细胞因子对白血病细胞B7-1基因表达及诱导外周血T细胞活化的影响

目的：观察γ干扰素（ＩＦＮγ）、白细胞介素（ＩＬ）１０、ＩＬ１２对转染Ｂ７１白血病细胞Ｂ７１基因表达及其诱导健康人外周血单个核细胞（ＰＢＭＣ）产生ＩＦＮγ、ＩＬ２的影响。方法：用逆转录聚合酶链反应（ＲＴＰＣＲ）和酶联免疫吸附反应（ＥＬＩＳＡ）方法检测ＩＦＮγ、ＩＬ２基因表达和蛋白质合成。结果：发现ＩＦＮγ、ＩＬ１２增强ＰＢＭＣ产生ＩＬ２、ＩＦＮγ，ＩＬ１０抑制其产生，同时发现ＩＦＮγ、ＩＬ１２增强转染Ｂ７１白血病细胞Ｂ７１基因表达，ＩＬ１０抑制其表达。结论：细胞因子ＩＦＮγ、ＩＬ１０、ＩＬ１２影响转染Ｂ７１白血病细胞诱导ＰＢＭＣ产生ＩＦＮγ、ＩＬ２，其可能是通过影响Ｂ７１基因表达实现的     

脐血CD3AK细胞体外抗肿瘤活性的实验研究

目的　探讨抗ＣＤ３ 单克隆抗体（ＡｎｔｉＣＤ３ＭｃＡｂ）＋ 重组人白细胞介素２（ｒＩＬ２） 激活的脐血杀伤细胞（ＣＤ３ＡＫ） 细胞对白血病细胞株Ｋ５６２ 、ＨＬ６０ 的杀伤作用。方法　采用间接玫瑰花结法测定脐血单个核细胞表面分化抗原,ＥＬＩＳＡ双抗夹心法测定肿瘤坏死因子α（ＴＮＦα）、ＩＬ６ 和ＩＬ８ ,用β液闪仪测定３Ｈ胸腺嘧啶核苷标记的靶细胞杀伤活性。结果　①经ＡｎｔｉＣＤ３ＭｃＡｂ＋ ｒＩＬ２ 激活的脐血单个核细胞免疫表型发生明显变化;②细胞因子水平较未激活组明显增高;③脐血ＣＤ３ＡＫ 细胞对Ｋ５６２、ＨＬ６０细胞均有杀伤作用,最佳杀伤条件：脐血单个核细胞浓度为１ ×１０６／ｍｌ,ＡｎｔｉＣＤ３ＭｃＡｂ １ μｇ／ｍｌ,ｒＩＬ２ １０００ Ｕ／ｍｌ,作用时间７２ 小时,效靶比１００∶１。结论　脐血单个核细胞能被ＡｎｔｉＣＤ３ ＭｃＡｂ＋ ｒＩＬ２ 激活为杀伤细胞,激活后有较强的细胞毒作用,且对白血病细胞株有明显的杀伤作用,该研究为应用活化脐血进行肿瘤的过继免疫治疗提供理论依据。     

CD_3单抗诱导的T细胞功能检测法

建立了用特异性刺激原白细胞分化抗原３（ＣＤ＿３）单克隆抗体（单抗）诱导外周血淋巴细胞（ＰＢＬ）增殖转化、产生白细胞介素－２（ＩＬ－２）及ＩＬ－２受体（ＩＬ－２Ｒ）表达等检测Ｔ细胞功能的方法，并对其实验影响因素进行探讨。结果表明：ＣＤ＿３单抗诱导ＰＢＬ活化的过程与Ｔ细胞在体内的活化过程相符；ＣＤ＿３单抗的丝裂原作用所需浓度范围广、用量少；由ＣＤ＿３单抗诱导的ＰＢＬ转化能力受ＣＤ＿３单抗的浓度和培养时间的影响；ＣＤ＿３单抗与植物血凝素（ＰＨＡ）活化Ｔ细胞的效应，在Ｔ细胞增殖方面二者呈显著正相关，而在ＩＬ－２活性和ＩＬ－２Ｒ表达方面则无相关性。     

