N-甲基亚硝基脲诱导小鼠胸腺淋巴瘤TCR基因重排分析

目的探讨N-甲基亚硝基脲（MNU）诱导的小鼠胸腺淋巴瘤的单克隆起源。方法采用巢式PCR方法,对8例MNU诱导的胸腺淋巴瘤组织进行T细胞受体β链（TCRβ）和γ链（TCRγ）克隆性基因重排分析,并对TCRγ基因重排的PCR产物直接测序。结果 8例胸腺淋巴瘤检测TCRβ和TCRγ均呈克隆性基因重排。DNA序列测定证实TCRγ基因PCR扩增产物为基因重排产物。结论巢式PCR TCR基因重排检测及DNA序列分析证实,MNU诱导的小鼠胸腺淋巴瘤是来源于T细胞的肿瘤。     

T细胞受体基因转导T细胞免疫治疗技术的研究进展

T细胞受体(T cell receptor,TCR)基因转导的T细胞疗法(TCR-T)是目前发展较快的一种新的过继性细胞免疫疗法,该方法主要是将肿瘤特异的TCR基因通过各种载体转入自体或异体的淋巴细胞中,再回输至患者体内以达到杀伤肿瘤细胞的目的。因此,肿瘤特异的高亲和性的TCR基因的获取是提高TCR-T细胞治疗的一个重要因素,TCR基因的高水平表达和TCR双链的正确配对也是确保TCR能够在T细胞表面发挥正常抗原识别功能的必要条件。现对TCR的表达及调控机制、TCR基因转导和亲和力的优化策略,以及TCR-T在肿瘤治疗临床试验中的进展与所面临的问题做了详细的阐述。     

PLAC1特异性TCR基因修饰T细胞对乳腺癌的抗肿瘤作用

目的研究胎盘特异性基因1（PLAC1）特异性T细胞受体（TCR）基因修饰T细胞对乳腺癌的抗肿瘤作用。 方法磁珠分选人类白细胞抗原分型为A2（HLA-A2）的志愿者外周血单个核细胞（PBMC）中的CD8⁺ T细胞,流式检测CD8⁺ T细胞的表型。通过慢病毒载体构建、包装,将可识别乳腺癌肿瘤抗原PLAC1的HLA-A2限制性的TCR基因导入CD8⁺ T细胞（称为TCR-T细胞）,以慢病毒空载体包装、感染的CD8⁺ T细胞（NC-T细胞）作为对照细胞,通过流式细胞术检测PLAC1特异性TCR的表达效率。免疫荧光和流式细胞术检测乳腺癌细胞MCF-7和MDA-MB-231（三阴性乳腺癌细胞）的PLAC1和HLA-A2血清型的表达。WST-1法检测不同效靶比（5?:?1、10?:?1和20?:?1）TCR-T细胞或NC-T细胞与乳腺癌细胞MCF-7或MDA-MB-231作用后的细胞毒性,并通过ELISA检测共培养后T细胞IFN-γ的释放量。通过裸鼠皮下人乳腺癌移植瘤模型检测TCR-T细胞以及NC-T细胞的抗肿瘤作用。采用单因素方差分析及独立t检验进行统计学分析。 结果磁珠分选出的CD8⁺ T细胞CD3⁺ CD8⁺比例达到（98.89±0.30）%。经慢病毒感染、五聚体检测,TCR-T细胞中PLAC1特异性TCR的正确表达率为（24.58±0.82）%,NC-T细胞不表达PLAC1特异性TCR。免疫荧光和流式结果显示乳腺癌细胞MCF-7和MDA-MB-231为HLA-A2和PLAC1双阳性表达细胞。其中流式检测结果显示,MCF-7和MDA-MB-231细胞中HLA-A2的表达效率分别为（93.04±1.36）%和（98.72±0.12）%。在效靶比为20?:?1时,TCR-T细胞对MCF-7杀伤率为（51.5±1.37）%,高于NC-T细胞对MCF-7的杀伤率（5.93±2.40）%,t = 15.507,P < 0.01;TCR-T细胞对MDA-MB-231杀伤率为（44.34±2.20）%,高于NC-T细胞对MDA-MB-231杀伤率（5.15±2.40）% （t?= 10.694,P < 0.01）。在相同效靶比情况下,TCR-T细胞对MCF-7或MDA-MB-231细胞的细胞毒性高于NC-T细胞,且随着效靶比的增加杀伤效果增强。在效靶比为20?:?1时,与MCF-7共培养后TCR-T细胞IFN-γ的分泌水平[（347.49±4.10）pg/ml]高于NC-T细胞[（18.14±6.22）pg/ml]（t = -76.638,P < 0.01）;与MDA-MB-231共培养后TCR-T细胞IFN-γ的分泌水平为（255.25±6.85）pg/ml,高于NC-T细胞[（14.70±6.38）pg/ml] （t = -44.526,P < 0.01）,且随着效靶比的增加分泌量升高。在裸鼠皮下人乳腺癌移植瘤实验中,生理盐水组和NC-T细胞移植组小鼠的肿瘤生长迅速,TCR-T细胞治疗组小鼠肿瘤生长相对缓慢,在移植后第35天,生理盐水组、NC-T细胞组和TCR-T细胞组小鼠肿瘤的平均体积分别为（5?636.96±2?879.55）mm³、（5?522.12±3?391.48）mm³和（1?403.85±1?394.31）mm³,TCR-T细胞治疗组小鼠肿瘤体积明显小于生理盐水组（F = 0.1813,P < 0.05）和NC-T细胞组（F = 0.1307,P?< 0.05）。 结论PLAC1特异性TCR基因修饰T细胞对乳腺癌细胞具有较强的抗肿瘤作用,PLAC1可作为乳腺癌治疗的潜在靶标;PLAC1特异性TCR基因修饰T细胞治疗是PLAC1表达阳性的乳腺癌治疗的新策略。     

