title: Optimizing the transduction efficiency of capsid-modified AAV6 serotype vectors in primary human hematopoietic stem cells in vitro and in a xenograft mouse model in vivo.
abstract: OBJECTIVE
  Although recombinant adeno-associated virus serotype 2 (AAV2) vectors have gained attention because of their safety and efficacy in numerous phase I/II clinical trials, their transduction efficiency in hematopoietic stem cells (HSCs) has been reported to be low. Only a few additional AAV serotype vectors have been evaluated, and comparative analyses of their transduction efficiency in HSCs from different species have not been performed.
  
  
  METHODS
  We evaluated the transduction efficiency of all available AAV serotype vectors (AAV1 through AAV10) in primary mouse, cynomolgus monkey and human HSCs. The transduction efficiency of the optimized AAV vectors was also evaluated in human HSCs in a murine xenograft model in vivo.
  
  
  RESULTS
  We observed that although there are only six amino acid differences between AAV1 and AAV6, AAV1, but not AAV6, transduced mouse HSCs well, whereas AAV6, but not AAV1, transduced human HSCs well. None of the 10 serotypes transduced cynomolgus monkey HSCs in vitro. We also evaluated the transduction efficiency of AAV6 vectors containing mutations in surface-exposed tyrosine residues. We observed that tyrosine (Y) to phenylalanine (F) point mutations in residues 445, 705 and 731 led to a significant increase in transgene expression in human HSCs in vitro and in a mouse xenograft model in vivo.
  
  
  CONCLUSIONS
  These studies suggest that the tyrosine-mutant AAV6 serotype vectors are the most promising vectors for transducing human HSCs and that it is possible to increase further the transduction efficiency of these vectors for their potential use in HSC-based gene therapy in humans.
authors.affiliation: Experimental Hematology Laboratory, Department of Physiology, School of Basic Medical Sciences, Central South University, Changsha, China.
authors.forename: Liujiang
authors.initials: L
authors.lastname: Song
authors.forename: M Ariel
authors.initials: MA
authors.lastname: Kauss
authors.forename: Etana
authors.initials: E
authors.lastname: Kopin
authors.forename: Manasa
authors.initials: M
authors.lastname: Chandra
authors.forename: Taihra
authors.initials: T
authors.lastname: Ul-Hasan
authors.forename: Erin
authors.initials: E
authors.lastname: Miller
authors.forename: Giridhara R
authors.initials: GR
authors.lastname: Jayandharan
authors.forename: Angela E
authors.initials: AE
authors.lastname: Rivers
authors.forename: George V
authors.initials: GV
authors.lastname: Aslanidi
authors.forename: Chen
authors.initials: C
authors.lastname: Ling
authors.forename: Baozheng
authors.initials: B
authors.lastname: Li
authors.forename: Wenqin
authors.initials: W
authors.lastname: Ma
authors.forename: Xiaomiao
authors.initials: X
authors.lastname: Li
authors.forename: Lourdes M
authors.initials: LM
authors.lastname: Andino
authors.forename: Li
authors.initials: L
authors.lastname: Zhong
authors.forename: Alice F
authors.initials: AF
authors.lastname: Tarantal
authors.forename: Mervin C
authors.initials: MC
authors.lastname: Yoder
authors.forename: Kamehameha K
authors.initials: KK
authors.lastname: Wong
authors.forename: Mengqun
authors.initials: M
authors.lastname: Tan
authors.forename: Saswati
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Arun
authors.initials: A
authors.lastname: Srivastava
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D002460:Cell Line; D000229:Dependovirus; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D057809:HEK293 Cells; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells; D006801:Humans; D020014:K562 Cells; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D014161:Transduction, Genetic / Q000379:methods*
chemical_list: D018952:Antigens, CD34
keywords: AAV vectors; gene expression; gene transfer; hematopoietic stem cells