TCR Engineering of Quiescent Primary Human T Cells

描述(申请人提供)：对肿瘤细胞表达的抗原的免疫反应可用于治疗癌症患者。最近的临床试验表明，过继T细胞转移(ACT)联合非清髓性化疗经常对晚期黑色素瘤患者产生客观的临床反应。然而，肿瘤反应性T细胞很难从大多数恶性肿瘤中获得，因此大多数癌症患者不符合ACT的条件。为了绕过这一障碍，我们开发了一种TCR基因转移方法，它可以提供任何患者的自体肿瘤反应性T细胞的来源。使用TCR基因修饰的T细胞进行早期临床试验的结果相对令人失望。一个潜在的原因是，为了有效地进行转导，所使用的T细胞被完全激活。遗憾的是，这可能会导致效应细胞不能持续存在并分化为体内有效抗肿瘤活动所需的“正确”表型。我们最近开发了一种新的方法来选择转导细胞，这是基于我们的病毒载体中包含了一个修改的CD34盒。这一改进的CD34盒允许我们使用临床适用的方法，快速丰富转导的T细胞培养，以获得高纯度的重定向效应细胞。在这一探索性应用中，我们建议将CD34选择系统与慢病毒载体相结合，以确定是否可以将转导的静止的人T细胞以中等频率重定向的T细胞浓缩到足够的纯度用于治疗。静息重定向T细胞的功能将在体外和体内异种模型中进行评估，以确定静止的TCR转导的T细胞是否优于完全激活的T细胞。这项研究是对静息TCR基因修饰T细胞的首次评估，这项研究的结果可能很快被纳入未来的TCR基因转移临床试验，为患者提供一种具有更大治疗潜力的新型自体肿瘤反应性T细胞。 公共卫生相关性：这项建议与公共卫生的相关性是产生一种新型的效应性T细胞群体，可用于领养T细胞转移。使用我们开发的新技术的组合，我们将重新引导NAOVE休息的人类T细胞识别黑色素瘤/黑素细胞相关抗原酪氨酸酶的特异性；我们希望在人类黑色素瘤的小鼠模型中证明这些TCR基因修饰的NAOVE T细胞优于它们完全激活的同类细胞。如果是真的，下一步将是在治疗晚期黑色素瘤患者的临床试验中评估这些新的效应物。

DESCRIPTION (provided by applicant): Immune responses to antigens expressed by tumor cells can be exploited for treating cancer patients. Recent clinical trials have shown that adoptive T cell transfer (ACT) in combination with non-myeloablative chemotherapy frequently cause objective clinical responses in patients with advanced melanoma. However, tumor reactive T cells are difficult to obtain from most malignancies and the majority of cancer patients are thus ineligible for ACT. To circumvent this hurdle, we have developed a TCR gene transfer approach which can provide a source of autologous tumor reactive T cell from any patient. Results from early clinical trials using TCR gene-modified T cells have been relatively disappointing. One potential reason is that the T cells used, in order to be efficiently transduced, were fully activated. Regrettably, this may render the effector cells incapable of persisting and differentiating into the "correct" phenotype needed for effective anti-tumor activity in vivo. We have recently developed a novel method for selecting transduced cells based on the inclusion of a modified CD34 cassette in our viral vectors. This modified CD34 cassette allows us to rapidly enrich transduced T cell cultures for redirected effector cells to high purity using clinically applicable methodologies. In this exploratory application, we proposed to combine this CD34 selection system with lentiviral vectors to determine if it is feasible to enrich transduced quiescent human T cells, with moderate frequency of redirected T cells, to sufficient purity for therapy. The function of the resting redirected T cells will be evaluated in vitro and in a xenogenic in vivo model to determine if quiescent TCR transduced T cells are superior to their fully activated counterparts. This study represents the first evaluation of resting TCR gene-modified T cells and the results from this study could be rapidly incorporated into future TCR gene transfer clinical trials that offer patients a novel type of autologous tumor reactive T cells with greater therapeutic potential. PUBLIC HEALTH RELEVANCE: The relevance of this proposal to public health is to generate a novel type of effector T cell population that can be used for adoptive T cell transfer. Using a combination of novel technologies we developed, we will redirect the specificity of naove resting human T cells to recognize the melanoma/melanocyte associated antigen tyrosinase; we hope to demonstrate in a mouse model for human melanoma that these TCR gene- modified naove T cells are superior to their fully activated counterparts. If true, the next step would be to evaluate these novel effectors in clinical trial treating advanced stage melanoma patients.