Zebrafish Mutagenesis Study of Host Determinants of Mycobacterial Infection Outcome

This thesis describes a large-scale forward genetic screen in zebrafish for host determinants of mycobacterial infection outcome that I participated in. Zebrafish larvae from families randomly mutagenized with N-ethyl-N-nitrosourea were infected with Mycobacterium marinum and monitored over time. Larvae with increased susceptibility to infection were identified by the presence of mycobacterial cording, a phenotypic proxy for failure of immunity. 279 unrelated families have so far been screened with isolation of phenotypic larvae from 31 families. Genetic mapping has been carried out on phenotype sorted larvae from 5 families to identify genomic regions harbouring causative mutations. Positional cloning has been completed on one such mutant, Guaguancó which was found to map to a nonsense mutation in the gene ubiquitously expressed transcript (uxt), a poorly characterised gene not previously associated with anti-mycobacterial immunity. Subsequent cellular characterisation demonstrated that uxt mutants manifest a normal immune response in the early stages of infection, but then show accelerated macrophage death resulting in granuloma failure. Pharmacological inhibition of cell death pathways associated with mycobacterial infection did not influence uxt mutant susceptibility to infection, suggesting that uxt deficiency results in a novel form of death in mycobacterium-infected macrophages.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2020

Author dc:creator

• Televantos, Constantinos

Advisor dc:contributor.advisor

• Ramakrishnan, Lalita

• uxt
• prefoldin
• Tuberculosis
• Forward Genetics
• uri1
• pfdn
• M. marinum

Licence

• https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/41190dcb-f0c5-41d0-b80a-8a68159617a9/download
• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

eng

Author Identifier

0000-0003-0692-5533

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/311419