Monoclonal antibody to beta peptide, recognizing amyloid deposits, neuronal cells and lipofuscin pigments in systemic organs.

A monoclonal antibody (AmT-1) produced against synthetic amyloid beta peptide (1-28 residues) was revealed to be reactive with amyloid beta peptide blotted on nitrocellulose membrane, but not with that dissolved in sodium dodecyl sulfate and electrophoresed. AmT-1 immunostained senile plaques of typical, primitive and diffuse type, as well as amyloid deposits in cerebral vessels. It also reacted with neuronal and glial cells of normal and Alzheimer's disease (AD) brains. In addition, AmT-1 was also reactive strongly with lipofuscin pigments of adrenal reticular cells, and weakly with those of eccrine glands and liver cells. A rat neural cell line (PC12h) was reactive with AmT-1. By immunoelectron microscopy, a positive reaction was seen in ribosomes along the rough endoplasmic reticulum of nerve cells and PC12h cells. By immunoprecipitation, AmT1 reacted with a band at 36 kDa in the brain homogenates from Ad patients as well as from normal aged subjects. By immunoblotting analysis, AmT1 reacted with a band at 36 kDa in the cytosolic fraction of PC12 cells, and three bands (12-17 kDa) in the lipopigment fraction of the adrenal gland. These findings suggest that the cerebral amyloid deposits contain substance(s) having an epitope common to neuronal cells and lipofuscin pigments. The possible relationship between cerebral amyloid deposits and lipofuscin pigments in systemic organs is discussed.