Dr Praveena Thirunavukkarasu is a Group leader at the Biomedicine Discovery Institute and currently an NHMRC EL1 Investigator fellow (2026-2030). She was previously an Australian Research Council DECRA fellow (2023-2025). After completing her M.Sc. at Madras University, India, Dr. Thirunavukkarasu secured two highly competitive international scholarships to pursue her PhD at Monash University. She gained her PhD in 2017 in Biochemistry and Molecular Biology, and her research was focused on elucidating the molecular mechanism of recognition of lipid-based antigens by a new class of Natural Killer T (NKT) cells in humans termed atypical NKT cells. She then joined the Monash Biomedicine Discovery Institute as a Research Fellow under the mentorship of Professor Jamie Rossjohn FRS to further explore the recognition mechanism of lipids produced in the human gut microbiota by NKT cells.

Dr Thirunavukkarasu’s international standing in the field of structural immunology is evidenced by her original publications in highly reputed journals, including Nature, Science, Nature Communications and Proceedings of the National Academy of Sciences USA. Her ground-breaking first-authored work published in the prestigious journal Nature (2021) unravelled the mechanism by which lipids produced by the gut microbe, Bacteroides fragilis, are presented by antigen-presenting cells and are recognised by NKT cells, thus shaping the host’s immune response. The significance of her work has been highlighted by commentaries and also has attracted media attention, including featured articles in MedicalXpress, EurekAlert! and ScienceDaily.

Dr Thirunavukkarasu leads a team with a vision to transform our understanding of T-cell immunity in the context of the gut microbiome-NKT cell axis.

An unconventional T cell subset termed Natural Killer T (NKT) cells could recognise lipid-based antigens (Ags) upon presentation by the non-polymorphic MHC class 1-like molecule CD1d. Little is known about the spectrum of lipid Ags presented by CD1d and their mechanism of activation of NKT cells, as this is crucial to manoeuvre their biological outcomes. Notably, NKT cells have great implications for autoimmunity, microbial immunity and mucosal immunity. Emerging evidence suggests that the gut microbiota comprising a large number of symbiotic microbes plays a crucial role in shaping the mammalian host’s T cell-mediated immune responses in the context of NKT cells.

Our team focuses on this unchartered area of T cell immunity driven by human gut microbiota-produced lipids. We aim to address a few major fundamental questions: (1) What is the breadth of diverse CD1d-specific lipid Ags produced by the gut microbiota? (2) What molecular factors govern the presentation of these produced lipid Ags? (3) How are these lipid Ags recognised by TCRs and modulate T cell immunity? Using multidisciplinary approaches including molecular biology, protein chemistry, X-ray crystallography, cellular immunology and various biophysical techniques, we aim to address the role of lipid Ags in T cell immunity towards the ‘Microbiome-NKT cell’ axis.

Ultimately, our research seeks to uncover a molecular-level understanding of the presentation and recognition of gut microbiota-produced lipids by NKT cells, thus providing a rationale for the design of drugs to treat inflammatory bowel diseases.