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07 Mar 2023

Unlocking the secrets of our immune system: T cells in the lungs

As new variants continue to emerge with COVID-19, raising concerns about vaccine efficacy and public health, a recent paper has examined the current scientific knowledge on how T cells work to recognise and fight these ever-evolving strains.  

Published in Nature Reviews Immunology the paper looked at the leading discoveries in immunology research and concluded that specific T cells that normally reside in organs have divergent potential, and can provide greater long-term protection against localised infection or produce rapid inflammation. 

Author of the paper University of Melbourne Professor Francis Carbone said his analysis shows that while local T cells would normally be expected to be the most effective in fighting infectious agents, like the virus responsible for COVID-19, those in the lungs appear predisposed to abandon the tissue, which would reduce long-term immunity in that organ.  

“For an unknown reason, T cells in the lungs aren’t very good at sticking around to protect against future infection like we find in other parts of the body,” Professor Carbone said.  

“This feature may have specifically evolved to limit immune related organ damage evident in the worst cases of COVD-19, even if it means a trade off with less than bullet-proof immunity.  

“Given the ability of T cells to respond rapidly to infection, we need to better understand their behaviour within the respiratory system, especially in settings that support their long-term survival.” 

Professor Carbone said the discoveries have important implications not only for public health but for vaccine development.  

“Vaccines work by exposing our immune system to a harmless form of a virus or bacteria, which then triggers an immune response to develop immunity against that virus.  

“T cells are the most versatile immune components when it comes to dealing with emerging variants, so by understanding how T cells behave in the lung, we’ll be able to develop vaccines that are more effective when it comes to tackling COVID-19.” 

Peer review: Nature Reviews Immunology