慢性粒细胞白血病树突状细胞对特异性抗白血病T细胞的作用

树突状细胞（ＤＣ）是有效的抗原呈递细胞,我们从初诊慢性粒细胞白血病慢性期（ＣＭＬＣＰ）患者的外周血中培养出ＤＣ,探讨其对特异性抗白血病Ｔ细胞（ＡｎｔｉＬＢＴ）的作用。病例和方法１　病例　初诊ＣＭＬＣＰ患者１６例。均有ｔ（９;２２）染色体异常。其中男１０例,女６例。年龄３２（１８～４５）岁。分别将与其中６例患者ＨＬＡ相合的６名健康亲属作为正常对照。２　单个核细胞（ＭＮＣ）的分离制备　取肝素抗凝的外周血或骨髓２～３ｍｌ,按文献［１］分离外周血单个核细胞（ＰＢＭＮＣ）或骨髓单个核细胞（ＢＭＭＮ…     

CD28单克隆抗体共刺激检测T细胞功能

目的 为深入研究了Ｔ细胞功能，探讨一种更为实用可靠的实验方法。方法 应用白细胞表面分化抗原２８（ＣＤ２８）单克隆抗体（单抗）共刺激检测Ｔ细胞功能，并观察其影响因素。ＣＤ２８单抗协同ＣＤ３单抗或植物血凝素（ＰＨＡ）诱导外周血淋巴细胞增殖转化及细胞因子（白细胞介素２、４及γ干扰素）产生，分别用氚胸腺嘧啶（＾３Ｈ－ＴｄＲ）掺入法和酶联免疫法检测。结果 单独ＣＤ２８单抗几乎不能诱导外周血淋巴细胞活化及细胞     

激发型抗CD407单克隆抗体对CD40^＋B细胞恶性肿瘤的生长抑制 …

目的 研究ＣＤ４０抗原在恶性Ｂ淋巴细胞肿瘤中的表达及其ＣＤ４０抗原激发所致的生物学效应。方法 将激发型ＣＤ４０单克隆抗体（单抗）５Ｃ１１加入肿瘤细胞的体外培养体系,采用细胞计数,流式细胞仪分析等分析单抗５Ｃ１１对不同肿瘤细胞株的作用。结果５Ｃ１１能引起ＣＤ４０表达强阳性的多发性骨髓瘤（ＭＭ）细胞ＸＧ２发生同型聚集,抑制其生长并介导细胞凋亡;５Ｃ１１可引起ＣＤ４０＾＋的恶性Ｂ淋巴细胞株Ｄａｕｄｉ发     

自身免疫性疾病研究新进展：CD28／B7共同刺激通路

幼稚ＣＤ４＾＋Ｔ细胞的活性需要两个不同的信号。在针对外来抗原的免疫反应中Ｔ细胞分子ＣＤ２８的作用尤其重要。当它与抗原提呈细胞上的配体Ｂ７－１及Ｂ７－２结合后便传递有效的共同刺激。一旦阻断Ｂ７分子，便阻断了它与ＣＤ２８的相互作用，并阻断ＣＤ２８共同刺激的传递，而且改变了针对自身抗原的免疫反应。本文综述了ＣＤ２８／Ｂ７共同刺激通路的免疫生物学性状及其介导的调节Ｂ细胞和Ｔ细胞的模型，以及ＣＤ２８／Ｂ７通     

