检测Epstein—Barr病毒特异性细胞毒性T淋巴细胞方？…

目的 建立一种非放射性、简便易行的可检测特异性细胞毒性Ｔ淋巴细胞的方法，并且初步应用于Ｅｐｓｔｅｉｎ－Ｂａｒｒ病毒的细胞免疫应答。方法 用重组的ＥＢＶ－ＬＭＰ１痘苗病毒、ＴＫ＾＋痘苗病毒和杆状病毒系统表达的ＥＢＶ－ＬＭＰ！蛋白分别免疫Ｂａｌｂ／Ｃ小鼠，用Ｐ８１５细胞和乳酸脱氢酶法检测ＥＢ病毒特异性细胞毒性Ｔ细胞的杀伤效应。结果 重组ＥＢＶ－ＬＭＰ１痘苗病毒免疫组原发ＣＴＬ水平和体外诱生的二次ＣＴＬ     

转基因表达HBV抗原特异性细胞毒性T淋巴细胞受体

目的 通过逆转录病毒介导HBV抗原特异性细胞毒性T细胞(CTL)的T细胞受体(TCR)转基因表达,初步观察其结合活性.方法 从HLA-A2阳性急性乙肝患者外周血中诱导、分选、克隆和扩增HBV抗原特异性CTL;提取细胞RNA,用RT-PCR、5'-RACE和OVER-LAP PCR等方法获取TCR的α和β链编码基因;构建TCR重组逆转录病毒,介导特异性TCR分别在人Jurkat T细胞和HLA-A2阳性健康人CD8 T淋巴细胞上表达.结果 从1例HLA-A2阳性急性乙肝患者样本中分别获得了2组TCR Vα、Vβ配对,分别命名为α21β13、α15β13,包装的重组逆转录病毒滴度为(1.5 ～5.0)×105 IU/mL,用针对目标TCR的特异性Vβ链抗体(抗Vβ13 TCR-PE)和HLA-A2限制性表位特异性五聚体(pentamer)进行免疫荧光染色,重组TCR在T细胞表面获得表达:其中在Jurkat细胞上转入的Vβ13链表达细胞占1.06％ ～2.25％,在HLA-A2阳性健康人T细胞上Vβ13阳性细胞和pentamer阳性细胞分别占到1.03％ ～2.06％和1.05％ ～1.12％,在HLA-A2阴性健康人T细胞上Vβ13阳性细胞和pentamer 阳性细胞均低于0.05％.结论 通过逆转录病毒介导可以使HBV特异性CTL TCR获得转基因表达,具有结合HLA-A2限制性表位的活性.     

EB病毒特异性细胞毒性T淋巴细胞与肿瘤免疫治疗研究进展

EB病毒（EBV）与多种人类肿瘤的密切关系已引起人们的高度重视,它在不同的肿瘤细胞上有不同的病毒基因表达谱。近来,EBV特异性CTL开始被用于EBV相关肿瘤的免疫治疗并已取得初步疗效,但仍存在诸多问题,如病毒抗原免疫原性很弱及肿瘤细胞本身分泌的某些细胞因子均减弱了EBV特异性CTL对肿瘤细胞的杀伤作用。本文就上述内容作一综述。     

人脐带血抗巨细胞病毒和EB病毒的特异性细胞毒性T细胞的建立

目的:探讨用人的脐带血单个核细胞体外同时扩增对抗EB病毒(EBV)和巨细胞病毒(CMV)的特异性细胞毒性T淋巴细胞的可行性。方法:利用人的脐带血单个核细胞(CBMC),通过EBV感染转化成B成淋巴细胞细胞株(BLCL),再通过逆转录病毒载体,将CMV蛋白基因pp65导入BLCL,用这种细胞体外刺激同一供者脐带血的CBMC产生细胞毒性T细胞(CTL),经[⁵¹Cr]释放实验(CRA)检测产生的CTL的杀伤功能。结果: 经免疫印迹 (Western Blot)检测,我们获得了同时表达EBV和CMV特异性抗原的抗原递呈细胞BLCLpp65,免疫组化结果表明,BLCLpp65细胞表达CMVpp65抗原的阳性率高达95%。CRA结果证实,用BLCLpp65刺激产生的CTL同时对EBV和CMV都有细胞毒作用。用免疫磁珠法将CD₄⁺和CD₈⁺ T细胞分离后再进行CRA,表明特异性的细胞毒性作用主要是CD₈⁺ CTL介导的。结论:BLCLpp65是很好的抗原递呈细胞,在体外能同时表达EBV和CMV蛋白抗原,用其刺激血清病毒抗体阴性的CBMC,能够扩增出同时针对EBV和CMV的特异性CTL,其中CD₈⁺CTL起主要作用。     

