Seeding selectivity and ultrasensitive detection of tau aggregate conformers of Alzheimer disease

Allison Kraus, Eri Saijo, Michael A. Metrick, Kathy Newell, Christina J. Sigurdson, Gianluigi Zanusso, Bernardino Ghetti, Byron Caughey

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Alzheimer disease (AD) and chronic traumatic encephalopathy (CTE) involve the abnormal accumulation in the brain of filaments composed of both three-repeat (3R) and four-repeat (4R) (3R/4R) tau isoforms. To probe the molecular basis for AD’s tau filament propagation and to improve detection of tau aggregates as potential biomarkers, we have exploited the seeded polymerization growth mechanism of tau filaments to develop a highly selective and ultrasensitive cell-free tau seed amplification assay optimized for AD (AD real-time quaking-induced conversion or AD RT-QuIC). The reaction is based on the ability of AD tau aggregates to seed the formation of amyloid fibrils made of certain recombinant tau fragments. AD RT-QuIC detected seeding activity in AD (n = 16) brains at dilutions as extreme as 107–1010-fold, but was 102–106-fold less responsive when seeded with brain from most cases of other types of tauopathy with comparable loads of predominant 3R or 4R tau aggregates. For example, AD brains had average seeding activities that were orders of magnitude higher than Pick disease brains with predominant 3R tau deposits, but the opposite was true using our previously described Pick-optimized tau RT-QuIC assay. CTE brains (n = 2) had seed concentrations comparable to the weakest of the AD specimens, and higher than 3 of 4 specimens with 3R/4R primary age-related tauopathy. AD seeds shared properties with the tau filaments found in AD brains, as AD seeds were sarkosyl-insoluble, protease resistant, and reactive with tau antibodies. Moreover, AD RT-QuIC detected as little as 16 fg of pure synthetic tau fibrils. The distinctive seeding activity exhibited by AD and CTE tau filaments compared to other types of tauopathies in these seeded polymerization reactions provides a mechanistic basis for their consistent propagation as specific conformers in patients with 3R/4R tau diseases. Importantly, AD RT-QuIC also provides rapid ultrasensitive quantitation of 3R/4R tau-seeding activity as a biomarker.

Original languageEnglish (US)
JournalActa Neuropathologica
DOIs
StateAccepted/In press - Jan 1 2018

Fingerprint

Alzheimer Disease
Tauopathies
Seeds
Brain
Polymerization
Biomarkers
Pick Disease of the Brain
Molecular Probes
Aptitude
Amyloid
Protein Isoforms
Peptide Hydrolases
Antibodies
Growth

Keywords

  • Alzheimer disease
  • Biomarker
  • Chronic traumatic encephalopathy
  • Diagnosis
  • RT-QuIC
  • Seeds
  • Tau aggregate
  • Tauopathy

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Clinical Neurology
  • Cellular and Molecular Neuroscience

Cite this

Kraus, A., Saijo, E., Metrick, M. A., Newell, K., Sigurdson, C. J., Zanusso, G., ... Caughey, B. (Accepted/In press). Seeding selectivity and ultrasensitive detection of tau aggregate conformers of Alzheimer disease. Acta Neuropathologica. https://doi.org/10.1007/s00401-018-1947-3

Seeding selectivity and ultrasensitive detection of tau aggregate conformers of Alzheimer disease. / Kraus, Allison; Saijo, Eri; Metrick, Michael A.; Newell, Kathy; Sigurdson, Christina J.; Zanusso, Gianluigi; Ghetti, Bernardino; Caughey, Byron.

In: Acta Neuropathologica, 01.01.2018.

Research output: Contribution to journalArticle

Kraus, Allison ; Saijo, Eri ; Metrick, Michael A. ; Newell, Kathy ; Sigurdson, Christina J. ; Zanusso, Gianluigi ; Ghetti, Bernardino ; Caughey, Byron. / Seeding selectivity and ultrasensitive detection of tau aggregate conformers of Alzheimer disease. In: Acta Neuropathologica. 2018.
@article{b3b026bea2684835be79101803d18f56,
title = "Seeding selectivity and ultrasensitive detection of tau aggregate conformers of Alzheimer disease",
abstract = "Alzheimer disease (AD) and chronic traumatic encephalopathy (CTE) involve the abnormal accumulation in the brain of filaments composed of both three-repeat (3R) and four-repeat (4R) (3R/4R) tau isoforms. To probe the molecular basis for AD’s tau filament propagation and to improve detection of tau aggregates as potential biomarkers, we have exploited the seeded polymerization growth mechanism of tau filaments to develop a highly selective and ultrasensitive cell-free tau seed amplification assay optimized for AD (AD real-time quaking-induced conversion or AD RT-QuIC). The reaction is based on the ability of AD tau aggregates to seed the formation of amyloid fibrils made of certain recombinant tau fragments. AD RT-QuIC detected seeding activity in AD (n = 16) brains at dilutions as extreme as 107–1010-fold, but was 102–106-fold less responsive when seeded with brain from most cases of other types of tauopathy with comparable loads of predominant 3R or 4R tau aggregates. For example, AD brains had average seeding activities that were orders of magnitude higher than Pick disease brains with predominant 3R tau deposits, but the opposite was true using our previously described Pick-optimized tau RT-QuIC assay. CTE brains (n = 2) had seed concentrations comparable to the weakest of the AD specimens, and higher than 3 of 4 specimens with 3R/4R primary age-related tauopathy. AD seeds shared properties with the tau filaments found in AD brains, as AD seeds were sarkosyl-insoluble, protease resistant, and reactive with tau antibodies. Moreover, AD RT-QuIC detected as little as 16 fg of pure synthetic tau fibrils. The distinctive seeding activity exhibited by AD and CTE tau filaments compared to other types of tauopathies in these seeded polymerization reactions provides a mechanistic basis for their consistent propagation as specific conformers in patients with 3R/4R tau diseases. Importantly, AD RT-QuIC also provides rapid ultrasensitive quantitation of 3R/4R tau-seeding activity as a biomarker.",
keywords = "Alzheimer disease, Biomarker, Chronic traumatic encephalopathy, Diagnosis, RT-QuIC, Seeds, Tau aggregate, Tauopathy",
author = "Allison Kraus and Eri Saijo and Metrick, {Michael A.} and Kathy Newell and Sigurdson, {Christina J.} and Gianluigi Zanusso and Bernardino Ghetti and Byron Caughey",
year = "2018",
month = "1",
day = "1",
doi = "10.1007/s00401-018-1947-3",
language = "English (US)",
journal = "Acta Neuropathologica",
issn = "0001-6322",
publisher = "Springer Verlag",

