Project description:We used an adenine base editor to target the translation start site and mRNA splicing site of Camk2d in order to knock out CaMKIIδ. We found that editing the 5' splice site of intron 7 can lead to premature translation termination, effectively knocking out CaMKIIδ.
Project description:We used an adenine base editor to target the translation start site and mRNA splicing site of Camk2d in order to knock out CaMKIIδ. We found that editing the 5' splice site of intron 7 can lead to premature translation termination, effectively knocking out CaMKIIδ.
Project description:Adeno-associated virus (AAV)-based gene therapy could be facilitated by the development of molecular switches to control the magnitude and timing of expression of therapeutic transgenes. RNA interference (RNAi)-based approaches hold unique potential as a clinically proven modality to pharmacologically regulate AAV gene dosage in a sequence-specific manner. We present a generalizable RNAi-based rheostat wherein AAV transgene expression is silenced using the clinically validated modality of chemically modified short interfering RNA (siRNA) conjugates or vectorized co-expression of short hairpin RNA (shRNA). For transgene induction, we employ REVERSIR technology, a synthetic high-affinity oligonucleotide complementary to the siRNA or shRNA guide strand to reverse RNAi activity and rapidly recover transgene expression. For potential clinical development, we report potent and specific siRNA sequences that may allow selective regulation of transgenes while minimizing unintended off-target effects. Our results establish a conceptual framework for RNAi-based regulatory switches with potential for infrequent dosing in clinical settings to dynamically modulate expression of virally-delivered gene therapies.
Project description:We show that delivering the mitochondrial base editor DdCBEs via AAV transduction of somatic cells efficiently produces precise base editing of the intended region.
Project description:Prion disease is caused by misfolding of the prion protein (PrP) into pathogenic self-propagating conformations, leading to rapid onset dementia and death. However, elimination of endogenous PrP can halt prion disease progression. Here, we describe CHARM, a compact, enzyme-free epigenetic editor capable of silencing transcription through programmable targeted DNA methylation. Using a histone H3 tail-Dnmt3l fusion, CHARM recruits and activates the endogenous DNA methyltransferases, thereby reducing transgene size and bystander effects. When delivered to the mouse brain by an adeno-associated viral (AAV) vector, PRNP-targeted CHARM ablates PrP expression across the brain. We temporally limit editor expression by implementing a kinetically-tuned self-silencing approach. CHARM represents a broadly applicable strategy to programmably prevent expression of pathogenic proteins, including those implicated in other neurodegenerative diseases.