Host-Microbe Interactome
Lipid Dynamics during Mycobacterial Infections
Tuberculosis (Tb) is caused by Mycobacterium tuberculosis and remains one of the deadliest infectious diseases. The World Health Organization (WHO) estimates that in 2021, Tb killed 1.6 million people emphasizing the importance to develop new drugs, vaccines and diagnostic tools to reduce this burden in the future.
M. tuberculosis employs multiple strategies to survive intracellularly. One of its most striking adaptations is its ability to utilize host lipids such as fatty acids and sterols to: (i) generate energy, (ii) build its characteristic lipid-rich cell wall and (iii) produce storage lipids during infection. To be constantly in a fatty acid-rich environment, the pathogen actively contributes to generate the “foamy” phenotype in host macrophages, for which the accumulation of host lipid droplets (LDs) is characteristic.
Using the Dictyostelium discoideum/M. marinum infection system, we found that mycobacteria access host LDs to build up their own lipid storage organelles and exploit ER-derived phospholipids when LDs are lacking (Barisch et al., 2015; Barisch & Soldati, 2017). Moreover, we observed that mycobacteria that escaped from the Mycobacterium-containing vacuole (MCV) into the cytosol recruit LD-derived enzymes and regulatory proteins on their hydrophobic surface.
Key Interests
The Barisch lab aims to unravel the molecular mechanisms by which pathogenic mycobacteria acquire lipids from their host to support chronic infection. Combining the application of functionalized lipid probes with mass spectrometry-based lipidomics and advanced microscopy techniques, the group analyses metabolic lipid flows between mycobacteria and their host at the subcellular and ultrastructural level.
More information: www.barischlabcssb.com
Balancing Act: How a perturbation in fatty acid homeostasis impacts on vacuolar escape of mycobacteria
To import fatty acids from their environment, mycobacteria are equipped with sophisticated transport machineries. However, the mechanism by which fatty acids are esterified with coenzyme A (“fatty acid activation”), an essential step for their further turnover, remains elusive. This project aims to characterize the function of fatty acid-activating enzymes in lipid synthesis and vacuolar escape of mycobacteria using the D. discoideum/M. marinum system.
To characterize fatty acid flows and metabolism in host and bacteria mutants depleted in fatty acid-activating enzymes, a protocol that combines the use of bifunctional FA probes with expansion microscopy and lipidomics is established. - This project is part of the SPP2225.
Functional impact of lipid logistics during mycobacterial infection
This project aims to identify lipid metabolic pathways that are hijacked by intracellular mycobacteria to exploit lipids from the host. To monitor alterations in lipid levels, we are establishing mass spectrometry lipidomics and thin layer chromatography for the D. discoideum/M. marinum system. In the future, we will determine the consequences of blocking specific lipid supply routes on various stages of the mycobacterial infection course. Collectively, these efforts may uncover novel therapeutic targets to fight mycobacteria infection.
Induction of membrane contact sites during mycobacterial infection
Various intracellular pathogens, including M. tuberculosis, damage the membrane of their vacuoles to impair fundamental innate immune functions and to trigger their translocation into the host cytosol. The host counteracts membrane damage by recruiting membrane repair machineries to retain the pathogen inside the vacuole.
Using advanced imaging approaches, our group investigates the role of ER-dependent membrane repair and other repair machineries during mycobacteria infection. For example, to investigate the formation of membrane contact sites between the ER and the MCV, we employ advanced imaging techniques. Specifically, we utilize several 3D-CLEM approaches that include high-pressure freezing and TEM-tomography (as described in Franzkoch and Anand et al., 2023, BioRxiv) as well as serial block-face SEM (Anand et al., 2023, BioRxiv). This, together with spinning disc live cell imaging and flow cytometry, uncovered that ER-dependent repair constitutes a host defense mechanism against intracellular pathogens such as M. tuberculosis (Anand et al., 2023, BioRxiv). - This project is part of the SFB1557 @Uni Osnabrück.
- 2019 – 2022
SFB944 – P25: „Functional impact of lipid logistics on mycobacterial infection in Dictyostelium“ @Uni Osnabrück - 2020 – 2023
SPP2225: „Functional impact of mycobacterial lipids during the infection of Dictyostelium with M. marinum“ - 2023 – 2026
SFP1557 – P1: „Remodelling and exploitation of the host lipid trafficking machinery by pathogenic mycobacteria“ @Uni Osnabrück
- Live cell microscopy (Spinning Disc and Lattice Lightsheet)
- Classical immunofluorescence
- Correlative light and electron microscopy
- Expansion microscopy
- Thin layer chromatography
- Mass spectrometry (lipidomics and proteomics)
2024
Listian, SA, Mazur, A-C, Kol, M, Ufelmann, E, Eising, S, Fröhlich, F, Walter, S, Holthuis, JCM & Barisch, C 2024, 'Complex sphingolipid profiling and identification of an inositol-phosphorylceramide synthase in Dictyostelium discoideum', iScience, Jg. 27, Nr. 9, S. 110609. https://doi.org/10.1016/j.isci.2024.110609
2023
Listian SA, Kol M, Ufelmann E, Eising S, Fröhlich F, Walter S, Holthuis JCM, Barisch C (2023). Complex sphingolipid profiling and identification of an inositol phosphorylceramide synthase in Dictyostelium discoideum. BioRxiv.
*Franzkoch R, *Anand A, Psathaki OE, Barisch C (2023). Resolving exit strategies of mycobacteria by combining high-pressure freezing with 3D-correlative light and electron microscopy. Mol Micro. *authors contributed equally
Anand A, Mazur A-C, Rosell-Arevalo P, Franzkoch R, Breitsprecher L, Listian SA, Hüttel SV, Müller D, Schäfer DG, Vormittag S, Hilbi H, Maniak M, Gutierrez MG, Barisch C (2023). ER-dependent membrane repair of mycobacteria-induced vacuole damage. BioRxiv and accepted for publication in mBio.
Barisch C, Holthuis JCM, Cosentino K (2023). Membrane damage and repair: A thin line between life and death. Biol. Chem. REVIEW.
Vormittag S, Hüsler D, Haneburger I, Kroniger T, Anand A, Prantl M, Barisch C, Maaß S, Becher D, Letourneur F, Hilbi H (2023). Legionella- and host-driven lipid flux at LCV-ER membrane contact sites promotes vacuole remodeling. EMBO Rep.
2022
Foulon M, Listian S A, Soldati T, Barisch C (2022). Chapter 6. Conserved mechanisms drive host lipid access, import and utilisation in Mycobacterium tuberculosis and M. marinum. In Developments in Microbiology, Biology of Mycobacterial Lipids, Academic Press. Edited by Fatima Z, Canaan S. REVIEW.
Head
Staff
Zentrum für strukturelle Systembiolgie (CSSB)
DESY, Gebäude 15
Notkestraße 85
D-22607 Hamburg
Assoziiert mit dem Fachbereich Biologie & der MIN-Fakultät der Universität Hamburg
Tel: +49 (0)40-8998-87620
https://www.barischlabcssb.com