International Journal of Cell Cloning, Vol 10, 161-165, Copyright © 1992 by AlphaMed Press
Enhancement of cell production in long-term bone marrow culture
JS Schultz, IM Naumov, F Vecchini, MA Virji and SS Boggs
Center for Biotechnology and Bioengineering, University of Pittsburgh, Pennsylvania 15261.
In an effort to increase the long-term production of hematopoietic cells in
vitro, Origen hybridoma cloning factor (HCF) was added at the initiation of
Dexter type cultures, in which whole bone marrow (BM) was seeded into
tissue culture flasks and formed an adherent stromal layer that supported
the proliferation and differentiation of primitive cells. After about six
weeks, all the cultures were fully established, and continuous production
of nonadherent cells was maintained for at least 27 weeks. In the groups
with 20% HCF, there was a significant (three- to fourfold) increase in the
steady-state cell production of 106 +/- 17 x 10(4) cells/ml compared to 26
+/- 10 x 10(4) in controls. In some cases the ability of HCF to increase
productivity was limited by the nutrients and metabolic products in the
culture medium. Cell number varied inversely with glucose and pH. HCF
increased the concentration and absolute number of myeloid progenitors
(granulocyte- macrophage colony forming units and spleen colony forming
units) in the nonadherent layer and shifted the differentiation of
granulocyte- macrophage colony forming units toward the production of cells
of the monocyte/macrophage lineage. Spleen colonies produced from 10(5)
cells from cultures with HCF were more numerous (8 +/- 2 versus 4 +/- 2)
and larger than those from control cultures (2.6 versus 0.2 mg/colony), but
they contained the usual cell lineages (erythrocytic, granulocytic and
megakaryocytic).
