Amyloid Beta Peptide 1-40 (Ab1-40)

Amyloid beta-protein (Aβ) is a peptide composed of 40 to 42 (43) amino acids, and is said to be cleaved out of the precursor protein APP (a protein composed of 695, 751, or 770 amino acids) by the action of β- or γ-secretase.

Abeta1-40 stimulated microglial cells and macrophages primed by interferon-gamma in a dose-dependent manner. Co-administration of Abeta1-40 with LPS or Pam3Cys led to an additive release of nitric oxide (NO) and tumour necrosis factor alpha (TNF-alpha). This may be one reason for the clinical deterioration frequently observed in patients with Alzheimer's disease during infections. In contrast, co-application of Abeta1-40 with CpG led to a substantial decrease of NO and TNF-alpha release compared with stimulation with CpG alone. Abeta1-40 and CpG did not co-localize within the same subcellular compartment, making a direct physicochemical interaction as the cause of the observed antagonism very unlikely.