半滑舌鳎外周血T淋巴细胞的分离、鉴定及TCRβ基因免疫应答分析

为开展半滑舌鳎(Cynoglossus semilaevis)免疫学研究提供细胞平台, 利用密度梯度离心法分离半滑舌鳎外周血淋巴细胞, 采用短期细胞培养法分离悬浮淋巴细胞, 悬浮淋巴细胞在含有0.3 μg/mL的PHA的DMEM完全培养基, 于24℃条件下可连续培养3—4d左右, 采用自制的尼龙毛柱可将悬浮淋巴细胞中的非黏附淋巴细胞和黏附淋巴细胞成功分离; 利用流式细胞仪结合特异抗体检测对非黏附淋巴细胞和黏附淋巴细胞进行鉴定, 结果表明, 非黏附细胞与鼠抗人FTIC-CD3单克隆抗体特异结合, 为T样淋巴细胞; 黏附细胞和鼠抗人FTIC-CD19单抗特异结合, 为B样淋巴细胞。T细胞表面抗原受体TCRβ基因可特异性的在非黏膜细胞中表达, 而在黏附细胞中不表达, 证明分离获得的非黏膜细胞为T淋巴细胞, 采用qRT-PCR (Quantitative Real-Time PCR)方法检测TCRβ基因表达, 结果表明, TCRβ基因在半滑舌鳎肝、脾、头肾、后肾、小肠、胃、血液、鳃、皮肤、肌肉、心脏、脑、卵巢组织中均有表达, 其中在肠、胃、脾、头肾中表达量较高; 鳗弧菌感染后TCRβ基因在肝、脾、鳃中呈现明显的上调表达, 且表达峰值出现在感染后72—96h, 表明TCRβ基因在获得性免疫应答中起重要作用。     

Dual-RMCE介导的T细胞受体基因置换系统的建立

抗肿瘤T细胞受体(T cell receptor,TCR)基因治疗在临床上已获得了巨大进展,但仍然存在一些技术瓶颈。例如,内外源性TCR链随机组合形成自身反应性TCR分子、外源基因随机插入导致抑癌基因灭活等。为解决这些问题,作者提出建立低/单拷贝TCR基因置换技术:即结合逆转录病毒和重组酶介导的盒式交换(recombinase mediated cassette exchange,RMCE)技术,实现TCR基因定点置换以构建TCR稳定表达系统。首先,通过逆转录病毒转导在16.113和Jurkat76细胞引入了含有lox P和FRT位点的EGFP(enhanced green fl uorescent protein)基因;然后,利用RMCE方法将EGFP置换成MAGE-A1的TCRαβ基因,置换效率高达5%。在Jurkat76细胞表面检测到了TCR和CD3分子,并能与MAGE-A1特异性HLA-A2多聚体结合。预计利用这一TCR基因置换系统结合干细胞技术可快速产生抗原特异性的T细胞,为TCR-T细胞治疗的安全应用提供一个新策略。     

