In vitro pharmacological characterisation of the role of ACKR3 on CXCR4-dependent and -independent function

Capoferri, Davide (2020) In vitro pharmacological characterisation of the role of ACKR3 on CXCR4-dependent and -independent function. PhD thesis, University of Glasgow.

Abstract

CXC-motif chemokine Receptor 4 (CXCR4) and Atypical ChemoKine Receptor 3 (ACKR3) are two 7-transmembrane domain receptors often studied together due to their common ligand CXC-motif chemokine Ligand 12 (CXCL12) and the implication of said ligand in several pathophysiological processes, cancer growth and metastasis formation among them.
This thesis project started with the aim of clarifying the interaction between these receptors and their second messengers, namely the different G proteins and arrestins, upon stimulation with different ligands, establishing a relationship between them in order to adjust the model of biased agonism to this system. Chapter 3 indeed gathers the efforts made to design and test molecular sensors that might have helped to understand whether the two receptors, alone or combined, give different types of signal in relation to differences in their expression or to different ligands. Even though several approaches were followed, this goal was not reached in full. The products generated from this first big molecular part had been propedeutical to the characterization of a new class of nanobodies against CXCR4 and ACKR3 synthesized by a project partner company.
Further, the focus narrowed on ACKR3, whose role on CXCR4-dependent cell migration was investigated in vitro through CRISPR. Indeed the first part of Chapter 4 describes that the lack of human ACKR3 in Jurkat cells showed a significant reduction in the amount of cells migrated towards CXCL12, indicating that ACKR3 has an indirect role in CXCR4-dependent cell migration. In the second part tumor growth dependent of ACKR3 alone was investigated: the knock-out of murine ACKR3 in LLC cells demonstrated that ACKR3 has a positive role in tumor growth regardless the expression of CXCR4.
Finally, the project headed towards the characterization of a very discussed interaction, namely that between human ACKR3 and human Adrenomedullin. Chapter 5 was dedicated to this topic, and several approaches led to the conclusions that this interaction exists, is slightly less potent than that with canonical chemokine ligands, but has a therapeutic potential still undiscovered. The results and the models build a strong body of evidence that converge on the aforementioned conclusions, and constitute a cue to consider this interaction worthy of further consideration.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Supervisor's Name: Milligan, Prof Graeme
• Date of Award: 2020
• Depositing User: Davide Capoferri
• Unique ID: glathesis:2020-81538
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 28 Jul 2020 07:32
• Last Modified: 01 Sep 2022 14:07
• Thesis DOI: 10.5525/gla.thesis.81538
• URI: https://theses.gla.ac.uk/id/eprint/81538