Involvement of CD4^＋CD25^＋ regulatory T cells in the pathogenesis of polycythaemia vera

Background Regulatory T cells （mreg） have been shown to play an important role in the regulation of hematopoietic activity. However, there is no information about the effect of Treg cells in the pathogenesis of polycythaemia vera （PV）. Methods In this study, we investigated the percentage and function of Treg cells in the peripheral blood of 21 PV patients and 25 healthy donors, mreg cells were identified and characterized as CD4^＋CD25^＋FOXP3^＋ by flow cytometry. The suppressive activity of CD4^＋CD25^＋ Treg cells was assessed by the proliferation and cytokine secretion of the co-cultured CD4^＋CD25^- fractions. Results The results showed that the percentage of Treg cells in the peripheral blood of PV patients significantly increased compared to healthy controls （（10.93±4.02）% vs （5.86±1.99）%, P 〈0.05）. Moreover, the mRNA and protein expression of FOXP3 was higher in CD4^＋CD25^＋ Treg cells. Coordinately, when co-cultured with the activated CD4^＋CD25^- cells, the CD4^＋CD25^＋ Treg cells showed enhanced suppressive function in PV. Yet, the underlying mechanism for the increased frequency and function of CD4^＋CD25^＋ Treg cells is still to be clarified. Conclusion Treg cells expansion might account for the abnormal T cell immunity in PV patients and thus contribute to the pathogenesis of PV.     

An Association between Immunosenescence and CD^4＋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.     

Impact of baseline CD4^＋ T cell counts on the efficacy of nevirapinebased highly active antiretroviral therapy in Chinese HIV/AIDS patients： a prospective,multicentric study

Background CD4^＋T cell counts have been used as the indicator of human immunodeficiency virus type 1 （HIV-1） disease progression and thereby to determine when to start highly active antiretroviral therapy （HAART）. Whether and how the baseline CD4^＋T cell count affects the immunological and viral responses or adverse reactions to nevirapine （NVP）-containing HAART in Chinese HIV-1 infected adults remain to be characterized. Methods One hundred and ninety-eight HIV-seropositive antiretroviral therapy （ART）-naive subjects were enrolled into a prospective study from 2005 to 2007. Data were analyzed by groups based on baseline CD4^＋T cell counts either between 100-200 cells/μl or 201-350 cells/μl. Viral responses, immunologic responses and adverse events were monitored at baseline and at weeks 4, 12, 24, 36, 52, 68, 84, 100. Results Eighty-six and 112 subjects ranged their CD4^＋T cell counts 100-200 cells/μl and 201-350 cells/μl, respectively. The pre-HAART viral load in CD4 201-350 cells/μl group was significantly lower than that in CD4 100-200 cells/μl group （P=0.000）. After treatment, no significant differences were observed between these two groups either in the plasma viral load （pVL） or in the viral response rate calculated as the percentage of pVL less than 50 copies/ml or less than 400 copies/ml. The CD4^＋T cell counts were statistically higher in the 201-350 group during the entire follow-ups （P 〈0.01） though CD4^＋ T cell count increases were similar in these two groups. After 100-week treatment, the median of CD4^＋ T cell counts were increased to 331 cells/μl for CD4 100-200 cells/μl group and to 462 cells/μl for CD4 201-350 cells/μl group. Only a slightly higher incidence of nausea was observed in CD4 201-350 cells/μl group （P=0.05） among all adverse reactions, including rash and liver function abnormality. Conclusions The pVLs and viral response rates are unlikely to be associated with the baseline CD4^＋T cell counts. Initiating HAART in Chinese HIV-1 infected patients with higher baseline CD4^＋T cell counts could result in higher total CD4^＋T cell counts thereby achieve a better immune recovery. These results support current guidelines to start HAART at a threshold of 350 cells/μl.     

