Autologous upregulation mechanism allowing optimized cell type-specific and regulated gene expression cells
    5.
    发明申请
    Autologous upregulation mechanism allowing optimized cell type-specific and regulated gene expression cells 审中-公开
    自体上调机制允许优化的细胞类型特异性和调节基因表达细胞

    公开(公告)号:US20070166366A1

    公开(公告)日:2007-07-19

    申请号:US10555109

    申请日:2004-04-30

    IPC分类号: A61K48/00 A61K9/127 C12N15/88

    摘要: The present invention provides methods for high level, regulated transgene transcription that is restricted to cell populations of specific types. The process is designed to work with any inducible expression regulation systems, adapting them to a tissue-specific expression pattern while simultaneously delivering maximal achievable expression levels. In particular, the invention utilizes hybrid promoters that contain the DNA elements for both cell type-specific and regulated transcription. By placing the gene of the transcriptional activation factor (TAF) under the control of this tissue-specific/drug-regulated (TSDR) promoter, this invention achieves high expression levels of TAF in specific target cells by first initiating TAF expression using cell-type specific transcription elements, and subsequently amplifying transcriptional activity by establishing an autoregulatory positive feedback loop. In non-target cells, cell type-specific elements of the TSDR promoter will be inactive, the TAF expression will not be initiated, and auto-upregulation will not occur. For cell type-specific promoters with leaky low-level activity in non-target cells, a variation of this system has been developed which combines autologous upregulation of TAF with the expression of cross-competing transcriptional silencers (TSi) to achieve a type of eukaryotic “genetic switch”—either shutting off transgene and TAF expression completely or promoting maximal expression levels, depending on the original activity level of the specific promoter in that particular cell.

    摘要翻译: 本发明提供限于特定类型的细胞群体的高水平,调节转基因转录的方法。 该过程被设计为与任何可诱导的表达调节系统一起工作,使其适应组织特异性表达模式,同时提供最大可实现的表达水平。 特别地,本发明利用含有细胞类型特异性和调节转录的DNA元件的杂合启动子。 通过将转录激活因子(TAF)的基因置于该组织特异性/药物调节(TSDR)启动子的控制下,本发明通过首先使用细胞型开始TAF表达来实现特异性靶细胞中TAF的高表达水平 特异性转录元件,随后通过建立自动调节阳性反馈环来扩增转录活性。 在非靶细胞中,TSDR启动子的细胞类型特异性元件将是无活性的,TAF表达将不会启动,并且不会发生自上调。 对于在非靶细胞中具有低水平低活性的细胞型特异性启动子,已经开发了该系统的变体,其将TAF的自体上调与交叉竞争的转录沉默子(TSi)的表达相结合以实现真核生物 “遗传开关” - 根据特定细胞中特异性启动子的原始活性水平,完全关闭转基因和TAF表达或促进最大表达水平。