ADOPTIVE TRANSFER OF SHIV-SPECIFIC CD8+ T CELLS

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。HIV感染的特征是免疫系统无法维持对病毒的控制。实验性地增强免疫系统是一种治疗策略，有可能提高宿主控制病毒的能力。CD8+HIV特异性细胞由于分化而失去共刺激分子CD28的表达，与CD8 T细胞不能产生IL-2有关，而IL-2是病毒控制所必需的自分泌增殖/生长。初步研究表明，强迫HIV特异性CD8+T细胞克隆表达CD28使其能够在特异性抗原识别时分泌IL-2。我们预测，在体内注入病毒特异性CD8+T细胞可能会提高持久性和对病毒复制的控制，因为这种对人类T细胞的遗传修饰需要安全的证据，我们继续开发了一个猕猴模型，并将这些经过挑选、扩增和转基因的细胞注入自体猕猴。首先，在两周的时间里，输注同一亚克隆的CD8+CD28+和CD8+CD28-亚群中的108个细胞，然后是109个细胞。这项实验的结果表明，移植后CD28+T细胞在外周CD8+T细胞中维持在低水平(0.2-0.6%)6周，然后消失，细胞输注短暂地增加了已经有病毒感染的猕猴的血浆病毒。所有细胞均被转导表达截短的神经生长因子受体作为跟踪标记。然而，这些细胞迅速从血液中消失，可能是因为细胞激活后下调了表达。我们正在确定输注细胞在周围部位的定位，包括淋巴结和肠道组织。所描述的模型为研究维持对艾滋病毒的控制的细胞免疫的定性和定量要求提供了一个独特的环境。

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. HIV infection is characterized by an inability of the immune system to maintain control of the virus. Experimentally boosting the immune system represents a treatment strategy with the potential to improve the host's ability to control virus. The loss of expression of the co-stimulatory molecule CD28 by CD8+ HIV-specific cells as consequence of differentiation is linked to the inability of CD8 T cells to produce IL-2 as an autocrine proliferation/growth necessary for viral control. Preliminary studies have shown that forcing the expression of CD28 on HIV-specific CD8+ T cell clones confers them the ability to secrete IL-2 upon specific antigen recognition. We predicted that infusing virus-specific CD8+ T cells in vivo might improve persistence and control over viral replication and because such genetic modification of T cells in humans requires evidence of safety, we went on to develop a macaque model and infuse these selected, expanded and genetically modified cells in an autologous macaque. First 108 then 109 cells of both CD8+ CD28+ and CD8+ CD28- subpopulations of the same subclone were infused in a 2-week period. Results from this experiment have shown that the CD28+ population persisted at low levels (0.2-0.6%) of peripheral CD8+ T cells for 6 weeks after transfer then disappeared and that the infusion of cells transiently increased plasma virus in an already viremic macaque. All cells were transduced to express truncated nerve growth factor receptor as a tracking marker. However, the cells rapidly disappeared from the blood potentially due to down-regulation after cell activation. We are determining localization of infused cells in peripheral sites including lymph nodes and gut tissues. The described model offers a unique setting to study the qualitative and quantitative requirements of cellular immunity to maintain control over HIV.