Project Reference: ICS27-MED-JN1

Project title: Mitochondrial DNA Damage and Innate Immune Activation in the Airway Epithelium

Project outline

Mitochondria are central hubs of cellular metabolism, ROS signalling, and innate immune regulation. The mitochondrial genome (mtDNA) is uniquely vulnerable to oxidative damage owing to its proximity to the electron transport chain, its limited repair capacity, and its high copy number (~1,000–10,000 per cell). Damaged mtDNA released into the cytosol or extracellular space functions as a potent damage-associated molecular pattern (DAMP) activating innate immune sensors including cGAS-STING. How these pathways operate in a differentiated human epithelium is poorly understood. Key questions remain: what determines whether damaged mtDNA is released or retained? How do cells distinguish self-derived from pathogen-derived nucleic acids? What cell-intrinsic factors set the threshold for innate immune activation?

This project uses primary human airway epithelial air-liquid interface (ALI) cultures to address these questions. Defined mitochondrial stressors (graded hypoxia, exogenous oxidants, mitochondria-targeted genotoxins) will induce and characterise mtDNA damage by long-amplicon qPCR, whole-mitochondrial genome sequencing, and ddPCR-based heteroplasmy measurement. Minczuk Group mtDNA base-editing tools will engineer defined lesions, enabling direct causal testing on innate immune activation. Cytosolic and extracellular mtDNA will be quantified by subcellular fractionation and vesicle isolation. Single-cell transcriptomics and proteomics will define cell-intrinsic determinants of susceptibility across epithelial subtypes (ciliated, secretory, basal).

The student will be trained in ALI methodology (Nathan lab), mitochondrial genomics and mtDNA engineering (Minczuk Group/MRC MBU), bioenergetic profiling, flow cytometry, and single-cell multi-omics. The GSK partnership provides additional research perspective and a placement opportunity.

Principal Supervisor

Professor James Nathan

Email address: jan33@cam.ac.uk

Department / Partner Institute: Medicine / Cambridge Institute for Therapeutic Immunology and Infectious Disease (CITIID)

Website: https://jamesnathanlab.co.uk/

Industrial Partner

GSK (GlaxoSmithKline)

BBSRC strategic theme

Understanding the rules of life