Differential roles of regulatory T cells in Alzheimer's disease

•The majority of evidence support the neuroprotective effects of Treg cells in AD.•During AD, Treg cells polarize microglia and astrocytes into neuroprotective states.•Treg cells induce microglia/astrocytes to phagocytosis Aβ deposits in early stage of AD.•Treg cells inhibit Th1-, and Th17 cell-induced neurodegeneration in late stage of AD.•Restoration of Treg cell function can be considered as a strategy to manage AD pathogenesis.