调节性T细胞的分子靶向作用与肿瘤免疫治疗

调节性T细胞(Treg)具有免疫抑制功能,可通过在细胞表面表达细胞毒性T淋巴细胞相关抗原、穿孔素-颗粒酶介导的细胞毒作用、分泌细胞因子如白细胞介素-10(IL-10)、转化生长因子-β(TGF-β)等途径实现免疫抑制.采用抗体、疫苗和化学药物能够实现对FOXP3+CD25+CD4+调节性T细胞的靶向作用,使调节性T细胞在各种肿瘤患者外周血及肿瘤组织中的表达水平下调,降低其抑制免疫的功能,增强肿瘤免疫疗法的疗效.     

乳腺癌患者淋巴结CD4＋CD25＋T细胞和相关细胞因子的检测及相关性分析

目的探讨CD4＋CD25＋T细胞在乳腺癌发生、发展中的作用。方法将取自35例乳腺癌患者的105个肿大淋巴结,制备成单细胞悬液,应用流式细胞仪检测CD4＋CD25＋T细胞比例及CD4＋CD25-、CD8＋T细胞、NK细胞的相对水平。采用定量RT-PCR法,检测IL-2、IL-10、TGF-β1和IFN-γ的细胞因子水平。结果乳腺癌患者淋巴结中的CD4＋CD25＋T细胞水平（在CD4＋T细胞中的百分含量）与淋巴结转移相关,转移淋巴结中其水平明显高于未转移淋巴结。乳腺癌患者淋巴结中CD4＋CD25＋T细胞与CD4＋CD25-、CD8＋T细胞和NK细胞的水平呈负相关关系。乳腺癌患者淋巴结中CD4＋CD25＋T细胞水平与TGF-β1呈正相关,与IL-2、IL-10、IFN-γ无相关性。乳腺癌患者淋巴结中TGF-β1、IL-10、IFN-γ水平与淋巴结转移相关,转移淋巴结中TGF-β1、IL-10含量高而IFN-γ含量较低。IL-2与淋巴结转移无相关性。结论乳腺癌患者转移淋巴结中的CD4＋CD25＋T细胞水平高于未转移淋巴结。     

化疗对乳腺癌患者外周血中Treg细胞数目的影响及意义

目的研究化疗药物对乳腺癌患者根治术后外周血中Treg(CD4 CD25 调节性T细胞)的影响及意义.方法采集52例乳腺癌术后患者化疗前1天及化疗后第10天外周静脉血,应用流式细胞技术检测外周血中Treg细胞以及CD3 、CD4 、CD8 T细胞占T淋巴细胞百分比,采用ELLSA法检测外周血中IL-4、IL-10、TGF-β1和IFN-γ的表达水平.结果化疗后乳腺癌患者外周血中Treg细胞占T淋巴细胞百分比(4.75±1.60)%较化疗前(5.59±1.81)%减少(P＜0.05),且与淋巴结有无转移、转移数量以及绝经状态无关(P＞0.05).化疗前后CD3 细胞占T淋巴细胞比例分别为(64.690±7.469)%,(64.357±9.356)%(P＞0.05).化疗前后CD4 T细胞占T淋巴细胞比例分别为(38.048±10.671)%,(36.536±9.664)%(P＞0.05).化疗后CD8 T细胞占T淋巴细胞比例(28.129±10.900)%较化疗前(24.876±6.631)%升高(P＜0.05).化疗后CD4 /CD8 (1.506±0.691)较化疗前(1.680±0.704)降低(P＜0.05).化疗后乳腺癌患者外周血中IL-4、IL-10、TGF-β1浓度较化疗前降低,而IFN-γ浓度增高(P均＜0.05).化疗前后Treg细胞比例变化与细胞因子IL-4、IL-10、TGF-β1和IFN-γ浓度变化无关(P＞0.05).结论化疗可使乳腺癌患者外周血中Treg细胞占T淋巴细胞比例降低,从而达到治疗肿瘤的效果.     

