value of CD4^+CD25^+ Tregs as a valuable biomarker for patients with sepsis in ICU

BACKGROUND: Sepsis is a common complication ofinfections, burns, traumas, surgeries, poisonings, and post-cardiopulmonary resuscitation. The present study aimed to investigate prognostic value of CD4+CD25+ regulatory T cells(Treg) in peripheral blood of patients with sepsis.METHODS: Periphery blood from 28 patients diagnosed with sepsis was collected on day 1 and 7 after hospitalization in the ICU of Shanghai Changzheng Hospital between December 2013 to April 2014. The blood was used for analyses of Treg ratio using flow cytometry and for analyses of blood routine test, C-reactive protein(CRP), bilirubin, procalcitonin(PCT), and coagulation. APACHE II and sequential organ failure assessment(SOFA) scores were also investigated. The results were compared between two outcome groups of survival or death to evaluate prognostic value for sepsis.RESULTS: The patients had an average age of 60.36±15.03 years, APACHE II score 16.68±7.00, and SOFA score 7.18±3.78. Among the 28 patients, 12 had severe trauma(42.9%), 10 had septic shock(35.7%), and 9(32.2%) died. The median ratio of Tregs was 2.10%(0.80%, 3.10%) in the survival group vs. 1.80%(1.15%, 3.65%) in the death group(Z=–0.148, P=0.883) on day 1; however it was signifi cantly changed to 0.90%(0.30%, 2.80%) vs. 5.70%(2.60%, 8.30%)(Z=–2.905, P=0.004).CONCLUSION: With better prospects for clinical application, dynamic monitoring of Tregs ratio in peripheral blood has potential value in predicting prognosis of sepsis.

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.

Hepatocellular carcinoma and macrophage interaction induced tumor immunosuppressionvia Treg requires TLR4 signaling

AIM: To investigated the interaction between toll-like receptor 4 (TLR4)-activated hepatoma cells and macrophages in the induction of tumor-immune suppression mediated by CD4+CD25high family of transcription factor P3 (FOXP3) regulatory T cells (Tregs). METHODS: The proportion of FOXP3+ Tregs was identified in peripheral blood and tumor tissues of 60 hepatocellular carcinoma (HCC) patients. TLR4 expression was examined in tumor tissues and cell lines. The correlation was examined between FOXP3+ Tregs in peripheral blood and TLR4 expression of HCC tissues. Following activation of TLR4 in H22 murine hepatoma cells pre-incubated with lipopolysaccharide (LPS) and co-cultured with macrophage cell line RAW246.7, the synthesis of cytokines tumor necrosis factor-α, CCL22, and interleukin (IL)-10 by the two cell lines was detected and analyzed. RESULTS: FOXP3+ Tregs were enriched in tumor sites, and circulating FOXP3+ Tregs were increased in HCC patients in correlation with multiple tumor foci and up-regulated TLR4 expression in HCC tissues. Semi-quantitative analysis indicated that TLR4 was over-expressed in HCC compared with the matched normal tissues. Cell cultivation experiments indicated that the mRNAs of IL-10 and CCL22 were significantly up-regulated in the RAW246.7 cell line when co-cultured with LPS preincubated H22 cells. CONCLUSION: In hepatoma cell lines, TLR4 may indirectly facilitate the recruitment of Tregs to the tumor site and promote intrahepatic metastasis through its interaction with macrophages.

Alterations of peripheral CD4^(+)CD25^(+)Foxp3^(+)T regulatory cells in mice with STZ-induced diabetes

