CD274 and tauopathy: In the present study, we show that revitalizing systemic immunity using antibodies that block either PD-1 or its ligand, PD-L1, could modify brain pathology and restore cognitive performance in a mouse model of tauopathy, in addition to its effect in a beta-amyloid AD model, and that this effect is mediated, at least in part, via recruitment of monocyte-derived macrophages.