调节性T细胞及Th1/Th2细胞因子在急性白血病中的表达及意义

目的:探讨调节性T细胞（Tregs）及Th1/Th2型细胞因子在急性白血病发病中的作用。方法:采用流式细胞术检测37例急性白血病患者［包括急性髓细胞性白血病（acute myeloid leukemia,AML）24例,急性淋巴细胞白血病（acute lymphocytic leukemia,ALL）13例］及28例健康对照者外周血CD4+CD25+Foxp3+Tregs的比例,酶联免疫吸附法（ELISA）法检测血浆IL-2、IFN-γ、IL-10、IL-4和TGF-β水平。结果:AML和ALL患者外周血CD4+CD25+Foxp3+Tregs比例均高于健康对照组 (P＜0.05);AML及ALL患者血浆IL-4、IL-10和TGF-β水平均较健康对照组升高 (P＜0.05);IFN-γ水平较健康对照组降低 (P＜0.05);IL-2水平与健康对照组比较无明显差异 (P＞0.05)。结论:Tregs与Th1/Th2细胞因子同时参与了急性白血病的发生;急性白血病患者机体Th1/Th2细胞因子失衡,Th2占优势状态,这可能是导致急性白血病细胞免疫逃逸的原因之一;Tregs可能通过影响Th1/Th2细胞因子平衡参与急性白血病的发病。     

非小细胞肺癌患者引流区淋巴结中CD4+CD25+调节性T细胞的检测及临床意义

目的分析非小细胞肺癌(NSCLC)患者引流区淋巴结中CD4 CD25 调节性T细胞在淋巴结局部免疫抑制状态的形成以及在肺癌发生发展中的作用。方法手术切除53例NSCLC患者引流区淋巴结,采用双标记的间接免疫荧光法检测CD4 CD25 调节性T细胞数量,实时荧光定量逆转录-聚合酶链反应(RT-PCR)法检测细胞因子TGF-β1、IL-10的表达水平,常规免疫组化方法检测CD8 T细胞的数量。结果NSCLC患者引流区转移淋巴结中,CD4 CD25 调节性T细胞(28.80%±8.06%)明显高于未转移淋巴结(15.48%±4.66%,P<0.01)。随肺癌的进展,引流区淋巴结中CD4 CD25 调节性T细胞数量增多。在转移的纵隔淋巴结(N2)和肺内淋巴结(N1)中,CD4 CD25 调节性T细胞数量分别为32.58%±7.52%和22.76%±4.67%(P<0.01)。在进展期(Ⅲ)和早期(Ⅰ Ⅱ)NSCLC患者引流区淋巴结中,CD4 CD25 调节性T细胞数量分别为30.42%±7.47%和16.22%±4.88%(P< 0.01)。NSCLC患者引流区淋巴结中的CD4 CD25 调节性T细胞数量与其自身的CD8 T细胞的数量呈负相关(r=-0.756,P<0.001)。在NSCLC患者引流区淋巴结中,CD4 CD25 调节性T细胞数量与抑制性细胞因子TGF-β1和IL-10的表达水平呈正相关(TGF-β1:r=0.645,P<0.001;IL-10:r=0.769,P<0.001)。结论NSGLC患者引流区淋巴结的CD4 CD25 调节性T细胞数量与肺癌的发展密切相关。一方面,检测肺癌患者引流区淋巴结的免疫状况为评价NSCLC患者疾病的进展程度和预后提供了一个新的免疫学指标;另一方面,在NSCLC的生物治疗中,控制CD4 CD25 调节性T细胞数量,阻断其发挥免疫抑制作用,具有广阔的临床应用前景。     

