In comparison to EV mice, hαSyn PD PBS controls showed significantly elevated CD4+ (Fig. 5A–C) and CD8+ T cell numbers (Fig. 5D–F) in the SN and the striatum accompanied by increased numbers of CD11b+ microglia and other myeloid cell counts (Fig. 5G–I), indicative for neuroinflammation in the hαSyn PD model. Here, CD4 is linked to Parkinson disease.