Figure 1.

nano-Self peptides are designed as competitive inhibitors based on CD47’s key binding loop. (A) “Marker of Self” CD47 is expressed on all cells and inhibits phagocytosis of “Self” cells when it binds its receptor SIRPα on macrophages (Protein Database accession number: 2JJS). (B) The nS-wt peptide consists of eight amino acids (blue) that bind the SIRPα binding pocket (yellow). Substitutions of the Thr residue (red) generate nS peptides as competitive antagonists against SIRPα. nS-X is a scrambled sequence. Bivalent peptides were constructed by linking monomers to (di-PEG)-lysine via their C-termini.