Changes of Regulatory T Cells in Graves＇ Disease

The immune mechanism of Graves＇ diseases （GD） and the roles of regulator T cells were investigated. In 32 patients with GD （GD group） and 20 healthy volunteers （control group）, flow cytometry was used to detect the proportion of CD4^＋CD25^＋ cells, MACS to isolate CD4^＋ CD25^＋ cells, RT-PCR to assay the expression of FOXP3, and ELISA to test the leyel of IL-10, respectively. It was found that there was no significant change in the proportion of CD4^＋CD25^＋ T cells between GD group and control group （P〉0.05）, while secretion of IL-10 and expression of FOXP3 in GD group were lower than control group （P〈0.01 and P〈0.05, respectively）. In conclusion, though the proportion of regulatory T cells of peripheral blood lymphocytes in the patients with GD, the functions of them were significantly weakened, which might be a pathogenic factor in GD.     

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.     

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 exac-erbation 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.     

HIV-Specific IL-2^＋ and/or IFN-γ^＋ CD8^＋ T Cell Reponses during Chronic HIV-1 Infection in Former Blood Donors

Objective Conflicting data have been generated from previous studies to determine which kind of relationship exists between HIV-1 specific CD8 Tcell responses and HIV-1 viral load or CD4 count over the course of infection.In this study,153 HIV-1 infected LTNPs were enrolled to investigate the role of HIV-1 specific CD8 T-cell responses in chronic HIV-1 infection among HIV-1 infected former blood donors.Methods The patients were stratified into three groups according to CD4 count：CD4≥500 cells/μL;350 cells/μL≤CD4〈500 cells/μL;CD4〈350 cells/μL.PBMCs were isolated from the patients＇ anticoagulated blood samples.IL-2 and IFN-γ secretions of CD 8 T cells against 17 HIV-1 consensus B full peptide pools were analyzed by using ICS assay.Results An overall inverse correlation were observed between CD4 count and plasma viral load.Although no significant difference was observed during the comparisons of frequency/breadth of HIV-1 specific CD8 T cell responses,CD4 count stratification analysis showed that different correlation pattern existed in three strata：as for patients whose CD4 counts were less than 350 cells/μL,no significant correlations were identified between frequency/breadth of HIV-1 specific CD8 T cell responses and CD4 count/viral load;as for patients whose CD4 counts ranged from 350 cells /μL to 500 cells/μL,significant correlation was only observed between the response breadth of IL-2＋IFN-γ＋ CD8 T cells and CD4 count;however,as for patients whose CD4 counts were more than 500 cells/μL,direct correlations were identified between IL-2＋IFN-γ＋/IL-2＋/IFN-γ＋ CD8 T cells and viral load or CD4 count.Conclusions Universal consistent inverse correlation was only indentified between CD4 count and viral load.The relationship between HIV-1 specific CD8 T cell responses and CD4 count/viral load varied in different CD4 strata,which showed that better preserved CD4 T cells were correlated with better CD8 T cell functions.     

Frequencies and characterization of HBV-specific cytotoxic T lymphocytes in self-limited and chronic hepatitis B viral infection in China

Hepatitis B virus （HBV）-specific cytotoxic T lymphocytes （CTLs） are believed to play a major role in viral clearance and disease pathogenesis during HBV infection. To clarify the differences in host immune responses between self-limited and chronic HBV infections, we constructed three HLA-A＊0201/HBV tetramers with immunodominant epitopes of core18-27, polymerase 575-583 and envelope 335-343, and analyzed the HBV-specific CTLs in peripheral blood mononuclear cells （PBMCs） from patients infected with HBV. The frequencies and expansion ability of HBV-specific CD8＋T cells in most self-limited HBV infected individuals were higher than those in chronic HBV-infected patients. HBV-specific CD8＋T cells could be induced by in vitro peptide stimulation from chronic patients with a low level of serum HBV-DNA but not from those with a high level of serum HBV-DNA. In chronic infection, no significant correlation was found either between the frequencies of HBV-specific CD8^＋ T cells and the viral load, or between the frequencies and the levels of alanine transaminase. Our results suggested that the frequencies of HBV-specific CTLs are not the main determinant of immune-mediated protection in chronic HBV infection and immunotherapeutic approaches should be aimed at not only boosting a HBV-specific CD8^＋T response but also improving its function.     

