Distinct fractional Aβ release patterns in human mononuclear phagocytes

The presence of cells of the mononuclear phagocyte lineage surrounding neuritic and vascular β-amyloid (Aβ) plaques is a hallmark of Alzheimer's disease (AD) neuropathology. The fractional Aβ peptide patterns released by human mononuclear phagocyte (MNP), lymphocyte and PBMC cultures were assessed by Aβ-SDS-PAGE/immunoblot and compared with the Aβ patterns in neuronal supernatants, in cerebrospinal fluid (CSF), and plasma. MNP released substantial amounts of Aβ peptides and the Aβ pattern contrasted with that in neuronal supernatants, CSF and plasma by reduced Aβ1–42 and increased proportions of N-truncated Aβ species. MNP derived from early AD patients released significantly more total Aβ peptides than age-matched controls. The proportion of Aβ1–42 was not altered.