Improved Specificity and Safety of Anti-Hepatitis B Virus TALENs Using Obligate Heterodimeric FokI Nuclease Domains

Autor: Kristie Bloom, Tiffany S. Smith, Prashika Singh, Patrick Arbuthnot, Abdullah Ely, Kay O. Chmielewski, Toni Cathomen
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Viruses
Volume 13
Issue 7
Viruses, Vol 13, Iss 1344, p 1344 (2021)
ISSN: 1999-4915
DOI: 10.3390/v13071344
Popis: Persistent hepatitis B virus (HBV) infection remains a serious medical problem worldwide, with an estimated global burden of 257 million carriers. Prophylactic and therapeutic interventions, in the form of a vaccine, immunomodulators, and nucleotide and nucleoside analogs, are available. Vaccination, however, offers no therapeutic benefit to chronic sufferers and has had a limited impact on infection rates. Although immunomodulators and nucleotide and nucleoside analogs have been licensed for treatment of chronic HBV, cure rates remain low. Transcription activator-like effector nucleases (TALENs) designed to bind and cleave viral DNA offer a novel therapeutic approach. Importantly, TALENs can target covalently closed circular DNA (cccDNA) directly with the potential of permanently disabling this important viral replicative intermediate. Potential off-target cleavage by engineered nucleases leading to toxicity presents a limitation of this technology. To address this, in the context of HBV gene therapy, existing TALENs targeting the viral core and surface open reading frames were modified with second- and third-generation FokI nuclease domains. As obligate heterodimers these TALENs prevent target cleavage as a result of FokI homodimerization. Second-generation obligate heterodimeric TALENs were as effective at silencing viral gene expression as first-generation counterparts and demonstrated an improved specificity in a mouse model of HBV replication.
Databáze: OpenAIRE
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