| Current antiviral therapies, including pegylated interferon and nucleos(t)ide analogues (NAs), significantly reduce the morbidity and mortality of patients with chronic hepatitis B (CHB), neither of them can readily cure it. NAs can effectively suppress viral replication to undetectable levels by inhibition of hepatitis B virus (HBV) polymerase, but rebound viremia almost inevitably occurs after stopping NAs unless HBsAg loss is achieved. Persistence of covalently closed circular DNA (cccDNA) forms a major barrier to eradication of HBV. Thus, curing CHB requires the novel therapeutic strategy to eliminate or permanently inactivate HBV cccDNA in which CRISPR-mediated gene editing is straightforward to specifically cleave and destroy HBV genome in vivo, promising its therapeutic potential for HBV cure. However, the clinical application of CRISPR gene editing in HBV treatment faces several daunting challenges, including off-target editing and in vivo delivery efficacy. To overcome this hurdle we will discuss the above-mentioned challenges by 1) optimize the CRISPR-mediated base editing machinery for HBV cccDNA ; 2) take advantage of lipid nanoparticle (LNP) for in vivo delivery of Cas9-CBE mRNA in mouse models of HBV persistence. We aim to demonstrate the clinical applicability and safety in a preclinical setting, paving the way towards development of HBV cure. |
