thesis
The nature and function of fibroblastoid reticular cells in the hemopoietic stroma
- Publication date
- 6 November 1985
- Publisher
- The experimental work of this thesis, described in the appendix papers,
is aimed at characterization of the nature and function of fibroblastic reticular
cells in the hemopoietic stroma. A number of experimental models was
employed to elucidate different aspects of these cells.
In the first appendix paper characteristics are described of fibroblastoid
colony-forming cells (CFU-F) from murine bone marrow and their in yitro
progeny. The data indicate that these fibroblastoid cells differ frorrlm~
phages and endothelial cells, and can be discriminated from fibroblastoid
cells from other organs.
The second appendix paper describes three monoclonal antibodies that
specifically recognize a determinant on non-phagocytic and phagocytic reticular
eel ls in the hemopoietic stroma of fetal and adult mice. Reticular stromal
cells with this specific determinant(s) are restricted to sites of adulttype
hemopoiesis.
In the third appendix paper the regulatory capacity of a spleen-derived
fibroblastoid cell line on in vitro myelopoiesis is described. This cell line
is shown to produce two solUble regulators and one cell-associated activity
by which in vitro myelopoiesis is modulated.
The fourth appendix paper describes the transplantabil ity of CFU-F after
lethal total body irradiation and bone marrow transplantation. Evidence is
presented indicating that CFU-F can efficiently lodge in the recipients bone
marrow.
The fifth appendix paper represents a study of the long-term recovery of
CFU-F after lethal total body irradiation and bone marrow transplantation.
This recovery is slow and incomplete, independent of graft size and presence
of adherent stromal cells in the graft. If present in the graft, donor stromal
cells do contribute to the recipients stroma. but they do not influence the
total CFU-F recovery. Subsequent treatment with a sublethal dose of endotoxin
allows full recovery of the CFU-F population.
The sixth appendix paper describes the kinetics of hemopoietic and stromal
cells in phenylhydrazine-treated mice. In addition, evidence is presented
that under these conditions CFU-F migrate into spleen and bone marrow via the
blood stream.
In the seventh appendix paper a strong correlation is described between
CFU-F numbers and the regenerative capacity of ectopically transplanted stroma
in femurs of mice treated with several doses of gamma irradiation.