CD34+造血祖细胞的定向诱导分化研究

目的：探讨不同细胞因子组合定向诱导ＣＤ３４＋细胞向红系、粒系、巨核系及树突状细胞（ＤＣ）分化的能力。方法：利用免疫磁珠法（ＭＡＣＳ）分离纯化脐血ＣＤ３４＋细胞，在液体培养体系中经不同细胞因子组合的诱导，检测各系祖细胞及ＤＣ的扩增倍数。结果：干细胞因子、白细胞介素（ＩＬ）３、ＩＬ６、粒巨噬细胞集落刺激因子（ＧＭＣＳＦ）、粒细胞集落刺激因子、红细胞生成素、血小板生成素的不同组合，可使红系、粒系或巨核系细胞优势生长，其祖细胞可分别被扩增１４．９７±２．８９，１４．４６±３．１９及３４．６７±４．６２倍，ＣＤ４１ａ＋细胞增加了１７．２９±２．３４倍，ＦＬＴ３配基＋ＧＭＣＳＦ＋ＩＬ４＋肿瘤坏死因子α的组合可诱导ＣＤ３４＋细胞形成大量树突状细胞，ＣＤ１ａ＋细胞的比例增至２４．２８％±２．１４％（对照组为０．３６％±０．２８％）。结论：不同细胞因子组合可定向诱导ＣＤ３４＋细胞向红系、粒系、巨核系及树突状细胞分化，这在造血调控研究、造血细胞支持治疗及肿瘤免疫治疗中具有广阔的应用前景     

CD3单抗诱导的T细胞功能检测法

建立了用特异性刺激原白细胞分化抗原３（ＣＤ３）单克隆抗体（单抗）诱导外周血淋巴细胞（ＰＢＬ）增殖转化、产生白细胞介素－２（ＩＬ－２）及ＩＬ－２受体（ＩＬ－２Ｒ）表达等检测Ｔ细胞功能的方法，并对其实验影响因素进行探讨。结果表明：ＣＤ３单抗诱导ＰＢＬ活化的过程与Ｔ细胞在体内的活化过程相符；ＣＤ３单抗的丝裂原作用所需浓度范围广、用量少；由ＣＤ３单抗诱导的ＰＢＬ转化能力受ＣＤ３单抗的浓度和培养时间的影响；     

维甲酸诱导HL-60细胞分化中对细胞周期素依赖性激酶活性的影响

目的探讨维甲酸（ＲＡ）对ＨＬ６０细胞的增殖抑制和诱导分化作用与细胞周期素依赖性激酶（ＣＤＫ）活性变化的相关性。方法用５×１０－６ｍｏｌ／Ｌ全反式维甲酸（ＡＴＲＡ）或芳维甲（ＡＥ）处理ＨＬ６０细胞１～４天,在观察细胞生长、四氮唑蓝（ＮＢＴ）还原实验以及细胞周期分析的基础上,用组蛋白Ｈ１激酶活性分析技术检测ＣＤＫ２的活性,免疫沉淀法分析结合于ＣＤＫ２和ＣＤＫ４上的相应的细胞周期素（ｃｙｃｌｉｎ）Ｅ和Ｄ的量。结果ＨＬ６０细胞在ＡＴＲＡ或ＡＥ作用下,细胞增殖减慢,对ＮＢＴ的还原能力明显增强,９０％左右的细胞被阻滞在Ｇ１／Ｇ０期;在Ｇ１到Ｓ期转换过程中起关键作用的ｃｙｃｌｉｎＥ／ＣＤＫ２的活性显著下降,结合于ＣＤＫ４上的ｃｙｃｌｉｎＤ１的量减少。结论ＲＡ抑制ＨＬ６０细胞增殖并诱导其分化可能与ＣＤＫ２和ＣＤＫ４的活性下降有密切关系     

