STRATEGIES TO ENHANCE ADOPTIVE TRANSFER OF T CELL CLONES

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。原则上，过继转移针对病原体或恶性细胞表达的抗原的细胞毒性T淋巴细胞(CTL)克隆可以在治疗上有效，并允许精确控制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的感染控制。新的方法，包括给药动态平衡的细胞因子，如IL15，已被提出以促进T细胞的持久性和移植后T细胞记忆的建立。为了检验这种可能性，我们采用了一种非人类-灵长类动物模型，使用与人类研究相同的培养条件和细胞剂量进行过继T细胞转移。在两只免疫活性猕猴上进行的初步实验旨在评估过继转移的自体CMV特异性CD8+CTL克隆的内在存活特性。用有限稀释法分离克隆，转导表达截短的CD19基因，为追踪注入的CTL提供唯一的表面标记，并进行体外扩增。输注3-6×108 CD19+CD8+CTL/kg是安全的，并导致血液中高水平的转移细胞，并保持5个月。在移植后14天的淋巴结和骨髓标本中也发现了这些CTL。输注后，CD19+CD8+CTL表现为效应表型(CD62L‘CD127’)，但在体内重新获得中枢记忆T细胞(Tcm)的标志(CD62L+CD127+)。一部分细胞也重新获得了中医的功能属性，包括直接溶解活性减弱和对抗原的快速增殖。因此，CTL克隆的一部分保留了保持和恢复到中医的能力。对3只猕猴的研究已经开始，以确定一种IL15方案，该方案是安全的，并对内源性CD8+T细胞具有生物学效应。我们现在正在研究使用IL15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.