胃癌患者化疗前后Th1/Th2细胞因子的检测及其临床意义

目的 研究胃癌患者化疗前后CD4+T淋巴细胞中Th1、Th2类细胞因子的表达水平和Th1/Th2值的变化及其临床意义.方法 60例胃癌患者接受FOLFOX4方案化疗,应用流式细胞仪对化疗前后患者外周血特异性细胞因子的表达变化进行分析.结果 化疗后,全组胃癌患者外周血CD4+T淋巴细胞分泌的γ干扰素(IFN-γ)的表达水平为11.4%±5.0%,较化疗前升高(P＜0.05);白介素10(IL-10)的表达水平为3.6%±1.2%,较化疗前降低(P＜0.05);Th1/Th2(IFN-γ/IL-4)的值为3.4±1.0,与化疗前比较,无明显变化(P＞0.05).15例化疗后疗效为部分缓解的患者,外周血CD4+T淋巴细胞分泌的IFN-γ和肿瘤坏死因子-α(TNF-α)的表达水平分别为14.8%±8.0%和5.9%±2.0%,均较化疗前升高(均P＜0.05);Th1/Th2(IFN-γ/IL-4)的值为4.0±1.5,明显高于化疗前水平(P＜0.01).结论 有效的化疗可减轻患者机体的肿瘤负荷,降低Th1类细胞因子向Th2类细胞因子漂移的程度;但胃癌化疗的有效率较低,因此对胃癌化疗者,改善机体免疫功能仍是很重要的治疗措施.     

胃癌患者外周血中CD4~+CD25~(high)FOXP3~+调节性T细胞的检测及临床意义

目的探讨胃癌患者外周血CD4+CD25highFOXP3+调节性T细胞(Treg)的检测及临床意义。方法选取60例胃癌患者(胃癌组)和60例健康体检者(健康对照组),采用流式细胞仪检测外周血中CD4+CD25highFOXP3+Treg细胞、CD4+CD25highT细胞及CD4+T细胞水平,酶联免疫吸附法检测外周血白介素10(IL-10)和转化生长因子β1(TGF-β1)浓度。结果与健康对照组相比,胃癌组患者外周血中CD4+CD25highFOXP3+Treg细胞和CD4+CD25highT细胞比例增高;IL-10和TGF-β1浓度增高,差异均有统计学意义(均P<0.05)。结论 CD4+CD25highFOXP3+Treg细胞可能与胃癌发生发展密切相关,为胃癌免疫治疗提供新思路。     

卵巢癌腹水CD4+ CD25+调节性T细胞免疫抑制功能及机制的研究

  目的  研究卵巢癌患者腹水内CD4+ CD25+调节性T细胞（Treg）免疫抑制功能与患者临床病理特点的关系及其与患者初治及复发状态是否相关,并进一步探讨卵巢癌腹水内CD4+ CD25+调节性T细胞（Treg）发挥免疫调节性作用的具体机制。  方法  应用免疫磁珠分选法分选28例卵巢癌患者腹水内CD4+ CD25+调节性T细胞及CD4+ CD25- T细胞,采用羧基荧光素二醋酸盐琥珀酰亚胺酯（carboxyfluorescein succinimidylester,CFSE）标记CD4+ CD25- T细胞,CD4+ CD25+ Treg与自体CFSE标记CD4+ CD25- T细胞以1:1比例共培养,经流式检测CFSE表达及Modfit软件分析CD4+ CD25- T增殖指数（PI）,计算各标本内Treg对自体CD4+ CD25- T细胞增殖抑制率。应用中合性抗IL-10抗体及中合性抗TGF-β1抗体探究腹水内CD4+ CD25+ Treg介导免疫逃逸作用是否通过抑制性细胞因子IL-10或TGF-β1发挥作用。  结果  Ⅲ~Ⅳ期卵巢癌腹水内CD4+ CD25+ Treg对自体CD4+ CD25- T细胞增殖抑制率为（75.72±17.04）%,较Ⅰ~Ⅱ期Treg抑制率（59.61±16.97）%显著增强（P < 0.05）。复发卵巢癌患者腹水内Treg对自体CD4+ CD25- T细胞增殖抑制率为（85.89±7.07）%,较初治卵巢癌患者腹水Treg抑制率（52.82±8.18）%显著增强（P=0.000 1）。共培养体系内加入中合性抗IL-10抗体或/及中和性抗TGF-β1抗体,Treg对自体CD4+ CD25- T细胞增殖抑制率较对照组均显著降低（P < 0.05）。  结论  卵巢癌腹水内CD4+ CD25+ Treg介导免疫逃逸能力与肿瘤分期及复发、初治状态相关,且发挥免疫逃逸作用可能是与分泌抑制性细胞因子IL-10及TGF-β1有关。      

