Abstract: The present invention relates to the treatment of type 2 inflammation or mast-cell dependent disease. The inventors showed that, when exposed to domestic allergic alarms, activation of TRPV1+Tac1+ nociceptor-MRGPRB2+ MC sensory clusters might represent a key early event controlling the development of frequent mast cell-dependent allergic disorders. The human ortholog of MRGPRB2 (MRGPRX2) can thus be a good target to treat type 2 inflammation or mast cell-dependent disorders. Thus, the present relates to a MRGPRX2 inhibitor for use in the treatment of a type 2 inflammation or mast cell-dependent disorders in a subject in need thereof.

Abstract: The present invention relates to methods and kits for detecting basophil cells activation. The inventors showed that fluorescent avidin binds to basophil cell surface upon degranulation and that this probe can be used to monitor basophil degranulation More specifically the present invention relates to methods for monitoring of basophil degranulation using avidin-based probes. The method of the invention described here allows to measure direct basophil degranulation following Fc?RI crosslinking with allergen. This method provides a direct measurement of degranulation by staining exteriorized granules and unambiguously detects activated basophils degranulated. The extent of the degranulation can be directly deduced from the intensity of fluorescence of fluorochrome-labelled avidin measured on basophils. When applied to allergic patient samples the avidin-based method detected efficiently specific basophil responses.

Abstract: Non-human transgenic animal models and cells derived therefrom are provided for RabGEF1 function. RabGEF1 is a negative regulator of Fc?RI-dependent mast cell activation and T cell activation via the T cell receptor and a lack of RabGEF1 results in the development of skin inflammation in vivo. The mast cells derived from such animals exhibit enhanced Ras-mediated signaling and functional responses when activated through high affinity IgE receptors. These cells show significant potentiation of IgE and antigen-dependent secretion of 3 classes of mast cell mediators, providing a useful source of mast cells for screening assays.