The main research axis of the laboratory of experimental allergology (LEA) is house dust mite allergy. In this context, the two principal objectives are the study of the allergenicity of the house dust mite allergens showing proteolytic activity as well as the design of new immunotherapeutics against this allergy.
Out of the twenty identified mite allergens, four of them are proteases and their proteolytic activity could partly explain why these enzymes induce allergic response. Consequently, LEA more particularly investigates the action of these proteases on two cell types: the airway epithelial cell because this is the first host-cell in contact with this aeroallergens and the dendritic cell as, after the crossing of the epithelial barrier, the allergens are taken up by this cell to be presented to adaptive immune system. In the research, we identified and characterized the cellular receptors targeted by these proteases as well as the signalling pathways triggered after this activation.
Thanks to genetic engineering, it is now possible to create hypoallergenic variants of mite allergens which maintain T-cell reactivity but do not display IgE reactivity. LEA successfully expressed several recombinant forms of these mite allergens. The therapeutic as well as the prophylactic potential of these compounds is evaluated in a murine model of house dust mite allergy. The induced immune responses are characterized at the level of the induction of specific antibodies but also at the level of the cytokine profile and the airway inflammation. In these experiments, several adjuvants as well as delivery systems are tested to optimize the anti-allergic immune responses. In this context, LAE focused the research on the use of probiotic bacteria as their immunomodulatory properties are appropriate to prevent or to revert allergy. These commensal bacteria can be considered as natural adjuvants but can be used as delivery vectors of modified allergens.