胃癌患者调节性T细胞胞内外细胞因子的检测及其意义

背景与目的:目前认为CD4 CD25 调节性T细胞与胃癌患者的免疫功能抑制密切相关,但CD4 CD25 调节性T细胞发挥免疫抑制功能的作用机制并不十分清楚.本研究通过检测胃癌患者CD4 CD25 调节性T细胞产生具有不同生物活性的细胞因子干扰素-γ(interferon-γ,IFN-γ)、白介素4(interleukin-4,IL-4)、IL-10及肿瘤生长因子-β(tumor growth factor-β,TGF-β)的分泌情况,进一步探讨这些细胞因子在胃癌患者CD4 CD25 调节性T细胞发挥免疫抑制功能的作用.方法:按常规方法制备患者外周血单个核淋巴细胞,采用免疫磁珠分选方法分离CD4 CD25 T细胞及CD4 CD25-T细胞后,用细胞内细胞因子染色法及ELISA法分别研究CD4 CD25 T细胞在胞内及胞外产生具有不同生物活性的细胞因子IFN-γ、IL-4、IL-1O及TGF-β的水平.结果:(1)与健康对照组比较,胃癌患者分泌内细胞因子IFN-γ、IL-4及IL-10的CD4 CD25 T细胞占CD4 细胞的百分比均显著增高(P＜0.05).(2)培养96 h后,上清液的各种细胞因子水平,无论是胃癌患者还是健康对照组,CD4 CD25 T细胞分泌的IL-10及TGF-β均显著高于CD4 CD25-T细胞(P＜0.05).CD4 CD25 T细胞分泌的IFN-γ显著低于CD4 CD25-T细胞(P＜0.05).结论:CD4 CD25 调节性T细胞体外免疫抑制作用的发挥可能与一些抑制性细胞因子有关,特别是细胞因子TGF-β在胃癌CD4 CD25 调节性T细胞的免疫抑制功能中起着相当重要的作用.     

调节性T细胞与肿瘤

调节性T细胞是具有免疫抑制功能的T细胞亚群,在维持机体免疫平衡和自身免疫耐受中起重晏作用,最新研究表明,FOXP3+ CD25+ CD4+调节性T细胞在各种肿瘤患者的外周血与肿瘤组织内大量表达,并且与肿瘤发生、发展及预后有明显的关系.     

乳腺癌患者外周血CD4+CD25+调节性T细胞的检测及意义

目的探讨乳腺癌患者外周血中CD4+CD25+调节性T细胞的变化及意义.方法采用流式细胞技术检测64例乳腺癌患者外周血中CD4+CD25+调节性T细胞,采用ELISA法检测外周血中转化生长因子-β1(TGF-β1)的表达水平.结果乳腺癌患者外周血中CD4+CD25+调节性T细胞占T淋巴细胞的百分比为(5.1±2.9)%,高于乳腺良性肿物患者和健康志愿者(P均<0.05).乳腺癌患者外周血中CD4+CD25+T细胞水平与肿物大小、TGF-β1呈正相关(r分别为0.511和0.253),与CD8+CD28+T细胞和NK细胞呈负相关(r分别为-0.243和-0.301).结论乳腺癌患者外周血中具有免疫抑制活性的CD4+CD25+调节性T细胞水平较高,对乳腺癌患者具有免疫抑制作用.     

CD4~+T 细胞与肿瘤免疫

CD4~+T细胞不仅辅助激活CD8~+T细胞,而且对记忆性细胞毒性T淋巴细胞(CTL)应答的产生和维持起重要作用,并具有直接的抗肿瘤功能.另外,CD4~+CD25~+ 调节性T细胞(Tregs)具有免疫负调控功能,在肿瘤免疫抑制及免疫逃逸中发挥重要作用,是肿瘤免疫治疗失败的重要原因.近年肿瘤免疫治疗已获得很大进步,相关肿瘤疫苗的研究也备受关注.     

CD4+ CD25+调节性T细胞及其与肿瘤的关系

CD4+CD25+调节性T细胞是体内自然存在的,能够分泌IL-4、IL-10、转化生长因子-β(TGF-β),表达IL-2Rα(CD25)、细胞毒性T淋巴细胞抗原4(CTLA-4)分子,对效应性T细胞具有抑制作用,是调节性T细胞的重要亚群,参与肿瘤的生长、自身免疫性疾病的发生及耐受移植排斥.现就该类细胞抑制作用机制的研究近况及相关免疫治疗主要是肿瘤免疫治疗的研究进展作一综述.     

