Soluble, pre-fibrillar oligomeric tau (oligo-tau) has been identified as a major source of neurodegeneration in tauopathies. Injection of oligo-tau in wild-type and transgenic mice induces tau pathology, and propagates toxicity through cell-to-cell transmission. Antibodies specific to oligo-tau are an essential tool for mechanistic studies, and potential tools for diagnostic biomarkers as well as therapeutic intervention. This proposal aims to address three major limitations in existing anti-oligo-tau antibodies. First, all known oligo-tau antibodies are mouse immunoglobulins. This limit translating existing results from oligo-tau antibodies in humans, in particular to study antibody-mediated inhibition of cell-to-cell transmission. Second is the lack of high affinity oligo-tau antibodies. In mouse models of AD, only a small fraction of tau is oligomerized, and it is estimated that even smaller fraction would be found extracellularly. Antibodies that can engage these trace amounts of oligo-tau would lead to detection in clinical samples and potentially inhibition of cell-to-cell transmission. Finally, further distinction of oligo-tau species based on molecular signature would be necessary. Many distinct toxic soluble tau strains are known to exist in brain homogenates, and they induce distinct patterns of pathology and propagation. In particular, considering that post-translational modifications (PTMs) such as site-specific phosphorylation and acetylation have been also associated with disease progression, classifying oligo-tau based on PTM state would lead to novel insights. This proposal aims to address these challenges by developing high affinity human antibodies targeting oligo-tau. Based on the evidence that existing oligo- tau specific or conformation-specific antibodies recognize discontinuous epitopes, we hypothesize that recognizing discontinuous epitopes within tau would be critical for oligomer specificity. We will develop a novel antibody engineering strategy that mimics the somatic hypermutation process to enable the recognition of discontinuous epitopes, leading to high affinity without compromising antibody specificity.

Public Health Relevance

Tau oligomers have been identified as a major source of toxicity in neurodegenerative disorders such as Alzheimer's disease. The proposed work will develop high quality human antibodies specific to tau oligomers. These antibodies will enable sensitive, robust detection for studying disease progression, and may lead to the development of therapeutics.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21NS111358-01A1
Application #
9896514
Study Section
Cellular and Molecular Biology of Neurodegeneration Study Section (CMND)
Program Officer
Mcgavern, Linda
Project Start
2020-04-01
Project End
2022-03-31
Budget Start
2020-04-01
Budget End
2022-03-31
Support Year
1
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Connecticut
Department
Engineering (All Types)
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
614209054
City
Storrs-Mansfield
State
CT
Country
United States
Zip Code
06269