Complications arising from abnormal immune responses are the major causes of mortality and morbidity in diabetic patients.CD4^(+)CD25^(+)T regulatory cells(Tregs)play pivotal roles in controlling immune homeostasis,immunity and tolerance.The effect of hyperglycemia on CD4^(+)CD25^(+)Tregs has not yet been addressed.Here we used streptozotocin(STZ)-induced diabetic mice to study the effects of long-term hyperglycemia on CD4^(+)CD25^(+)Tregs in vivo.Four months after the onset of diabetes,the frequency of CD4^(+)CD25^(+)Foxp3^(+)T regulatory cells was significantly elevated in the spleen,peripheral blood lymphocytes(PBLs),peripheral lymph nodes(pLNs)and mesenteric LNs(mLNs).CD4^(+)CD25^(+)Tregs obtained from mice with diabetes displayed defective immunosuppressive functions and an activated/memory phenotype.Insulin administration rescued these changes in the CD4^(+)CD25^(+)Tregs of diabetic mice.The percentage of thymic CD4^(+)CD25^(+)naturally occurring Tregs(nTregs)and peripheral CD41Helios1Foxp31 nTregs were markedly enhanced in diabetic mice,indicating that thymic output contributed to the increased frequency of peripheral CD4^(+)CD25^(+)Tregs in diabetic mice.In an in vitro assay in which Tregs were induced fromCD4^(+)CD25^(+)T cells by transforming growth factor(TGF)-b,high glucose enhanced the efficiency of CD4^(+)CD25^(+)Foxp3^(+)T inducible Tregs(iTregs)induction.In addition,CD4^(+)CD25^(+)T cells from diabetic mice were more susceptible to CD4^(+)CD25^(+)Foxp3^(+)TiTreg differentiation than those cells from control mice.These data,together with the enhanced frequency of CD4^(+)CD25^(+)Foxp3^(+)T iTregs in the periphery of mice with diabetes,indicate that enhanced CD4^(+)CD25^(+)Foxp3^(+)T iTreg induction also contributes to a peripheral increase in CD4^(+)CD25^(+)Tregs in diabetic mice.Our data show that hyperglycemia may alter the frequency of CD4^(+)CD25^(+)Foxp3^(+)T Tregs in mice,which may result in late-state immune dysfunction in patients with diabetes.

Hepatitis C virus core protein triggers expansion and activation of CD4＋CD25＋ regulatory T cells in chronic hepatitis C patients

CD4＋CD25＋FoxP3 ＋ regulatory T ceils （Tregs） are increased in patients with chronic hepatitis C, which may contribute to the sustained suppression of hepatitis C virus （HCV）-specific T-cell responses and viral persistence in HCV-infected individuals. We postulated that HCV core protein （HCVc） directly contributes to the expansion of Tregs in HCV-infected patients, and we provide evidence to support this hypothesis in the report. Peripheral blood mononuclear cells （PBMCs） and sera were collected from 87 treatment-naive chronic HCV-infected patients, CD4＋CD25＋ Tregs were measured by flow cytometry, and HCV RNA and HCVc levels were detected using qPCR and enzyme-linked immunosorbent assay （ELISA）, respectively. CD4＋, CD8＋, CD4＋CD25＋ and CD4＋CD25- T cells were purified from healthy donors and cultured with recombinant HCVc and Toll-like receptor （TLR） ligands. Flow cytometry was used to analyze cell proliferation, and ELISA was performed to measure cytokine production. In the 87 chronic HCV-infected patients, HCVc showed a significant correlation with HCV RNA and CD4＋CD25＋Tregs. Mechanistic studies showed that HCVc, together with anti-CD3 antibody, augmented CD4＋CD25＋ Treg proliferation, but inhibited CD4＋CD25- T-cell proliferation and IFN-γ production, in a dose-dependent and Treg-dependent manner. Moreover, unlike the TLR3 ligand （poly hC） and the TLR4 ligand （lipopolysaccharide, LPS）, the TLR2 ligand （lipoteichoic acid, LTA） and HCVc both inhibited TCR-induced CD4＋ T-cell proliferation and IFN-γ secretion in a Treg-dependent manner. These data indicate that HCVc, like other TLR2 ligands, triggers CD4＋CD25＋ Treg activation and expansion to inhibit host immune responses, which may play a critical role in viral persistence in HCV-infected patients.

CD^＋4 CD^＋25 调节性T细胞与急性髓细胞白血病关系的研究

目的 探讨CD^＋4 CD^＋25 调节性T细胞（CD^＋4 CD^＋25 Treg细胞）在急性髓细胞白血病（AML）患者化疗前后外周血中的表达水平及其临床意义。方法 采用流式细胞术检测AML初发组（A组）、缓解3年内组（B组）、缓解3年以上组（C组）及正常对照组外周血中CD^＋4 CD^＋25 CDlow127 T细胞所占比例。结果 A组和B组外周血中CD^＋4 CD^＋25 Treg细胞比例均高于对照组（P＜0.05）；C组外周血CD^＋4 CD^＋25 Treg细胞比例与对照组相比差异无统计学意义（P＞0.05）；B组外周血中CD^＋4 CD^＋25 Treg细胞比例高于C组（P＜0.05）；A组外周血中CD^＋4 CD^＋25 Treg细胞比例明显高于B、C两组（P＜0.05）。结论 CD^＋4 CD^＋25 Treg细胞与AML发生有关，尤其与3年内容易复发密切相关。