Foote, Juliet Rachel;
(2019)
The NADPH oxidase-induced phagosomal environment of neutrophils and other phagocytes.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Juliet Foote PhD thesis 2018.pdf - Accepted Version Download (8MB) | Preview |
Abstract
The central focus of this thesis is to understand some of the fundamental physiology of the neutrophil phagosome in relation to the effects of the NADPH oxidase. The NADPH oxidase, when activated and assembled at the phagosomal membrane, translocates electrons into the phagosome which create superoxide anions and initiates a cascade of reactive oxygen species. This negative charge across the membrane must be compensated to allow further oxidase activity. We know that the proton channel, HVCN1, plays a major role in neutrophil charge compensation, but other ion channels must be involved as Hvcn1-/- mice still have some oxidase activity. One way to measure ionic flow and potentially identify ion channels involved is recording phagosomal pH, using the ratiometric indicator SNARF-1. The first results chapter describes using knockout mouse models lacking different ion channels, and the use of ion channel inhibitors to measure any effects on phagosomal pH or area and oxidase activity in neutrophils. While the effects of some broad-spectrum channel inhibitors suggested involvement of chloride and potassium conductances in the neutrophil phagosome, they and the mouse models failed to convincingly identify a specific channel. The second results chapter aimed to characterise a mouse neutrophil cell line as an alternative tool to investigate the neutrophil phagosome. The Hoxb8 cell line is made up of conditionally immortalised mouse myeloid progenitor cells that can be differentiated into neutrophils. The wildtype C57BL/6 and Hvcn1-/- Hoxb8 lines were studied and compared to primary bone marrow neutrophils to validate their use as a neutrophil model. Finally, other human primary phagocytes were investigated and compared to neutrophils. This aimed to provide insight into the function and effect of the NADPH oxidase in these cells by measuring pH with and without the oxidase inhibitor DPI and measuring oxidase activity.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | The NADPH oxidase-induced phagosomal environment of neutrophils and other phagocytes |
| Event: | UCL (University College London) |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2019. Original content in this thesis is licensed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) Licence (https://creativecommons.org/licenses/by/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| Keywords: | neutrophil, NADPH oxidase, pH, ion channels, monocyte, macrophage, dendritic cell, Hoxb8 |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10065611 |
Archive Staff Only
 |
View Item |
