Distinct fractional Abeta release patterns in human mononuclear phagocytes.

The presence of cells of the mononuclear phagocyte lineage surrounding neuritic and vascular beta-amyloid (Abeta) plaques is a hallmark of Alzheimer's disease (AD) neuropathology. The fractional Abeta peptide patterns released by human mononuclear phagocyte (MNP), lymphocyte and PBMC cultures were assessed by Abeta-SDS-PAGE/immunoblot and compared with the Abeta patterns in neuronal supernatants, in cerebrospinal fluid (CSF), and plasma. MNP released substantial amounts of Abeta peptides and the Abeta pattern contrasted with that in neuronal supernatants, CSF and plasma by reduced Abeta(1-42) and increased proportions of N-truncated Abeta species. MNP derived from early AD patients released significantly more total Abeta peptides than age-matched controls. The proportion of Abeta(1-42) was not altered.