Disclosed herein are recombinant AAV variant (e.g., variant serotype 3B (AAV3B)) capsid proteins and variant capsid protein-containing viral particles with enhanced ability to transduce hepatic cells. Viral particles containing these capsid variants are capable of evading neutralization by the host humoral immune response. The recombinant AAV3B variant proteins and viral particles disclosed herein were identified from a variant AAV3B capsid library that was engineered by making substitutions in only the variable regions of the capsid. Some embodiments of the AAV3B capsid variants disclosed herein comprise the AAV3B-G3 variant and the AAV3B-E12 variant. Compositions of these variant AAV particles are provided that are useful for transducing and delivering therapeutic transgenes to cells, such as liver cells, and thus treat diseases and disorders pertaining to these cells.

Disclosed herein are engineered AAV VP capsid polypeptides with the ability to assemble into virus particles and having improved tissue tropism to, for example, CNS tissues. The capsids are engineered using the high throughput discovery system described herein. In certain embodiments, provided herein are recombinant adeno-associated virus (AAV) VP capsid polypeptides having at least one mutation in a residue corresponding to residue 581 to residue 589 in SEQ ID NO: 1.

The disclosure in some aspects relates to recombinant adeno-associated viruses having distinct tissue targeting capabilities. In some aspects, the disclosure relates to gene transfer methods using the recombinant adeno-associated viruses. In some aspects, the disclosure relates to isolated AAV capsid proteins and isolated nucleic acids encoding the same.

The present invention provides methods and compositions comprising an adeno-associated vims (AAV) synthetic inverted terminal repeat (ITR), wherein the ITR may have modified promoter transcriptional function. Additionally provided are vectors and virus particles comprising the same, as well as methods of their use.

A method for reducing a contaminating DNA content of a preparation containing AAV capsids and contaminating DNA, comprising the steps of a) Performing an extraction of DNA with a solid phase bearing positive charges at its surface said solid phase is contacted with the preparation at a pH of 7.0±1.0, and a salt concentration of 10 mM to 200 mM yielding a first fraction, (b) Diafiltering the first fraction by a first tangential flow filtration to obtain a second fraction, (c) Treating the second fraction with DNase, (d) Diafiltering the DNase treated second fraction obtained by step c) by a second tangential flow, (e) filtration to a buffer with pH of 7.0±1.0, and a salt concentration of 10 mM to 20 mM to yield a third fraction, and optionally (f) Concentrating the third fraction by tangential flow filtration before supplemental chromatography.

Provided herein are methods and compositions useful in the production of recombinant AAV (rAAV) in host producer cells, such as insect cells. In some embodiments, methods, uses and compositions are provided that comprise recombinant VP1 genes comprising modified Kozak sequences to express AAV VP1 proteins in amounts that are useful for producing infective rAAV particles. These infective rAAV particles may comprise a gene of interest.

Methods for in vivo administration of the coding sequence of the sirt6 gene. In particular, methods that include the administration of adeno-associated virus vectors or recombinant adeno-associated virus vectors including the coding sequence of the sirt6 gene.

Provided herein are methods for determining the serotype of a virus particle and/or or determining the heterogeneity of a virus particle (e.g., an AAV particle). In other embodiments, the invention provides methods to determine the heterogeneity of AAV particles. In some aspects, the invention provides viral particles (e.g., rAAV particles) with improved stability and/or improved transduction efficiency by increasing the acetylation and/or deamidation of capsid proteins.

Methods for determining the relative abundance of viral capsid components in a sample of viral particles are disclosed. In embodiments, methods for determining the relative abundance of empty capsids, partially-full capsids and full capsids (e.g., containing a heterologous nucleic acid molecule) of adeno-associated virus are disclosed.

Closed-ended, linear, duplex (CELID) DNA molecules, recombinant AAV (rAAV), particles comprising CELID DNA, methods of making such molecules and particles, and therapeutic applications of such particles.