CD4 and multiple system atrophy: T cell infiltration alongside the inflammatory microgliosis was observed both in postmortem brain tissues of MSA patients and in a virus-mediated mouse model of MSA.301 Meanwhile, in the same MSA mouse model, the proportion of Th1 T cells and the level of INF-γ cytokine in the striatal tissue were significantly increased.301 Moreover, MSA mice with Tcrb (CD4 and CD8 T cell knockout) or Cd4 (CD4 T cell knockout) genetic deletion showed reduced inflammation and demyelination after exposure to syn301 (Fig. 4).