Tissue-resident immune cells are ready to fight infection

Researchers from the Peter Doherty Institute for Infection and Immunity have discovered that tissue-resident memory T cells — specialised immune cells that live in tissues such as the skin and lung — play an important role in protecting against infection. This is because they are ready to fight infection at the site of viral entry.

Through a series of laboratory experiments, a team led by Dr Laura Mackay and Professor Francis Carbone determined how these cells are mobilised into action, which could have the potential to transform how researchers design vaccines. This is in contrast to previous vaccine trials, which have focused on boosting the immune system’s antibodies or disease-fighting T cells in the blood.

“In our most recent study, we found that the signals required to generate these [tissue-resident memory] T cells were completely different to those required to generate immune cells in the blood,” Dr Mackay said. “By learning to control these cells, we can harness their protective function to prevent infectious diseases.”

Doherty Institute Director Professor Sharon Lewin said the notion of T cells in the tissue being totally different to T cells in blood completely changes the way we think about the immune response to viruses.

“For example, to block transmission of HIV, we want the immune system ready to go in the vaginal and rectal mucosa,” she said. “Tissue-resident T cells are likely to be a key factor in generating a local and effective response.

“This is an exciting piece of research with the potential to transform the way we think about the immune system and in designing future vaccine studies.”

The team will now test ways to convert T cells in the blood to tissue-resident memory T cells, and evaluate their therapeutic potential against a wide range of pathogens. Their latest research has been published in the journal Immunity.