Exploring the Immunomodulatory Effects of Agaricus bisporus Strains Using In Vitro and In Vivo Murine Models

Background/Objectives: This study evaluated the immunomodulatory effects of multiple A. bisporus strains, applying both in vitro and in vivo murine models and aiming to identify specific strains with immune modulatory properties. Methods: Sixteen A. bisporus strains were screened in a dendritic cell (DC)–CD4+ T cell co-culture system, using cells from female C57BL/6 mice, for their capacity to induce Th1- and Th17-associated cytokine production. Based on these cytokine profiles, three potent strains (MES01856, MES01706, MES01637), one non-responder strain (MES01515), and the commercially available A15 strain were selected for investigation in a murine model, an ovalbumin (OVA)-induced allergic food allergy. In these sensitized female C3H/HeOuJ mice, ear swelling, anaphylactic shock scores, OVA-specific IgE, and serum mouse mast cell protease-1 (mMCP-1) were measured following an allergen challenge. Additionally, IL-6, IL-10, and TNF-α secretion from bone marrow-derived dendritic cells (BMDCs) was measured after stimulation with these A. bisporus fresh ground extracts (FGEs). Results: In vitro, increases in cytokine production were obtained, with MES01856, MES01706, and MES01637 identified as the most potent inducers. In vivo, OVA sensitization elicited significant ear swelling and elevated shock scores in the mice. Dietary supplementation with MES01706 or MES01515 significantly reduced ear swelling, while the other strains resulted in non-significant changes. No significant changes were observed in shock scores, OVA-specific IgE, or mMCP-1. Conclusions: Multiple different A. bisporus strains elicit specific immunomodulating effects both in vitro and in in vivo murine models, identifying the MES01706 strain as one with the highest potential to beneficially affect immune function.