Abstract: The present invention relates to allergy field. Several independent groups have recently investigated the implication of PCSK9 on inflammation and sepsis but none of them have determine its impact on allergies and/or asthma which is a global health burden. Inventors have obtained preliminary data on wild-type (PCSK9+/+) or PCSK9-deficient mice (PCSK9 ?/?) and shown that, under basal condition and in the absence of a particular stimulus, PCSK9 deficiency significantly increases the percentage of regulatory T cells in the spleen, the mesenteric lymph nodes and Peyer's patches. Moreover, inventors have shown the effect of allergic challenge Non primary human bronchial epithelial cells on PCSK9 expression and secretion. Very interestingly, their first results obtained by Q-PCR showed that HDM and LPS increase PCSK9 mRNA levels. Accordingly, the present invention relates to inhibitors of PCSK9 for use in the treatment of asthma and/or allergic disease, such as food allergy.

Abstract: The present invention relates to a method of treating allergic asthma in a subject in need thereof comprising a step of administering to said subject a therapeutically effective amount of a polypeptide comprising or consisting of a biologically active fragment of the house-dust mite Dermatophagoides pteronyssinus Der p 2.1. Inventors have used a model allergy in a severe asthma allergic (mouse Balbc). They have surprisingly found that when they injected twice the polypeptide derp2.1 in the mouse model after a third asthma attack, the mouse presents a respiratory improvement, reduction of neutrophils and eosinophils in the broncho-alveolar lavage (BAL), an increase of regulators lymphocytes T and reduction of natural killer cells in the BAL. Thus, the polypeptide derp2.1 is a new tool to treat the allergic asthma by a restoration of lung function and reduction of inflammatory environment.