After a single intravenous injection of native PHF-tau proteins from AD brains (in the absence of adjuvants), we observed an increased neuroinflammation in the dentate gyrus of 5XFAD mice in absence of anti-tau antibodies in their serum, suggesting that the observed neuroinflammation did not result from an immune reaction due to the generation of anti-tau antibodies. Here, MAPT is linked to Alzheimer disease.