Sustained Correction of a Murine Model of Phenylketonuria following a Single Intravenous Administration of AAVHSC15-PAH.

Phenylketonuria is an inborn error of metabolism caused by loss of function of the liver-expressed enzyme phenylalanine hydroxylase and is characterized by elevated systemic phenylalanine levels that are neurotoxic. Current therapies do not address the underlying genetic disease or restore the natural metabolic pathway resulting in the conversion of phenylalanine to tyrosine. A family of hepatotropic clade F adeno-associated viruses (AAVs) was isolated from human CD34 hematopoietic stem cells (HSCs) and one (AAVHSC15) was utilized to deliver a vector to correct the phenylketonuria phenotype in Pah mice.

Clade F AAVHSCs cross the blood brain barrier and transduce the central nervous system in addition to peripheral tissues following intravenous administration in nonhuman primates.

The biodistribution of AAVHSC7, AAVHSC15, and AAVHSC17 following systemic delivery was assessed in cynomolgus macaques (Macaca fascicularis). Animals received a single intravenous (IV) injection of a self-complementary AAVHSC-enhanced green fluorescent protein (eGFP) vector and tissues were harvested at two weeks post-dose for anti-eGFP immunohistochemistry and vector genome analyses. IV delivery of AAVHSC vectors produced widespread distribution of eGFP staining in glial cells throughout the central nervous system, with the highest levels seen in the pons and lateral geniculate nuclei (LGN).

Stem cell-derived clade F AAVs mediate high-efficiency homologous recombination-based genome editing.

The precise correction of genetic mutations at the nucleotide level is an attractive permanent therapeutic strategy for human disease. However, despite significant progress, challenges to efficient and accurate genome editing persist. Here, we report a genome editing platform based upon a class of hematopoietic stem cell (HSC)-derived clade F adeno-associated virus (AAV), which does not require prior nuclease-mediated DNA breaks and functions exclusively through BRCA2-dependent homologous recombination.

Low Seroprevalence of Neutralizing Antibodies Targeting Two Clade F AAV in Humans.

To assess the therapeutic utility of AAVHSC15 and AAVHSC17, two recently described Clade F adeno-associated viruses (AAVs), the seroprevalence of neutralizing antibodies (NAbs) to these AAVs was assessed in a representative human population and compared to that of AAV9. NAb levels were measured in 100 unique human sera of different races (34, Black, 33 Caucasian, and 33 Hispanic) and sex (49% female, 51% male) collected within the United States. Fifty-six sera were tested in Huh7 cells and 44 sera were tested in 2V6.

Aurintricarboxylic acid increases yield of HSV-1 vectors.

Production of large quantities of viral vectors is crucial for the success of gene therapy in the clinic. There is a need for higher titers of herpes simplex virus-1 (HSV-1) vectors both for therapeutic use as well as in the manufacturing of clinical grade adeno-associated virus (AAV) vectors. HSV-1 yield increased when primary human fibroblasts were treated with anti-inflammatory drugs like dexamethasone or valproic acid.

Inhibition of choroidal neovascularization in a nonhuman primate model by intravitreal administration of an AAV2 vector expressing a novel anti-VEGF molecule.

Inhibition of vascular endothelial growth factor (VEGF) for the management of the pathological ocular neovascularization associated with diseases such as neovascular age-related macular degeneration is a proven paradigm; however, monthly intravitreal injections are required for optimal treatment. We have previously shown that a novel, secreted anti-VEGF molecule sFLT01 delivered by intravitreal injection of an AAV2 vector (AAV2-sFLT01) gives persistent expression and is efficacious in a murine model of retinal neovascularization. In the present study, we investigate transduction and efficacy of an intravitreally administered AAV2-sFLT01 in a nonhuman primate (NHP) model of choroidal neovascularization (CNV).