Board of Governors' Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America.
PLoS One. 2011;6(8):e23523. doi: 10.1371/journal.pone.0023523. Epub 2011 Aug 29.
CD8(+) T cells infiltrate the brain during an anti-viral immune response. Within the brain CD8(+) T cells recognize cells expressing target antigens, become activated, and secrete IFNγ. However, there are no methods to recognize individual cells that respond to IFNγ. Using a model that studies the effects of the systemic anti-adenoviral immune response upon brain cells infected with an adenoviral vector in mice, we describe a method that identifies individual cells that respond to IFNγ. To identify individual mouse brain cells that respond to IFNγ we constructed a series of adenoviral vectors that contain a transcriptional response element that is selectively activated by IFNγ signaling, the gamma-activated site (GAS) promoter element; the GAS element drives expression of a transgene, Cre recombinase (Ad-GAS-Cre). Upon binding of IFNγ to its receptor, the intracellular signaling cascade activates the GAS promoter, which drives expression of the transgene Cre recombinase. We demonstrate that upon activation of a systemic immune response against adenovirus, CD8(+) T cells infiltrate the brain, interact with target cells, and cause an increase in the number of cells expressing Cre recombinase. This method can be used to identify, study, and eventually determine the long term fate of infected brain cells that are specifically targeted by IFNγ. The significance of this method is that it will allow to characterize the networks in the brain that respond to the specific secretion of IFNγ by anti-viral CD8(+) T cells that infiltrate the brain. This will allow novel insights into the cellular and molecular responses underlying brain immune responses.
CD8(+) T 细胞在抗病毒免疫反应期间浸润大脑。在大脑中，CD8(+) T 细胞识别表达靶抗原的细胞，被激活，并分泌 IFNγ。然而，目前还没有方法可以识别对 IFNγ 有反应的单个细胞。使用一种在感染腺病毒载体的小鼠脑细胞中研究系统性抗病毒免疫反应影响的模型，我们描述了一种识别对 IFNγ 有反应的单个细胞的方法。为了识别对 IFNγ 有反应的单个小鼠脑细胞，我们构建了一系列腺病毒载体，其中包含一个转录反应元件，该元件被 IFNγ 信号选择性激活，即 γ 激活位点（GAS）启动子元件；GAS 元件驱动转基因 Cre 重组酶（Ad-GAS-Cre）的表达。IFNγ 与其受体结合后，细胞内信号级联激活 GAS 启动子，驱动转基因 Cre 重组酶的表达。我们证明，在针对腺病毒的系统性免疫反应被激活后，CD8(+) T 细胞浸润大脑，与靶细胞相互作用，并导致表达 Cre 重组酶的细胞数量增加。该方法可用于鉴定、研究、并最终确定被 IFNγ 特异性靶向的感染脑细胞的长期命运。该方法的意义在于，它将使我们能够描述大脑中对浸润大脑的抗病毒 CD8(+) T 细胞特异性分泌的 IFNγ 作出反应的网络。这将为大脑免疫反应的细胞和分子反应提供新的见解。
