STRATEGIES TO ENHANCE ADOPTIVE TRANSFER OF T CELL CLONES

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。原则上，对病原体或恶性细胞表达的抗原特异性的细胞毒性t淋巴细胞（CTL）克隆的过继转移可能具有治疗效果，并且可以精确控制t细胞免疫的特异性、功能和大小。然而，在临床试验中输注培养的CTL克隆未能根除肿瘤或提供长期控制感染。新的方法包括使用稳态细胞因子如il - 15来促进t细胞的持久性和转移后t细胞记忆的建立。为了检验这种可能性，我们采用了非人类灵长类动物过继t细胞转移模型，使用与人类研究相同的培养条件和细胞剂量。在两只具有免疫能力的猕猴中设计了初步实验，以评估过继转移的自体cmv特异性CD8+ CTL克隆的内在存活特性。通过限制稀释分离克隆，转导表达截断的CD19基因，为跟踪注入的CTL提供独特的表面标记，并在体外扩增。3-6x108 CD19+ CD8+CTL/kg输注是安全的，并导致血液中高水平的转移细胞持续存在5个月。在移植后14天的淋巴结和骨髓样本中也发现了这些CTL。在输注后，CD19+CD8+ CTL表现出效应表型（CD62L'CD127'），但在体内重新获得了中央记忆T细胞（TCM）的标记（CD62L+CD127+）。一部分细胞也重新获得了中药的功能属性，包括直接裂解活性降低和对抗原的快速增殖。因此，CTL克隆的一部分保留了持续存在并恢复到TCM的能力。在3只猕猴中开展了一项研究，以确定一种安全且对内源性CD8+ T细胞具有生物学效应的il15方案。我们现在正在研究il - 15是否可以进一步提高t细胞转移的效率。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In principle, the adoptive transfer of cytotoxic T-lymphocyte (CTL) clones specific for antigens expressed by pathogens or malignant cells could be therapeutically effective and allow precise control of specificity, function, and magnitude of T-cell immunity. However, the infusion of cultured CTL clones in clinical trials has failed to eradicate tumors or provide long-term control of infection. Novel approaches including administration of homeostatic cytokines such as IL15 have been proposed to promote T-cell persistence and establishment of T-cell memory after transfer. To examine this possibility, we employed a nonhuman-primate model of adoptive T-cell transfer using culture conditions and cell doses identical to those in human studies. Initial experiments in two immunocompetent macaques were designed to evaluate the intrinsic survival properties of adoptively transferred autologous CMV-specific CD8+ CTL clones. The clones were isolated by limiting dilution, transduced to express a truncated CD19 gene to provide a unique surface marker for tracking infused CTL, and expanded in vitro. The infusion of 3-6x108 CD19+ CD8+CTL/kg was safe and resulted in high levels of transferred cells in the blood which remained present 5 months. These CTL were also found in lymph node and bone marrow samples obtained 14 days after transfer. Upon infusion, the CD19+CD8+ CTL exhibited an effector phenotype (CD62L'CD127'), but reacquired markers of central memory T cells (TCM) in vivo (CD62L+CD127+). A subset of the cells also reacquired functional attributes of TCM including diminished direct lytic activity and rapid proliferation in response to antigen. Thus, a portion of the CTL clone retained the capacity to persist and revert to TCM. Studies in 3 macaques have been initiated to identify an IL15-regimen which is safe and confers a biologic effect on endogenous CD8+ T cells. We are now examining whether administration of IL15 can further improve the efficiency of T-cell transfer.