research
The distinct nature of hematopoietic stem cell subpopulations studied in long-term stroma-associated culture in the mouse
- Publication date
- 10 June 1993
- Publisher
- In this thesis a number of experiments is described which give evidence for the notion
of a distinct nature of CFU-S and cells with LTRA in the mouse. The distinct nature is
illustrated by the difference in growth characteristics of CFU-S and LTRA cells on preestablished
bone marrow-derived stromal cell layers. We have exploited the culture of
stem cells on stromal layers for the development of an in vitro assay for the
quantification of long-term repopulating stem cells, marrow repopulating stem cells, and
spleen colony forming stem cells. The basic principle for this assay is the presence of a
functional hematopoietic micro-environment in vitro, formed by the marrow-derived
stromal layer. Stromal layers of long-term bone marrow cultures were studied on their
ability to maintain stem cells with L TRA. For the measurement of L TRA we adapted a
syngeneic sex-mismatched bone marrow transplantation model. In addition, the
interaction of hematopoietic stem cells with fibronectin, a constituent of the hematopoietic rnicro~environment, was studied.
The thesis starts with a description of the current definitions of hematopoietic stem cells
(Chapter 2). This is followed by an outline of the in vivo and in vitro hematopoietic
micro-environment of the bone marrow (Chapter 3). These two chapters precede the
experimental work, which is described and discussed throughout the Chapters 4-8. An
overview of the present state of research on the cell adhesion properties of fibronectin,
focused on the hematopoietic cells, is part of Chapter 8. Finally, the most important
results are discussed in Chapter 9.