抗B7分子抗体诱导T细胞免疫耐受研究

目的：联合应用抗B7分子的单克隆抗体（单抗）体外诱导T细胞免疫耐受模型，并探讨B7分子在T细胞免疫耐受中的作用及其机制。方法：体外联合应用抗B7单抗诱导T细胞免疫耐受，^3H-TdR掺入法检测T细胞增殖，逆转录－聚合酶链反应（RT－PCR）检测T细胞细胞因子mRNA合成。为了排除其它粘附分子的作用，应用联合转染DR7或（和）B7分子基因的CHO细胞系作为人工抗原递呈细胞（APC）介导混合淋巴细胞反应（MLR）。结果：T细胞增殖实验显示，B7－1（CD80）和B7－2（CD86）单抗单独应用可以部分阻MLR,人中CD86单抗的阻断作用更为明显。两种抗体联合应用时，可以明显阻断MLR。RT－PCR显示：应用抗B7单抗联合阻断后24h,IFN-γ及IL－2 mRNA合成明显减少，而IL－4 mRNA合成较前明显增加。人工APC介导的MLR显示，仅有第一信号（DR7）时也可以使T细胞增殖，但需要达到一定的信号强度。给予DR7信号同时给予共刺激信号CD80可以增强T细胞反应，增强效应可以被抗CD80单抗所阻断。结论：B7分子在T细胞免疫反应中具有重要的作用，可以非特异性增强T细胞免疫反应。阻断B7／CD28信号传导通路，可以诱导T细胞免疫耐受形成，其中CD86分子的作用可能更为重要。抗B7单抗诱导的T细胞无反应性后，向Th2方向分化，这可能是阻断B7分子共刺激后T细胞免疫耐受形成的机制之一。     

CD28/B7共刺激信号及其临床意义

T细胞活化需要两个信号，一个是抗原特异的，由T细胞受体识别并结合抗原呈递细胞表面的MHC－抗原肽的第一信号；第二信号是由T细胞上的CD28与抗原呈递细胞上的B7分子的结合而提供的，只有两个信号都存在时，T细胞开始增殖并分泌细胞因子，CTLA4是B7的另一个受体，它在T细胞活化时上调表达，其功能为抑制T细胞增殖，阻断或给予第二信号，可以人为调节免疫应答使之增强或抑制，对免疫治疗提供了新的手段。阻断CD28／B7途径导致免疫耐受，降低机体的免疫应答，可应用于自身免疫性疾病，器官移植及移植物抗宿主病的治疗，激活CD28／B7途径太应用于免疫系统识别并清除侵犯系统的肿瘤。     

抗原负载对树突状细胞激发T细胞功能的影响

目的 研究抗原负载对树突状细胞（ＤＣ）表型及功能的影响。方法 将外周血单个核细胞来源的ＤＣ在体外进行肿瘤抗原的负载,再用这种ＤＣ激发自体的Ｔ细胞,通过对ＤＣ分泌白细胞介素１２（ＩＬ－１２）的测定和对Ｔ细胞表型 的分析和功能的鉴定,与未负载抗原的ＤＣ进行比较。结果 ＤＣ经过抗原负载后,其表型没有明显改变,但其分泌的ＩＬ－１２含量明显增加?而且其激发的细胞多为ＣＤ４＾＋Ｔ细胞,这种ＣＤ４＾＋Ｔ细胞本射     

Costimulation by CD48 and B7-1 induces immunity against poorly immunogenic tumors

Genetic modification of many types of mouse tumors to express the B7-1 or B7-2 molecules, natural ligands for the T cell-costimulatory molecule CD28, increases their immunogenicity. However, even after transfection with the B7-1 and/or B7-2 genes, poorly immunogenic tumors fail to elicit and efficient immune response. We report here that two such tumors, the Ag104A sarcoma and the K1735-M2 melanoma, become immunogenic after transfection of the genes encoding murine B7-1 together with CD48, which is the natural ligand for CD2. Tumor-specific CD8+ cytotoxic T lymphocytes were readily generated and were effective for adoptive immunotherapy of metastasis induced by wild-type Ag104A sarcoma cells. A similar approach may be useful for developing therapy for other poorly immunogenic tumors, including those in humans.     

