Data from: Development of an adipose-tropic AAV capsid ablating liver tropism

AAV vectors are mainstream delivery platforms in gene therapy, yet
AAV-mediated gene transfer to adipose tissue is underdeveloped due to low
efficiency of natural AAVs. We previously demonstrated that an engineered
capsid Rec2 displayed improved adipo-tropism but with the caveat of liver
transduction. To generate highly adipo-tropic capsid, we modified Rec2
capsid by site-specific mutagenesis and found the variant V7 with F503Y,
Y708D and K709I substitution to harbor highly selective adipo-tropism
while diminishing liver transduction. Intraperitoneal injection favored
transduction to visceral fat while intravenous administration favored
subcutaneous fat.  Intraperitoneal administration of V7 vector
harboring human leptin and adiponectin as single transcript normalized the
metabolic dysfunction of ob/ob mice at a low dose. Moreover, introducing
the same mutagenesis to AAV8 capsid diminished liver transduction
suggesting F503, Y708 and K709 critical for liver transduction. The
Rec2.V7 vector may provide a powerful tool for basic research and potent
vehicle for adipose-targeting gene therapy.

AAV载体是基因治疗中的主流递送平台，但由于天然AAV效率低下，AAV介导的脂肪组织基因转移研究尚不完善。我们此前证实，经工程改造的衣壳Rec2显示出改善的脂肪趋向性，但存在肝脏转导的问题。为生成高脂肪趋向性的衣壳，我们通过位点特异性诱变修饰Rec2衣壳，发现携带F503Y、Y708D和K709I替换的变体V7具有高度选择性的脂肪趋向性，同时减少肝脏转导。腹腔注射更利于内脏脂肪的转导，而静脉注射则更利于皮下脂肪的转导。腹腔注射携带人瘦素和脂联素单转录本的V7载体，在低剂量下即可使ob/ob小鼠的代谢功能障碍恢复正常。此外，将相同诱变引入AAV8衣壳可减少肝脏转导，表明F503、Y708和K709对肝脏转导至关重要。Rec2.V7载体或可为基础研究提供强有力的工具，并成为脂肪靶向基因治疗的有效载体。