title: Impaired nuclear transport and uncoating limit recombinant adeno-associated virus 2 vector-mediated transduction of primary murine hematopoietic cells.
abstract: Controversies abound concerning hematopoietic stem cell transduction by recombinant adeno-associated virus 2 (AAV) vectors. For human hematopoietic cells, we have shown that this problem is related to the extent of expression of the cellular receptor for AAV. At least a small subset of murine hematopoietic cells, on the other hand, does express both the AAV receptor and the coreceptor, yet is transduced poorly. In the present study, we have found that approximately 85% of AAV genomes were present in the cytoplasmic fraction of primary murine c-Kit(+)Lin- hematopoietic cells. However, when mice were injected intraperitoneally with hydroxyurea before isolation of these cells, the extent to which AAV genomes were detected in the cytoplasmic fraction was reduced to approximately 40%, with a corresponding increase to approximately 60% in the nuclear fraction, indicating that hydroxyurea facilitated nuclear transport of AAV. It was apparent, nonetheless, that a significant fraction of the AAV genomes present in the nuclear fraction from cells obtained from hydroxyurea-treated mice was single stranded. We next tested whether the single-stranded AAV genomes were derived from virions that failed to undergo uncoating in the nucleus. A substantial fraction of the signal in the nuclear fraction of hematopoietic cells obtained from hydroxyurea-treated mice was also resistant to DNase I. That AAV particles were intact and biologically active was determined by successful transduction of 293 cells by virions recovered from murine hematopoietic cells 48 hr postinfection. Although hydroxyurea facilitated nuclear transport of AAV, most of the virions failed to undergo uncoating, thereby leading to only a partial improvement in viral second- strand DNA synthesis and transgene expression. A better understanding of the underlying mechanism of viral uncoating has implications in the optimal use of recombinant AAV vectors in hematopoietic stem cell gene therapy.
authors.affiliation: Department of Microbiology and Immunology, Walther Oncology Center, Walther Cancer Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Zhong
authors.forename: Weiming
authors.initials: W
authors.lastname: Li
authors.forename: Zuocheng
authors.initials: Z
authors.lastname: Yang
authors.forename: Keyun
authors.initials: K
authors.lastname: Qing
authors.forename: Mengqun
authors.initials: M
authors.lastname: Tan
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hansen
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Li
authors.forename: Linyuan
authors.initials: L
authors.lastname: Chen
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Chan
authors.forename: Daniela
authors.initials: D
authors.lastname: Bischof
authors.forename: Njeri
authors.initials: N
authors.lastname: Maina
authors.forename: Kirsten A
authors.initials: KA
authors.lastname: Weigel-Kelley
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhao
authors.forename: Steven H
authors.initials: SH
authors.lastname: Larsen
authors.forename: Mervin C
authors.initials: MC
authors.lastname: Yoder
authors.forename: Weinian
authors.initials: W
authors.lastname: Shou
authors.forename: Arun
authors.initials: A
authors.lastname: Srivastava
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects*; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D004279:DNA, Viral / Q000032:analysis; D000229:Dependovirus / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000008:administration & dosage*; D006412:Hematopoietic Stem Cells / Q000378:metabolism* / Q000821:virology; D006918:Hydroxyurea / Q000494:pharmacology; D007763:Lac Operon / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008957:Models, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D022021:Tacrolimus Binding Proteins / Q000235:genetics / Q000378:metabolism; D014161:Transduction, Genetic / Q000379:methods*; D014771:Virion / Q000502:physiology
chemical_list: D004279:DNA, Viral; D011994:Recombinant Proteins; D022021:Tacrolimus Binding Proteins; C403485:tacrolimus binding protein 4; D006918:Hydroxyurea