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+ 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+ regulatory T cells in patients with gastrointestinal malignancies: possible involvement of regulatory T cells in disease progression

BACKGROUND: Active suppression by CD4+CD25+ regulatory T cells plays an important role in the down-regulation of the response of T cells to foreign and self antigens. Experimental tumor models in mice revealed that regulatory T cells inhibit antitumor immune responses. The purpose of the current study was to demonstrate the possible involvement of CD4+CD25+ regulatory T cells in immune system impairment in patients with gastrointestinal malignancies. METHODS: The phenotypes of lymphocytes, particularly those of CD4+CD25+ T cells, were analyzed in peripheral blood in 149 patients with gastrointestinal malignancies and in ascites in 7 patients with peritoneal dissemination. In addition, cytokine production after in vitro stimulation was examined in CD4+CD25+ and CD4+CD25- T cells isolated from patients with malignant disease. RESULTS: Compared with healthy volunteers, patients with gastrointestinal malignancies had a higher proportion of CD4+CD25+ T cells in peripheral blood, due to the presence of a drastically smaller number of CD4+CD25- T cells. Among patients with gastric carcinoma, those with higher percentages of CD4+CD25+ T cells had a poorer prognosis than did those with lower percentages. CD4+CD25+ T cells also were present in greater proportions in ascites from patients who had advanced-stage disease with peritoneal dissemination. Isolated CD4+CD25+ T cells from patients with malignant disease produced interleukin (IL)-4 and IL-10 but not IL-2 or interferon-gamma; these cells also inhibited cytokine production by CD4+CD25- T cells after in vitro stimulation. CONCLUSIONS: The relative increase in CD4+CD25+ regulatory T cells may be related to immunosuppression and tumor progression in patients with gastrointestinal malignancies. This finding suggests that the use of immunomodulatory therapy to treat patients with gastrointestinal malignancies may be an effective strategy.     

Human CD4+ CD25+ regulatory T cells suppress NKT cell functions

CD4+CD25+ regulatory T cells play an important role in peripheral tolerance. These cells have been reported to be capable of suppressing the response of CD4+CD25- T cells in vitro. The depletion of these cells evokes effective immune responses to tumor cells in vivo. In this study, we demonstrate that CD4+CD25+ T cells also suppress all subsets of Valpha24+NKT cells (Valpha24+CD4-CD8- double negative, Valpha24+CD4+, and Valpha24+CD8+) in both proliferation and cytokine production [IFN-gamma, interleukin-4 (IL-4), IL-13, and IL-10]. This suppression is mediated by cell-to-cell contact but not by a humoral factor or the inhibition of antigen-presenting cells. Moreover, the cytotoxic activity of Valpha24+NKT cells against some tumor cell lines is suppressed by CD4+CD25+ T cells. This finding is important in developing an effective immunotherapy for cancer.     

