1. Research background:
The overarching goal of the Pernas lab is to understand how human metabolism influences the progression of infectious disease at the cellular and organismal level. A key focus of our studies therefore is elucidating the inputs that rewire metabolism during infection. Ageing has profound effects on metabolism and the response to microbial infection and therefore provides an optimal angle to begin dissecting these inputs. We use the genetically tractable human parasite Toxoplasma gondii as a model pathogen and combine advanced live cell imaging, protein and metabolite profiling, and genomic screens with molecular and biochemical approaches.
2. Research questions addresses by the group:
- How do organelles sense and respond to intracellular pathogens?
During infection, certain organelles including mitochondria, peroxisomes, and lipid droplets traffic to and surround microbes, yet we do not understand the signals that drive the organellar response, nor how they change in aging or differing metabolic states.
- How is the metabolism of a host cell or organism rewired to prevent pathogens from accessing nutrients important for their growth?
Intracellular microbes are limited to the nutrient pools of the host and therefore host metabolism is inextricably linked to pathogen proliferation. We know little about the underlying mechanism by which it does so, nor how physiological changes that profoundly affect metabolism, such as ageing, affect this relationship.
- How does the nutrient scavenging behavior of a pathogen differ in different hosts?
Microbes like the parasite Toxoplasma gondii can grow in practically in any mammalian host of any age, but we know little of the nutrient sensing mechanisms and acquisition strategies that give the parasite its metabolic versatility.
3. Possible projects:
- Investigating the impact of ageing-related mitochondrial dysfunction on susceptibility to microbial infection.
- Studying how ageing influences the metabolic host-pathogen interaction.
- Determining whether ageing-related susceptibilities to microbial infection are detectable at the cellular level.
4. Applied methods and model organisms:
Applied methods will depend on the nature of the project, but the possibility of approaches we will use are multidisciplinary:
- Imaging: live microscopy and electron microscopy
- Biochemical: approaches to allowing the purification and analysis of whole organelles (from in vivo and in vitro samples)
- Genomic: we utilize CRISPR/Cas9 engineering to make genetic modifications in mammalian and Toxoplasma cell lines. We also harness the power of CRISPR by performing CRISPR/Cas9 loss-of-functino screens.
- Models: As our model pathogen we use Toxoplasma gondii, a human parasite that is genetically tractable and from the same family as the causative agent of malaria. To determine whether the discoveries we make in vitro are also relevant in vivo, we will use and generate mouse models.
5. Desirable skills and qualifications:
Candidates passionate about metabolism and microbes and with prior experience(s) in cell culture, CRISPR/Cas9-mediated gene editing, protein and RNA analysis, imaging, and biochemistry are encouraged to apply for this position.
- Pernas, L., Bean, C., Boothroyd, J.C., and Scorrano, L. (2018). Mitochondria restrict growth of the intracellular parasite Toxoplasma by limiting its uptake of fatty acids. Cell Metabolism. 27(4):886-897. PMID: 29617646 (*selected for preview: Zuzarte-Luis V, Mota MM, Cell Metab., 27(4):708-709. PMID: 29617637)
- Pernas, L. and Scorrano, L. RevAMPing Mitochondrial Shape to Live Longer. (2017) Cell Metabolism. 26(6):805:806. PMID: 29211978
- Pernas, L. and Scorrano, L. (2016) Mito-morphosis: mitochondrial fusion, fission, and cristae remodeling as key mediators of cellular function, Annu. Rev. Physiol. 78, 505-31. PMID: 26667075
- *Pernas, L., Adomako-Ankomah, Y., Shastri, A.J., Ewald, S.E., Treeck M,Boyle, J.P., and Boothroyd, J.C. (2014). Toxoplasma effector MAF1 mediates recruitment of host mitochondria and impacts the host response. PLoS Biology. 12:e1001845 PMID: 24781109 (*selected for synopsis: Sedwick C, PLoS Biol., 12:e1001846, F1000 Prime Article)
- Pernas, L., Ramirez, R., Holmes, T.H., Montoya, J.G., and Boothroyd, J.C. (2014). Immune-profiling of pregnant Toxoplasma-infected US and Colombia patients reveals surprising impacts of infection on peripheral blood cytokines. J Infect Dis. 210, 923-31. PMID: 24664173