title: Engineered proteolytic nanobodies reduce Abeta burden and ameliorate Abeta-induced cytotoxicity.
abstract: Deposition of beta-amyloid (Abeta) is considered an important early event in the pathogenesis of Alzheimer's disease (AD), and reduction of Abeta levels in the brain could be a viable therapeutic approach. A potentially noninflammatory route to facilitate clearance and reduce toxicity of Abeta is to degrade the peptide using proteolytic nanobodies. Here we show that a proteolytic nanobody engineered to cleave Abeta at its alpha-secretase site has potential therapeutic value. The Asec-1A proteolytic nanobody, derived from a parent catalytic light chain antibody, prevents aggregation of monomeric Abeta, inhibits further aggregation of preformed Abeta aggregates, and reduces Abeta-induced cytotoxicity toward a human neuroblastoma cell line. The nanobody also reduces toxicity induced by overexpression of the human amyloid precursor protein (APP) in a Chinese hamster ovary (CHO) cell line by cleaving APP at the alpha-secretase site which precludes formation of Abeta. Targeted proteolysis of APP and Abeta with catalytic nanobodies represents a novel therapeutic approach for treating AD where potentially harmful side effects can be minimized.
authors.affiliation: Harrington Department of Bioengineering, Arizona State University,Tempe, Arizona 85287, USA.
authors.forename: Srinath
authors.initials: S
authors.lastname: Kasturirangan
authors.forename: Shanta
authors.initials: S
authors.lastname: Boddapati
authors.forename: Michael R
authors.initials: MR
authors.lastname: Sierks
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D053829:Amyloid Precursor Protein Secretases / Q000235:genetics / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism* / Q000627:therapeutic use; D006801:Humans; D058255:Protease Nexins; D011956:Receptors, Cell Surface
chemical_list: C545487:APP protein, human; D016564:Amyloid beta-Protein Precursor; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D053829:Amyloid Precursor Protein Secretases