共刺激分子CD28和B7在胃肠道肿瘤的表达

目的 检测胃肠道肿瘤患者外周血中CD28^＋T细胞数量及原代细胞表面B7表达水平,以探讨胃肠道肿瘤患者共刺激通路是否异常。方法 采用流式细胞术检测胃肠道肿瘤患者外周血中CD28^＋T细胞与胃肠道肿瘤患者原代细胞B7分子表达,并与胃肠道良性疾病进行比较。结果 胃肠道肿瘤患者CD28^＋T细胞数明显低于对照组（P〈O．01）;其原代细胞表面B7-1、B7-2表达水平低于对照组（P〈O．01）。结论胃肠道肿瘤患者外周血T细胞低表达CD28分子,胃肠道肿瘤细胞低表达B7分子,从而影响B7-CD28共刺激通路,使T细胞不能有效地清除肿瘤。     

CD28 interaction with B7 costimulates primary allogeneic proliferative responses and cytotoxicity mediated by small, resting T lymphocytes

Engagement of the CD3/T cell antigen receptor complex on small, resting T cells is insufficient to trigger cell-mediated cytotoxicity or to induce a proliferative response. In the present study, we have used genetic transfection to demonstrate that interaction of the B7-BB1 B cell activation antigen with the CD28 T cell differentiation antigen costimulates cell-mediated cytotoxicity and proliferation initiated by either anti-CD2 or anti-CD3 monoclonal antibody (mAb). Moreover, a B7-negative Burkitt's lymphoma cell line that fails to stimulate an allogeneic mixed lymphocyte response is rendered a potent stimulator after transfection with B7. The mixed leukocyte reaction proliferative response against the B7 transfectant is inhibited by either anti-CD28 or B7 mAb. We also demonstrate that freshly isolated small, resting human T cells can mediate anti-CD3 or anti-CD2 mAb-redirected cytotoxicity against a murine Fc receptor-bearing mastocytoma transfected with human B7. These preexisting cytotoxic T lymphocytes in peripheral blood are present in both the CD4 and CD8 subsets, but are preferentially within the CD45RO+ "memory" population. While small, resting T cells apparently require costimulation by CD28/B7 interactions, this requirement is lost after T cell activation. Anti-CD3 initiates a cytotoxic response mediated by in vitro cultured T cell clones in the absence of B7 ligand. The existence of functional cytolytic T cells in the small, resting T cell population may be advantageous in facilitating rapid responses to immune challenge.     

胃癌患者B7-CD28共刺激通路的研究

目的　探讨胃癌患者外周血中CD28 T细胞数量和患者胃癌原代细胞表面B7的表达水平,以探讨胃癌患者共刺激通路是否异常。方法　采用流式细胞术检测胃癌患者外周血中CD28 T细胞与胃癌患者原代细胞B7分子的表达,并与胃良性疾病作比较。结果　胃癌患者CD28 T细胞数低于对照组(P<0. 01)。胃癌患者原代细胞表面B7 -1(CD80)、B7- 2(CD86)表达水平低于对照组(P<0. 01)。结论　胃癌患者外周血T细胞低表达CD28分子,胃癌细胞低表达B7分子,从而影响B7- CD28共刺激通路,使T细胞不能有效地清除肿瘤。     

Expression of CD28 and CD86 by human eosinophils and role in the secretion of type 1 cytokines (interleukin 2 and interferon gamma): inhibition by immunoglobulin a complexes.

Eosinophils are the source of various immunoregulatory cytokines, but the membrane molecules involved in their secretion have not been clearly identified. Here we show that peripheral blood eosinophils from hypereosinophilic patients could express membrane CD86 but not CD80. The T cell costimulatory molecule CD28 is also detected on the eosinophil surface. CD28 ligation but not CD86 ligation resulted in interleukin (IL)-2 and interferon (IFN)-gamma secretion by eosinophils, whereas IL-4, IL-5, and IL-10 were not detected. In contrast to T cells requiring two signals for effective stimulation, CD28 ligation alone was sufficient for optimal eosinophil activation. Eosinophil-derived IL-2 and IFN-gamma were biologically active, as supernatants from anti-CD28-treated cells were able to induce CTLL-2 proliferation and major histocompatibility complex class II expression on the colon carcinoma cell line Colo 205, respectively. Addition of secretory immunoglobulin (Ig)A-anti-IgA complexes, which could induce the release of IL-10, very significantly inhibited both CD28-mediated IL-2 and IFN-gamma release. These results suggest that the release of type 1 (IFN-gamma and IL-2) versus type 2 cytokines by eosinophils is not only differential but also dependent on cross-regulatory signals. They confirm that through activation of costimulatory molecules, eosinophils could function as an immunoregulatory cell involved in the release of both type 1 and type 2 cytokines.     

