The Colony Stimulating Factors (CSFs) are a family of haemopoietic hormones that likely share a common ancestral origin and stimulate white blood cell development. They display unique but overlapping biological functions and stimulate the survival, proliferation, differentiation and functional activation of granulocytes and monocytes/macrophages and their precursor cells in vitro and in vivo. Each hormone has been purified and produced in active recombinant form. Recombinant G-CSF and GM-CSF are now being used around the world in a variety of clinical situations (e.g., in conjunction with chemotherapy and bone marrow transplantation) to promote the formation and function of these leukocytes. These molecules are among the first of a new generation of biological agents that will impact enormously on clinical medicine.
Introduction: The vast majority of in vitro research on microglia are based on cells isolated from
neonatal animals (3-5 days of age). Studying microglia of adults has been limited by the lack of a suitable culture system that supports their growth. In this study, we describe a protocol for growing microglia of adults based on modifications of the technique for culturing microglia isolated from neonatal rats. Methods: Mixed glia isolated from adult rats (age range of 1 month to 3 years old) were seeded in
culture flasks coated with poly-L-lysine. Cells were maintained in DMEM media supplemented with
insulin-transferrin-selenium (ITS) and recombinant human macrophage colony-stimulating factor
(M-CSF). Mild trypsinisation was carried out to isolate microglia from mixed glia culture. Results:
Microglia cells of adult rats were successfully grown in vitro. For the expansion of adult microglia,
it was observed that coating the cell culture flasks with poly-L-lysine was crucial to encourage cell
adherence. The substitution of insulin in culture media with ITS was found to improve cell yield and
reduced the number of days required for culture from 28 days to 14 days. Addition of M-CSF to cell
culture medium, along with the improvisations described above provided the best adult microglia cell
yield (2.91 ± 0.56 x 106 cells) compared to the technique of replating cells (0.91 ± 0.65 x 106 cells;
p