Expression of surface markers on peripheral CD4＋CD25^high T cells in patients with atopic asthma： role of inhaled corticosteroid

Background CD4^＋CD25^＋ regulatory T cells （Tregs） mediate immune suppression through cell-cell contact with surface molecules, particularly cytotoxic T lymphocyte-associated antigen 4 （CTLA-4）, glucocorticoid-induced tumor necrosis factor receptor family-related protein （GITR）, and transforming growth factor β （TGF-β）, but little is known about the exact role of Tregs in the pathogenesis of asthma. This study sought to characterize the expression of surface markers on peripheral blood mononuclear cells-derived Tregs in patients with atopic asthma and healthy subjects, and to investigate the effect of inhaled corticosteroid on them.
Methods The expression of surface molecules on CD4^＋CD25^high Tregs was detected by flow cytometry. The effect of inhaled corticosteroid on expression of the surface molecules on Tregs was determined in vivo and in vitro. Total serum immunoglobulin E （IgE） and high-sensitivity C-reactive protein were measured by enzyme linked immunosorbent assay and latex enhanced immunoturbidimetric assay, respectively. Results Equivalent numbers of peripheral Tregs were found in patients with atopic asthma （stable and acute） and healthy subjects. Tregs preferentially expressed CTLA-4, GITR, toll-like receptor 4 （TLR4）, latency-associated peptide （LAP/FGF-β1）, and forkhead box P3 （FOXP3）. Patients with acute asthma had decreased numbers of CD4^＋CD25^highLAP^＋ T cells compared to healthy subjects and stable asthmatics. Inhaled corticosteroid enhanced the percentage of Tregs expressing LAP in vivo and in vitro dose-dependently. Furthermore, the percentages of Tregs expressing LAP were negatively correlated with total serum IgE levels and severity of asthma, but positively correlated with forced expiratory volume in one second percentage of the predicted value in patients with asthma.
Conclusions The results suggest that membrane-bound TGF-β1 is a potential candidate for predicting the severity of asthma, and may contribute to the sustained remission     

慢性乙型肝炎患者CD4+ CD25+调节性T细胞免疫抑制功能的研究

目的 探讨慢性乙型肝炎患者CD4+ CD25+调节性T细胞(Treg)免疫抑制功能.方法 收集北京大学人民医院22例慢性乙型肝炎(CHB)患者外周血单个核细胞(PBMC)以及18名健康对照的PBMC标本,以流式分析对PBMC中CD4+ CD25+ Treg的频率进行分析;5-溴脱氧尿嘧啶核苷(BrdU)掺入法评价CD4+ CD25+ Treg的免疫抑制功能;并同时通过磁珠分选去除CHB患者PBMC中的CD4+ CD25+ Treg,分别以MHC-肽-五聚体法和酶联斑点免疫法(Elispot)检测HBVcore18-27抗原肽刺激对HBV特异性的细胞毒性T淋巴细胞(CTLs)的频率以及IFN-γ的分泌.结果 CHB患者外周血中CD4+ CD25+ Treg细胞群所占CD4+T细胞群的比例明显高于健康对照(t=3.74,P＜0.01);CHB患者CD4+ CD25+ Treg细胞可非特异抑制自身活化的CD4+ CD25- T细胞,并呈剂量依赖的特点,且抑制能力与健康对照相比无明显差异;在经HBVcore18-27抗原肽诱导条件下,去除CD4+ CD25+ Treg CHB患者,HBVcore18-27特异性CTLs的频率以及CTLs分泌IFN-γ的频数与未去除CD4+ CD25+ Treg组比出现显著上调(t=4.75,t=7.828,P＜0.01).结论 CHB患者循环中CD4+ CD25+ Treg细胞频率升高.在体外去除CHB患者PBMC的CD4+ CD25+ Treg后可显著地增强HBV抗原诱导的抗HBV细胞免疫应答.     

