autologous blood and marrow transplantation - Blog Science ...

554 Chapter 10: Graft Manipulation
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days of culture
Figure 1. Development of numbers of total nucleated cells, CFCs, and LTC-ICs during ex
vivo expansion ofCD34 +
blood progenitor cells in serum-free medium in the presence ofFltí
ligand (300 ng/mL), SCF (100 ng/mL), IL-3 (100 ng/mL). The symbols give the mean values
(total cell numbers, CFC) or the LTC-1C content determined via incidence analysis through
limiting dilution culture ofaliquots taken at the indicated intervals from a representative 100-
mL clinical scale culture.
grown in the presence of FCS, they started to proliferate several weeks after
isolation and displayed purities of >95% cytokeratin-positive cells. When
cytokines (in this case a combination of SCF, IL-1, -3, and -6, and erythropoietin,
according to a clinically established ex vivo expansion protocol of plasma/serum
supported CD34 +
cell expansion) were added, no change was seen in their growth
behavior (Table 2). In contrast, addition of TGF-(31 resulted in a fivefold reduction
of tumor cell numbers, corresponding to a complete cessation of tumor cell growth,
and induction of cell death. This result was observed both in the presence or
absence of the hematopoietic cytokines, and regardless of whether total tumor cell
numbers or clonogenic tumor cells were analyzed (Table 2).
The presence of CD34 +
cells did not detectably influence the survival of
mammary carcinoma cells in culture, as assessed after PKH labeling of the tumor
cells and a 3-day observation period (Table 2). Coincubation of CD34 +
cells and
tumor cells at a ratio of about 1:100 also did not show altered tumor cell proliferation
as observed when tumor cells were cultured alone (data not shown).
In contrast, when FCS-supported medium was exchanged for serum-free
medium, a strong (10- to 100-fold) reduction in tumor cell numbers occurred