We never really understood how gold therapy worked in autoimmune diseases like rheumatoid arthritis (we figured the therapeutic effect was due in part to the happiness of eldery ladies receiving injections of precious metals).
But no, this story pointed us to a recent issue of Nature Chemical Biology in which Harvard researchers home in on the mechanism:
Harvard researchers say gold helps treat autoimmune disease by stripping bacteria and virus particles from the grasp of a key immune system protein.
The protein is indeed key: MHC Class II, found on immune cells, and essential for activating CD4+ T cells. When gold binds to MHC-II, the T cells don’t get stimulated, and immune-mediated inflammation is avoided (but we still like our happy-old-lady theory).
The Nature Chemical Biology article…