CD4^＋CD25^highFOXP3^＋调节性T细胞与肿瘤的研究进展

调节性T细胞 (regulatory T cells , Treg)是具有一定免疫抑制功能的T细胞亚群.随着分子生物学技术的不断进步, 以及对FOXP3基因功能的明确,近年来对调节性T细胞的认识有了新的界定(即是一群CD 4+C D25highFOXP3+ regulatory T cell).其在临床自身免疫性疾病,移植物抗宿主反应以及肿瘤等领域有着重要的作用,尤其是对于肿瘤的发生发展及临床治疗和预后有着重要的意义[1].本文就CD4+CD25highFOXP3+调节性T细胞与肿瘤的最新研究进展作一简要综述.     

调节性T细胞与妇科恶性肿瘤免疫研究进展

调节性T细胞(regulatory T cell, Treg)是一群具有抑制其他免疫细胞功能的负调控细胞,包括CD4+ Treg、CD8+ Treg、自然杀伤T细胞(natural killer T cell,NKT)和双阴性Treg(double negative Treg,DN Treg)细胞等4大类。Treg细胞在妇科恶性肿瘤免疫抑制及逃逸机制中起重要作用。肿瘤可诱导生成特异性Treg细胞,CD4+ CD25+ T细胞向Treg细胞的转化可能是引起肿瘤微环境中Treg细胞数量增多的原因。本文就CD4+ CD25+ Treg细胞与妇科恶性肿瘤免疫抑制及逃逸之间的关系进行综述。     

肿瘤免疫中Treg细胞与趋化因子及受体的研究进展

近年来的研究发现,趋化因子系统和调节性T细胞在肿瘤发生、发展及转移中发挥重要作用。作为一种免疫抑制性调节细胞,CD4+CD25+调节性T细胞(regulatory T cells,以下简称Treg细胞)在体内通过多种途径发挥抑制效应性T细胞增殖,在诱导机体对肿瘤的免疫耐受和免疫逃逸中发挥关键作用。肿瘤可以通过多种途径来引导调节性T细胞在肿瘤局部的聚集和维持,其中最重要的一种方式为肿瘤细胞表面高表达趋化因子。现将近年来国内外对趋化因子及受体(特别是趋化因子受体5)与Treg细胞关系的研究进行综述。     

CD+4CD+25Foxp+3调节性T细胞在T细胞非霍奇金淋巴瘤中的研究进展

 CD+4 CD+25 调节性T细胞（CD+4 CD+25 Treg）是一个具有独特免疫调节功能的T细胞亚群, 天然的CD+4 CD+25 Treg起源于胸腺,获得性CD+4 CD+25 Treg可在外周由CD+4 CD-25 T细胞诱导产生,其分子表面表达特异性的转录抑制因子Foxp3,又可表达CD4、CD25、CTLA-4 （CD152） 、GITR等膜分子,主要功能具有免疫抑制性和免疫无能性。近年来研究发现,其在非霍奇金淋巴瘤（NHL）中存在表达异常,某些NHL外周血中或瘤内均存在CD+4 CD+25 Treg表达升高,且有研究表明其表达量随肿瘤增长和分期而增加。增加的CD+4 CD+25 Treg可加速肿瘤生长及再发,且可抑制自身效应性T细胞（CD+4 T／CD+8 T）功能,在肿瘤免疫逃逸机制中发挥一定作用。文章就CD+4 CD+25 Foxp3+调节性T细胞在T细胞非霍奇金淋巴瘤（T-NHL）（主要为皮肤T细胞淋巴瘤及成年人T细胞淋巴瘤）中的研究进展进行综述。     

调节性T细胞与肿瘤免疫

调节性T细胞( Treg)是一类有负调节作用的T细胞亚群,包括CD4+ Treg、CD8+ Treg、NKT Treg和DN Treg细胞等4大类,主要发挥抑制性免疫调节功能,是肿瘤免疫逃逸的重要因素.这些机制包括分泌多种免疫抑制性细胞因子、分泌颗粒酶和穿孔素杀伤效应细胞、竞争和抑制IL-2、通过T淋巴细胞毒性相关抗原(CTLA)-4影响Treg的分化和增殖等.以Treg及免疫抑制性分子作为靶点,清除Treg,控制Treg的数量和功能,增强机体对肿瘤的免疫应答,为肿瘤免疫治疗提供了新思路.     