基因修饰细胞介导的肿瘤治疗

肿瘤的基因治疗,最终都是通过基因修饰细胞介导完成的,这些基因修饰细胞可分为（1）免疫基因修饰的肿瘤细胞疫苗;（2）自杀基因或抑癌基因修饰的细胞疫苗;（3）基因修饰的树突状细胞（DC）疫苗;（4）基因修饰造血干细胞;（5）基因修饰淋巴细胞;（6）基因修饰血管内皮细胞及其它。它们在肿瘤的基因治疗中各有特点,本主要介绍这些方面的研究进展。     

肿瘤免疫中TCR的有效多样性研究

T细胞是抗癌免疫系统的主要组成部分,其表面表达的特定T细胞受体(T cell receptor, TCR)负责识别抗原肽并引发免疫反应。在肿瘤免疫研究中,分析TCR的多样性和特异性对于理解适应性免疫应答和免疫治疗至关重要。目前的研究侧重于单独分析多样性或特异性,尽管这两者都与肿瘤的有效免疫相关,但并非总是呈现正相关。本文探讨了肿瘤免疫中TCR的多样性和特异性研究进展及面临的挑战,指出综合分析多样性和特异性的必要性,给出综合性概念——TCR有效多样性的定义,介绍并讨论了已有的少量相关研究成果。揭示有效多样性的科学意义需要综合分析TCR的多样性、特异性和有效性,结合充分的实验来进行建模和量化表征。有效多样性对于深入了解TCR在肿瘤中的作用至关重要,对于未来的癌症早筛、治疗和预后具有潜在的重要意义。     

表达人TCRα转基因小鼠1型糖尿病模型的建立及其免疫机制的初步研究

目的建立T细胞介导的1型糖尿病(type 1 diabetes mellitus,T1DM)动物模型,为进一步研究该病发病免疫机理奠定基础。方法将雌雄各10只系统表达人T细胞受体α基因(T cell receptor,TCRα)小鼠随机分为模型组和对照组,其中模型组小鼠腹腔注射链脲佐菌素(streptozotocin,STZ)每次100 mg/(kg·bw),间隔1 d后再注射一次,对照组注射等量的生理盐水;注射后每周测定一次血糖和体重,当出现重度糖尿病临床表现时处死,其余小鼠注射后8周处死,观察胰腺组织病理学改变,并进行外周血淋巴细胞亚群,以及血清胰岛素和细胞因子的测定。结果模型组小鼠发病率为10/10,对照组为0/10;模型组外周血T细胞亚群CD3+、CD4+、CD8+、CD4+/CD8+水平较对照组均有显著降低(P<0.01),B细胞表型CD19+水平与对照组差异无显著性(P>0.05);注射STZ后约8周,模型组血清胰岛素、IFN-γ、TNF-β较对照组差异有显著性(P<0.01),IL-2高于对照组但差异无显著性(P>0.05)。结论在系统表达人TCRα基因小鼠腹腔注射链脲佐菌素(STZ)后2～8周可建立稳定1型糖尿病的小鼠模型。     

TCR基因重排在蕈样肉芽肿诊断中的应用

T细胞在成熟过程中通过T细胞表面受体基因重排,从而具有特异性识别抗原的能力,在这一过程中的任何失调都会导致疾病。蕈样肉芽肿是由于淋巴细胞的恶性增殖所导致的,病变组织表现出T细胞受体基因重排克隆性。通过Southern印迹分析技术和PCR技术来检测T细胞受体基因重排。T细胞受体基因重排的检测在蕈样肉芽肿的诊断的应用上有重要的参考价值。     

TCR基因重排在T淋巴细胞浸润亲表皮疾病中的应用

目的:探讨具有亲表皮现象的疾病T细胞受体γ链基因重排的情况.方法:用免疫组化标记筛选17例T细胞淋巴瘤、30例可疑为T细胞淋巴瘤和10例副银屑病,采用聚合酶链式反应扩增方法检测T细胞受体γ链基因重排.结果:17例T细胞淋巴瘤中12例出现T细胞受体γ链基因重排,30例可疑为T细胞淋巴瘤和10例副银屑病均无T细胞受体γ链基因重排.结论:T细胞受体γ链基因重排检测是区分T淋巴细胞浸润的亲表皮疾病鉴别诊断的有效方法,且对T细胞淋巴瘤的确诊有重要参考价值与显著意义.     

