Abstract: Applicants sought to express human iduronate-2-sulfatase (hIDS) in the brain endothelium of a mouse model of Mucopolysaccharidosis type II (MPSII, Hunter's syndrome) to enable enzyme secretion into the brain parenchyma. In this disorder, IDS deficiency results in the pathophysiological accumulation of heparan and dermatan sulfate GAGs. To test the hypothesis, Applicants chose AAV-BI30, an AAV9-derived capsid that has an enhanced in vivo tropism specific to the endothelium in the rodent CNS and can transduce human brain vascular endothelial cells in vitro more efficiently than AAV9. Applicants show that systemic delivery of AAV-BI30: hIDS restored IDS enzyme activity in the brain, liver, and serum of IDS-KO mice (FIG. 1). Importantly, AAV-BI30-mediated gene transfer resulted in the correction of GAG accumulation in the brain (FIG. 2). This effect was not observed when using the AAV-BI30 vector packaging a non-secreting version of hIDS.

Abstract: An engineered AAV capsid is provided, in which at least one protein on the capsid is modified to include a n-mer motif, which promotes transduction of the capsid into the central nervous system (CNS) through interaction with the Transferrin receptor. Further embodiments provide a vector system comprising one or more vectors encoding AAV capsids and a method of delivering cargo to the CNS. The method comprises administering, in vivo or in vitro, a AAV capsid according to embodiments described herein and the AVV capsid comprises one or more cargo molecules.

Abstract: Engineered capsid scaffolds comprising one or more modified capsid proteins are described exhibiting properties of improved thermostability while producing at similar levels to the naturally occurring capsid serotype. Embodiments include use and delivery of the engineered capsid scaffolds to allow for increased tolerance for manipulation and mutagenesis.

Abstract: An engineered AAV capsid is provided, in which at least one protein on the capsid is modified to include a n-mer motif, which promotes transduction of the capsid into the central nervous system (CNS). Further embodiments provide a vector system comprising one or more vectors encoding AAV capsids and a method of delivering cargo to the CNS. The method comprises administering, in vivo or in vitro, a AAV capsid according to embodiments described herein and the AVV capsid comprises one or more cargo molecules.

Abstract: Highly selective targeting moieties and compositions comprising the targeting moieties are described herein to efficiently transduce endothelial cell of the central nervous system vasculature. Embodiments include use and delivery of the targeting moieties and compositions to selectively direct delivery of cargo.

Abstract: Provided are compositions and kits comprising recombinant adeno-associated viruses (rAAVs) with tropisms showing increased specificity and efficiency of viral transduction in targeted cell-types, for e.g., the brain and the liver. Therapeutic and bio-medical research applications of the rAAVs are also described, including without limitation methods of discovering rAAVs using a multiplexed Cre recombination-based AAV targeted evolution (M-CREATE) method, and methods of treating various diseases and conditions by rAAV-mediated transgene therapy.