β-glucans show promise as adjuvants for allergy treatment

A recent study carried out by a research team from the Paul-Ehrlich-Institut investigated the immunomodulating properties of β-glucans. These are natural sugar compounds found in bacteria, fungi and grains. The results indicate that β-glucans can target the immune system and modulate pro-inflammatory responses. Their potential to suppress allergic reactions and offer new approaches to allergy treatment is particularly promising. The research was published in the International Journal of Molecular Sciences.

β-glucans’ potential as an adjuvant is particularly promising. One use for adjuvants is as a vaccine ingredient to strengthen the immune response and thus strengthen vaccination protection.

Adjuvants are also used for therapeutic allergens, which assist in influencing (modulating) the immune system in a way that contributes to reducing the allergic reactions and to helping the patient adapt to the allergen.

Allergen-specific immunotherapy involves researching adjuvants in order to modulate allergen-specific (known as Th2) immune reactions in a targeted manner and to re-establish tolerance toward certain allergens.

A research group led by PD Dr. Stefan Schülke, head of the Research Allergology Division at the Paul-Ehrlich-Institut conducted a study to test six different β-glucans, including zymosan and its variants, as well as other known β-1,3 glucans for their influence on the immune system.

The group found that these substances activate different immune cells and influence the release of certain pro-inflammatory substances in different ways. Zymosan and β-1,3 glucan in particular were able to reduce the production of inflammatory markers in the experiments and showed a promising ability to suppress allergy-related immune responses.

The results of the study are promising and could help to develop new therapeutic approaches for the treatment of allergies. In the future, β-glucans could play an important role in preventing allergic reactions and controlling the immune response in a targeted manner.

Highlighted results in detail

The study analyzed both immunological (receptor activation, cytokine secretion, T-cell modulation) and metabolic parameters (metabolic state) in dendritic cells—specific immune cells—derived from the bone marrow of mice. It was found that all of the β-glucans tested activated the C-type lectin receptor (CLR) Dectin-1a, while the “Toll”-like receptor 2 (TLR2) was particularly strongly triggered by zymosan. The β-glucans also led to different degrees of cytokine secretion and activation of cell metabolism in the dendritic cells.

A more detailed study of the β-glucans zymosan, β-1,3 glucan and β-1,3/1,6 glucan showed that these β-glucans increased the activation of the dendritic cells and upregulated the important surface markers CD40, CD80, CD86 and MHCII to varying degrees. Another finding: the cytokine secretion induced by β-glucans was partly dependent on the activation of the intracellular Dectin-1 adapter molecule Syk.

In co-cultures of dendritic cells with mouse T cells sensitized to the major birch pollen allergen Bet v 1, four of the β-glucans tested suppressed allergen-induced IL-5 secretion. However, only zymosan and β-1,3 glucan significantly reduced the secretion of interferon gamma (IFNγ). This suggests that the β-glucans tested have different impacts on the ability of dendritic cells to target T cells for allergens.

Provided by
Paul-Ehrlich-Institut