Taken together, the results of this study suggest that CCL5 promotes the differentiation of Th17 cells and the expression of LFA-1 by promoting the phosphorylation of LCK and ZAP70 in PD, which is conducive to the migration and infiltration of Th17 cells into the SN and causes the loss of DA neurons, aggravating the onset and progression of PD. This evidence concerns the gene ITGAL and Parkinson disease.