Colony stimulating factor 1(CSF 1) and interleukin-34 mediate signaling and play key rules in regulating the development and function of tissue macrophages.
CSF1R is a cell surface receptor that can be activated by colony stimulating factor1 and is expressed in monocytes and macrophages.
The binding of CSF1 to CSF1R actively promotes the differentiation of monocytes into macrophages and the survival and proliferation of both cell types.
Excessive CSF1R a signaling and macrophage activation is implicated in inflammatory processes, and overactivation of the pathway can lead to chronic inflammation and progression of diseases such as rheumatoid arthritis, idiopathic pulmonary fibrosis, chronic graft versus host disease.
CSF1R signaling dependent monocytes and macrophages are mediators of inflammation in fibrosis in chronic GVHD and auto immune diseases.
Axatilmab, a humanized IgG4 monoclonal antibody, inhibits CSF1R signaling, and can affect differentiation and function of sites and macrophages: it use results in high incidence of response among patients with recurrent or refractory chronic GVHD.