Food allergy - towards predictive testing for novel foods

The risks associated with IgE-mediated food allergy highlight the need for methods to screen for potential food allergens. Clinical and immunological tests are available for the diagnosis of food allergy to known food allerge ns, but this does not extend to the evaluation, or prediction of allergenic ity in novel foods. This category includes foods produced using novel proce sses, genetically modified (GM) foods, and foods that might be used as alte rnatives to traditional foods. Through the collation and analysis of the pr otein sequences of known allergens and their epitopes, it is possible to id entify related groups which correlate with observed clinical cross-reactivi ties. 3-D modelling extends the use of sequence data and can be used to dis play eptiopes on the surface of a molecule. Experimental models support seq uence analysis and 3-D modelling. Observed crossreactivities can be examine d by Western blots prepared from native 2-D gels of a whole food preparatio n (e.g. hazelnut, peanut), and common proteins identified. IgEs to novel pr oteins can be raised in Brown Norway rat (a high IgE responder strain), and the proteins tested in simulated digest to determine epitope stability. Us ing the CSL serum bank, epitope binding can be examined through the ability of an allergen to cross-link the high affinity IgE receptor and thereby re lease mediators using in vitro cell-based models. This range of methods, in combination with data mining, provides a variety of screening options for testing the potential of a novel food to be allergenic, which does not invo lve prior exposure to the consumer.