CD4+CD25+调节性T细胞对直肠癌过继免疫治疗效应细胞的影响和作用

目的 探讨CD4+CD25+调节性T细胞（Treg）在直肠癌过继免疫治疗中对免疫杀伤细胞的负性调节作用。方法 利用流式细胞仪分别检测15例直肠癌患者和健康志愿者外周血中CD4+CD25+调节性T细胞的含量；分离提取直肠癌患者外周血CD4+T细胞，免疫磁珠法去除 CD4+CD25+调节性T细胞，同灭活的LOVO直肠癌细胞珠共培养并扩增为肿瘤抗原特异性CTL，以LOVO细胞为靶细胞行肿瘤杀伤实验，观察各实验组CTL对肿瘤细胞的杀伤效应。结果 直肠癌患者外周血中CD4+CD25+调节性T细胞占CD4+T细胞总数的（11.12±0.57）%，显著高于健康对照组（8.77±0.66）%（t=2.687，P＝0.012）；去除Treg细胞后诱导产生的抗原特异性CTL对靶细胞的杀伤效率为（33.74±4.42）%，显著高于未去除Treg细胞的对照组CTL的杀伤效率[(17.39±2.54)%; t=3.206, P=0.0034]。结论　直肠癌患者外周血中调节性T细胞含量明显增高，并且对肿瘤抗原诱导的CTL的免疫杀伤功能具有明显抑制作用。     

鼻咽癌患者外周血HLA-DR-CD33+CD14-CD11b+的MDSC检测

目的 探讨鼻咽癌患者外周血HLA-DR-CD33+ CD14-CD11 b+的髓源性抑制细胞(MDSC)的分布比例,为鼻咽癌免疫治疗提供有益指导.方法 选择该院肿瘤科收治的45例鼻咽癌患者和20例健康志愿者作为健康对照组,均在第1次化疗前和第2周期诱导化疗后7d抽取患者外周血标本,同时抽取健康对照组人群外周血;并在流式细胞仪上做HLA-DR-CD33+CD14-CD1 1b+的MDSC测定.结果 鼻咽癌患者外周血存在MDSC比例明显高于健康对照组(P＜0.05).而且随着Ⅱ、Ⅲ、Ⅳ期分期的升高,鼻咽癌患者外周血MDSC比例也逐渐升高(P＜o.05)..鼻咽角化癌、鼻咽分化型非角化癌和未分化型非危化癌3种不同病理类型鼻咽癌患者外周血MDSC比例均高于健康对照组(P＜0.05).3种不同病理类型的鼻咽癌患者外周血MDSC比例也差异有统计学意义(P＜0.05).经过2周期诱导化疗后各期鼻咽癌的患者外周血MDSC比例均有显著降低(P＜0.05),但其比例水平仍然高于健康对照组人群.结论 鼻咽癌患者外周血HLA-DR-CD33+ CD14-CD1 1b+的MDSC比例明显升高,提示可能与鼻咽癌免疫选避有关,值得进一步研究.     

Identification of an HLA-A＂ 0201-restricted CD8~ T-cell epitope SSp-1 of SARS-CoV spike protein

Identification of an HLA-A~* 0201-restricted CD8~+ T-cell epitope SSp-1 of SARS-CoV spike protein     

Recombinant Vaccinia Virus is an Effective and Non—perturbing Vector for Human Dendritic Cells Transfected with Epstein—Barr Virus Latent Membrane Protein 2A

