The collateral activity of RfxCas13d can induce lethality in a RfxCas13d knock-in mouse model
Yunfei Li, Junjie Xu, Xuefei Guo, Zhiwei Li, Lili Cao, Shengde Liu, Ying Guo, Guodong Wang, Yujie Luo, Zeming Zhang, Xuemei Wei, Yingchi Zhao, Tongtong Liu, Xiao Wang, Huawei Xia, Ming Kuang, Qirui Guo, Junhong Li, Luoying Chen, Yibing Wang, Qi Li, Fengchao Wang, Qinghua Liu, Fuping You
Abstract
BACKGROUND: The CRISPR-Cas13 system is an RNA-guided RNA-targeting system and has been widely used in transcriptome engineering with potentially important clinical applications. However, it is still controversial whether Cas13 exhibits collateral activity in mammalian cells. RESULTS: Here, we find that knocking down gene expression using RfxCas13d in the adult brain neurons caused death of mice, which may result from the collateral activity of RfxCas13d rather than the loss of target gene function or off-target effects. Mechanistically, we show that RfxCas13d exhibits collateral activity in mammalian cells, which is positively correlated with the abundance of target RNA. The collateral activity of RfxCas13d could cleave 28s rRNA into two fragments, leading to translation attenuation and activation of the ZAKα-JNK/p38-immediate early gene pathway. CONCLUSIONS: These findings provide new mechanistic insights into the collateral activity of RfxCas13d in mammalian cells and warn that the biosafety of the CRISPR-Cas13 system needs further evaluation before application to clinical treatments.