T cells bully influenza virus into submission

Australian researchers are at the forefront of developing a vaccine which could lead to lifelong immunity against the influenza virus.

A Melbourne-based team of international researchers have spent the last four years studying human T cells to determine how they recognise and then attack the new mutant strains of influenza that infect up to 5 million people around the world every year.

The use of crystallography technology at the Australian Synchrotron has been ‘absolutely crucial’ to the research, according to senior author Dr Stephanie Gras of Monash University, in scrutinising T cell structure and working out how they manage to identify new mutant flu strains and then bully them into submission.

The research has been published in Proceedings of the National Academy of Sciences and was led by Associate Professor Katherine Kedzierska of the Peter Doherty Institute for Infection and Immunity at the University of Melbourne. She describes their discoveries as a “game changer in flu research”.

“Previous research has shown us that T cells provide universal, protective immunity to influenza, but we didn’t know why or how until now,” she said.

Using the Australian Synchrotron allowed the researchers to examine the T cells one cell at a time and see how they react to both viruses they had previous exposure to as well as new mutant strains. This technology has never previously been used in influenza research.

Previous research had determined that about one seventh of people naturally have a universal immunity to influenza. They still get infected but symptoms are mild and easily managed; “the difference between a runny nose and being bedridden”, according to Associate Professor Kedzierska. Using cutting-edge single-cell technology, the researchers have been able to examine the immune response of those who have this natural immunity.

 “By using state-of-the-art procedures, this study enabled us to dissect the immune response to understand how this immunity occurs,” Associate Professor Kedzierska said.

The ultimate goal is lifelong immunity to the influenza virus through a one-shot T cell-mediated vaccine. This could mean the difference between life and death for the 3 to 5 million people who are infected annually by influenza, according to World Health Organization estimates.

The next challenge is to find the receptors in people who have natural immunity and elicit a similar response that can be isolated and developed into a universal vaccine.

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