It appears that the Fox Foundation is sponsoring research concerning a-synuclein. However reading about what these researchers are working on, I found nothing concerning anti rejection drugs. It seems that what ever they may come up with it will take many years of clinical trials, where as anti rejection drugs are FDA approved.
If you want to email these people doing the sponsored studies, Fox has a website giving their names and programs. Or, email Fox directly.

Parkinson's Disease Grants funded by the Michael J. Fox Foundation | Parkinson's Disease

Small-Molecule Pharmacological Chaperones Reverse Alpha-synuclein-impaired Debris Removal | Parkinson's Disease

Contact The Michael J. Fox Foundation for Parkinson’s Research | Parkinson's Disease

Alpha-synuclein and Parkinson's Disease | Parkinson's Disease