This seems to me to be a significant piece of work, and I'm hoping that AlzForum (or SoPD, or ...) do a writeup of it. The research is focused on a (possible) role for the adaptive immune system in the cause of neurodegeneration in PD.
Note that the innate immune system is also thought to (possibly) play a role in the cause of neurodegeneration in PD, and this is discussed in the following AlzForum article:
Does Taming Killer Astrocytes Spare Neurons in Parkinson’s Disease? | ALZFORUM