Digested Ara h 1 has sensitizing capacity in Brown Norway rats

Sensitization with 7S globulins from peanut, hazelnut, soy or pea induces IgE with different biological activities which are modified by soy tolerance

BACKGROUND

It is not known why some foods sensitizing via the gastrointestinal tract are prevalent allergenic foods and others are not. Eating habits, processing, and the food matrix have been suggested to influence the allergenicity of a given food. Factors related to protein structure, such as stability to digestion, have also been suggested. 7S globulins from peanut, hazelnut, soy, and pea were studied to determine whether related proteins would induce a similar sensitization when removed from their 'normal' matrix.

METHODS

Brown Norway rats (soy tolerant or nontolerant) were immunized i.p. 3 times with 100 μg purified peanut, hazelnut, soy, or pea 7S without adjuvant. Sera were analyzed for specific antibodies by different ELISAs (IgG1, IgG2a, and IgE), inhibition ELISA, and rat basophilic leukemia cell assay.

RESULTS

The 4 related 7S globulins induced a response with an almost identical level of specific antibodies, but peanut 7S induced IgE of higher avidity than hazelnut and pea 7S which, again, had a higher avidity than IgE induced by soy 7S. Soy tolerance reduced the functionality of IgE without influencing antibody titers.

CONCLUSIONS

Although the 4 7S globulins are structurally related allergens, they induce antibodies with different antigen-binding characteristics. Peanut 7S induces IgE of a higher avidity than hazelnut and pea 7S which, again, has a higher avidity than IgE induced by soy 7S. We also show that soy tolerance influences the function of antibodies to peanut 7S. These findings may help explain how antibodies of different clinical significances can develop in different individuals sensitized to the same allergen.

Developments in the field of allergy in 2009 through the eyes of Clinical and Experimental Allergy

In 2009 the journal published in the region of 200 papers including reviews, editorials, opinion pieces and original papers that ran the full gamut of allergic disease. It is instructive to take stock of this output to determine patterns of interest and where the cutting edge lies. We have surveyed the field of allergic disease as seen through the pages of Clinical and Experimental Allergy (CEA) highlighting trends, emphasizing notable observations and placing discoveries in the context of other key papers published during the year. The review is divided into similar sections as the journal. In the field of Asthma and Rhinitis CEA has contributed significantly to the debate about asthma phenotypes and expressed opinions about the cause of intrinsic asthma. It has also added its halfpennyworth to the hunt for meaningful biomarkers. In Mechanisms the considerable interest in T cell subsets including Th17 and T regulatory cells continues apace and the discipline of Epidemiology continues to invoke a steady stream of papers on risk factors for asthma with investigators still trying to explain the post-second world war epidemic of allergic disease. Experimental Models continue to make important contributions to our understanding of pathogenesis of allergic disease and in the Clinical Allergy section various angles on immunotherapy are explored. New allergens continue to be described in the allergens section to make those allergen chips even more complicated. A rich and vibrant year helpfully summarized by some of our associate editors.