Objective To study the effects of dendritic cells(DC) transfected with recombinant vaccinia virus encoding Epstein-Barr virus(EBV) latent membrane protein 2A(LMP2A) gene,and to provide evidence for further investigation on the therapeutic uaccines against EBV-associated malignancies.Methods Mature DC were transfected with EVB-LMP2A recombinant vaccinia virus(rVV-LMP2A).Before and after the transfection,the expression of surface antigens on mature DC including CD1a,CD83,CD40,CD80,HLA-DR was measured by fluorescence activated cell sorter(FACS) and the function of DC to stimulate allogeneic T cells proliferation was measured by mixed leukocyte reactions(MLR).Results LMP2A protein was highly expressed (66.1%) in DC after the transfection of rVV-LMP2A.No significant changes in the primary surface antigens expression and in the MLR were detected during the transfection.Transfected DC still had strong potential in stimulating the proliferation of allogeneic T cells.Conclusion Recombinant vaccinia virus was an effective and non-perturbing vector to mediate the transfection of LMP2A into DC.The functions of mature DC were not affected significantly by the transfection of Vac-LMP2A.This study could provide evidence for the further immunotherapy of EBV-associated malignancies,e.g.nasopharyngeal carcinoma(NPC).     

EB病毒感染对儿童传染性单核细胞增多症T细胞亚群的影响

目的 观察EB病毒(EBV)感染对儿童传染性单核细胞增多症(IM)T细胞亚群的影响.方法 选取2013年1月至2016年1月陕西省汉中市人民医院儿科收治的80例IM患儿作为研究对象,所有患儿均接受抗病毒治疗,观察患儿治疗后的EBV-DNA转阴率.比较EBV-DNA阳性及阴性患儿的T细胞亚群分布,分析EBV-DNA未转阴的相关因素.结果 经过治疗后,67例(83.75％)患儿EBV-DNA转阴.治疗后,EBV-DNA阴性组CD3±和CD8+比例低于EBV-DNA阳性组,CD4+比例和CD4+/CD8+高于EBV-DNA阳性组,差异有统计学意义(P＜0.05).对患儿EBV-DNA未转阴的相关因素进行分析:性别、白细胞计数(WBC)及淋巴细胞计数与EBV-DNA转阴无相关性(P＞0.05),干扰素的使用、年龄及初始Ct与EBV-DNA未转阴具有相关性(P＜0.05).结论 EB病毒感染可以引起IM患儿T细胞亚群的紊乱,临床上应采取积极的抗病毒治疗.     

Epstein-Barr病毒感染相关性肝损伤对循环血T淋巴细胞亚群影响的相关性分析

目的 探讨Epstein-Barr病毒（EBV）感染相关性肝损伤对循环血T淋巴细胞亚群的影响。方法 回顾性分析2012年6月—2018年8月川北医学院附属医院确诊为EBV感染致相关性肝损伤的56例患者的临床资料并对其进行相关性分析。结果 56例EBV病毒感染者中,单纯EBV病毒感染者36例（64.29%）,EBV合并感染者20例（35.71%）,其中合并甲型肝炎病毒（HAV）感染2例（3.57%）,合并乙型肝炎病毒（HBV）感染8例 （14.29%）,合并丙型肝炎病毒（HCV）感染1例（1.79%）,合并科萨奇B组病毒（CVB）感染2例（3.57%）,合并 带状疱疹病毒（VZV）感染3例（5.36%）,合并HBV、VZV 4例（7.14%）;单纯EBV病毒感染与EBV病毒合并感染组的肝损伤指标均较健康对照组升高（P?<0.05）,EBV合并感染组肝损伤程度较EBV单纯感染组重,两者间比较,差异有统计学意义（P?<0.05）;治疗前单纯EBV感染组,EBV合并感染组的CD3+T、CD8+T细胞亚群水平高于健康对照组,CD4+T、CD4+/CD8+T水平低于健康对照组（P?<0.05）,EBV合并感染组CD3+T、CD8+T高于EBV单纯感染组,CD3+T、CD4+/CD8+T水平低于EBV单纯感染组（P?<0.05）;治疗后CD3+T、CD8+T较治疗前下调,CD4+T、EBV合并感染组的CD4+/CD8+T上调（P?<0.05）,CD3+T、CD4+T、CD8+T水平高于EBV单纯感染组（P?<0.05）;单纯EBV感染与EBV合并感染组治疗前后CD3+T、CD4+T、CD8+T、CD4+/CD8+T水平与EBV-DNA载量无相关性（P?>0.05）。结论 EBV感染不仅可引起不同程度的肝功能损害,也会导致T淋巴细胞亚群功能紊乱,重视EBV病毒筛查有利于早诊断、早治疗。     

