H1 - Other Cellular and Regenerative Therapies (including Cell and Tissue Transplantation)
846: Intrauterine Cellular Therapy Using a Non-Human Primate (NHP) Model
Type: Poster Session
Poster Board Number: 846
Presentation Details
Session Title: Wednesday Posters: Other Cellular and Regenerative Therapies
In utero haematopoietic stem cell transplantation (IUHSCT) for the treatment of congenital hematological disorders has been proposed to be an ideal form of therapy. This is due to the immature immune system of the early gestation fetus that allows the development of donor-specific tolerance. Hopefully within the fetal environment, the haematopoietic stem cells (HSC) would be able to survive and proliferate. In this work, we have used a macaque model to transplant GFP-labelled maternal cells into the fetus in order to study the rate of engraftment and fate of the maternal cells. Maternal HSC were harvested from bone marrow aspirates, magnetically enriched for CD34+ cells, and labeled with eGFP using a simian immnodeficiency virus (20-70% GFP+). Transduced CD34+ cells were CD26 inhibited prior to intravenous injections at ~ 1x 108 cells/ estimated fetal weight (kg) with a final 1-3% CD3+ in the inoculum into 0.4-0.5 gestation fetal macaques. Following transplant, fetal subjects (n=6) were delivered via cesarean section and hand-reared. Fetal tissue harvested at 12 weeks post-IUHSCT showed chimerism levels ranged from 0.05% to 3.31%. Whereas cord blood collected at birth was evaluated for presence of GFP cells by both qPCR and FACs, demonstrating levels to be very low if not absent (<0.05%). Mixed lymphocyte reaction between treated offspring and same-donor (maternal) CD45 cells showed evidence of tolerance towards maternal cells. Postnatal same donor boosting of offspring with GFP labelled cells was performed after busulfan treatment. Chimerism in the blood and bone marrow was still low (<1%) after 20weeks post boost. NSG (Nod-Scid Gamma) mouse model was used to evaluate how long the GFP labelled cells were able to proliferate and continue to express GFP in vivo. GFP-labelled HSC were injected into irradiated newly born mice. Engraftment was assessed through regular blood sampling and labeling of NHP and mice blood cells by FACs analysis. Results show that NHP chimerism in the NSG blood was low <1% even after 14 weeks. Cells expressing GFP in blood circulation decreased at 14 weeks in some animals. NHP chimerism levels were higher in the bone marrow and spleen than peripheral blood at 14 weeks, although less than 1%. These tissues also have GFP expressing NHP cells in the tissues indicating that the GFP can still be expressed at 14 weeks post injection. Prenatal maternal donor IUHSCT with postnatal boosting has been shown to be efficacious in murine and canine models. However, we were unable to demonstrate that maternal donor cells were able to engraft in a fetal macaque model.
Julie Yeo1, Nuryanti Johana1, Yi Wan Tan1, Yiping Fan1, Citra N. Mattar2,3, Fritz Lai4, Qingfeng Chen4, Arijit Biswas2,3, Mahesh Choolani2,3, Simon Waddington5, William Peranteau6, Alan W. Flake7, Els Verhoeyen8, Jerry Chan9
1KKH Women's and Children's Hospital, Singapore, Singapore,2National University of Singapore, Singapore, Singapore,3National University Health System, Singapore, Singapore,4Institute of Molecular and Cell Biology, Singapore, Singapore,5University College London, London, United Kingdom,6The Children's Hospital of Philadelphia, Philadelphia, PA,7Childrens Hospital of Philadelphia, Philadelphia, PA,8INSERM/CIRI/EVIR, Lyon, France,9KK Women's and Children's Hospital / Duke NUS Medical School, Singapore, Singapore"
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