特异性细胞毒性T细胞检测方法的建立及其在重组痘苗病毒活疫苗细胞免疫研究中的应用

报道了用ＣＢＡ／Ｊ小鼠、Ｌ９２９细胞及ＭＴＴ比色法建立的特异性细胞毒性Ｔ细胞（ＣＴＬ）的检测方法及其在重组痘苗病毒活疫苗细胞免疫研究中的应用。通过检测痘菌病毒特异性初发ＣＴＬ的动态变化及其二次反应ＣＴＬ，表明，本法能较好地检测初发及二次反应ＣＴＬ水平的变化。用本法检测了不同启动子控制下的表达Ｅｐｓｔｅｉｎ－Ｂａｒｓ（ＥＢ）病毒膜抗原（ＥＢＶ－ＭＡ）的重组痘菌病毒ＥＢＶ－ＭＡ特异性ＣＴＬ、以及与表达人白细胞介素－２的重组痘苗病毒联合免疫时的ＥＢＶ－ＭＡ特异性ＣＴＬ。结果表明，Ｐ７５００启动子表达的ＥＢＶ－ＭＡ比Ｐ１１０００启动子表达的ＥＢＶ－ＭＡ诱导的ＥＢＶ－ＭＡ特异性ＣＴＬ高，但无显著性差异。当上述重组痘苗病毒与表达人白细胞介素－２的重组痘苗病毒联合免疫时，均能使二者的ＥＢＶ－ＭＡ特异性ＣＴＬ增高，但增高幅度本身及其二者之间均无显著性差异。     

丙型肝炎发病中特异性细胞毒性T细胞的作用及其意义

随着对丙型肝炎病毒致病机理的深入研究，ＨＣＶ特异性细胞毒性Ｔ细胞的作用日益引起人们的重视。研究表明，ＨＣＶ感染者肝小叶内活化ＣＤ８＾＋Ｔ细胞润，识别感染肝细胞表达的抗原 要组织相容性抗原ＭＨＣ分子复合物，杀伤靶细胞，清除病毒。     

EB病毒对人T淋巴细胞感染的研究

为了确定ＣＲ２受体是否在ＥＢ病毒对Ｔ淋巴细胞的感染中起一定的作用。研究了ＣＲ２受体在Ｔ细胞的ＥＢ病毒对Ｔ细胞的感染。从正常人外周血分离的ＣＤ＾＋４和ＣＤ＾＋８Ｔ细胞其纯度达９８％以上。经逆转录多聚酶链反应和双色荧光抗体染色并结合流式细胞分析仪分析的结果证明，在ＣＤ＾＋４和ＣＤ＾＋８Ｔ细胞检测不到ＣＲ２ｍＲＮＡ和细胞表面的ＣＲ２抗原。     

中国人群HIV-1B亚型Nef蛋白特异性细胞毒性T细胞反应的研究

目的探讨中国人群HIV-1B亚型Nef蛋白特异性细胞毒性T细胞(CTL)反应特征及其与病毒载量以及CD4细胞数量间的关系。方法选取33例HIV-1B亚型感染者。用合成的HIV-1B亚型Nef全基因序列肽库作为抗原,ELISPOT方法检测HIV-1B亚型Nef蛋白特异性CTL反应,同时测定病毒载量及CD4细胞数量。结果70％的感染者对Nef产生特异性CTL反应,单一肽段能够被识别的频率不超过40％,应答强度为(1102±2136)SFC(斑点形成细胞数)／106 PBMC。HIV-1B亚型Nef特异性CTL应答的强度和频率之间没有显著的相关性。HIV-1 Neff特异性CTL反应强度与病毒载量间存在显著负相关,与CD4细胞数量间存在显著正相关。结论初步确定了Nef蛋白CTL应答的优势区域。这些区域主要集中在一些高度保守的氨基酸序列。提示HIV-1B亚型Nef特异性CTL应答在疾病进展中对机体具有保护性作用。     

丙型肝炎发病中特异性细胞毒性T细胞的作用及其意义

随着对丙型肝炎病毒致病机理的深入研究，ＨＣＶ特异性细胞毒性Ｔ细胞的作用日益引起人们的重视。研究表明，ＨＣＶ感染者肝小叶内活化ＣＤ８＋Ｔ细胞浸润，识别感染肝细胞表达的抗原与主要组织相容性抗原ＭＨＣ分子（对于人类又名人类白细胞抗原ＨＬＡ）复合物，杀伤靶细胞，清除病毒。对ＨＣＶ特异性ＣＴＬ的研究可能使丙型肝炎的发病机理和防治研究进一步深入。     

Absence of Epstein-Barr virus-specific, HLA class II-restricted CD4+ cytotoxic T lymphocytes in infectious mononucleosis.

