A multidisciplinary study of allergy : mouse models, immune modulation and lifestyle

Allergic diseases affect a substantial part of the global population. Although extensive studies have elucidated the allergic mechanism, no conclusive answer has yet been found that will prevent the onset of an allergic disease. Literature suggests that no single factor like a gene mutation, environmental factor or lifestyle component can be hold accountable for the allergic cascade. Therefore, the main goal of this research project was to use a multidiscipli¬nary approach to allergies, by combining information on the genetic components, lifestyles and in vivo and in vitro assessment of the immune cells involved in allergy.
The accomplishment of this multidisciplinary goal required knowledge on the genetic factors involved in the immunopathology of allergic diseases, but also immunological and cell biological knowledge. In addition, we investigated the influence of environmental factors on the allergic response which also required knowledge on sociology and economics to assess involved lifestyle factors. Within the multidisciplinary research areas, allergic responses are studied at multiple levels. For example, the genetic differences can be studied by means of mice with different genetic backgrounds (BALB/c, STS/A, C57BL/6) or in knock-out (CD4 or CD8 knock-out) or transgenic (IL-5 transgenic) mice. These differences in the genetic background on their turn have an effect on the expression of the allergic disease characteristics. Examples of the assessed allergic characteristics comprise antigen-presentation by specialized antigen-presenting cells, the presence of T helper 2 cells, the involvement of Th2 produced cytokines like IL-4 and IL-5, and the isotype switching of B cells towards allergen-specific IgE. Alterations of the allergic characteristics were studied by the use of in vitro cultures of human peripheral blood mononuclear cells (PBMC) that display all above mentioned characteristics when they are properly isolated, cryopreserved and cultured. These alterations were elicited by the use of heat-treatment of allergens or the exposure to fungal derived proteins or polysaccharides. Taken together, these different levels within the allergic individual can on their turn be influenced by environmental and nutritional factors. To study this, lifestyle factors have been assessed by the use of a personalized internet-based questionnaire and these data were thereafter linked to allergen-specific immunoglobulin levels. To further stress the importance of multilevel research within a multidisciplinary study, a more detailed description of the separate chapters within this thesis are combined with their major results, and finalized with future perspectives.