In Vitro and In Vivo Gene Therapy Vector Evolution via Multispecies Interbreeding and Retargeting of Adeno-Associated Viruses

Abstract

Adeno-associated virus (AAV) serotypes differ broadly in transduction efficacies

Directed evolution of adeno-associated virus to an infectious respiratory virus

“…However, the search for AAV variants with novel properties through a variety of algorithms-such as isolating naturally occurring AAV, site-directed mutants, or (most recently) laboratory-evolved variants-has yielded various chimeric AAV viruses with distinct transduction profiles (17,(41)(42)(43)(44). Family shuffling of the AAV capsids and subsequent selection in nonhuman models have established the power and potential of this method to generate novel capsids tailored to specific applications (23,41,42). Here we demonstrate the human therapeutic potential of a customized AAV vector.…”

Heart-targeted adeno-associated viral vectors selected by in vivo biopanning of a random viral display peptide library

“…9 Under these conditions, however, repeated rounds of selection and the progressive enrichment of targeting peptides has not been achieved. Another selection protocol of viruses present in the target tissue solely based on PCR amplification of virus library genomes in the target tissue (tumour or lung) after in vivo application of AAV peptide display libraries lead to the isolation of vectors displaying characteristic peptide motifs; however, gene transduction studies showed only an expansion of vector tropism, but not a restriction to the target tissue.…”

“…[1][2][3][4][5][6] Capsids of adeno-associated virus (AAV)-derived vectors have been modified for receptor targeting basically in three ways: (1) by conjugating receptorbinding ligands to their capsids, (2) by genetic insertion of ligands into the capsid (for reviews see Muzyczka and Warrington 1 and Buning et al 7 ) and (3) by DNA shuffling from different AAV serotypes. [8][9][10] Pseudotyping of AAV vectors with capsids of different serotypes also expanded the range of infectable cells, 11 but has not resulted in cell type-selective transduction after systemic application.…”

“…Genetic modification of the AAV2 capsid by oligonucleotide insertions, random mutagenesis or DNA shuffling is able to circumvent some of these limitations. [8][9][10][17][18][19] Whereas larger peptides up to the size of GFP (238 amino acids) could be accommodated at the VP2 N-terminus 15,[20][21][22][23][24][25] the addition of small peptides up to 34 amino acids is tolerated at several positions of the AAV2 capsid. 1 Among the tolerated insertion sites for small peptides, insertions in the AAV2 heparin binding domain 26,27 adjacent to amino acids 587 or 588 was most successful.…”

“…A major step forward to improve the target peptide design has been the development of virus display peptide libraries [33][34][35][36][37] or libraries of random capsid chimeras derived from different AAV serotypes. [8][9][10] In such libraries, a multitude of potentialtargeting motifs is presented within the restrictions of capsid assembly and genome packaging. Selection of targeting motifs occurs by amplification of viruses, which have successfully delivered their genomes to the target cell, for example by using not only the right entry receptor but also the appropriate post-entry pathway.…”