Objective To explore whether Th17 cells play a role in the neuroinflammatory process of Parkinson's disease (PD).Methods C57BL/6 mice were injected intraperitoneally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD models.Saline-injected and naive mice were used as controls.In substantia nigra compact (SNc) part,double-immunofluorescence staining was used to observe glucose transporter (Glut 1+) and CD4+ T cells or retinoic acid-related orphan nuclear receptor γt (ROR γt) and intedeukin (IL)-17.Real-time PCR was employed to examine the mRNA expressions ofIL-17 and IL-22 in the SNc.Results PD models were successfully induced in the mice; CD4+ T cells invaded into the brain parenchyma of PD mice models.Besides,the mount of CD4+ T cells on the seventh day of MPTP injection was more than that of the second day of MPTP injection.The expressions ofROR γt and IL-17 increased in the SNc of the PD mice; a co-localization ofROR γt and IL-17 in SNc indicated that invasive CD4+ T cells contained Thl7 cells.There was evident up-regulation in the expressions ofIL-17 and IL-22 mRNAs in PD mice as compared with the saline-injected or intact mice,which was much more evident in the late phase of disease (the seventh day of MPTP) than in the early stage (the second day of MPTP injection).Conclusion Neuroinflammation induced by infiltration of Th17 cells participates in the process of PD.