Biodistribution of LV-TSTA transduced rat bone marrow cells used for "ex-vivo" regional gene therapy for bone repair.
"Ex vivo" regional gene therapy using lentiviral (LV) vectors to over-express bone morphogenetic protein 2 (BMP-2) is an effective way to enhance bone healing in animal models. Here, we evaluated two different "ex vivo" approaches using either "same day" rat bone marrow cells (SDRBMCs) or cultured rat bone marrow cells (C-RBMCs), both transduced with a LV based two-step transcriptional activation system overexpressing GFP (LV-TSTA-EGFP), to assess the fate of the transduced cells and the safety of this approach. The transduced cells were implanted in femoral defects of syngeneic rats. Animals were sacrificed at 4, 14, 28 and 56 days after surgery (n=5 per group). Viral copies were detectable in the defect site of SD-RBMC group and gradually declined at 8w (5 log decrease compared to 4d). In the C-RBMC animals, there was a 2-4 log decline in the viral copy numbers at 2w and 4w, but at 8w there was a relative rise (about 100 fold) in the number of the viral vectors in the defect site of 4 (out of 5) animals compared to the previous time points. For both gene transfer approaches, the pattern of tissue distribution was non-specific and no histological abnormalities were noted in either group. In summary, we demonstrated that the LV-TSTA transduced cells remain in the defect site for at least 56 days, though the numbers decreased over time. There were no consistent findings of viral copies in internal organs which is encouraging with respect to the development of this strategy for use in humans.
Farhang
F
Alaee
Cynthia
C
Bartholomae
Osamu
O
Sugiyama
Mandeep S
MS
Virk
Hicham
H
Drissi
Qian
Q
Wu
Manfred
M
Schmidt
University of Southern California, Keck School of Medicine, Department of Orthopaedic Surgery, 1520 San Pablo Street #2000, Los Angeles, CA, 90033, USA. jay.lieberman@med.usc.edu.
Jay R
JR
Lieberman
D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism* / Q000821:virology*; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D001842:Bone and Bones / Q000378:metabolism / Q000821:virology*; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D014018:Tissue Distribution / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics; D014161:Transduction, Genetic / Q000379:methods
C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2