Metals such as platinum and gold keep certain proteins from stimulating the body's immune response, a study finds. The results suggest how some metal-based drugs might ease autoimmune symptoms, the researchers say.
They were screening compounds in search of a chemical that would blunt the action of a set of immunological proteins that usually bind to protein fragments, or peptides, from foreign objects such as viruses and bacteria. These class II major histocompatibility complex (MHC) proteins present the peptides to immune cells called helper T cells, which coordinate the body's response. The cells initiate inflammation and the production of antibodies.
As part of the natural regulation of the immune system, the body uses a catalyst to make class II MHC proteins release a temporary cargo before presenting a peptide.
In an autoimmune disease, the proteins present peptides from a person's own body, leading to a self-attack.