Distinct genomic integration of MLV and SIV vectors in primate hematopoietic stem and progenitor cells.
Murine leukemia virus (MLV)-derived vectors are widely used for hematopoietic stem cell (HSC) gene transfer, but lentiviral vectors such as the simian immunodeficiency virus (SIV) may allow higher efficiency transfer and better expression. Recent studies in cell lines have challenged the notion that retroviruses and retroviral vectors integrate randomly into their host genome. Medical applications using these vectors are aimed at HSCs, and thus large-scale comprehensive analysis of MLV and SIV integration in long-term repopulating HSCs is crucial to help develop improved integrating vectors. We studied integration sites in HSCs of rhesus monkeys that had been transplanted 6 mo to 6 y prior with MLV- or SIV-transduced CD34(+)cells. Unique MLV (491) and SIV (501) insertions were compared to a set of in silico-generated random integration sites. While MLV integrants were located predominantly around transcription start sites, SIV integrants strongly favored transcription units and gene-dense regions of the genome. These integration patterns suggest different mechanisms for integration as well as distinct safety implications for MLV versus SIV vectors.
Hematti
Peiman
P
Hematology Branch, National Institutes of Health Bethesda, Maryland, USA.
Hong
Bum-Kee
BK
Ferguson
Cole
C
Adler
Rima
R
Hanawa
Hideki
H
Sellers
Stephanie
S
Holt
Ingeborg E
IE
Eckfeldt
Craig E
CE
Sharma
Yugal
Y
Schmidt
Manfred
M
von Kalle
Christof
C
Persons
Derek A
DA
Billings
Eric M
EM
Verfaillie
Catherine M
CM
Nienhuis
Arthur W
AW
Wolfsberg
Tyra G
TG
Dunbar
Cynthia E
CE
Calmels
Boris
B
D000818:Animals; D018952:Antigens, CD34 / Q000096:biosynthesis; D001665:Binding Sites; D002460:Cell Line; D003001:Cloning, Molecular; D016000:Cluster Analysis; D017931:DNA Primers / Q000737:chemistry; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D016678:Genome; D006412:Hematopoietic Stem Cells / Q000821:virology*; D009052:Leukemia Virus, Murine / Q000378:metabolism*; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D012190:Retroviridae / Q000235:genetics; D015302:Simian Immunodeficiency Virus / Q000378:metabolism*; D013234:Stem Cells / Q000821:virology*; D013997:Time Factors; D014158:Transcription, Genetic
D018952:Antigens, CD34; D017931:DNA Primers