TCR transgenes and transgene cassettes for TCR gene therapy: status in 2008

The genetic introduction of T cell receptor genes into T cells has been developed over the past decade as a strategy to induce defined antigen-specific T cell immunity. With the potential value of TCR gene therapy well-established in murine models and the feasibility of infusion of TCR-modified autologous T cells shown in a first phase I trial, the next key step will be to transform TCR gene transfer from an experimental technique into a robust clinical strategy. In this review, we discuss the different properties of the TCR transgene and transgene cassette that can strongly affect both the efficacy and the safety of TCR gene transfer. This paper is a focussed research review based on a presentation given at the sixth annual meeting of the Association for Immunotherapy of Cancer (CIMT), held in Mainz, Germany,15–16 May 2008.     

Requirements for effective antitumor responses of TCR transduced T cells

Adoptive transfer of TCR gene-modified T cells has been proposed as an attractive approach to target tumors for which it is difficult or impossible to induce strong tumor-specific T cell responses by vaccination. Whereas the feasibility of generating tumor Ag-specific T cells by gene transfer has been demonstrated, the factors that determine the in vivo effectiveness of TCR-modified T cells are largely unknown. We have analyzed the value of a number of clinically feasible strategies to enhance the antitumor potential of TCR modified T cells. These experiments reveal three factors that contribute greatly to the in vivo potency of TCR-modified T cells. First, irradiation-induced host conditioning is superior to vaccine-induced activation of genetically modified T cells. Second, increasing TCR expression through genetic optimization of TCR sequences has a profound effect on in vivo antitumor activity. Third, a high precursor frequency of TCR modified T cells within the graft is essential. Tumors that ultimately progress in animals treated with this optimized regimen for TCR-based adoptive cell transfer invariably display a reduced expression of the target Ag. This suggests TCR gene therapy can achieve a sufficiently strong selective pressure to warrant the simultaneous targeting of multiple Ags. The strategies outlined in this study should be of value to enhance the antitumor activity of TCR-modified T cells in clinical trials.     

TCR mispairing in genetically modified T cells was detected by fluorescence resonance energy transfer

Adoptive transfer of T lymphocytes genetically modified with antigen-specific T cell receptor (TCR) constitutes a promising approach for the treatment of malignant tumors and virus infections. One of the challenges in this field of TCR gene therapy is TCR mispairing defining the incorrect pairing between an introduced TCR α or β chain and an endogenous TCR β or α chain, which results in diluted surface expression of the therapeutic TCR αβ. Although there is currently no clinical evidence for TCR mispairing-induced autoreactivity, the generation of autoreactive TCRs upon TCR mispairing cannot be excluded. So it is important to detect TCR mispairing to evaluate the efficiency of TCR gene therapy. Currently there is no available quantitative assay for the measurement of TCR mispairing. Fluorescence resonance energy transfer (FRET) is a powerful approach for identifying biologically relevant molecular interactions with high spatiotemporal resolution. In this study, we described the method of FRET for the measurement of TCR mispairing. It was found that the average FRET efficiency was 12.2 ± 7.5% in HeLa cells and 8.4 ± 3.3% in Jurkat cells (P = 0.026605). The reduction of FRET efficiency in lymphocytes reflected the presence of mispaired TCRs, indicating there were ~30% TCR mispairing in lymphocytes. This study provides a quantitative intracellular assay that can be used to detect TCR mispairing in genetically modified T lymphocytes.     

Gene transfer of human TCR in primary murine T cells is improved by pseudo-typing with amphotropic and ecotropic envelopes

BACKGROUND: T cell receptor (TCR) gene therapy represents an attractive anti-cancer treatment but requires further optimization of its efficacy and safety in clinically relevant models, such as those using a tumor antigen and TCR of human origin. Currently, however, there is no consensus as to what protocol is most optimal for retroviral human TCR gene transfer into primary murine T cells, most notably with respect to virus pseudo-type. METHODS: Primary murine T cells were transduced, expanded and subsequently tested for transgene expression, proliferation and antigen-specific function. To this end, murine leukemia virus (MLV) retroviruses were produced upon transfection of various packaging cells with genes encoding either green fluorescent protein (GFP) or TCRalphabeta specific for human melanoma antigen gp100(280-288) and the helper elements GAG/POL and ENV. Next to viral pseudotyping, the following parameters were studied: T cell densities; T cell activation; the amounts of IL-2 and the source of serum used to supplement medium. RESULTS: The pseudo-type of virus produced by packaging cells critically determines T cell transduction efficiencies. In fact, MLV-A and MLV-E pseudo-typed viruses derived from a co-culture of Phoenix-A and 293T cells resulted in T cell transduction efficiencies that were two-fold higher than those based on retroviruses expressing either VSV-G, GALV, MLV-A or MLV-E envelopes. In addition, T cell densities during transduction were inversely related to transduction efficiencies. Further optimization resulted in transduction efficiencies of over 90% for GFP, and 68% for both a murine and a human (i.e. murinized) TCR. Importantly, TCR-transduced T cells proliferate (i.e. showing a log increase in cell number in a few days) and show antigen-specific function. CONCLUSIONS: We set up a quick and versatile method to genetically modify primary murine T cells based on transient production of TCR-positive retroviruses, and show that retroviral gene transfer of a human TCR into primary murine T cells is critically improved by viral pseudo-typing with both MLV-A and MLV-E envelopes.     

