Modified AAV capsids and uses thereof
The present disclosure provides adeno-associated virus (AAV) virions with altered capsid protein that binds heparan sulfate proteoglycans, where the AAV virions exhibit greater infectivity of retinal cells, altered tropism and/or the ability to bind and cross the inner limiting membrane following intravitreal injection. The present disclosure further provides methods of delivering a gene product to a retinal cell in an individual, and methods of treating ocular disease.
1. A polynucleotide comprising a nucleic acid sequence encoding a non-naturally-occurring modified AAV capsid protein, comprising one or more amino acid modifications, wherein the modification confers heparan sulfate binding to the capsid protein, wherein the AAV is an AAV2.5T/7m8.
2. The polynucleotide of claim 1 , wherein the AAV2.5T/7m8 is an AAV2.5T/7m8(+3), an AAV2.5T/7m8(0), an AAV2.5T/7m8(−12), or an AAV2.5T/7m8(−3).
3. The polynucleotide of claim 1 , wherein at least one of the one or more amino acid modifications comprises:
(a) a S576R point mutation;
(b) a T579R point mutation;
(c) a substitution of amino acid residues 576-579 or 576-581 with the following amino acid residues:
(SEQ ID NO: 5)
RGNRQA;
(d) a substitution of amino acid residues 576-581 with the following amino acid residues: RGNRQAAP (SEQ ID NO:6);
(e) a substitution of amino acid residues 573-579, 573-581 or 573-584 with the following amino acid residues: NLQRGNRQAATA (SEQ ID NO:7); or
(f) a substitution of amino acid residues 573-581 or 573-584 with the following amino acid residues:
(SEQ ID NO: 8)
NLQRGNRQAATAAP.
4. The polynucleotide of claim 1 , wherein at least one of the one or more amino acid modifications comprises:
(a) a point mutation corresponding to a S576R point mutation in AAV2.5T;
(b) a point mutation corresponding to a T579R point mutation in AAV2.5T;
(c) a substitution corresponding to a substitution of amino acid residues 576-579 or 576-581 in AAV2.5T with the following amino acid residues: RGNRQA (SEQ ID NO:5);
(d) a substitution corresponding to a substitution of amino acid residues 576-581 in AAV2.5T with the following amino acid residues: RGNRQAAP (SEQ ID NO:6);
(e) a substitution corresponding to a substitution of amino acid residues 573-579, 573-581, 573-583, 573-584, 576-579, 576-581, 576-583 or 576-584 in AAV2.5T with the following amino acid residues: NLQRGNRQAATA (SEQ ID NO:7); or
(f) a substitution corresponding to a substitution of amino acid residues 576-583, 576-584, 573-583 or 573-584 in AAV2.5T with the following amino acid residues:
NLQRGNRQAATAAP (SEQ ID NO:8).
5. The polynucleotide of claim 4 , comprising a capsid sequence set forth in any of SEQ ID NOs:1-3.
6. The polynucleotide of claim 1 , comprising a sequence shown in FIGS. 3 A- 3 B .
7. An expression vector comprising the polynucleotide of claim 1 , wherein the nucleic acid sequence encoding the modified capsid protein is operably linked to a promoter sequence.
8. A cell comprising the expression vector of claim 7 .
9. The cell of claim 8 , further comprising a polynucleotide that encodes a therapeutic protein.
10. The cell of claim 8 , further comprising a polynucleotide that encodes a rep protein.
11. The cell of claim 10 , wherein the cell is a packaging cell in which the rep protein and the modified AAV capsid protein are stably maintained.
12. The cell of claim 11 , wherein the cell is a HEK293, SF-9, A549, or HeLa cell.
13. A method of making a non-naturally occurring modified AAV capsid protein, comprising one or more amino acid modifications, wherein the modification confers heparan sulfate binding to the capsid protein, comprising expressing the polynucleotide sequence of claim 1 in a cell.