Engineering of an anti-PAI-1 antibody with tissue specific activation

Antibody-based therapies can have shortcomings if on-target activity causes dose-limiting toxicities. A pro-antibody, inspired by naturally occurring, proteolytically activated pro-forms of endogenous proteins, is an antibody variant which remains masked for antigen binding until activated locally by an organ-selective protease. This approach is useful to redirect the activity of an antibody recognising a widely distributed target to the site of the underlying pathology of the disease. Pro-antibodies have been described for targeting the tumour microenvironment which has a very specific protease expression signature. My aim is to investigate the use of pro-antibodies for tissue targeting. By using anti-PAI-1 pro-antibodies to specifically target the kidney for the treatment of chronic kidney disease to minimise observed cardiotoxicities, my work aims to validate this technique as a POC. To this end, I have designed a pro-antibody, based on the PAI-1 antibody MEDI-579. Two different types of masking domains are described, peptides and DARPins, which I selected against the MEDI-579 paratope. Using human and rodent transcriptomics data, three proteases, renin, hepsin and MMP-7, were identified that appear restricted to the kidney and have a specific cleavage signature. Activation of the pro-antibody with the renin protease has been demonstrated in vitro and ex vivo and work is on-going to demonstrate the activation in vivo and to characterise the properties of the anti-PAI-1 pro-antibody.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2021

Author dc:creator

• Bleuez, Chloe

Advisors dc:contributor.advisor

• Hollfelder, Florian
• Jermutus, Lutz

• antibody
• specificity
• kidney

Licence

• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

eng

DOI dc:identifier.doi

https://doi.org/10.17863/CAM.92119

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/344696