In vivo cervical cancer growth inhibition by genetically engineered cytotoxic T cells

Purpose: The CD44 v7/8 splice variant that is frequently expressed in cervical carcinoma and rarely expressed in normal tissues displays promising properties as a target antigen for cancer immune therapy. In this study, cytotoxic T lymphocytes (CTLs) were genetically engineered to gain CD44v7/8 target specificity. Methods: Clone 96 (CI96), an established murine cytotoxic T-cell line, and naïve murine T cells were retrovirally transduced with a fusion gene construct encoding for the single chain fragment scFv of the monoclonal antibody VFF17 and for the chain of the T-cell receptor (TCR). The therapeutic potential of genetically engineered T cells was tested in vitro and in vivo. Results: Surface expression of the chimeric TCR on infected Cl96 and naïve T cells was shown by FACS analysis. CD44v7/8-positive target cells were efficiently lysed by transduced Cl96 and naïve T cells, demonstrating the functionality and specificity of the chimeric TCR. In a xenograft BALB/c mouse model, efficient growth retardation of CD44v7/8-positive tumours was mediated by genetically engineered Cl96(VFF17)cyYZ cells. Conclusions: We were able to reprogramme the target specificity of recombinant Cl96 and naïve CTLs resulting in efficient cytolysis of CD44v7/8-positive cervical cancer cells. High transduction rates and the specific cytolysis of CD44v7/8-redirected CTLs are promising tools for an immune gene therapy approach for advanced cervical cancer.Abbreviations Ab Antibody - CTL Cytolytic T lymphocyte - mAb Monoclonal antibody - TCR T-cell receptor     

Peptide fine specificity of anti-glycoprotein 100 CTL is preserved following transfer of engineered TCR alpha beta genes into primary human T lymphocytes

TCR with known antitumor reactivity can be genetically introduced into primary human T lymphocytes and provide promising tools for immunogene therapy of tumors. We molecularly characterized two distinct TCRs specific for the same HLA-A2-restricted peptide derived from the melanocyte differentiation Ag gp100, yet exhibiting different stringencies in peptide requirements. The existence of these two distinct gp100-specific TCRs allowed us to study the preservation of peptide fine specificity of native TCRalphabeta when engineered for TCR gene transfer into human T lymphocytes. Retroviral transduction of primary human T lymphocytes with either one of the two sets of TCRalphabeta constructs enabled T lymphocytes to specifically kill and produce TNF-alpha when triggered by native gp100(pos)/HLA-A2(pos) tumor target cells as well as gp100 peptide-loaded HLA-A2(pos) tumor cells. Peptide titration studies revealed that the cytolytic efficiencies of the T lymphocyte transductants were in the same range as those of the parental CTL clones. Moreover, primary human T lymphocytes expressing either one of the two engineered gp100-specific TCRs show cytolytic activities in response to a large panel of peptide mutants that are identical with those of the parental CTL. The finding that two gp100-specific TCR, derived from two different CTL, can be functionally introduced into primary human T lymphocytes without loss of the Ag reactivity and peptide fine specificity, holds great promise for the application of TCR gene transfer in cancer immunotherapy.     

A single cell analysis of TCR AV24AJ18+ DN T cells.

