The Use of CRISPR/Cas9 as a Tool to Study Human Infectious Viruses

Abstract

Clustered regularly interspaced short palindromic repeats (CRISPR) systems are a set of versatile gene-editing toolkit that perform diverse revolutionary functions in various fields of application such as agricultural practices, food industry, biotechnology, biomedicine, and clinical research. Specially, as a novel antiviral method of choice, CRISPR/Cas9 system has been extensively and effectively exploited to fight against human infectious viruses. Infectious diseases including human immunodeficiency virus (HIV), hepatitis B virus (HBV), human papillomavirus (HPV), and other viruses are still global threats with persistent potential to probably cause pandemics. To facilitate virus removals, the CRISPR/Cas9 system has already been customized to confer new antiviral capabilities into host animals either by modifying host genome or by directly targeting viral inherent factors in the form of DNA. Although several limitations and difficulties still need to be conquered, this technology holds great promises in the treatment of human viral infectious diseases. In this review, we will first present a brief biological feature of CRISPR/Cas9 systems, which includes a description of CRISPR/Cas9 structure and composition; thereafter, we will focus on the investigations and applications that employ CRISPR/Cas9 system to combat several human infectious viruses and discuss challenges and future perspectives of using this new platform in the preclinical and clinical settings as an antiviral strategy.

Antiviral Targeting of Varicella Zoster Virus Replication and Neuronal Reactivation Using CRISPR/Cas9 Cleavage of the Duplicated Open Reading Frames 62/71

“…The goal of this study was to establish proof of principle that the CRISPR targeting of VZV genomes could be used as an antiviral strategy eventually leading to therapeutic applications. The results obtained here add to a growing body of knowledge in which several human DNA viruses (and RNA viruses with DNA genome intermediates) have been targeted by gene editing [31,33,57,[82][83][84]. While gene editing can be performed with designer meganucleases and transcription factor-like endonucleases (TALENS), the complexity of their design and expense of their generation has made the more simple and widely available RNA-guided CRISPR/Cas technology more attractive.…”

CRISPR-Cas9-Based Technology for Studying Enteric Virus Infection

“…3) The gRNA-Cas9 complex targets complementary sequences of the re-invading pathogen’s genomic DNA, leading to the creation of a double stranded break (DSB) in the RNA-guided targeted genome element, resulting in its elimination. Cas9-mediated cleavage occurs only when a protospacer adjacent motif (PAM) sequence (e.g., NGG for Streptococcus pyogenes Cas9) is located upstream of the target nucleotides, which grants specific cleavage of non-self DNA ( Puschnik et al, 2017 ; Ishino et al, 2018 ; Lin et al, 2021 ).…”

“…Characterization of viral-host interactions is necessary to gain a clear view of the infection and replication mechanisms, which will contribute to developing host-directed drugs against pathogenic viruses. Genome-wide genetic screening is one of the most powerful and rapid tools to uncover new insights into the viral lifecycle through a comprehensive search for host factors associated with viral infection ( Puschnik et al, 2017 ; Lin et al, 2021 ). Recently, a novel technology, called clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 system made a breakthrough in screening approach.…”

The State-of-the-Art of Gene Editing and its Application to Viral Infections and Diseases Including COVID-19

“…Off-target effects of CRISPR/Cas9 comprise the principal barrier in conducting a clinical trial of the CRISPR/Cas system. This must be addressed vigilantly when applied to in vivo studies to prove the safety profile of the viral vectors ( Kim et al., 2015 ; Lin et al., 2021 ). Other crucial obstacles for in vivo applications are the specificity and accuracy of the editing process and the delivery method of the CRISPR/Cas9 system.…”

“…The delivery of the engineered Cas9/multiplexed-sgRNA system into the human cells HEK293 has shown successful results in abolishing the intracellular various or parvoviral genome compared to an individual targeting Cas9 ( Liao et al., 2015 ). Nevertheless, Cas9/multiplexed-sgRNA system has grown targeting the two coreceptor genes such as CCR5 and CXCR4 has not yet been accomplished ( Lin et al., 2021 ).…”