Use this URL to cite or link to this record in EThOS:
Title: An investigation into the role of optineurin in macrophage-mediated acute antibacterial response in inflammatory bowel disease
Author: Chew, T. S.
ISNI:       0000 0004 5359 0833
Awarding Body: University College London (University of London)
Current Institution: University College London (University of London)
Date of Award: 2015
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
Crohn’s disease (CD) is now recognised to be due to defective host responses to bacteria in genetically susceptible individuals. Others in our research group previously found defective neutrophil recruitment, bacterial clearance and monocyte-derived macrophage (MDM) proinflammatory cytokine secretion in CD. To investigate the defective cytokine secretion, we performed transcriptomic analysis and identified reduced MDM optineurin (OPTN) expression in 10% CD patients. Here, I show that macrophages stimulated with E. coli, bacterial Toll-like and NOD-like receptor ligands upregulate OPTN, a Golgi complex protein that regulates vesicle transport. In vitro, Optn-/- bone marrow-derived macrophages (BMDM) stimulated with E. coli secrete significantly lower levels of proinflammatory TNF and IL6 cytokines, which is normalised to wildtype levels on addition of lysosomal function inhibitors. In vivo, Optn-/- mice develop a more severe Citrobacter colitis with greater mortality, an early defective neutrophil recruitment to the bowel and lower levels of serum proinflammatory cytokines. The Optn-/- mice also demonstrated a similar phenotype of defective neutrophil recruitment and lower serum proinflammatory cytokines in an E. coli-induced peritonitis. These results indicate that the low OPTN expression originally identified in CD macrophages has likely contributed to an attenuated antibacterial response, which potentially led to the development of bowel inflammation.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available