Mucosally applied, ELLI-inactivated parasites for the treatment of allergies (MELLIPA)

For decades, allergic diseases have been on the increase in industrialized nations. The fact that infectious diseases are on the decline in these countries can be seen as an indication that the immune system is being activated incorrectly by environmental antigens or autoantigens. In humans, this is usually detectable through the induction of special IgE antibodies. In the case of a parasite infestation, these IgE antibodies play an important role in the immune response. They are mainly induced by certain helper cells (Th2 cells) of the immune system. The decline in parasitic diseases could thus lead or have led to the immune system being redirected towards other, actually harmless structures. For several years now, products have been available on the market that restore the natural balance in the immune system by artificially stimulating it with parasitic antigens (e.g. by balanced induction of Th1 and Th2-mediated immune cells). This is to avoid an overshooting of Th2-activated immune cells when they come into contact with harmless allergens and the associated increased formation of allergen-specific IgE antibodies.

In addition to these established standard therapies with biologicals or oral corticosteroids for more severe forms of inflammatory airway disease, local administration in the respiratory tract represents a promising alternative. The MELLIPA project aims to treat or prevent allergies in animal models by administering inactivated parasites. Parasites are inactivated using low-energy electron irradiation (LEEI) and then formulated and applied nasally via the mucous membrane. The irradiation ensures that the parasite preparation is no longer infectious or pathogenic potential emanates from the parasite preparation, but that there is sufficient immunostimulatory effect to restore the lost balance between Th1 and Th2-mediated immune responses. The project focuses on the parasite Toxoplasma gondii, whose native cellular material is highly active against various allergies and which, after LEEI inactivation, is administered mucosally.

The MELLIPA project is building on the CIMD project MucoRSV and the BMBF project APICOMPLEXA at the Fraunhofer IZI and is focusing on direct therapeutic application. 

MELLIPA is based on the collaboration between the Fraunhofer Institutes ITEM, ITMP and IAP, FEP and IPA.  The Department of Vaccines and Infection Models at the Fraunhofer IZI carries out the irradiation and the in vitro and in vivo validation of the irradiated parasites.