GRANULES IN GLIAL-CELLS OF PATIENTS WITH ALZHEIMERS-DISEASE ARE IMMUNOPOSITIVE FOR C-TERMINAL SEQUENCES OF BETA-AMYLOID PROTEIN

Granular structures that are recognized by antibodies specific for the C-terminal but not the N-terminal sequences of the beta-amyloid prote in (A beta) fragments are present in a subset of microglia and astrocy tes in Alzheimer brain tissue. The immunohistochemical profile indicat es that the A beta in these granules is truncated between the residues 17 and 31 and terminates at the residue 42 or 43, Such granule-contai ning glia occur only in brain areas with the heavy A beta deposits. Wh ether the intraglial A beta fragments accumulate as a result of phagoc ytosis of extracellular A beta or are formed intracellularly by glial cells from amyloid precursor protein (APP) remains unknown.