Colony Stimulating Factor 1 Receptor (CSF1R, CD115, M-CSF-R) is the receptor for the cytokine CSF1 (MCSF; CSF-1), which controls the growth, function, and differentiation of macrophages. This interaction drives the development and survival of Tumor-Associated Macrophages (TAMs), which in turn suppress the local immune response to the cancer. An alternative ligand is IL-34, which has been implicated in neuroprotective and survival signals following brain injury and neurodegeneration.

As a tyrosine kinase transmembrane receptor, activation of CSF1R by its ligand initiates a vast array of intracellular activity, including activation of the MAPK/ERK signaling pathway. When phosphorylated by ERK, Elk1 forms a complex with Serum Response Factor (SRF) and binds to Serum Response Element (SRE), resulting in the expression of numerous mitogen-inducible genes.

CFS1R-SRE-Luciferase

DMEM +10%FBS+200ug/ml hygromycin+1ug/ml puromycin

Figure 1. Recombinant HEK293 cell line expressing firefly luciferase gene under the control of SRE response elements with constitutive expression of CSF1R(Colony Stimulating Factor 1 Receptor)

Figure 2. Detect Luciferase assay by Ultra Luciferase Detection Kit RQPH0001（we strongly suggest to purchase from Reqbio). HEK293/CFS1R-SRE Luciferase Reporter cells were stimulated by CSF1, the EC50 was 3.75ng/ml.

 Figure 3. Inhibition of CSF1 (100 ng/ml) -induced SRE reporter actity by CSF1R inhibitors.