CD4+CD25+CCR6+调节性T细胞在小鼠乳腺癌模型中对CD8+T细胞的抑制作用

目的：观察CD4+CD25+CCR6+调节性T细胞（简称CCR6+Tregs）体内对CD8+T细胞功能的抑制作用,并探讨其与肿瘤免疫逃逸的关系。方法：建立4T1乳腺癌细胞荷瘤裸鼠模型,FACS分选CCR6+Tregs,检测其Foxp3的表达;FACS分选4T1特异性CD8+T细胞,CFSE标记后分别与CCR6+Tregs或CCR6Tregs共同过继转输入4T1荷瘤裸鼠体内,观察荷瘤裸鼠肿瘤生长情况和小鼠存活时间;FACS检测肿瘤组织中CD8+T细胞的增殖、细胞因子IFNγ的产生和颗粒酶B的表达情况。结果：CCR6+Tregs和CCR6Tregs均高表达Foxp3;CCR6+Tregs和CD8+T细胞共转输组4T1荷瘤裸鼠肿瘤的生长明显快于CCR6Tregs共转输组和CD8+T细胞单转输组,同时该组荷瘤裸鼠生存时间也明显缩短（P<0.05）;CCR6+Tregs和CD8+T细胞共转输组CD8+T细胞的增殖、IFNγ的产生和颗粒酶B的表达均明显低于CCR6Tregs共转输组和CD8+T细胞单转输组（P<0.05）。结论：CCR6+Tregs在体内可以有效抑制CD8+T细胞的功能,其在肿瘤免疫逃逸和肿瘤发生、发展中发挥重要作用。     

CD4＋CD25＋Foxp3＋Treg细胞调控肿瘤免疫抑制微环境的研究进展

目的： CD4＋CD25＋Foxp3＋调节性T细胞（ Treg ）是肿瘤免疫抑制微环境的主要组成部分,其在肿瘤的免疫抑制微环境中分泌IL－10、IL－35、TGF－β1和FGL2等细胞因子发挥免疫抑制作用。Treg细胞抑制CD4＋T、CD8＋T淋巴细胞和NK细胞,进而抑制特异性抗肿瘤免疫反应使肿瘤细胞更容易逃避免疫监视。进一步研究Treg细胞在肿瘤免疫中的作用机制,对深入了解恶性肿瘤的发病机制及免疫治疗具有重要的理论意义。此外,Treg细胞及其分泌的细胞因子在肿瘤治疗和预后评估等方面也具有广阔的临床应用前景。     

FOXP3+ regulatory T cells affect the development and progression of hepatocarcinogenesis.

PURPOSE: Tumor-infiltrating lymphocytes represent the host immune response to cancer. CD4+CD25+FOXP3+ regulatory T cells (Tregs) suppress the immune reaction. The aim of the present study was to investigate the clinicopathologic significance and roles of Tregs and CD8+ T cells during hepatocarcinogenesis. EXPERIMENTAL DESIGN: We examined the infiltration of FOXP3+ Tregs and CD8+ T cells in the tumor stroma and nontumorous liver parenchyma using 323 hepatic nodules including precursor lesions, early hepatocellular carcinoma (HCC), and advanced HCC, along with 39 intrahepatic cholangiocarcinomas and 59 metastatic liver adenocarcinomas. We did immunohistochemical comparative studies. RESULTS: The prevalence of Tregs was significantly higher in HCC than in the nontumorous liver (P<0.001). The patient group with a high prevalence of Tregs infiltrating HCC showed a significantly lower survival rate (P=0.007). Multivariate analysis revealed that the prevalence of Tregs infiltrating HCC was an independent prognostic factor. The prevalence of Tregs increased in a stepwise manner (P<0.001) and that of CD8+ T cells decreased during the progression of hepatocarcinogenesis (P<0.001). Regardless of the presence of hepatitis virus infection or histopathologic evidence of hepatitis, the prevalence of Tregs was significantly increased in nontumorous liver bearing primary hepatic tumors. CONCLUSIONS: Tregs play a role in controlling the immune response to HCC during the progression of hepatocarcinogenesis. It has been suggested that primary hepatic cancers develop in liver that is immunosuppressed by a marked infiltration of Tregs. A high prevalence of Tregs infiltrating HCC is thought to be an unfavorable prognostic indicator.     

