Characterization of the allergenic potential of proteins: an assessment of the kiwifruit allergen actinidin
Article first published online: 10 JUN 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Journal of Applied Toxicology
Volume 34, Issue 5, pages 489–497, May 2014
How to Cite
Dearman, R. J., Beresford, L., Foster, E. S., McClain, S. and Kimber, I. (2014), Characterization of the allergenic potential of proteins: an assessment of the kiwifruit allergen actinidin. J. Appl. Toxicol., 34: 489–497. doi: 10.1002/jat.2897
- Issue published online: 26 MAR 2014
- Article first published online: 10 JUN 2013
- Manuscript Revised: 18 APR 2013
- Manuscript Accepted: 18 APR 2013
- Manuscript Received: 7 MAR 2013
- genetically modified;
- kiwi fruit;
- animal models
Assessment of the potential allergenicity (IgE-inducing properties) of novel proteins is an important challenge in the overall safety assessment of foods. Resistance to digestion with pepsin is commonly measured to characterize allergenicity, although the association is not absolute. We have previously shown that specific IgE antibody production induced by systemic [intraperitoneal (i.p.)] exposure of BALB/c strain mice to a range of proteins correlates with allergenic potential for known allergens. The purpose of the present study was to explore further the utility of these approaches using the food allergen, actinidin. Recently, kiwifruit has become an important allergenic foodstuff, coincident with its increased consumption, particularly as a weaning food. The ability of the kiwifruit allergen actinidin to stimulate antibody responses has been compared with the reference allergen ovalbumin, and with the non-allergen bovine haemoglobin. Haemoglobin was rapidly digested by pepsin whereas actinidin was resistant unless subjected to prior chemical reduction (reflecting intracellular digestion conditions). Haemoglobin stimulated detectable IgG antibody production at relatively high doses (10%), but failed to provoke detectable IgE. In contrast, actinidin was both immunogenic and allergenic at relatively low doses (0.25% to 1%). Vigorous IgG and IgG1 antibody and high titre IgE antibody responses were recorded, similar to those provoked by ovalbumin. Thus, actinidin displays a marked ability to provoke IgE, consistent with allergenic potential. These data provide further encouragement that in tandem with analysis of pepsin stability, the induction of IgE after systemic exposure of BALB/c strain mice provides a useful approach for the prospective identification of protein allergens. Copyright © 2013 John Wiley & Sons, Ltd.