CD25+细胞在鼻咽癌中的表达及与EBV的关系

目的探讨CD25^＋细胞在鼻咽癌组织中的表达情况及EB病毒感染对CD25表达的影响。方法用免疫组织化学方法检测CD25^＋细胞在鼻咽癌组织和鼻咽慢性炎症组织中的表达情况。并用组织原位杂交技术检测EB病毒对其表达的影响。对照组选取鼻咽慢性炎症组织。结果CD25^＋淋巴细胞在鼻咽癌组织中比在鼻咽慢性炎症组织中的表达明显升高．差异具有显著性意义（P〈0．001），且在未分化癌中表达高于角化型癌和非角化型癌（P〈0．05）。原位杂交显示EB病毒与CD25^＋淋巴细胞高表达有关。结论CD25^＋淋巴细胞在鼻咽癌组织中表达高于慢性炎症组织，EB病毒感染与CD25^＋淋巴细胞表达间存在相关性。     

恶性肿瘤患者外周血CD4+CD25high Foxp3+调节性T细胞的检测及临床意义

目的：研究CD4⁺CD25^high Foxp3⁺调节性T细胞(Tregs)在恶性肿瘤患者外周血单个核细胞(PBMC)中的表达,探讨其在肿瘤发病中的作用及临床意义。方法：采用流式细胞术检测61例不同分期恶性肿瘤患者PBMC中CD4⁺CD25⁺/CD4⁺CD4⁺CD25^high/CD4⁺T细胞百分比,进一步分析CD4⁺CD25⁺及CD4⁺CD25^highT细胞中表达Foxp3⁺T细胞的百分比,并与正常对照组(n=32)进行比较。结果：与正常对照组比较,Ⅰ及Ⅱ期恶性肿瘤患者PBMC中CD4⁺CD25⁺/CD4⁺及CD4⁺CD25^high/CD4⁺T细胞百分比均无明显变化(P>0.05),Ⅲ及Ⅳ期恶性肿瘤患者均明显增高(P<0.05),随肿瘤恶性程度增高,CD4⁺CD25⁺/CD4⁺及CD4⁺CD25^high/CD4⁺T细胞的百分比也逐渐增高;恶性肿瘤患者CD4⁺CD25⁺ 及CD4⁺CD25^high Foxp3⁺T细胞表达水平较正常对照组均增高,组间比较差异均有显著性(P< 0.01)。结论:恶性肿瘤患者外周血调节性T细胞增高可能是恶性肿瘤发病及免疫机制异常的主要原因之一,定期检测外周血中上述指标的变化,有利于了解恶性肿瘤患者的病情变化及预后判断。     

痘苗病毒载体介导爱泼斯坦-巴尔病毒潜伏期膜蛋白2A基因转染树突状细胞对其功能的影响

目的：探讨痘苗病毒载体介导爱泼斯坦－巴尔病毒（EBV）潜伏期膜蛋白2A（LMP2A）基因转染树突状细胞（DC）对DC的表型和功能的影响，以及EBV相关肿瘤免疫治疗性疫苗的可行性，方法：用EBV－LMP2A基因重组痘苗病毒（Vac-LMP2A)转染成熟的DC，流式细胞术（FACS）检测转染前后DC表面分子CD1a,CD83,CD40,CD80,HLA-DR变化，3H－TdR掺入法检测转染前后DC刺激同种异体T淋巴细胞增殖等功能的改变。结果：转染后LMP2A蛋白在DC细胞内高表达，Vac-LMP2A转染成熟DC前后对其表面共刺激分子及特征性表面标志无影响，转染后的DC仍具有较强的刺激同种异体TI林巴细胞增殖的能力。结论：痘苗病毒载体是介导外源基因LMP2A转染DC的有效载体，Vac-LMP2A转染成熟DC对DC表型和功能无明显影响，是EBV相关肿瘤如鼻咽癌免疫治疗的理想载体。