Crispr/casrx proof-of-concept for rna degradation: A future tool against rna viruses?

Abstract

Influenza viruses provide a great threat for the human population, causing highly con-tagious respiratory infections that can lead to serious clinical complications. There are a limited variety of influenza antivirals, and these antivirals are subjected to the constant emergence of re-sistances. Therefore, the development of new antiviral strategies to combat influenza viruses and other RNA viruses must be promoted. In this work, we design a proof-of-concept of a recently described CRISPR/Cas tool that has been proposed as a possible future RNA virus antiviral, named CRISPR/CasRx. For this, we verified the efficiency of the CasRx endonuclease in the degradation of the eGFP mRNA reporter gene and we established the best conditions for, and the efficient per-formance of, the CRISPR/CasRx system. The results were measured by fluorescence microscopy, flow cytometry, and qRT-PCR. The analyses demonstrated a reduction in fluorescence, regardless of the amount of eGFP reporter plasmid transfected. The analyses showed an 86–90% reduction in fluorescence by flow cytometry and a 51–80% reduction in mRNA expression by qRT-PCR. Our results demonstrate that the CasRx endonuclease is an efficient tool for eGFP mRNA knockdown. Therefore, subsequent experiments could be useful for the development of a new antiviral tool.