A Minimal-Tag Bioorthogonal Labelling Approach to Protein Uptake, Traffic and Delivery

Project Information

TagIt

Grant agreement ID: 676832

DOI

10.3030/676832

Project closed

EC signature date 8 July 2016

Start date 1 October 2016

End date 31 March 2023

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 499 106,00

EU contribution

€ 1 499 106,00

Coordinated by

THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE
United Kingdom

Periodic Reporting for period 4 - TagIt (A Minimal-Tag Bioorthogonal Labelling Approach to Protein Uptake, Traffic and Delivery)

Reporting period: 2021-04-01 to 2023-03-31

Summary of the context and overall objectives of the project

The ability to probe dynamic cellular events involved disease-associated proteins is limited, to a large degree, by the development of a strategy that uses small-sized coupling partners that react in a selective fashion with very rapid kinetics and without interfering with biological function(s) and localisation. In this ERC project, we developed an antibody against a relevant receptor in leukemias. Using the bioorthogonal reaction we developed, it was possible to characterise the internalisation and intracellular trafficking pathways when the antibody forms a complex with the correspondent receptor. This information was in turn used to design antibody-drug conjugates that target cancer cells that overexpress the target.

Our research and approach is important because it allows an informed design of conjugates that are able to deliver a toxic payload to cancer cells while minimising adverse side-effects.

In the context of our research, we also developed a new self-immolative linker that is specifically cleaved in cancer cells. This new linker when combined with the specificity of antibodies (or other ligands) for cancer cells allows the construction of highly selective conjugates for cancer therapy.

Overall, our approach project highlighted how chemistry-driven approaches improve our understanding of complex biological phenomena that will inform the next generation of therapeutics.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The main results achieved during this project included:

1) the development of a novel bioorthogonal reaction that allow to specifically label a protein of interest in live cells. In particular, we developed a new biorthogonal labelling reaction between small-sized alkyne trifluoroborates and tetrazines that has allowed us to characterise the uptake and intracellular trafficking of a target receptor in leukemias;

2) the development of an antibody against the leukemia-specific receptor that enabled to characterise the downstream effects of binding to the the receptor;

3) we developed a new-self immolative linker that allows the cleavable of a C–C bond to release intracellularly an ortho-quinone drug;

4) we built conjugates that were shown to selectively induce cancer cell death both in cells and mouse models of cancer;

5) this research lead to discoveries that are the basis of the award of two proof-of-concept ERC grants to bring discoveries from the bench into the clinic.

Exploitation and dissemination of the results of the project included peer-reviewed publications in high impact journals, presentations at conferences and IP protection (which is now licensed). In addition, I have participated in a number of events in secondary schools where I discuss the role of basic science in health and the need for interdisciplinary approaches to major research questions.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

There were two key developments beyond the state of the art in this project:

1) first, we developed the first on-demand activable bioorthogonal reaction. This means, we can trigger the reactivity to allow a super fast reaction (complete within 9 seconds) that does not interfere with endogenous cellular processes

2) secondly, and in our search for the best linker+payload, we ended up developing a new self-immolative linker strategy for the protection of ortho-quinone payloads. Importantly, we showed for the first time that a C–C bond may be cleaved in vivo through a 1,6-elimination reaction.

Chemistry is at the center of our research. While the bioorthogonal chemistry provided insight into the internalisation and intracellular trafficking of a relevant receptor overexpressed in cancer cells, the second allows for specific intracellular releaase of a drug once the complex antibody/receptor is internalised. This combination led to the construction of conjugates which we showed to be safe and highly efficacious in relevant models of leukemia.

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