Sci Immun: Scientists find T-cell subgroups that reduce risk of respiratory allergies and asthma

Introduction: It is well known that genetics and the environment are the two main causes of allergies and asthmaBut how allergies and asthma begin and develop remains a mysteryIn a recent article published in the journal ScienceImmunology, researchers identified a previously unknown subgroup of T-cells that can control the development of allergies and asthma, raising new hopes for allergy and asthmapreventionand treatmentthe world is full of dust mitesDo some cleaning and you may stir up someSince everyone has immune cells that respond to common allergens, such as house dust mites (HDM), most of us have no allergy symptomsdespite this, many people still experience typical allergy symptoms: sneezing, runny nose, itchy nose, swellingOthers have a more severe response: life-threatening asthma attacksIn order to treat allergies and asthma, researchers need to understand the root causes of allergies and asthma so that they know exactly what separates these patients from healthy peoplein a new study published June 12, 2020 in the journal Science Immunology, scientists at the La Jolla Institute of Immunology (LJI) provide a clue as to why non-allergy populations do not react strongly to indoor dust mitesThey found a previously unknown t-cell subgroup that controls allergic immune responses and the development of asthma to cope with indoor dust mites and other possible allergens"We found new immunocellular subgroups and new therapeutic opportunities, which may be an unknown mechanism that explains why healthy people do not develop inflammation when inhaling allergens," said DrGregory Seumois, co-lead, lecturer and director of lJI Sequencing Core and New Research"This study highlights the power of the unbiased single-cell genomics approach to revealing the power of new biology," said DrPanduranganVianand, a professor at LJI Professor and senior author of the new studyThethe study, conducted in the Vijayanand laboratory, is based on expertise in linking gene expression to disease developmentThe team also used the Immune Epirestdatabase, a resource led by LJI that contains information on how the immune system interacts with allergens such as housing dust mites (HDM)Whyis a house dust mite? These tiny creatures are hard to avoid, which means that almost everyone is exposed to house dust mitesEven in people without HDM allergies, the immune system may react in some way as it learns to recognize HDM moleculesThis makes HDM a useful model for studying the causes of allergies and asthma attacksThe LJI team used a technical part of the "genome revolution" tool library, called single-cell RNA-seq (or single-cell transcriptional histology), to accurately observe the reactions of T-cell-specific genes and molecules to HDM allergensThey tested the cells of four groups: asthma and HDM allergy patients, asthma patients without HDM allergies, only HDM allergy patients, and healthy subjectstheir analysis showed that in the blood of HDM allergic asthma patients, an auxiliary Group of HDM reactive cells called leukocyte interleukin (IL)-9 Th2 expression is more common than in patients who are allergic to HDM onlyFurther analysis showed that these IL9-TH2 cells were rich in a group of molecules/genes, increasing their toxic potentialIn other words, these specific T cells can kill other cells and trigger inflammation, in contrast, the other part of the T-cells was more prominent in non-allergy subjects These T cells express a "interferon response signal" and are rich in a gene that encodes the TRAIL protein The work done by Sumova and his colleagues suggests that TRAIL may be important because it inhibits the activation of auxiliary T cells this finding may mean that people with this particular cell population may have fewer T-cell-driven inflammation in the hdM allergen response Finally, this can provide a clue as to why some people develop allergies and asthma while others do not "Now, if functional studies confirm this inhibition, we're curious about whether there's a way to activate these T cells or induce them to multiply in people with asthma or allergies, and we can't take action on these cells before we have an asthma attack," said Sumova for example, genomics studies like this may one day help identify in children with at risk of asthma and allergies Early detection can open the door to the preventive effects of immune cells before allergies and asthma occur researchers say that while much research is needed in the future, the transcription method used in this study could accelerate future studies of asthma and allergies, the first large-scale single-cell RNA-seq transcription already conducted by LJI, and that much progress has been made