Antibody Mimics Incite Immune Responses

Researchers have developed molecules called synthetic antibody mimics (SyAMs) that target disease-related cells selectively and then recruit immune responses that kill the cells, similar to the functions of natural human antibodies (J. Am. Chem. Soc. 2014, DOI: 10.1021/ja509513c). David A. Spiegel of Yale University, who led the team that developed SyAMs, notes that they are small molecules that can potentially be administered orally, whereas antibodies are proteins that are broken down by the digestive system and must be delivered in other ways. To demonstrate the approach, Spiegel and coworkers designed SyAMs bearing two glutamate-urea groups that recognize prostate-specific membrane antigen, a protein characteristic of prostate cancer cells, and a pair of cyclic peptides that bind to IgG receptor type I, a surface receptor on immune-system macrophages. The SyAMs bind the cancer cells and then recruit macrophages to destroy them. The researchers believe SyAMs may have applications for treating other cancers and viral and bacterial conditions as well. “Currently there are no immediate plans for commercialization, but we have been speaking with several potential partners,” Spiegel says.