PMID- 9458240
OWN - NLM
STAT- MEDLINE
DCOM- 19980305
LR  - 20091119
IS  - 1043-0342 (Print)
IS  - 1043-0342 (Linking)
VI  - 9
IP  - 1
DP  - 1998 Jan 1
TI  - Dominant selection of hematopoietic progenitor cells with retroviral MDR1 
      co-expression vectors.
PG  - 33-42
AB  - When transferring the human multidrug resistance 1 (MDR1) cDNA, FMEV retroviral 
      vectors mediate high-dose multidrug resistance and, thus, background-free 
      selection in primary human hematopoietic progenitor cells. Here, we analyzed 
      strategies for co-expression of a second gene from an FMEV:MDR1 vector. When 
      linking the cDNAs with the internal ribosomal entry site (IRES) of poliovirus or 
      retroviral splice signals, almost all multidrug-resistant hematopoietic colonies 
      simultaneously coexpressed the 3' positioned second gene, 
      neomycin-phosphotransferase (neoR). The IRES strategy allowed functional 
      co-transfer of a 4.2-kb lacZ-neoR fusion gene, resulting in a total proviral 
      genome size of 11 kb, corresponding to the packaging limit of retroviral vectors. 
      Preselection based on multidrug resistance elevated the expression of the second 
      gene in IRES constructs, but not in splice vectors. Moreover, three intriguing 
      observations were made. First, up to 30% of cells preselected for functional 
      transfer of the 3' positioned cDNA (neoR) showed infunctional MDR1; this occurred 
      irrespective of the linking principle and was associated with instability of the 
      MDR1 transcription unit. Second, the levels of multidrug resistance achieved with 
      the co-expression vectors were moderately lower (15-30% reduced) than those 
      mediated by the monocistronic counterpart. Third, transduction with FMEV:MDR1 
      co-expression vectors still resulted in high-dose cancer drug resistance and 
      background-free selection of hematopoietic progenitor cells (including primary 
      human CD34+ colony-forming units). Thus, for the first time, we describe MDR1 
      co-expression vectors that maintain their desired function in early and primary 
      human hematopoietic cells. However, careful interpretation of the data reveals 
      that further vector improvements are required to obtain clinically useful MDR1 
      co-expression vectors.
FAU - Hildinger, M
AU  - Hildinger M
AD  - Department of Cell and Virus Genetics, Heinrich-Pette-Institute for Experimental 
      Virology and Immunology at the University of Hamburg, University Hospital 
      Hamburg-Eppendorf, Germany.
FAU - Fehse, B
AU  - Fehse B
FAU - Hegewisch-Becker, S
AU  - Hegewisch-Becker S
FAU - John, J
AU  - John J
FAU - Rafferty, J R
AU  - Rafferty JR
FAU - Ostertag, W
AU  - Ostertag W
FAU - Baum, C
AU  - Baum C
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Hum Gene Ther
JT  - Human gene therapy
JID - 9008950
RN  - 0 (Antigens, CD34)
SB  - IM
MH  - Antigens, CD34/physiology
MH  - Cell Culture Techniques
MH  - Cell Separation/methods
MH  - Gene Expression
MH  - Gene Transfer Techniques
MH  - Genes, MDR/*genetics
MH  - Genetic Vectors/genetics
MH  - Hematopoietic Stem Cells/*physiology
MH  - Humans
MH  - Retroviridae/genetics
MH  - Selection, Genetic
MH  - Transcription, Genetic
EDAT- 1998/02/11 00:00
MHDA- 1998/02/11 00:01
CRDT- 1998/02/11 00:00
PHST- 1998/02/11 00:00 [pubmed]
PHST- 1998/02/11 00:01 [medline]
PHST- 1998/02/11 00:00 [entrez]
AID - 10.1089/hum.1998.9.1-33 [doi]
PST - ppublish
SO  - Hum Gene Ther. 1998 Jan 1;9(1):33-42. doi: 10.1089/hum.1998.9.1-33.