Tumor-derived CD4+CD25+ Tregs Inhibit the Maturation and Antigen-Presenting Function of Dendritic Cells

CD4+CD25+regulatory T cells (Tregs) play a key role in regulation of immnue response and maintenance ofself-tolerance. Studies have found Tregs could suppress tumor-specific T cell-mediated immune response andpromote cancer progression. Depletion of Tregs can enhance antitumor immunity. Dendritic cells (DCs) areprofessional antigen-presenting cells and capable of activating antigen-specific immune responses, which makethem ideal candidate for cancer immunotherapy. Now various DC vaccines are considered as effective treatmentfor cancers. The aim of this study was to evaluate variation of Tregs in BALB/C mice with hepatocellular carcinomaand investigate the interaction between tumor-derived Tregs, effector T cells (Teff) and splenic DCs. We foundthe percentages of Tregs/CD4+ in the peripheral blood of tumor-bearing mice were higher than in normal mice.Tumor-derived Tregs diminished the up-regulation of costimulatory molecule expression on splenic DCs, evenin the presence of Teff cells and simultaneously inhibited IL-12 and TNF-α secretion by DCs.     

Increased Frequency of Foxp3+ Regulatory T Cells in Mice with Hepatocellular Carcinoma

The CD4+CD25+ regulatory T cell (Treg) is a special kind of T cell subset. Studies have showed that Tregcells are involved in a number of physiological processes and pathologic conditions such as autoimmune diseases,transplantation tolerance and cancer. Tregs with unique capacity for immune inhibition can impair anti-tumourimmunity and help tumor cells to escape from immune surveillance. The aim of our study was to investigatewhether Tregs are involved in hepatocellular carcinoma (HCC). A BABL/C mouse with HCC in situ model wasestablished to evaluate the Treg existence in carcinoma tissues and the changes of Tregs in spleen using flowcytometry and immunohistochemistry methods. Granzyme B expression in carcinoma tissues was analyzedby immunohistochemistry to investigate the tumor local immune status.The proportion of CD4+CD25+/CD4+spleen lymphocytes of tumor bearing mice (18.8%±1.26%) was found to be significantly higher than that innormal mice (9.99%±1.90%) (P<0.01 ). Immunohistochemistry of spleen tissue also confirmed that there wasan increase in Treg in tumor-bearing mice, while in carcinomas it showed Treg cells to be present in tumorinfiltrating lymphocyte areas while Granzyme B was rarely observed. Anti-tumour immunity was suppressed,and this might be associated with the increase of Tregs. Our observations suggest that the CD4+CD25+Treg/CD4+ proportion in spleen lymphocytes can be a sensitive index to evaluate the change of Tregs in hepatocellularcarcinoma mice and the Treg may be a promising therapeutic target for cancer.     

Enhanced functionality of CD4+CD25(high)FoxP3+ regulatory T cells in the peripheral blood of patients with prostate cancer

PURPOSE: CD4+CD25(high)FoxP3+ regulatory T cells (Treg) have been shown to inhibit the activation and function of T cells that participate in antigen-specific immune responses. Higher levels of Tregs have been reported in the peripheral blood of patients with several types of tumors. In this study, we investigated the number and functionality of CD4+CD25(high)FoxP3+ Tregs in patients with prostate cancer (PCa), and their potential role in inhibiting antitumor immune responses. EXPERIMENTAL DESIGN: Levels of Tregs in the peripheral blood of healthy donors and patients with biochemically progressive, localized, and metastatic PCa were each measured by flow cytometry. The functional activity of Tregs was determined by their ability to suppress the proliferation of CD4+CD25- T cells. Data were analyzed using Wilcoxon rank sum test and unpaired Student's t test. RESULTS: Although levels of Tregs in the peripheral blood of patients with PCa were not significantly higher than those in healthy donors, Tregs in patients with PCa had significantly greater suppressive functionality than Tregs from healthy donors (P < 0.05). Additionally, there was a direct correlation between the serum levels of prostaglandin E(2) and Treg functionality in patients with localized PCa, using Pearson's product-moment correlation coefficient (R). CONCLUSIONS: These findings further show the potential importance of Tregs in modifying immune responses in patients with PCa. Although longer studies are necessary to confirm these findings, these studies also show for the first time the differences in Treg populations in patients with various stages of PCa, and thus, provide a basis for determining which PCa patient populations are best suited for immunotherapy trials involving the inhibition of Tregs.     

