Allergen relative abundance in several wheat varieties as revealed via a targeted quantitative approach using MS.

Food allergy has become a major health issue in developed countries, therefore there is an urgent need to develop analytical methods able to detect and quantify with a good sensitivity and reliability some specific allergens in complex food matrices. In this paper, we present a targeted MS/MS approach to compare the relative abundance of the major recognized wheat allergens in the salt-soluble (albumin/globulin) fraction of wheat grains. Twelve allergens were quantified in seven wheat varieties, selected from three Triticum species: T. aestivum (bread wheat), T. durum (durum wheat), and T. monococcum. The allergens were monitored from one or two proteotypic peptides and their relative abundance was deduced from the intensity of one fragment measured in MS/MS. Whereas the abundance of some of the targeted allergens was quite stable across the genotypes, others like alpha-amylase inhibitors showed clear differences according to the wheat species, in accordance with the results of earlier functional studies. This study enriches the scarce knowledge available on allergens content in wheat genotypes, and brings new perspectives for food safety and plant breeding.

Probiotics, prebiotics, and synbiotics: impact on the gut immune system and allergic reactions.

Probiotics and prebiotics, alone or together (synbiotics), can influence the intestinal microbiota and modulate the immune response. They may therefore be tools that can prevent or alleviate certain pathologies involving the gut immune system, such as allergies for which no treatment is yet available. This review focuses first on the definitions of probiotics, prebiotics, and synbiotics and key cells in the gut immune system. It then discusses their effects on mucosal immune stimulation. Experimental findings suggest that different probiotic species have similar effects on innate immunity by improving the mechanisms of pathogen destruction. On the contrary, their impacts seem to be variable on the adaptive immune system. Prebiotics can also exert an influence on the gut immune system via the stimulation of the autochthonous bacteria metabolism. Finally, this review focuses on the effects of food supplements on allergy. Different studies performed in humans or rodents have supported a potential role for selected probiotics and prebiotics in reducing some allergic parameters. Probiotic effects on allergy treatment are unclear, especially in human studies. However, they are potentially effective at short-term for prevention when they are administered in perinatal conditions. A clinical study performed with an infant cohort revealed a beneficial effect of prebiotics in preventing allergic manifestations at long-term. Further studies are nonetheless essential to confirm these findings. Food supplements offer potential tools for the prevention or treatment of allergy, but insufficient evidence is available at present to recommend their use in clinical practice.

Generation and utilization of polyclonal antibodies to a synthetic C-terminal amino acid fragment of divercin V41, a class IIa bacteriocin.

Polyclonal antibodies have been generated by immunization of rabbits with a chemically synthesized C-terminal part of divercin V41 (DvnCt) conjugated to the carrier protein keyhole limpet hemocyanin (KLH). The sensitivity and reactivity of the DvnCt-KLH-generated antibodies were evaluated by enzyme-linked immunosorbent assay (ELISA) using supernatant from cultures of 13 representative lactic acid bacterium strains, and specificity was confirmed by Western blot analysis. Anti-DvnCt-KLH antibodies were able to recognize not only divercin V41 but also enterocin P and piscicocin V1b, two other members of the class IIa bacteriocins. Production and activity of DvnV41 were evaluated by ELISA and activity tests during the growth of Carnobacterium divergens V41 in MRS medium containing or not containing Tween 80. Divercin V41, enterocin P, and piscicocin V1b were therefore purified by a single-step immunoaffinity chromatography method using a Sepharose matrix CNBr-activated directed binding of anti-DvnCt-KLH polyclonal antibodies.