Background: Strategies to induce donor-specific allograft tolerance are best tested in preclinical models developed in nonhuman primates (NHPs). Most protocols prepare the recipient by infusing hematopoietic cells from the donor. We report here a procedure to isolate and characterize large numbers of bone marrow cells (BMCs) from cynomolgus monkeys (cynos) that can then successfully be transplanted into conditioned recipients.
Materials and methods: Vertebral columns of five cynos were excised en bloc and separated into individual vertebrae. The cancelous bone was extracted with a core puncher, fractionated, filtered, centrifuged, and resuspended in transplantation media before being analyzed by flow cytometry. In two instances, the collected BMCs were reinfused into allogeneic recipients preconditioned with a nonmyeloablative regimen. Chimerism was monitored using short-tandem repeat analysis.
Results: The mean total BMCs yield was 25.5 x 10(9) (range of 4.00 x 10(9) to 59 x 10(9)) with mean cell viability of 93.4% (range: 90-96%). CD34+ cells and CD3+ cells averaged 0.34 and 3.91% of total BMCs, respectively. This resulted in absolute cell number yields of 1.02 x 10(8) and 1.15 x 10(9) for CD34+ and CD3+ cells, respectively. Graft-versus-host disease was absent in both bone marrow infused animals, and a maximum level of chimerism of 18% was detected at 3 weeks after BMCs infusion.
Conclusion: We present here the first detailed report of a procedure to retrieve and characterize large numbers of BMCs from vertebral bodies of cynos and demonstrate that cells collected with this technique have the capability of engrafting in allogenic recipients.