I've searched for protocols to derive BMMs and most say that you use L929 conditioned media to obtain BMMs (example paper - weischenfeldt and porse (2008) csh protocols). The L929 is a source of m-csf to mature macrophages. However, Verreck et al., (2004) (PMID - 15070757) say that m-csf matures macrophages to an m2 phenotype (this work on humans). SO, just wanting to know if the l929 matured BMMs will be of an m2 phenotype only?
We get easy polarization with 10ng/ml of IL-4. This will strongly induce Relm-a and YM1, which are M2 markers. As for M1, you can "prime" with IFNg and then add either LPS or E-coli and then assess IL-6 or TNF-a. Both are strongly elevated.
For more details see our recent publication:
PIR-B Inhibits Pulmonary Fibrosis by Suppressing Profibrogenic Properties of Alveolar Macrophages.
Karo-Atar D, Moshkovits I, Eickelberg O, Königshoff M, Munitz A.
Am J Respir Cell Mol Biol. 2012 Dec 20
So, the M-CSF or GM-CSF doesn't polarise to a certain phenotype?
NOt necessrily and specifically not at baseline althouh they are "considered" a bit more M2-like but can certainly be polarized more....
