1 MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China .
2 Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China .
Hum Gene Ther. 2018 Nov;29(11):1264-1276. doi: 10.1089/hum.2018.018. Epub 2018 May 9.
CRISPR/Cas9 is an adaptive immune system where bacteria and archaea have evolved to resist the invading viruses and plasmid DNA by creating site-specific double-strand breaks in DNA. This study tested this gene editing system in inhibiting human immunodeficiency virus type 1 (HIV-1) infection by targeting the viral long terminal repeat and the gene coding sequences. Strong inhibition of HIV-1 infection by Cas9/gRNA was observed, which resulted not only from insertions and deletions (indels) that were introduced into viral DNA due to Cas9 cleavage, but also from the marked decrease in the levels of the late viral DNA products and the integrated viral DNA. This latter defect might have reflected the degradation of viral DNA that has not been immediately repaired after Cas9 cleavage. It was further observed that Cas9, when solely located in the cytoplasm, inhibits HIV-1 as strongly as the nuclear Cas9, except that the cytoplasmic Cas9 does not act on the integrated HIV-1 DNA and thus cannot be used to excise the latent provirus. Together, the results suggest that Cas9/gRNA is able to target and edit HIV-1 DNA both in the cytoplasm and in the nucleus. The inhibitory effect of Cas9 on HIV-1 is attributed to both the indels in viral DNA and the reduction in the levels of viral DNA.
CRISPR/Cas9 是一种适应性免疫系统，细菌和古菌通过在 DNA 上产生特定的双链断裂来抵抗入侵的病毒和质粒 DNA。本研究通过靶向病毒长末端重复序列和基因编码序列，测试了该基因编辑系统对人类免疫缺陷病毒 1 型（HIV-1）感染的抑制作用。Cas9/gRNA 对 HIV-1 感染的强烈抑制作用不仅来自于 Cas9 切割导致的病毒 DNA 插入和缺失（indels），还来自于晚期病毒 DNA 产物和整合病毒 DNA 水平的显著降低。后一种缺陷可能反映了 Cas9 切割后未立即修复的病毒 DNA 的降解。进一步观察到，Cas9 仅位于细胞质中时，就像核 Cas9 一样强烈抑制 HIV-1，只是细胞质 Cas9 不能作用于整合的 HIV-1 DNA，因此不能用于切除潜伏的前病毒。总之，这些结果表明 Cas9/gRNA 能够在细胞质和细胞核中靶向和编辑 HIV-1 DNA。Cas9 对 HIV-1 的抑制作用归因于病毒 DNA 中的 indels 和病毒 DNA 水平的降低。
