In Vitro TLR4 Stimulating Bioactivities of Amylase/Trypsin-Inhibitors from Wheat (Triticum aestivum L.) Bred from 1891 to 2010

Wheat amylase trypsin inhibitors (ATIs) are prominent allergens in Baker’s asthma and contribute to innate inflammation in non-celiac wheat sensitivity (NCWS), linking them to metabolic and autoimmune diseases. Their tetra-, di-, and monomeric forms, stabilized by disulfide bonds, confer resistance to digestion, baking, and heating. Although proteomic studies reveal minor variation in ATI subtypes among cultivars and major variation among species, the influence of environment and wheat genotype on ATI levels and TLR4-stimulating activity remains unclear. We assessed the effect of the environment on the in vitro inflammatory bioactivity of ATIs extracted from 60 German wheat genotypes focusing on breeding over time between 1891 and 2010, and cultivation across three climatically distinct years. We found considerable genotype-dependent variation in ATI bioactivity that did not correlate with ATI subtype abundance, and observed no consistent difference between old and modern cultivars. ATIs from samples grown in 2019, a warm and dry year, showed reduced TLR4 activity, highlighting the significant impact of environmental conditions on inflammatory ATI bioactivity.