Distribution of allergen specific cells in human effector and memory T cell subsets
Research area: Cellular Immunology
Group leaders: Federica Sallusto
Status: In progress
Allergic sensitization occurs early in childhood upon allergen encounter in persons who have an inherited atopic predisposition. Environmental factors, route, period, and dose of allergen encountered influence the development of the allergic immune response. In the case of allergic individuals, T cell responses show a preferential Th2 phenotype that leads to the production of IgE antibodies, while non-allergic individuals respond to allergens with IgG production and a balanced Th1/Th2 phenotype. IgE is the least abundant class of immunoglobulins but can elicit immediate and strong inflammation through activation of mast cells and basophils via the high affinity receptor FcεRI. We are revisiting the response studying the dynamics of antigen responding CD4 T cells upon natural exposure to allergens in allergic and non-allergic donors, both in and out of allergy season. We are using novel high through put cellular screening approaches to dissect in great detail the phenotype and function of T cells responding to seasonal allergens, like ragweed and timothy grass, or to perennial allergens, such as house dust mite. We are comparing allergic to non-allergic donors to define frequency, class, and distribution in different subsets of the allergen-specific T cells. Since both phenotype and function are related to the location of the antigen challenge, the type and strength of costimulation and cytokines seen during T cell priming, this project will give us insights into the process of sensitization and clinical manifestations which are associated with different types of allergens.