July 11, 2021  Print

For the first time, a team of WIMR scientists have demonstrated an approach that can identify the parts of proteins that cause a highly specific immune response to SARS-CoV-2 (the virus that causes COVID-19).

The study that describes these SARS-CoV-2 specific peptides was recently published in Journal of Virology and featured on ABC News

The WIMR team used an analysis pipeline that integrates protein network analysis and open-access databases to identify 18 peptide immunogens (antigens that can elicit an immune response) that are specific to COVID-19, and tested them in recovered COVID-19 patients.

One of the lead authors on this study, Dr Eunok Lee said that by determining the important regions of SARS-CoV-2 proteins, the team was able to identify 18 peptides, or small protein fragments, specific to the virus.

“Defining the cellular response during and after COVID-19 is key to understanding the association between T-cell immunity and disease severity and determining duration of natural immunity. However, one problem we faced was that in 40% of people, this T-cell immunity is similar for SARS-CoV-2 and the seasonal human coronaviruses that cause common colds,” said Dr Lee.

Co-senior author and leading virologist, WIMR’s Professor Sarah Palmer said, “The 18 peptides that we identified are not genetically similar to seasonal human coronaviruses, and therefore allow for the detection of cellular immune responses that are absolutely specific to SARS-CoV-2. This makes them promising candidates to help us distinguish COVID-19 immune response from other, pre-existing coronavirus immunity.

“These specific peptides can elicit an immune response that allows us to then assess the SARS-CoV-2 specific T-cell immunity that has been generated as the result of either recovering from COVID-19 or vaccination against SARS-CoV-2.”

Dr Lee explained that, of these 18 peptides, the team now aims to pick the best ones that can elicit a highly effective immune response and, in the future, use these to develop an easily accessible ‘tool kit’ to measure SARS-CoV-2 specific immune response.

“We anticipate that this approach will ultimately be able to accurately predict COVID-19 immune response in 80% to 100% of the global population.
“In addition, these SARS-CoV-2 specific peptides are identified from viral proteins that are highly unlikely to mutate. Therefore, tests that use these peptides can detect a cellular immune response resulting from infection caused by the global SARS-CoV-2 variants that are emerging and currently circulating.

“This initial study provides a proof-of-concept that this immunoinformatics analysis pipeline can accurately identify peptides that are capable of eliciting an immune response. 

“This has the potential to not only help predict how an individual’s immune system will respond during and after COVID-19, but it can also help to assess how effective a COVID-19 vaccine will be in each individual,” said Dr Lee.

Professor Sarah Palmer said that the long-term goals of this research are two-fold.

“We aim to create a universal tool for measuring T-cell immunity. This could have global applications across a vast range of infectious diseases including influenza and HIV.

“In fact, my core research revolves around finding ways to stop the spread of HIV. So, for this research study, the team took an existing HIV analysis platform and re-worked it so that it could be applied to COVID-19.

“Secondly, once we have completed all stages of our research, we aim to make this analysis tool universally available online. It will be an important tool, and readily available for medical practitioners and researchers around the world to use now, and for any future viral outbreaks.”

Leading virologist and co-senior author on this study, WIMR’s Professor Tony Cunningham AO said, “Together we are now using these tools in two ways. Firstly we we are determining the exact long term immunity after natural COVID-19 and after immunisation for the disease. Secondly we are examining whether these peptides can be constructed and used as boosters to current vaccines where needed, perhaps in ageing or immunocompromised people. They will be particularly valuable in targeting variants which are able to evade existing vaccines.”  

The second stage of this research study is now underway.