If molecular mimicry is at work in the rheumatoid synovium (assuming the presence of a foreign antigen), can a therapeutic vaccine (or several vaccines) be developed to “retrain” the immune system into choosing a different, unambiguous epitope? I assume each vaccine so devised (either peptide or DNA based) would have to be antigen specific. There are several well known suspected antigens that could serve as targets for such an approach.
You’ve laid out the possibilities nicely and yes it would be possible to use a vaccine in such a manner. However, despite the years of looking, and all the evidence that inflammation in the RA synovium is antigen driven, the antigen has yet to be identified. Many have tried and many have failed, but who knows what technology will yield next.