}

TY - JOUR

T1 - Seeding selectivity and ultrasensitive detection of tau aggregate conformers of Alzheimer disease

AU - Kraus, Allison

AU - Saijo, Eri

AU - Metrick, Michael A.

AU - Newell, Kathy

AU - Sigurdson, Christina J.

AU - Zanusso, Gianluigi

AU - Ghetti, Bernardino

AU - Caughey, Byron

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Alzheimer disease (AD) and chronic traumatic encephalopathy (CTE) involve the abnormal accumulation in the brain of filaments composed of both three-repeat (3R) and four-repeat (4R) (3R/4R) tau isoforms. To probe the molecular basis for AD’s tau filament propagation and to improve detection of tau aggregates as potential biomarkers, we have exploited the seeded polymerization growth mechanism of tau filaments to develop a highly selective and ultrasensitive cell-free tau seed amplification assay optimized for AD (AD real-time quaking-induced conversion or AD RT-QuIC). The reaction is based on the ability of AD tau aggregates to seed the formation of amyloid fibrils made of certain recombinant tau fragments. AD RT-QuIC detected seeding activity in AD (n = 16) brains at dilutions as extreme as 107–1010-fold, but was 102–106-fold less responsive when seeded with brain from most cases of other types of tauopathy with comparable loads of predominant 3R or 4R tau aggregates. For example, AD brains had average seeding activities that were orders of magnitude higher than Pick disease brains with predominant 3R tau deposits, but the opposite was true using our previously described Pick-optimized tau RT-QuIC assay. CTE brains (n = 2) had seed concentrations comparable to the weakest of the AD specimens, and higher than 3 of 4 specimens with 3R/4R primary age-related tauopathy. AD seeds shared properties with the tau filaments found in AD brains, as AD seeds were sarkosyl-insoluble, protease resistant, and reactive with tau antibodies. Moreover, AD RT-QuIC detected as little as 16 fg of pure synthetic tau fibrils. The distinctive seeding activity exhibited by AD and CTE tau filaments compared to other types of tauopathies in these seeded polymerization reactions provides a mechanistic basis for their consistent propagation as specific conformers in patients with 3R/4R tau diseases. Importantly, AD RT-QuIC also provides rapid ultrasensitive quantitation of 3R/4R tau-seeding activity as a biomarker.

AB - Alzheimer disease (AD) and chronic traumatic encephalopathy (CTE) involve the abnormal accumulation in the brain of filaments composed of both three-repeat (3R) and four-repeat (4R) (3R/4R) tau isoforms. To probe the molecular basis for AD’s tau filament propagation and to improve detection of tau aggregates as potential biomarkers, we have exploited the seeded polymerization growth mechanism of tau filaments to develop a highly selective and ultrasensitive cell-free tau seed amplification assay optimized for AD (AD real-time quaking-induced conversion or AD RT-QuIC). The reaction is based on the ability of AD tau aggregates to seed the formation of amyloid fibrils made of certain recombinant tau fragments. AD RT-QuIC detected seeding activity in AD (n = 16) brains at dilutions as extreme as 107–1010-fold, but was 102–106-fold less responsive when seeded with brain from most cases of other types of tauopathy with comparable loads of predominant 3R or 4R tau aggregates. For example, AD brains had average seeding activities that were orders of magnitude higher than Pick disease brains with predominant 3R tau deposits, but the opposite was true using our previously described Pick-optimized tau RT-QuIC assay. CTE brains (n = 2) had seed concentrations comparable to the weakest of the AD specimens, and higher than 3 of 4 specimens with 3R/4R primary age-related tauopathy. AD seeds shared properties with the tau filaments found in AD brains, as AD seeds were sarkosyl-insoluble, protease resistant, and reactive with tau antibodies. Moreover, AD RT-QuIC detected as little as 16 fg of pure synthetic tau fibrils. The distinctive seeding activity exhibited by AD and CTE tau filaments compared to other types of tauopathies in these seeded polymerization reactions provides a mechanistic basis for their consistent propagation as specific conformers in patients with 3R/4R tau diseases. Importantly, AD RT-QuIC also provides rapid ultrasensitive quantitation of 3R/4R tau-seeding activity as a biomarker.

KW - Alzheimer disease

KW - Biomarker

KW - Chronic traumatic encephalopathy

KW - Diagnosis

KW - RT-QuIC

KW - Seeds

KW - Tau aggregate

KW - Tauopathy

UR - http://www.scopus.com/inward/record.url?scp=85058853148&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85058853148&partnerID=8YFLogxK

U2 - 10.1007/s00401-018-1947-3

DO - 10.1007/s00401-018-1947-3

M3 - Article

JO - Acta Neuropathologica

JF - Acta Neuropathologica

SN - 0001-6322

ER -