Dimitra Chatzileontiadou group
Anti-viral immunity: understanding the immune system actions when facing viral infections
Dr Demetra Chatzileontiadou leads a research team within the laboratory of Prof Stephanie Gras in the La Trobe Institute for Molecular Science (LIMS), La Trobe University. Her research focuses on identifying and characterising immune cell responses towards different pathogens, with a particular emphasis on HIV and SARS-CoV-2 viruses. Pathogens are part of day-to-day encounters that the immune system needs to deal with. How the immune system “sees”, recognises and eliminates viral infection is not fully understood. Viruses are able to mutate in order to escape the immune system surveillance. If we were to develop better vaccines and drugs, or even a vaccine against viruses like HIV, it is essential to understand the mechanism of viral recognition and viral escape prior to this. As such, to understand the immune system actions when facing viral infections we use multisdisciplinary approaches, including biochemistry, molecular biology, crystallography and cellular/functional assays.
Demetra has been awarded many highly competitive research grants and awards including the AINSE Early Career Research Grant for her leading work in collaboration with the Australian Synchrotron (2020), ASMR Small Research Grant (2021) and Large Collaboration Internal Investment Scheme Grant (LTU, 2021), for her leading work on COVID-19 research. She was also awarded with the La Trobe Institute for Molecular Science Miller Postdoctoral Travel Fellowship (2022), the Australian and New Zealand Society for Immunology Career Advancement Award (2022), and the Excellence in Research Engagement and Impact Award (LTU, 2023) and the Eppendorf EDMAN ECR award (2025).
Demetra’s work has resulted in high impact publications including in the journals Nature (2023), Immunity (2021), Cell Reports (2024) as lead author and has drawn wide international attention, with the one in Nature being top 1% most cited article by media in history, with an amazing altmetric score of 2959 and top 1% of Nature papers published.
Research Areas
SARS-CoV-2 virus is responsible for COVID-19 disease. Our work on SARS-CoV-2 has provided fundamental knowledge on the understanding of the T cell immune response to this new virus. We use biochemistry, crystallography, and cellular immunology to provide the molecular basis and better understanding of the impact of SARS-CoV-2 infection. We have published the first structures of SARS-CoV-2 epitopes presented by Human Leukocyte Antigen (HLA) molecules that are the target of killer T cells. We have been the first in the world to find association with asymptomatic COVID-19 profile and the mechanism of pre-existing immunity.
Our aim is to discover the molecular mechanisms behind prevention of severe disease upon viral infection, using SARS-CoV-2 as a model, to establish solid foundations for subsequent translational outcomes to improve human health. Revealing the molecular mechanisms by which HLAs impact the course of the disease, could explain, in part, the wide variation of immune responses not only to SARS-CoV-2 but also other viral infections.
Despite the dramatic life improvement provided by anti-retroviral therapy, HIV and AIDS are still health burdens; it is unquestionable and imperative to develop new treatments and ideally, a vaccine for this virus.
Our work focuses on a subset of individuals, named HIV controllers, known to control HIV infection and/or delay disease progression. Although HIV infection impacts on multiple facets of the immune system (including T cells, Natural Killer cells, Treg cells), the strongest genetic link to HIV control shown to date has been the expression of specific “protective” human leukocyte antigen (HLA) molecules and their associated potent T cell responses. Understanding such superior T cell responses at the molecular level, specifically the interaction between HIV peptides presented by HLA complexes and T cell receptors, is central for informing the development of vaccines or immunotherapeutics against HIV.
Publications
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