Cytotoxic T lymphocytes (CTL) with the CD4+ phenotype that recognize major histocompatibility complex (MHC) class II antigens are detectable very frequently in cultures of human alloreactive or virus-specific T cells. The significance of these CD4+ CTL for an immune reaction in vivo is not clear. Since Epstein-Barr virus (EBV) transformed B cells express HLA-class I and class II antigens equally well both CD8+ and CD4+ CTL should be stimulated during an acute EBV infection. We analysed the MHC specificity and the phenotype of EBV-specific CTL from patients with infectious mononucleosis (IM). When tested directly without any previous culture, T cells from patients in the acute phase of IM showed specific MHC-restricted cytotoxicity against the autologous B cell line. Addition of a HLA class I specific monoclonal antibody (MoAb) but not of a HLA class II specific MoAb resulted in a complete blocking of the lytic activity. Cell sorting revealed that the entire cytotoxic activity was present in the CD8+ fraction whereas no specific CTL were detectable in the CD4+ fraction. The absence of cytotoxicity in CD4+ cells was not due to a lack of activation of these cells since both CD8+ and CD4+ cells were activated in situ, showing spontaneous growth in interleukin-2 (IL-2) and expressing the activation marker TP103. Frequency estimation revealed that 1/300-1/600 CD8+ but only 1/2000-1/4000 CD4+ T cells gave rise to a specific CTL colony after 10 days. If CD4+ colonies were tested repeatedly for cytotoxicity we found that CD4+ CTL acquired their cytotoxicity during in vitro culture. In addition, we isolated EBV-specific CD4+ T cell clones able to lyse their stimulator cells in the presence but not in the absence of lectin, even after a long period of culture. Taken together our results show that cytotoxicity mediated by CD4+ T cells does not play a role in an anti-viral immune response.     

Immunization of mice with the N-terminal (1–272) fragment of simian virus 40 large T antigen (without adjuvants) specifically primes cytotoxic T lymphocytes

Immunization of C57BL/6 (B6) mice (H-2^b) with the “large tumor antigen” (T-Ag) of simian virus 40 (SV40) in its soluble form without adjuvants primed CD8⁺ cytotoxic T lymphocytes (CTL) in vivo. CD8⁺ CTL primed in vivo by this non-structural 708-amino acid (aa) viral protein, and specifically restimulated in vitro, lysed H-2^b target cells, either transfected with an SV40 T-Ag-encoding vector, or transformed by SV40 infection. H-2^b RMA-S transfectants expressing the complete 708 aa T-Ag (which fail to transport peptides through the endoplasmic reticulum membranes) were not lysed. CTL were also efficiently primed in vivo by injection of the N-terminal 272 aa fragment of the T-Ag. Hence, this fragment contains the structure (s) required for a soluble protein to enter the “endogenous” class I-restricted antigen processing and presentation pathway for CD8⁺ CTL activation. In soluble form, the complete T-Ag or the N-terminal T-Ag fragment sensitized in vitro RBL5 cells for lysis by T-Ag-specific CTL lines and clones. This in vitro sensitization was blocked by brefeldin A. In contrast, specific recognition of RBL5 cells pulsed in vitro with synthetic, immunogenic nonapetides (derived from N-terminal T-Ag epitopes) by CTL lines was insensitive to brefeldin A. Hence, T-Ag and its 272-aa N-terminal fragment can enter the “endogenous” processing pathway and prime CD8⁺ CTL in vivo and in vitro.     

Characteristics of cytotoxic T lymphocytes eluted from allogeneic target cells

The increase in the specific cytotoxic effect of immune lymphocytes after their adsorption on the corresponding target cells (TC) and subsequent elution with pronase is due, not to increased cytotoxic activity of individual cells, but to a quantitative increase in the proportion of effector T cells in the population. The eluted and original immune lymphocytes are indistinguishable in the kinetics of their adsorption on TC. The fraction of eluted lymphocytes contains twice as many T cells and four to five times as many cells synthesizing DNA, on account of an increase in the percentage of medium-sized and large lymphocytes.Laboratory of Immunochemistry and Diagnosis of Tumors, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR G. V. Vygodchikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 1, pp. 50–53, January, 1977.     

