It is well established that allergen-specific immunotherapy (commonly known as allergy shots) is associated with changes in the activity of specialized cells recognizing specific allergen, referred to as immune memory cells (T and B cell repertoires). The non-specific responses (innate immune response) represent another crucial element of our body's immunity. The innate immune responses consists of various subsets of cells, including monocytes, dendritic cells, and innate lymphoid cells (ILCs), constituting the body's first line of defense against inviding environmental factors (including allergens).
It was considered that innate immune responses, unlike adaptive repertoires, lack immunological memory. Recently, however, it became clear that these cells can be trained through the activating factor and, in a way dependent on complex genetic mechanisms, acquire the so-called trained immunity or tolerance. In fact, these mechanisms prepare cells for a stronger reaction to secondary challenge (trained immunity) or a much weaker reaction to maintain tolerance (trained tolerance). Therefore, innate immune memory should be recognized as a functional adaptation that prepares cells for more effective responses to invading stressors.
In the latest issue of the Journal of Allergy and Clinical Immunology (JACI, the highest-ranked journal in the field of allergy and asthma research), members of the Department of Regenerative Medicine and Immune Regulation, in collaboration with the Swiss Institute of Allergy and Asthma Research, University of Zurich (SIAF) described longitudinal changes in the systemic innate immune cell repertoires in allergic individuals in the course of allergen-specific immunotherapy to birch and grass pollens (https://doi.org/10.1016/j.jaci.2020.08.042). The published report is the first such comprehensive evaluation of phenotype in innate immune cell repertoires. The authors found that allergen-specific immunotherapy affects the response potential of analyzed cells. Notably, this paper provides the first evidence of a trained allergen tolerance in the course of allergy shots. The Authors believe that presented results will help to better monitor effectiveness of allergen-specific immunotherapy. However, further studies are needed to better understand complex molecular mechanisms controlling observed phenomenon, and both groups will collaborate to elucidate them.
The work was also selected by the editor of the journal and featured in "the Editors' choice" section (https://doi.org/10.1016/j.jaci.2021.03.022)