CD4+CD25+调节性T细胞对晚期肺癌患者免疫抑制作用的研究

目的 探讨Treg及Th1/Th2类细胞因子在晚期肺癌肿瘤免疫抑制中的作用.方法 选取100例初治晚期肺癌患者及50例健康自愿者.采用流式细胞术检测其外周血中Treg、Th1类细胞因子(IFN-γ、IL-2、TNF-a)、Th2类细胞因子(IL-4、IL-6、IL-10)水平,同时分析CD4+CD25+Treg与Th1/Th2类细胞因子之间的相关性.结果 ①晚期肺癌患者外周血中Treg为(11.12±5.83)%,高于健康对照组(7.46±3.07)%,差异有统计学意义(P=0.003);②化疗前肺癌患者外周血中Treg为(11.12±5.83)%,明显高于化疗后(6.45±3.74)%,差异有统计学意义(P<0.001);③晚期肺癌患者与正常对照组Th1/Th2类细胞因子水平分别为:IFN-γ(8.56±3.62 vs 10.79±3.27,P=0.049)、IL-2(8.48±2.87 vs 10.22±4.03,P=0.03)、TNF-a(6.18±2.67vs8.14±2.87,P=0.007)、IFN-γ/IL-4(3.33±1.44 vs 4.09±1.00,P=0.028)、IL-4(3.17±1.19 vs 2.45±0.43,P<0.001)、IL-6(3.88±2.08 vs 2.33±0.88,P<0.001)、IL-10(3.64±1.73 vs 2.54±1.08,P=0.008),其中Th2类因子水平明显升高,差异有统计学意义(P均<0.05);④CD4+CD25+Treg与Th1类细胞因子IFN-γ、TNF-a、IL-2及IL-6无相关性(P均>0.05);与Th1/Th2(γ=-0.273,P=0.003)呈负相关;与Th2类细胞因子IL-4(γ=0.237,P=0.009)、IL-10(0.626,P<0.001)呈正相关(P均<0.05).结论 晚期肺癌患者CD4+CD25+Treg、Th2类细胞因子水平显著升高,Th1类细胞因子水平下降,它们共同导致肿瘤患者免疫抑制及肿瘤进展,监测其水平变化有助于判断肺癌患者疗效、预后,有效调控CD4+CD25+Treg及负性细胞因子水平可能是治疗肺癌的一个新策略.     

CD28 costimulation overcomes transforming growth factor-beta-mediated repression of proliferation of redirected human CD4+ and CD8+ T cells in an antitumor cell attack

The T-cell-mediated antitumor immune response is frequently repressed in the tumor environment by an immunologic barrier, the predominant mediators of which are thought to be interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta). We explored the effect of these cytokines on the individual T-cell effector functions on antigen engagement during an antitumor cell attack. Isolated CD4+ and CD8+ T cells were antigen-specifically redirected toward carcinoembryonic antigen (CEA)-positive tumor cells by expression of a recombinant T-cell receptor (immunoreceptor), which triggers T-cell activation via CD3zeta on binding to CEA. Immunoreceptor-activated T cells secrete IFN-gamma, proliferate, and lyse CEA+ but not CEA- tumor cells. Whereas IL-10 has no direct effect on immunoreceptor-triggered effector functions, TGF-beta represses proliferation of both CD4+ and CD8+ T cells but neither IFN-gamma secretion nor specific cytolytic activities. CD28 costimulation, however, overcomes TGF-beta-mediated repression in T-cell proliferation. Consequently, T cells redirected by a combined CD28-CD3zeta signaling immunoreceptor are largely resistant to TGF-beta-mediated repression. This is reflected in vivo by a more pronounced antitumor activity of T cells against TGF-beta-secreting tumors when redirected by a costimulatory CD28-CD3zeta than by a CD3zeta signaling immunoreceptor.     

CD4+CD25+ regulatory T cells in the peripheral blood of patients with breast cancer and non-small cell lung cancer

It is well known that immunosuppression may contribute to the progression and chemotherapy-resistance of cancer. Recent studies have demonstrated that lymphocytes with the phenotype of CD4+CD25+ regulatory T cells (T-regs) contribute to immune dysfunction in cancer patients, and a relative increase in CD4+CD25+ regulatory T cells is related to immunosuppression and tumor progression in patients with some malignancies. In the present study, we evaluated the prevalence of T-regs in the peripheral blood of patients with breast cancer and non-small cell lung cancer. The phenotype of lymphocyte CD4+CD25+ cells was analyzed in peripheral blood of patients with breast cancer (n=22) and non-small cell lung cancer (NSCLC) (n=17). The population of CD4+CD25+ cells in CD3+ and CD4+ cells was evaluated by flow cytometric analysis with triple-color staining. Patients with breast cancer did not have a higher percentage of CD4+CD25+ cells in the total CD3+ and CD4+ cells in their peripheral blood than healthy volunteers. In contrast, patients with recurrent NSCLC had significantly higher percentages of CD4+CD25+ cells in CD3+ (47.6%) and CD4+ (71.0%) than healthy volunteers (n=10) who had CD4+CD25+ cells in CD3+ (33.7%, p=0.02) and CD4+ (52.2%, p<0.03). The population of CD4+CD25+ T-regs in the peripheral blood of patients with non-small cell lung cancer was significantly higher than that in healthy volunteers but not in breast cancer patients. These findings suggest that the use of T-reg-targeted immunomodulatory therapy may be a more effective strategy for patients with non-small cell lung cancer than for those with breast cancer.     

