Abstract
Objectives: We have raised nanobodies against each of these receptors and multimerised them to identify the minimum number of epitopes to achieve robust activation of human platelets.
Methods: Divalent and trivalent nanobodies were generated using a flexible glycine-serine linker. Tetravalent nanobodies utilise a mouse Fc domain (IgG2a, which does not bind to FcγRIIA) to dimerise the divalent nanobody. Ligand affinity measurements were determined by surface plasmon resonance. Platelet aggregation, ATP secretion and protein phosphorylation were analysed using standardised methods.
Results: Multimerisation of the nanobodies led to a stepwise increase in affinity with divalent and higher-order nanobody oligomers having sub-nanomolar affinity. The trivalent nanobodies to GPVI, CLEC-2 and PEAR1 stimulated powerful and robust platelet aggregation, secretion and protein phosphorylation at low nanomolar concentrations. A tetravalent nanobody was required to activate FcγRIIA with the concentration-response relationship showing a greater variability and reduced sensitivity compared to the other nanobody-based ligands, despite a sub-nanomolar binding affinity.
Conclusions: The multivalent nanobodies represent a series of standardised, potent agonists for platelet glycoprotein receptors. They have applications as research tools and in clinical assays.
| Original language | English |
|---|---|
| Pages (from-to) | 271-285 |
| Number of pages | 15 |
| Journal | Journal of Thrombosis and Haemostasis |
| Volume | 22 |
| Issue number | 1 |
| Early online date | 7 Oct 2023 |
| DOIs | |
| Publication status | Published - Jan 2024 |
Bibliographical note
Copyright © 2023 The Author(s). Published by Elsevier Inc. on behalf of International Society on Thrombosis and Haemostasis. This is an open access article distributed under the terms of the Creative Commons Attribution License CC BY [https://creativecommons.org/licenses/by/4.0/], which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Acknowledgements: This work was funded by the Wellcome Trust Joint Investigator award (204951/Z/16Z). SPW is a BHF Chair (CH03/003). JCC, SJM, RJB, CK and AS were supported by the Accelerator Award from the BHF (AA/18/2/34218). SJM is supported by a BHF project grant (PG/23/11230). LAM was supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement (766118). CK was supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement (893262). We would like to thank Dr Steve Schoonooghe at VIB Nanobody core for assistance in the design and generation of the multivalent nanobody plasmid DNA. This is independent research funded by the providers named above and carried out at the National Institute for Health and Care Research (NIHR) Birmingham Biomedical Research Centre (BRC). The views expressed are those of the authors and not necessarily those of the funders, the NIHR or the Department of Health and Social Care.
Funding
Funding information This work was funded by the Wellcome Trust Joint Investigator award (204951/Z/16Z).This work was funded by the Wellcome Trust Joint Investigator award (204951/Z/16Z). S.P.W. is a BHF Chair (CH03/003). J.C.C., S.J.M., R.J.B., C.K., and A.S. were supported by the Accelerator Award from the BHF (AA/18/2/34218). S.J.M. is supported by a BHF project grant (PG/23/11230). L.A.M. was supported by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement (766118). C.K. was supported by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement (893262). We would like to thank Dr Steve Schoonooghe at VIB Nanobody core for assistance in the design and generation of the multivalent nanobody plasmid DNA. This is independent research funded by the providers named above and carried out at the National Institute for Health and Care Research (NIHR) Birmingham Biomedical Research Centre (BRC). The views expressed are those of the authors and not necessarily those of the funders, the NIHR or the Department of Health and Social Care.
| Funders | Funder number |
|---|---|
| NIHR Imperial Biomedical Research Centre | |
| National Institute for Health and Care Research | |
| Birmingham Biomedical Research Centre | |
| Horizon 2020 | |
| British Heart Foundation | CH03/003, PG/23/11230, AA/18/2/34218 |
| H2020 Marie Skłodowska-Curie Actions | 893262, 766118 |
| Wellcome Trust | 204951/Z/16Z |
Keywords
- Src kinases
- cell signalling
- ligands
- platelets
- tyrosine kinase linked receptors