Activated T cells induce expression of B7/BB1 on normal or leukemic B cells through a CD40-dependent signal

Cognate interactions between antigen-presenting B and T cells play crucial roles in immunologic responses. T cells that have been activated via the crosslinking of CD3 are able to induce B cell proliferation and immunoglobulin secretion in a major histocompatibility complex-unrestricted and contact-dependent manner. We find that such activated human CD4+ T cells, but not control Ig- treated T cells, may induce normal or leukemic B cells to express B7/BB1 and significantly higher levels of CD54 intercellular adhesion molecule 1 via a process that also requires direct cell-cell contact. To discern what cell surface molecule(s) may be responsible for signalling B cells to express B7/BB1, we added various monoclonal antibodies (mAbs) specific for T or B cell accessory molecules or control mAbs to cocultures of alpha-CD3-activated T cells and resting B cells. We find that only alpha-CD40 mAbs can significantly inhibit the increased expression of B7/BB1, suggesting that the ligand for CD40 expressed on activated T cells may be an important inducer of B7/BB1 expression. Subsequent experiments in fact demonstrate that alpha-CD40 mAbs, but not control mAbs, induce changes in B cell phenotype similar to those induced by activated T cells when the mAbs are presented on Fc gamma RII (CDw32)-expressing L cells. These phenotypic changes have significant effects on B cell function. Whereas chronic lymphocytic leukemia (CLL) B cells normally are very poor stimulators in allogeneic mixed lymphocyte reactions (MLRs), CLL-B cells preactivated via CD40 crosslinking are significantly better presenters of alloantigen, affecting up to 30-fold-greater stimulation of T cell proliferation than that induced by control treated or nontreated CLL-B cells. Similarly, the MLR of T cells stimulated by allogeneic nonleukemic B cells can be enhanced significantly if the stimulator B cells are preactivated via CD40 crosslinking. The enhanced MLR generated by such preactivated B cells may be inhibited by blocking B7/BB1-CD28 interaction with CTLA4Ig. These studies demonstrate a novel, CD40- dependent pathway for inducing B cell expression of B7/BB1 and enhancing B cell antigen-presenting cell activity that can be initiated via cell-cell contact with alpha-CD3-stimulated CD4+ T cells.     

The CD28 ligand B7/BB1 provides costimulatory signal for alloactivation of CD4+ T cells.

Activation via the T lymphocyte cell surface molecule CD28 provides a potent amplification signal for interleukin 2 (IL-2) production in several in vitro systems. The B lymphocyte activation antigen, B7/BB1, is a natural ligand for CD28. Here we investigate the role of CD28 and B7/BB1 in primary activation of CD4+ T lymphocytes stimulated with allogeneic B lymphoblastoid cell lines. A subset of peripheral CD4+ T cells that is unresponsive to crosslinking of CD3/T cell receptor (TCR) with CD3 monoclonal antibody (mAb) does proliferate in response to allogeneic B lymphoblasts. TCR binding to allogeneic major histocompatibility complex antigens was an absolute requirement for activation of these cells because mAbs to either CD3 or human histocompatibility leukocyte antigen (HLA) class II completely inhibited activation. CD28 and B7/BB1 antibodies inhibited T cell proliferation 90% and 84%, respectively. Similar results were obtained with the total CD4+ T lymphocyte population. Crosslinking of HLA-DR antigens on small, resting B cells induced rapid expression of B7/BB1, which peaked at 6 h and returned to baseline levels within 18 h. These data demonstrate that CD28-B7/BB1 binding provides an important early second signal for alloactivation of CD4+ T lymphocyte by B lymphoblasts. The results also suggest that T cells interacting with allogeneic resting B cells may induce B7/BB1 expression in the alloantigen-presenting cell as a consequence of interaction between the TCR and class II molecules.