Haemopoietic growth factor tyrosine kinase receptor expression profiles in normal haemopoiesis.
Expression profiles were generated for the haemopoietic tyrosine kinase receptors (HGF-TKRs or class III TKRs) by PCR on cDNA samples (RT-PCR) using a degenerate primer set. Each profile consisted of primary and secondary, i.e. enriched for less-expressed sequences, fingerprints. This method was applied on FACS-purified haemopoietic CD34+ cells, both from bone marrow (BM) and umbilical cord blood (UCB), and on mature cells from peripheral blood. CD34+ BM cells showed expression of c-fms. flt3, whereas CD34+ UCB cells expressed c-fms and, to a lesser extent, c-kit and flt3. In mature blood cells, only c-fms was observed in monocytes and a weaker flt3 expression in monocytes and T lymphocytes, whereas no known class III TKRs were detected in B lymphocytes and polymorphonuclear cells (PMNs). In all fractions a novel band could be observed, which appeared to be RET. Expression of RET was confirmed by RT-PCR and showed the highest levels in monocytes, followed by PMNs and CD34+ cells. B lymphocytes revealed low levels of expression. RET is known to be essential in neural development. Our results suggest a possible role for this receptor in haemopoiesis.
Visser
M
M
Department of Haematology, Leiden University Hospital, The Netherlands.
Sonneveld
R D
RD
Willemze
R
R
Landegent
J E
JE
D018952:Antigens, CD34 / Q000378:metabolism; D001402:B-Lymphocytes / Q000201:enzymology; D001483:Base Sequence; D006410:Hematopoiesis; D016298:Hematopoietic Cell Growth Factors / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000201:enzymology*; D006801:Humans; D008969:Molecular Sequence Data; D009000:Monocytes / Q000201:enzymology; D009504:Neutrophils / Q000201:enzymology; D016133:Polymerase Chain Reaction; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D013601:T-Lymphocytes / Q000201:enzymology
D018952:Antigens, CD34; D016298:Hematopoietic Cell Growth Factors; D020794:Receptor Protein-Tyrosine Kinases