Autologous Bone Marrow Transplantation - Blog Science Connections

Human ADA in Monkeys 711
to the SAX vector by plating into a dish containing a monolayer of irradiated
vector-producing cells. After an overnight co-cultivation, during which time
the donor monkey was lethally irradiated, the nonadherent bone marrow cells
were recovered from culture by gentle aspiration, washed, and infused into the
monkey through an indwelling catheter.
Despite close clinical coverage, the bone marrows of the first four
animals listed in Table 1 failed to fully reconstitute and the animals had to be
killed, either because they developed antibiotic-resistant sepsis or became
refractory to platelet transfusions. It became clear that the co-cultivation
protocol was not yielding satisfactory results, in part because of the
limitations it placed on the total number of cells that could be treated with
vector and in part because of excessive losses of bone marrow cells over the
lengthy time of treatment during co-cultivation.
Because of the problems encountered with the co-cultivation protocol,
we developed a procedure wherein bone marrow was no longer incubated
together with vector-producing cells. Instead, the supernatant virus-containing
medium from the producer cells was removed, filtered to remove any loose
cells, and then used to infect bone marrow cells. Large volumes of viral
supernatants could be collected and frozen while retaining their infective
quality. Test infections to generate drug-resistant CFCJs in vitro showed that
bone marrow could be infected by a 2-hour incubation at 37° C with the viral
Table 1. Primate BMT/Gene Transfer: Summary for hADA Gene
Reconstitution
ADA Analysis
No. Name Date Method
NPT ADA % AH % Endog
1 Bill (C) 7/12/85 C No Pos Pos 1