In a new study, researchers have discovered new immune cells that may lower airway allergy and asthma risk.
They’ve uncovered a previously unknown subset of T cells that may control allergic immune reactions and asthma from ever developing in response to house dust mites—and other possible allergens.
This new group of cells could be one, out of many unknown mechanisms, that explains why healthy people don’t develop inflammation when they breathe in allergens.
The research was conducted by scientists at La Jolla Institute for Immunology (LJI).
In a new study, the team focused on how the immune system interacts with allergens like house dust mites.
Why house dust mites? These microscopic critters are hard to avoid, which means nearly everyone has been exposed.
Even in people without a house dust mite (HDM) allergy, the immune system is likely to react in some way as it learns to recognize HDM molecules.
This makes HDM a useful tool for studying what causes allergies and asthma attacks.
The team tested cells from four groups of people: people with asthma and HDM allergy, people with asthma but no HDM allergy, people with only HDM allergy, and healthy people.
Their analysis suggests that a subset of helper T cells, called interleukin (IL)-9 Th2 expressing HDM-reactive cells, is more prevalent in the blood of people with HDM-allergic asthma compared with those who are only allergic to HDM.
Further analysis suggested that those IL9-TH2 cells are enriched in a group of molecules/genes that increased the cytotoxic potential of those cells. In other words, those specific T cells could kill other cells and drive inflammation.
In contrast, another subset of T cells stood out in the non-allergic people. These T cells express an “interferon response signature” and were enriched for a gene that encodes a protein called TRAIL.
This finding may mean that people with this specific cell population could have less T-cell driven inflammation in response to HDM allergens.
At last, this could provide a clue to why some people develop allergies and asthma while others do not.
The team says if functional studies confirm this dampening effect, they are curious if there is a way to boost the activation of these T cells or induce their proliferation in asthmatic or allergic people.
Genomics studies like this one may someday help identify children at risk of developing asthma and allergies.
Early detection could open the door to preemptively acting on immune cells before the development of allergy and asthma.
One author of the study is Grégory Seumois, Ph.D., instructor and director of LJI’s Sequencing Core.
The study is published in Science Immunology.
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