EVOLUTIONARY PERSPECTIVES ON AMYLOID AND INFLAMMATORY FEATURES OF ALZHEIMER-DISEASE

We propose that the amyloid deposits in senile plaques of Alzheimer's Disease (AD) result from ancient mechanisms in wound-healing and infla mmatory processes that preceded the evolution of the inducible combina torial immune responses characteristic of jawed vertebrates. AD plaque s are unlike active plaques in MS, because antibodies, T-cells and, B cells are not conspicuous components of senile plaques or other loci o f degeneration. However, senile plaques contain amyloids and other inf lammatory proteins of ancient origin that appear to be made by local b rain cells, including neurons, astrocytes, and microglia. We describe a highly convserved 16-mer found in pentraxins from mammals and from t he horseshoe crab. The senile plaque thus provides a novel opportunity to study primitive features of complement-mediated inflammatory respo nses in the absence of immunoglobulins.