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.

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.

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.

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.

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.

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.

Viral infection parameters not nucleoside analogue itself correlates with host immunity in nucleoside analogue therapy for chronic hepatitis B

AIM: To determine the relationship between host immunity and the characteristics of viral infection or nucleoside analogues (NAs) themselves in patients with chronic hepatitis B (CHB) receiving NA therapy.

Biological features of intrahepatic CD4^(+)CD25^(+)T cells in the naturally tolerance of rat liver transplantation

The biological features of intrahepatic CD4^(+)CD25^(+)T regulatory cells in the naturally tolerance of rat liver transplantation were explored.Orthotopic liver transplan-tation was performed in two allogeneic rat strain combina-tions,one with fatal immunosuppression despite a complete major histocompatibility complex mismatch.The subjects were divided into three groups according to different donors and recipients[Tolerance group:LEW-to-DA;Rejection group:DA-to-LEW;Syngegnic group(control group):DA-to-DA].The proportion of intrahepatic CD4^(+)CD25^(+)T cells from three groups was determined by flow cytometry(FCM)in different time.The intrahepaitc CD4^(+)CD25^(+)T cells were isolated by magnetic activated cell sorting(MACS)method and identified by FCM.The Foxp3 mRNA was detected by reverse transcriptase polymerase chain reaction(RT-PCR).And their suppression on the proliferation of CD4^(+)CD25^(-)T effector cells was analyzed by cell proliferation assay in vitro.Beginning immediately after transplantation,the proportion of Treg cells increased over time in both allogeneic groups but was significantly greater in the Rejection group.The pro-portion of Treg cells declined after day 5,and such reduction was more dramatic in the Rejection group than in the Tole-rance group.Animals in the Tolerance group showed a second increase in the proportion after day 14.Intrahepatic CD4^(+)CD25^(+)T cells isolated from spontaneous tolerance models inhibited the proliferation of mixed lymphocyte reaction.The purity of CD4^(+)CD25^(+)Tcells sorted by MACS was 86%–93%.The CD4^(+)CD25^(+)T cells could specifically express the Foxp3 gene compared with CD4^(+)CD25^(-)T cells.In vitro,the spleen cells from LEW rats can irritate the proliferation of CD4^(+)CD25^(+)T cells more obviously than the syngegnic spleen cells.CD4^(+)CD25^(+)Tr cells could suppress the proliferation of CD4^(+)CD25^(-)T cells,but the inhibition was reversed by exo-genous IL-2(200 U/mL).The CD4^(+)CD25^(+)T regulatory cells specifically express the Foxp3 gene,which may play animpor-tant role in the induction of liver transplantation tolerance by suppressing the reaction of effective T cells.

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.

Immune responses on allograft heart transplantation in inbred rats infected with Echinococcosis multilocularis

Background Alveolar echinococcosis （AE） is caused by the metacestode stage of Echinococcus multilocularis （E. multilocularis） and is a rare but life-threatening disease. This disease commonly is characterized by an infiltrative, tumor-like growth of the E. multilocularis metacestode in the liver of human. Liver transplantation is an effective therapy for end-stage of hepatic AE, but the characteristics of host immunity associated with E. multilocularis infection with organ transplantation are poorly defined. We hereby aimed to study the immunological status and allograft heart survival in inbred rats with E. multilocularis infection. Methods Rat models of AE were established by injecting the E. multilocularis suspension made from E. multilocularis infected tissues into the abdomen of Lewis （LEW） rats. Three months later, in the experimental group, allograft heart transplantation was performed from Brown-Norway （BN） rats to the E. multilocularis infected LEW rats. In the control group, we transplanted hearts from BN rats to healthy LEW rats. The influence of the disturbed immune system in E. multilocularis infected rats on the heart transplantation was assessed, including observation of allograft heart survival time, histopathological examination of grafts and immunohistochemical examination of infiltrating cells （CD4＋ T cells, CD8＋ T cells and eosinophile granulocytes）, measurement of interleukin （IL）-4 and interferon （IFN）-γ in the serum by enzyme-linked immunosorbent assay （ELISA） and analysis of CD4＋CD25＋ regulatory T cells in peripheral blood by fluorescence activated cell sorting （FACS） flow cytometric analysis. Results The survival time of recipients in the experimental group was prolonged compared with those in the control group. The numbers of graft infiltrating CD8＋ T cells were decreased whereas the graft infiltrating eosinophil granulocytes （CD15＋） were increased in grafts in the experimental group （P 〈0.05）. Furthermore, the proportion of CD4＋CD25＋regulatory T cells in the peripheral blood was 10.8% on average in the experimental group, which was significantly higher than that in the control group （6.1%）. In addition, the level of serum IL-4 in E. multilocularis infected rats was higher than that in the control group rats, whereas the level of serum IFN-γ in experimental group was lower than that in the control group when graft rejection occurred （P 〈0.05）. Conclusions This study suggests that E. multilocularis infection could prolong the allograft survival time through the polarization of Th1/Th2-type cells and induction of CD4＋CD25＋ regulatory T cells. This strategy may provide a new idea for establishing transplantation tolerance.