循环GMP-AMP是一种内源的第二信使,通过细胞核DNA传递天生的免疫信号
Jiaxi Wu1, Lijun Sun1,2, Xiang Chen1
1Department of Molecular Biology University of Texas Southwestern Medical Center Dallas, TX 75390-9148.
概括
细胞质DNA触发了一个新的信号通路. 这一途径产生循环GMP-AMP (cGAMP),激活STING并导致用于抗微生物防御的干扰素产生.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 细胞信号传输 细胞信号传输
背景情况:
- 细胞质DNA触发免疫反应,包括I型干扰素,对抗感染至关重要,但也与自身免疫性疾病有关.
- 细胞感知细胞质DNA并启动这些反应的确切机制仍然不完全理解.
- 该途径的关键组成部分包括适配蛋白STING和转录因子IRF3.
研究的目的:
- 阐明细胞质DNA感应的机制及其在启动先天免疫信号传递中的作用.
- 为了确定参与DNA触发的干扰素生产途径的特定分子.
主要方法:
- 在实验室中合成循环二核酸,使用哺乳动物细胞质提取物与ATP和GTP在DNA或RNA的存在下进行化.
- 哺乳动物细胞的DNA转染和DNA病毒感染以诱导内源信号传递.
- 生物化学分析检测循环GMP-AMP (cGAMP) 生产及其与STING结合.
主要成果:
- 哺乳动物细胞质提取物合成循环氨酸单酸 - 氨酸单酸 (cGAMP) 在体外提供DNA时,但不是RNA.
- 哺乳动物细胞中的DNA转染和DNA病毒感染导致cGAMP的产生.
- 合成的cGAMP直接与STING蛋白结合,随后激活IRF3并诱导干扰素β的产生.
结论:
- cGAMP在甲基动物中起到内源性第二信使的作用,调解细胞对细胞核DNA的细胞反应.
- cGAMP-STING-IRF3通路是响应DNA检测而产生干扰素的关键机制.
- 这一发现澄清了先天免疫力和DNA感应的一个关键方面.
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