Exploration of lipids in immune cell funcation and development

Over the past few years we have generated a new and exciting data set profiling the lipid compositions (lipidome) of 16 different human immune cells and the major mouse immune cell equivalents. This revealed striking diversity between various immune cells, particularly between the innate and adaptive immune system. We are now exploring two overall questions: 1. Do specific lipids drive immune cell function? 2. How do the lipidomes of immune cells form as they develop from stem cells. The specific project can be focused on either of the two questions above. Project 1: Exploring the contribution of lipids sensitive to peroxidation which confer susceptibility to a specific form of cell death known as ferroptosis. Hypothesis: Immune cells enriched in lipids that are sensitive to peroxidation undergo ferroptosis when exposed to ferroptotic agonists, while immune cells devoid in these lipids will be resistant. This project will involve manipulating human and mouse immune cells in culture. Techniques to explore this question will be cell death assays via flow cytometry and assessment of lipid peroxidation by mass spectrometry. Mouse models will also be used to test this hypothesis in vivo and depending on the applicant (hons/PhD) will use mouse models to genetically modify the lipid composition or ferroptotic pathway of specific immune cells. Project 2: Determining the contribution of particular lipids to immune cell development. Hypothesis: Specific lipids are critical to the development of immune cells This project will determine the lipidomes of haematopoietic stem cells and how they change as these cells mature down specific lineages to form mature immune cells. Given we have identified a very unique signature in blood neutrophils (i.e. an enrichment in ether lipids), this project will first explore what happens when we delete an enzyme called glyceronephosphate O-acyltransferase (GNPAT – rate limiting enzyme for the production of ether lipids) specifically in stem cells and explore the neutrophil maturation pathway in the bone marrow and blood. We will also explore some functional properties of neutrophils such as inflammatory signalling in response to bacterial stimuli and phagocytosis. These experiments will be conducted in mice using flow cytometry to quantify cell population and examine the functional readouts. We also have a similar project to the one above exploring how ether lipids and polyunsaturated fatty acids contribute to platelet production and function. We have generated a number of knockout mice to explore these questions in detail.