Establishment and epitope analysis of allo-specific cytotoxic T lymphocytes at a tumor site recognizing a spouse's HLA-A0206 molecule

PROBLEM: The molecular basis of allo-reactivity in reproductive immunity has not been fully clarified. METHOD OF STUDY: Cytotoxic T lymphocytes (CTLs) were established from tumor-infiltrating lymphocytes (TILs). The allo-reactivity of the CTLs against various tumor cell lines or human leukocyte antigen (HLA)-A allele-transfected COS-7 cells was measured by 51Cr-release or interferon-gamma production assay. RESULTS AND CONCLUSIONS: We have established CTLs reacting to an HLA-A0206 molecule that matched a spouse's HLA-A allele from the TILs of a 68-year-old multiparous patient with gastric cancer. The amino acids at positions 66 and 88 in the alpha1 domain of HLA-A0206, both of which were common in the other HLA-A2 subtypes, were involved in the recognition by the CTLs. Endogenous peptides in the groove were not involved in the recognition. These results suggest the presence of long-lasting memory CTLs raised by the reproduction process, and may facilitate a better understanding of the molecular basis of allo-recognition during reproduction.     

病毒逃避细胞毒性T细胞免疫研究进展

病毒感染期间,病毒与宿主免疫系统之间发生一系列复杂的互相作用,宿主的目的是清除感染及将病理影响减少至最低限度;而病毒则试图逃避清除,以便长期存在及播散至其他宿主.细胞介导的免疫反应特别是病毒特异性CD8细胞毒T细胞(cytotoxicTlymphocyte,CTL)反应,常常在清除病毒感染中起关键作用,故许多病毒的逃避策略即针对于此.在感染过程中,病毒蛋白上氨基酸改变可影响CTL对其表位的识别,而这种逃避机制在病毒感染过程中可引起发病/病情迁延.     

Collaboration of helper and cytotoxic T lymphocytes

Cytotoxic T lymphocytes are major effector cells in responses to viral infections and in allograft rejection and are implicated in many other immunological reactions. Efficient induction of cytotoxic activity in these cells in many but not all cases depends upon helper Tand antigen-presenting cells so that at least three different cell types have to work together. Here we present an in vitro model for the helper T cell-dependent induction of cytotoxic T lymphocytes which allows the investigation of the collaboration of helper and cytotoxic T cells. First results demonstrate that linkage of helper and killer epitopes on the surface of one antigen-presenting cell is a prerequisite for productive interaction between the two T cells that results in induction of cytolytic activity. T helper 1 and T helper 2 cells are equally efficient. The crucial roles of interleukin-2 and interferon-y in this process were confirmed. Activated CD4 cells can influence cytotoxic T lymphocytes in such a way that they produce interferon-y independent from recognition of cognate peptide. The possibility of direct T-T contacts mediated by adhesion molecules that promote collaboration of the two cells is discussed.     

致敏树突状细胞活化细胞毒性T细胞抗肿瘤作用的研究

目的：研究树突状细胞（DCs）激活的细胞毒性T细胞的抗肿瘤及预防肿瘤发生的作用。 方法： 细胞因子诱生人PBMC未成熟DCs，加入肿瘤细胞抗原提取物致敏DCs产生成熟DCs；通过细胞形态、表面标记鉴定成熟DCs，MTT法测成熟DCs活化的细胞毒性T细胞(CTL)的体外杀伤活性；裸鼠体内注射活化CTL观察其抑制移植瘤生长及发生的作用。 结果： 经过7 d培养，获得大量形态典型、具有强烈刺激增殖能力、高表达CD80(63.5%)、CD83（67.6%）和CD3/ HLA-DR(83.2%)的DCs。其活化的CTL在20∶1效靶比时对抗原来源细胞株自身的杀伤率达75%以上，对同系细胞株的杀伤活性为35%-45%，对其它种系肿瘤细胞仅有微弱杀伤力（P<0.01）。CTL对裸鼠结肠癌HT-29移植瘤有特异性的生长抑制和预防生成作用（P<0.05）。CTL治疗组肿瘤组织中PCNA表达水平显著低于对照组（P<0.05）。 结论： 肿瘤细胞抗原活化的DC诱导CTL对肿瘤有特异性的杀伤作用，体内应用可特异性抑制移植结肠癌的生长或预防小鼠结肠癌移植瘤的发生。