Immune Cells in Old and Young

A world-first discovery has revealed special immune cells called ‘killer T cells’ in older adults, directed against influenza viruses, closely resemble those found in newborns and children, but struggle to recognise infected cells — a finding that unlocks the potential for the development of better vaccines and therapies tailored to different age groups.

Killer T cells (also known as CD8+ T cells) play a critical role in the immune system by eliminating virus-infected cells. While much has been studied about these immune cells in adults, little was known about how they evolve and function across the human lifespan — until now.

In a pioneering research published in Nature Immunology and led by the Peter Doherty Institute for Infection and Immunity (Doherty Institute) and UNSW Sydney, researchers employed cutting-edge technologies to examine killer T cells in different age groups — newborns, school-aged children, adults and older adults (60+ years) — to understand how age shapes our immunity to influenza viruses.

University of Melbourne’s Dr Carolien van de Sandt, a Senior Research Fellow at the Doherty Institute and first author of the paper, said the team uncovered unexpected similarities in T cell responses between newborns/children and older adults.

University of Melbourne’s Professor Katherine Kedzierska, Head of the Human T cell Laboratory at the Doherty Institute and senior author on the paper, said this research greatly contributes to our understanding of how immunity changes over an individual’s lifespan, and has the potential to significantly advance the field of vaccinology.

“Our findings suggest that if we want to boost killer T cells through vaccination, the timing may play an essential role to maintain these optimal killer T cells into old age,” said Professor Kedzierska.

“This study is a turning point for the research into ageing immunity. It has far-reaching implications and opens up new possibilities for the development of better vaccines and therapies tailored to different age groups.”


Carolien E. van de Sandt, Thi H. O. Nguyen, Nicholas A. Gherardin, Jeremy Chase Crawford, Jerome Samir, Anastasia A. Minervina, Mikhail V. Pogorelyy, Simone Rizzetto, Christopher Szeto, Jasveen Kaur, Nicole Ranson, Sabrina Sonda, Alice Harper, Samuel J. Redmond, Hayley A. McQuilten, Tejas Menon, Sneha Sant, Xiaoxiao Jia, Kate Pedrina, Theo Karapanagiotidis, Natalie Cain, Suellen Nicholson, Zhenjun Chen, Ratana Lim, E. Bridie Clemens, Auda Eltahla, Nicole L. La Gruta, Jane Crowe, Martha Lappas, Jamie Rossjohn, Dale I. Godfrey, Paul G. Thomas, Stephanie Gras, Katie L. Flanagan, Fabio Luciani, Katherine Kedzierska. Newborn and child-like molecular signatures in older adults stem from TCR shifts across human lifespan. Nature Immunology, 2023; DOI: 10.1038/s41590-023-01633-8

The Peter Doherty Institute for Infection and Immunity. (2023, September 25). Study finds immune cells in older adults resemble those in newborns and children, but fall short in virus detection. ScienceDaily. Retrieved September 25, 2023 from

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