Analysis of cytotoxic activity of the CD4+ T lymphocytes generated by local immunotherapy.

We previously reported that the anti-tumour effect of OK-432 is considerably enhanced by its intratumoral injection together with fibrinogen. In the present study, we generated killer T cells by culturing tumour-infiltrating lymphocytes from thyroid cancer patients who had received this local immunotherapy. Phenotypic analysis revealed that the T cells were positive for CD3+, CD4+, Leu8-, CD45RO+ and T-cell receptor (TCR)alpha beta+, as well as showing strong surface expression of HLA-DR, CD25, LFA-1 and ICAM-1. The generated CD4+ T cells secreted interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, TNF-beta, and interleukin (IL)-6 (but not IL-4), and exhibited a high level of cytolytic activity against several tumour cell lines. The cytolytic activity of these T cells for Daudi cells was inhibited by preincubation with an anti-intercellular adhesion molecule (ICAM)-1 antibody, but not by preincubation with anti-TCR alpha beta, anti-CD2, or anti-LFA-1 antibodies. Pretreatment with anti-ICAM-1 antibody inhibited T-cell cytolytic activity, but not conjugation with target cells. In addition, incubation with immobilised anti-ICAM-1 enhanced the secretion of IFN-gamma by T cells. We conclude that ICAM-1 expressed on the effector cytotoxic CD4+ T lymphocytes delivers regulatory signals that enhance IFN-gamma secretion.     

T regulatory type 1 cells in squamous cell carcinoma of the head and neck: mechanisms of suppression and expansion in advanced disease

PURPOSE: Regulatory T cells play a major role in tumor escape from immunosurveillance. T regulatory cells type 1 (Tr1), a subset of regulatory T cells present in the tumor and peripheral circulation of patients with head and neck squamous cell carcinoma (HNSCC), mediate immune suppression and might contribute to tumor progression. EXPERIMENTAL DESIGN: CD4+CD25-T cells were isolated from peripheral blood mononuclear cells (PBMC) or tumor-infiltrating lymphocytes (TIL) of 26 HNSCC patients and 10 normal controls. The Tr1 cell phenotype was determined before and after culture in the presence of interleukin (IL)-2, IL-10, and IL-15, each at 10 to 20 IU/mL. Suppression was measured in carboxyfluorescein diacetate succinimidyl ester-based proliferation assays with or without neutralizing anti-IL-10 or anti-transforming growth factor-beta1 (TGF-beta1) monoclonal antibodies in Transwell systems. ELISA was used to define the Tr1 cytokine profile. RESULTS: Tr1 cells originate from CD4(+)CD25(-) precursors present in TIL and PBMC of HNSCC patients. Cytokine-driven ex vivo expansion of Tr1 precursors yielded CD4+CD25-Foxp3lowCD132+IL-10+TGF-beta1+ populations that mediated higher suppression than Tr1 cells of normal controls (P < 0.0001). Tr1 cells suppressed proliferation of autologous responders via IL-10 and TGF-beta1 secretion. Expression of these cytokines was higher in TIL-derived than PBMC-derived Tr1 cells (P < 0.0001). The Tr1 cell frequency and suppressor function were significantly higher in patients presenting with advanced than early disease stages and in patients "cured" by oncologic therapies than in those with active disease. CONCLUSIONS: In HNSCC, Tr1 cell generation is promoted at the tumor site. Tr1 cells use TGF-beta and IL-10 to mediate suppression. They expand during disease progression and also following cancer therapy in patients with no evident disease.