Adeno-associated vectors for enhanced transduction and reduced immunogenicity
Inventors
Chiorini, John A. • Wainer, Sandra • Agbandje-McKenna, Mavis • Halder, Sujata
Assignees
University of Florida Research Foundation Inc • US Department of Health and Human Services
Publication Number
US-10081659-B2
Publication Date
2018-09-25
Expiration Date
2036-04-06
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Abstract
A modified adeno-associated virus (AAV) capsid protein comprising at least one non-native amino acid that confers to the modified AAV particles new properties, such as increased transduction efficiency and reduced immunogenicity. These modified AAV proteins and particles are particularly useful for gene therapy and the treatment of various diseases and conditions.
Core Innovation
The invention relates to a modified adeno-associated virus (AAV) capsid protein having at least one non-native amino acid at a location involved in binding to a cellular receptor. Such modifications confer new properties to the modified AAV virions comprising these capsid proteins, including increased or decreased transduction efficiency and reduced immunogenicity, enabling enhanced use in gene therapy and other applications.
The problem addressed by the invention is the inefficiency and immunogenicity of current AAV vectors used in gene therapy. Many existing AAV vectors have limited delivery efficiency to target cells and provoke immune responses that hamper repeated administrations, thus limiting therapeutic efficacy. The invention provides modified AAV capsid proteins that overcome these limitations by altering receptor binding sites to enhance transduction and reduce recognition by neutralizing antibodies.
The inventors used X-ray crystallography, mutagenesis, and glycan arrays to identify sialic acid (SIA) binding sites on AAV5 capsid proteins, notably two sites designated A-site and B-site. They demonstrated that mutations at these sites can abrogate or alter sialic acid-dependent transduction and affect cell tropism and neutralization by antibodies. Modified capsid proteins thus alter receptor specificity and immunogenic profiles, enabling the creation of recombinant viruses with improved gene transfer capabilities and immune evasion properties.
Claims Coverage
The patent contains one independent claim and several dependent claims focusing on modified AAV capsid proteins with specific non-native amino acid substitutions and their therapeutic applications.
Modified AAV capsid protein with non-native amino acids at specific AAV5 positions
A modified AAV capsid protein comprising at least one non-native amino acid at a location corresponding to positions L587, M569, Y585, or T571 in the AAV5 capsid protein sequence.
Capsid proteins derived from various AAV serotypes including those binding sialic acid
The modified capsid protein is produced by modification from capsid proteins of multiple AAV serotypes, including AAV1, AAV2, AAV3, AAV3B, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, BAAV, AAAV, and AAV VR-942, with emphasis on those that bind sialic acid such as AAV1, AAV4, AAV5, and AAV6.
Modification involving substitution of amino acids at receptor binding sites not present in native AAV capsids
The modification comprises substitution of amino acids at receptor binding sites, where substituted amino acids are not present at corresponding locations in either sialic acid-binding or non-sialic acid-binding AAV capsid proteins, particularly affecting locations interacting with sialic acid.
Inclusion of modifications in A-site or B-site of AAV capsid protein
The modified capsid protein comprises at least one non-native amino acid within the structurally defined A-site or B-site regions of the capsid protein, which are involved in sialic acid binding and viral transduction.
Use of recombinant viruses possessing the modified capsid protein for therapeutic gene delivery
Recombinant viruses comprising the modified AAV capsid protein and heterologous nucleic acid molecules are used in methods to treat diseases by administering to individuals, targeting tissues such as the eye, central nervous system, liver, salivary glands, or muscle tissue.
Overall, the claims cover modified AAV capsid proteins with defined amino acid substitutions at sialic acid receptor binding sites, methods of producing such proteins and recombinant viruses, and therapeutic applications of these modified viruses demonstrating enhanced transduction and reduced immunogenicity.
Stated Advantages
The modified AAV capsid proteins provide increased transduction efficiency compared to wild-type AAVs.
The modified AAV virions exhibit reduced immunogenicity, including resistance to neutralizing antibodies.
Alterations in capsid protein allow changes in receptor specificity and cell tropism, improving targeting to specific tissues or cell types.
Documented Applications
Gene therapy use involving delivery of heterologous nucleic acid molecules to target tissues.
Treatment of diseases via administration of recombinant AAV containing modified capsid proteins and therapeutic nucleic acids to tissues such as eye, central nervous system, liver, salivary glands, muscle tissue, lung, brain, capillary epithelial cells, and tumor cells.
Ex vivo transduction of myoblasts and tumor cells for therapeutic and research purposes.
Delivery of therapeutic nucleic acids by various administration routes including subretinal injection, intravitreal injection, aerosol delivery to lungs, intravenous injection, targeted hepatic infusion, and intracranial injection.
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