Regulatory T cells in tumor immunity

Recent studies have revealed that Foxp3⁺CD25⁺CD4⁺ regulatory T cells (Tregs), which are physiologically engaged in the maintenance of immunological self‐tolerance, play critical roles for the control of antitumor immune responses. For example, a large number of Foxp3⁺Tregs infiltrate into tumors, and systemic removal of Foxp3⁺Tregs enhances natural as well as vaccine‐induced antitumor T‐cell responses. Tregs are recruited to tumor tissues via chemokines, such as CCL22 binding to CCR4 expressed by Tregs. They appear to expand and become activated in tumor tissues and in the draining lymph nodes by recognizing tumor‐associated antigens as well as normal self‐antigen expressed by tumor cells. These results indicate that cancer vaccines targeting tumor‐associated self‐antigens may potentially expand/activate Tregs and hamper effective antitumor immune responses, and that tumor immunity can therefore be enhanced by depleting Tregs, attenuating Treg suppressive function, or rendering effector T cells refractory to Treg‐mediated suppression. Recent attempts have indeed demonstrated that combinations of monoclonal antibodies capable of modulating Treg functions synergistically enhance antitumor activity and are more effective than a single monoclonal antibody therapy. Combination therapy targeting a variety of molecules expressed in antigen‐presenting cells, effector T cells and Tregs is envisaged to be a promising anticancer immunotherapy.     

Regulatory T cells‐derived IL‐35 promotes the growth of adult acute myeloid leukemia blasts

Tumor immune escape mechanism mediated by CD4+CD25+regulatory T cells (Tregs) is a key factor in the pathogenesis of acute myeloid leukemia (AML). IL‐35, as a novel inhibitory cytokine, is produced by Tregs specially and regulates functions of Tregs in murine. However, IL‐35 expression of Tregs in human is still disputed, and its role in AML is yet to be elucidated. In this study, we found that IL‐35 was expressed highly in peripheral blood plasma of adult patients with AML and significantly correlated with the clinical stages of malignancy. Tregs‐derived from adult AML patients produced IL‐35 in a stimulation‐dependent manner. IL‐35 promoted AML blasts immune escape by expanding Tregs and inhibiting CD4+CD25‐effector T cells (Teffs). Furthermore, IL‐35 directly promoted the proliferation of AML blasts and reduced the apoptosis of AML blasts. Together, our study demonstrates that IL‐35‐derived from Tregs promotes the growth of adult AML blasts, suggesting that IL‐35 has an important role in the pathogenesis of AML.     

Intratumoral regulatory T cells alone or in combination with cytotoxic T cells predict prognosis of hepatocellular carcinoma after resection

Tumor-infiltrating lymphocytes (TILs) represent the host immune response to cancer. CD8(+) cytotoxic T cells (CTLs) have a central role in the elimination of tumors, while regulatory T cells (Tregs) can suppress the immune reaction. The aim of this study was to investigate the prognostic value of TILs, especially Tregs and CTLs, in hepatocellular carcinoma (HCC) patients after resection. CD3(+), CD4(+), CD8(+), and FoxP3(+) TILs were assessed by immunohistochemistry in tumor tissue from 141 randomly selected HCC patients. Prognostic effects of low- or high-density TIL subsets were evaluated by Kaplan-Meier and Cox regression analysis using the median values as cutoff. The density of intratumoral Tregs (P = 0.040) and peritumoral CTLs (P = 0.004) were an independent factor for overall survival (OS), but not for disease-free survival (DFS). The density of CD3(+) and CD4(+) TILs, and the prevalence of Tregs and CTLs were associated with neither OS nor DFS. The presence of low intratumoral Tregs with high intratumoral CTLs was a negative independent prognostic factor for OS (P = 0.001), while that of low intratumoral Tregs and low peritumoral CTLs independently correlated with improved DFS (P = 0.008). Moreover, the combined analysis of Tregs and CTLs displayed better prognostic performances than any of them alone. Additionally, higher density of intratumoral Tregs correlated with both the presence of liver cirrhosis (P = 0.025) and increased tumor size (P = 0.050). Tregs within tumor environment are promising prognostic parameters for HCC patients, and their combination with CTLs can predict prognosis more effectively.