We have identified a peptide (nicknamed "UNO") that internalizes in M2 tumor associated macrophages (TAMs) by binding to CD206. Systemically administered UNO homed to M2 TAMs in 5 differerent solid tumor models and was able to carry with it a fluorescent payload and nanoscale polymeric vesicles, polymersomes. Importantly, the cyclic UNO peptide preferentially recognizes CD206 in the tumor and not in the healthy tissues, as it is activated by the reducing environment found in the tumor microenvironment.
Link to the paper: https://www.nature.com/articles/s41598-017-14709-x
Image: Cell-free interation of UNO with recombinant CD206. Increase of anisotropy indicates binding of the peptide to CD206. Credit: Pablo Scodeller and Sergei Kopanchuk.