Biomedical Engineering Reference
In-Depth Information
Table 10.5 Summary of some of the properties of G-CSF, M-CSF and GM-CSF
G-CSF
M-CSF
GM-CSF
Molecular mass (kDa)
21
45-90
22
Main producer cells
Bone marrow stromal
cell
Macrophages
Fibroblasts
Lymphocytes
Myoblasts
Osteoblasts
Monocytes
Fibroblasts
Endothelial cells
Macrophages
T-lymphocy tes
Fibroblasts
Endothelial cells
Main target cells
Neutrophils. Also
other haemopoietic
progenitors and
endothelial cells
Macrophages and their
precursor cells
Haematopoietic progenitor
cells
Granulocytes
Monocytes
Endothelial cells
Megakaryocytes
T-lymphocy tes
Erythroid cells
10.2.2 Granulocyte colony-stimulating factor
. Two slight variants are known, one consisting
of 174 amino acids and the other of 177. The smaller polypeptide predominates and also displays
signifi cantly greater biological activity than the larger variant.
G-CSF is a glycoprotein. It displays a single O-linked glycosylation site and an apparent mo-
lecular mass in the region of 21 kDa, and is synthesized by various cell types (Table 10.5). It func-
tions as a growth and differentiation factor for neutrophils and their precursor cells. It also appears
to activate mature neutrophils (which are leukocytes capable of ingesting and killing bacteria).
G-CSF also appears to act in synergy with additional haemopoietic growth factors to stimulate
growth/differentiation of various other haemopoietic progenitor cells. In addition, this cytokine
promotes the proliferation and migration of endothelial cells.
The G-CSF receptor has been well characterized. It is a single transmembrane polypeptide found
on the surface of neutrophils, as well as in various haemopoietic precursor cells, platelets, endothe-
lial cells and, notably, various myeloid leukaemias. (Myeloid means derived from bone marrow;
leukaemia refers to a cancerous condition in which there is uncontrolled overproduction of white
blood cells in the bone marrow or other blood-forming organs. The white cells produced are gener-
ally immature/abnormal and result in the suppression of production of healthy white blood cells.)
G-CSF is also known as pluripoietin and CSF-
β
10.2.3 Macrophage colony-stimulating factor
M-CSF serves as a growth, differentiation and activation factor for macrophages and their
precursor cells. It is also known as CSF-1. This cytokine is produced by various cell types
(Table 10.5). The mature form is a glycoprotein containing three potential N-linked glycosyla-
tion sites. Three related forms of human M-CSF have been characterized. All are ultimately
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