Selective recognition of human small transthyretin aggregates by a novel monoclonal antibody

Abstract

Biochemical characterisation of transthyretin variant TTR Y78F showed that this variant adopts a tetrameric conformation as normal TTR but exhibits some of the characteristics of an intermediate structure in the fibrillogenesis pathway. It was hypothesised that native Y78F might represent an early event in TTR amyloidogenesis. We immunised TTR knock out mice with recombinant variant TTR Y78F. One stable hybridoma named CE11, of the IgM isotype, was tested for reactivity towards several soluble recombinant TTR variants both amyloidogenic and non-amyloidogenic. CE11 only recognises the highly amyloidogenic TTR variants L55P, S52P, A97S, Y78F or acidified TTR wt preparations. At the same time, this clone was negative for TTR V30M, soluble wild type protein or TTR T119M. The reactivity increased with oligomer formation and decreased as mature fibrils grow. After size exclusion chromatography (SEC) followed by sandwich ELISA and native immunoblotting, the mAb recognised two peaks (i) peak 1 present in acidified and in soluble variant proteins preparations with material above 146 KDa (ii) peak 2 only present in soluble L55P and S52P TTR preparations with material between 66 and 146 KDa. mAb CE11 may be a potential tool to survey therapeutical agents against TTR aggregation.

Keywords:

• Transthyretin
• ATTRv amyloidosis
• monoclonal antibodies: oligomers
• amyloid

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Acknowledgements

The authors acknowledge the technical assistance of Unit Biochemical and Biophysical Technologies (B2Tech).

Disclosure statement

The authors report no conflict of interest.

Additional information

Funding

The work was funded by the project Norte-01-0145-FEDER-000008 - Porto Neurosciences and Neurologic Disease Research Initiative at I3S, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund. The transmission electronic microscopy was performed at the HEMS core facility at i3S, University of Porto, member of the national infrastructure PPBI – Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122) Portugal with the assistance of Ana Rita Malheiro e Rui Fernandes.