Isolation, characterization and preclinical development of human glial-restricted progenitor cells for treatment of neurological disorders.
OBJECTIVE
Glial-restricted progenitor cells (GRPs), a neural cell population that gives rise to astrocytes and oligodendrocytes both in vitro and in vivo, hold great promise as a cellular therapeutic for the treatment of demyelinating and neurodegenerative diseases of the CNS. The manufacturing and characterization protocols of human-derived GRPs (hGRPs; trade name Q-Cells) for use in a clinical setting that adhere to rigorous standards for their isolation, propagation, characterization and storage are presented.


METHODS
hGRPs, defined by their immunoreactivity with A2B5 antibodies, were isolated from fetal cadaver forebrain tissue of mice 17-24 weeks gestational age using Miltenyi paramagnetic bead cell separation technology. GRPs were grown in a defined xenobiotic-free medium for 6 days. At harvest, hGRPs were characterized using immunocytochemical techniques. Long-term cryopreservation and storage conditions, and viability upon freeze-thaw were determined. The phenotypic differentiation potential of hGRPs was determined by implantation experiments into the CNS of shiverer mice.


RESULTS
hGRPs were isolated from over 50 neural tissues of either sex during gestational ages of 17-24 weeks. Cells expanded out to 6 days in vitro in a xenobiotic-free medium demonstrated very consistent immunocytochemical profiles. No residual antibody used in the purification process was detected after 6 days of growth in vitro. GRPs could be frozen at up to 24 million cells/ml and were over 70% viable upon freeze-thaw. Thawed hGRPs transplanted into the brain of the dysmyelinated shiverer mouse model were observed to differentiate into both glial fibrillary acidic protein-positive astrocytes and myelin basic protein-positive oligodendrocytes; no human-derived NeuN-positive neuronal cells were observed and no abnormal cell proliferation was observed.


CONCLUSIONS
We demonstrate that hGRPs can be consistently obtained, propagated, cryopreserved and characterized using protocols that can be transferred to a good laboratory practice/good manufacturing practice setting for the manufacture of clinical-grade hGRP cellular therapeutics. Functional data demonstrate that cells manufactured under these conditions are able to differentiate into appropriate cellular phenotypes in an animal model of dysmyelination.
Sandrock
Robert W
RW
Q Therapeutics, Inc., 615 Arapeen Drive, Suite 102, Salt Lake City, UT 84108, USA.
Wheatley
Will
W
Levinthal
Cynthia
C
Lawson
Jennifer
J
Hashimoto
Brooke
B
Rao
Mahendra
M
Campanelli
James T
JT
D000818:Animals; D002454:Cell Differentiation; D017690:Cell Transplantation / Q000379:methods*; D000939:Epitopes / Q000737:chemistry; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D051379:Mice; D019636:Neurodegenerative Diseases / Q000378:metabolism* / Q000628:therapy; D009457:Neuroglia / Q000166:cytology*; D016548:Prosencephalon / Q000378:metabolism; D044968:Regenerative Medicine / Q000379:methods; D013234:Stem Cells / Q000166:cytology*
D000939:Epitopes