The T-cell receptor (TCR) BV gene of human TCR AV24+ double-negative (DN) T cells, a novel subset of natural killer (NK) T cells, was investigated by single-cell sorting and single-cell polymerase chain reaction (PCR) methods. Seven of eleven TCR AV24+ DN T-cell clones utilized TCR BV8, three BV9, and one BV6. Six of seven TCR AV24/BV8+ DN T-cell clones had identical TCR beta and alpha chains, indicating that they were the same clone. All three TCR AV24/BV9+ DN T-cell clones also demonstrated the same amino acids in the CDR3 region. These findings strongly suggest that the usage of TCR beta and alpha chains on TCR AV24+ DN T cells is extremely restricted, supporting the notion that these cells recognize highly limited T-cell epitopes on antigens. All TCR AV24+ clones expressed the NKR-P1A mRNA, and so were true NK T cells. IL-2 and IL-4 mRNAs were detected in all clones, suggesting that the majority of these cells were Th0-type T cells. Six clones overexpressed Fas-ligand (Fas-L) mRNA and Fas antigen was detected on all clones at the mRNA level. In conclusion, TCR AV24+ DN T cells might recognize restricted T-cell epitopes on antigens and function as Th0-type T cells, inducer cells to Th1- or Th2-type T cells (regulatory T cells), and as Fas-L-positive cytolytic T cells.     

T-cell receptor gene-modified cells: past promises,present methodologies and future challenges

Immunotherapy constitutes an exciting and rapidly evolving field, and the demonstration that genetically modified T-cell receptors (TCRs) can be used to produce T-lymphocyte populations of desired specificity offers new opportunities for antigen-specific T-cell therapy.Overall, TCR-modified T cells have the ability to target a wide variety of self and non–self targets through the normal biology of a T cell. Although major histocompatibility complex (MHC)–restricted and dependent on co-receptors, genetically engineered TCRs still present a number of characteristics that ensure they are an important alternative strategy to chimeric antigen receptors (CARs), and high-affinity TCRs can now be successfully engineered with the potential to enhance therapeutic efficacy while minimizing adverse events. This review will focus on the main characteristics of TCR gene-modified cells, their potential clinical application and promise to the field of adoptive cell transfer (ACT), basic manufacturing procedures and characterization protocols and overall challenges that need to be overcome so that redirection of TCR specificity may be successfully translated into clinical practice, beyond early-phase clinical trials.     

High efficiency TCR gene transfer into primary human lymphocytes affords avid recognition of melanoma tumor antigen glycoprotein 100 and does not alter the recognition of autologous melanoma antigens

The alpha- and beta-chains of the TCR from a highly avid anti-gp100 CTL clone were isolated and used to construct retroviral vectors that can mediate high efficiency gene transfer into primary human lymphocytes. Expression of this TCR gene was confirmed by Western blot analysis, immunocytometric analysis, and HLA Ag tetramer staining. Gene transfer efficiencies of >50% into primary lymphocytes were obtained without selection for transduced cells using a method of prebinding retroviral vectors to cell culture vessels before the addition of lymphocytes. The biological activity of transduced cells was confirmed by cytokine production following coculture with stimulator cells pulsed with gp100 peptides, but not with unrelated peptides. The ability of this anti-gp100 TCR gene to transfer high avidity Ag recognition to engineered lymphocytes was confirmed in comparison with highly avid antimelanoma lymphocytes by the high levels of cytokine production (>200,000 pg/ml IFN-gamma), by recognition of low levels of peptide (<200 pM), and by HLA class I-restricted recognition and lysis of melanoma tumor cell lines. CD4(+) T cells engineered with this anti-gp100 TCR gene were Ag reactive, suggesting CD8-independent activity of the expressed TCR. Finally, nonmelanoma-reactive tumor-infiltrating lymphocyte cultures developed antimelanoma activity following anti-gp100 TCR gene transfer. In addition, tumor-infiltrating lymphocytes with reactivity against non-gp100 melanoma Ags acquired gp100 reactivity and did not lose the recognition of autologous melanoma Ags following gp100 TCR gene transfer. These results suggest that lymphocytes genetically engineered to express anti-gp100 TCR may be of value in the adoptive immunotherapy of patients with melanoma.     

TCR gene therapy of spontaneous prostate carcinoma requires in vivo T cell activation

Analogous to the clinical use of recombinant high-affinity Abs, transfer of TCR genes may be used to create a T cell compartment specific for self-Ags to which the endogenous T cell repertoire is immune tolerant. In this study, we show in a spontaneous prostate carcinoma model that the combination of vaccination with adoptive transfer of small numbers of T cells that are genetically modified with a tumor-specific TCR results in a marked suppression of tumor development, even though both treatments are by themselves without effect. These results demonstrate the value of TCR gene transfer to target otherwise nonimmunogenic tumor-associated self-Ags provided that adoptive transfer occurs under conditions that allow in vivo expansion of the TCR-modified T cells.