GSBS Student Publications

Title

Reduction of IgG in nonhuman primates by a peptide antagonist of the neonatal Fc receptor FcRn

UMMS Affiliation

Graduate School of Biomedical Sciences; Syntonix Pharmaceuticals

Date

2-15-2008

Document Type

Article

Medical Subject Headings

Albumins; Amino Acid Sequence; Animals; Cell Line; HLA-A2 Antigen; Histocompatibility Antigens Class I; Humans; Immunoglobulin A; Immunoglobulin Fc Fragments; Immunoglobulin G; Immunoglobulin M; Macaca fascicularis; Molecular Sequence Data; Peptides; Protein Binding; Receptors, Fc; Solubility; Surface Plasmon Resonance

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

The neonatal Fc receptor FcRn provides IgG molecules with their characteristically long half-lives in vivo by protecting them from intracellular catabolism and then returning them to the extracellular space. Other investigators have demonstrated that mice lacking FcRn are protected from induction of various autoimmune diseases, presumably because of the accelerated catabolism of pathogenic IgGs in the animals. Therefore, targeting FcRn with a specific inhibitor may represent a unique approach for the treatment of autoimmune disease or other diseases where the reduction of pathogenic IgG will have a therapeutic benefit. Using phage display peptide libraries, we screened for ligands that bound to human FcRn (hFcRn) and discovered a consensus peptide sequence that binds to hFcRn and inhibits the binding of human IgG (hIgG) in vitro. Chemical optimization of the phage-identified sequences yielded the 26-amino acid peptide dimer SYN1436, which is capable of potent in vitro inhibition of the hIgG-hFcRn interaction. Administration of SYN1436 to mice transgenic for hFcRn induced an increase in the rate of catabolism of hIgG in a dose-dependent manner. Treatment of cynomolgus monkeys with SYN1436 led to a reduction of IgG by up to 80% without reducing serum albumin levels that also binds to FcRn. SYN1436 and related peptides thus represent a previously uncharacterized family of potential therapeutic agents for the treatment of humorally mediated autoimmune and other diseases.

Rights and Permissions

Citation: Proc Natl Acad Sci U S A. 2008 Feb 19;105(7):2337-42. Epub 2008 Feb 12. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal Title

Proceedings of the National Academy of Sciences of the United States of America

PubMed ID

18272495