A vaccine manages to block food allergens and pollens

An international team of researchers led by the Technical University of Denmark (DTU)in collaboration with the Complutense University of Madrid (UCM), IBIMA-BIONAND Platform (Málaga) and specialist doctors from the Vall d’Hebron and Clínic hospitals in Barcelona, ​​has developed a vaccine based on RNA that opens the door to treating multiple allergies with a single treatment, since it has managed to neutralize the effects of both food and pollen allergens in an animal model.

The study, which has just been published in the journal ‘Nature Communications’, presents an innovative immunotherapy platform specifically aimed at the allergy of polysensitized individuals against multiple homologous allergens, common in a large number of foods.

Currently, there is no simple treatment for this type of multiple allergies. In the clinic, if it is not possible to identify the primary source of sensitization, it is recommended in most cases to avoid all the foods involved, a strategy that is difficult to maintain when the allergenic sources are numerous and their accidental ingestion can lead to severe allergic reactions.

The only option with long-term curative potential is classic immunotherapy, which as they remember is “a long process that does not always guarantee complete protection” and which, in addition, can cause adverse reactions during treatment, which leads to a high dropout rate.

“We needed to design a therapy capable of attacking several allergies at the same time, quickly and safely,” he explains. Esperanza Rivera-de-TorreDTU researcher and one of the main authors of the study. To do this, the team used a consensus allergen, specifically they designed an artificial protein that represented the structural “average” of the entire family of allergens responsible for cross-reactivity.

Although this molecule does not exist in nature, it contains the immunogenic elements common to the most relevant members of this family, which makes it possible to induce an immune response against multiple sources with a single intervention. Its characterization was carried out in the group of Allergens from the Faculty of Chemical Sciences of the UCM.

On the other hand, the researchers used messenger RNA technology to administer this allergen, following an approach similar to that used with COVID-19 vaccines. In this case, RNA acts as a ‘Trojan horse’. The body’s own cells synthesize the allergen in a controlled manner inside, producing the offensive response of the immune system on the molecules responsible for the allergy, blocking their ability to trigger an allergic reaction, and instead favoring a protective immune response.

Administration is safe in an animal model

Experiments carried out in animal models demonstrated that this immunotherapy was capable of inducing antibodies capable of recognizing and block allergens from different food sources and pollenseven surpassing the protection obtained with immunotherapy with individual natural allergens. Furthermore, the administration of the treatment was safe in the models studied, without causing adverse reactions during immunization.

Although in a severe allergy model the treated animals still showed certain symptoms after exposure to the allergen, their immunological profile suggests that optimization of the formulation and administration route could allow, in the future, to develop an effective therapeutic solution for these patients.

Together, this work opens a new avenue for the development of broader, safer and customizable immunotherapies, and reinforces the role of international collaboration and the Complutense University of Madrid in cutting-edge biomedical research.

What are allergens

These allergies affect more than seven million people only in Europe and this approach could lay the foundations for the development of future therapies against other complex allergies.

The immune system of the allergic individual overreacts to generally harmless proteins, called allergens. The symptoms can manifest themselves in a mild way, or lead to more serious symptoms, with the patient potentially experiencing anaphylactic shock. Allergens are generally proteins that are structurally conserved between different plant species, which means that a person sensitized to a food may suffer an allergy to other foods or pollens through homologous allergens, despite having never had prior contact with sources.

This is the case of the so-called non-specific lipid transport protein (nsLTP) allergic syndrome, one of the most frequent forms of food allergy in southern Europe. The main peach allergen is perhaps the reference for this family of proteins, which has up to 40 different homologs in numerous fruits, nuts, legumes and pollens.