AAV-mediated expression of anti-tau scFvs decreases tau accumulation in a mouse model of tauopathy

Christina Ising, Gilbert Gallardo, Cheryl E.G. Leyns, Connie H. Wong, Hong Jiang, Floy Stewart, Lauren J. Koscal, Joseph Roh, Grace O. Robinson, Javier Remolina Serrano, David M. Holtzman. J Exp Med. 2017 May 1;214(5):1227-1238. doi: 10.1084/jem.20162125. Epub 2017 Apr 17. Read More

Abstract

Tauopathies are characterized by the progressive accumulation of hyperphosphorylated, aggregated forms of tau. Our laboratory has previously demonstrated that passive immunization with an anti-tau antibody, HJ8.5, decreased accumulation of pathological tau in a human P301S tau-expressing transgenic (P301S-tg) mouse model of frontotemporal dementia/tauopathy. To investigate whether the Fc domain of HJ8.5 is required for the therapeutic effect, we engineered single-chain variable fragments (scFvs) derived from HJ8.5 with variable linker lengths, all specific to human tau. Based on different binding properties, we selected two anti-tau scFvs and tested their efficacy in vivo by adeno-associated virus-mediated gene transfer to the brain of P301S-tg mice. The scFvs significantly reduced levels of hyperphosphorylated, aggregated tau in brain tissue of P301S-tg mice, associated with a decrease in detergent-soluble tau species. Interestingly, these mice showed substantial levels of scFvs in the cerebrospinal fluid without significant effects on total extracellular tau levels. Therefore, our study provides a novel strategy for anti-tau immunotherapeutics that potentially limits a detrimental proinflammatory response.

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Posted on May 27, 2017
Posted in: Clocks & Sleep, HPAN, Neurodegeneration, Publications Authors: ,