Protein Allergen

Kimber, I. et al., Assessment of protein allergenicity on the basis of immune reactivity animal models,. Environ. Health Perspect., Ill, 1125, 2003. 

It is appropriate here to consider briefly some of the experimental approaches that are contained within such decision trees, and that continue to provide the bases for protein allergenicity safety assessment. 

In summary, it is reasonable to conclude that bioinformatic analysis of structural similarities to, or of sequence homology with, known protein allergens, and evaluation of stability with SGF, can both contribute, if interpreted cautiously, to an overall assessment of sensitizing hazard. However, these analyses, neither alone nor in combination, provide a definitive answer regarding allergenic potential, and for this reason there has been interest in exploring a more holistic approach (and more definitive assessment) that may be provided by suitable animal models. 

Taylor, S.L., Protein allergenicity assessment of foods produced through agricultural biotechnology. Ann. Rev. Pharmacol. Toxicol., 42, 99, 2002. 

Silvanovich, A., Nemeth, M.A, Song, P., Herman, R., Tagliani, L. and Bannon, G.A., The value of short amino acid sequence matches for prediction of protein allergenicity. Toxicol. Sci., 90, 252, 2006. 

Dearman, R.J. and Kimber, I., Determination of protein allergenicity Studies in mice. Toxicol. Lett., 120, 181, 2001. 

Dearman, R.J., Kimber, I. and Basketter, D. A., Protein allergenicity Mouse models. Comments Toxicol. 8, 297, 2002. 

Kimber, I., Dearman, R.J., Penninks, A.H., Knippels, L.M.J., Buchanan, R.B., Hammer-berg, B., Jackson, H.A. and Helm, R.M., Assessment of protein allergenicity on the basis of immune reactivity animal models. Environ. Health Perspect., Ill, 1125, 2003. 

While all humans have IgE antibodies fhaf are involved in defense against parasitic infections, only humans who are predisposed to the development of allergies will produce IgE antibodies upon exposure fo certain protein allergens present in their environment including their diet. Only a few of the many proteins found in foods are capable of sfimulating the production of specific IgE antibodies in susceptible individuals (Taylor, 2002). With molluscan shellfish, only one, or perhaps a few, of the numerous proteins is known to provoke the production of IgE antibodies that specifically recognize one or more species of molluscan shellfish. 

Zorzet, A., Gustafsson, M., and Hammerling, U. 2002. Prediction of food protein allergenicity A bioinformatic learning systems approach. In Silico Biol 2 525-534. 

Dearman, R.J., Stone, S., Caddick, H.T., Basketter, D.A., and Kimber, I. 2003a. Evaluation of protein allergenic potential in mice Dose-response analyses. Clin Exp Allergy 33 1586-1594. 

Dearman, R.J., Skinner, R.A., Herouet, C., Labay, K., Debruyne, E., and Kimber, I. 2003b. Induction of IgE antibody responses by protein allergens Inter-laboratory comparisons. Food Chem Toxicol 41 1509-1516. 

Stickler, M., Mucha, J., Estell, D., Power, S., and Harding, F. 2003. A human dendritic cell-based method to identify CD4+ T-cell epitopes in potential protein allergens. Environ Health Perspect 111(2) 251—254. 

There are cases that indicate that goat protein allergens other than casein can be involved in food allergies to GM and even small quantities of protein can elicit clinical symptoms. A 27-year-old female patient experienced two episodes of urticaria after ingestion of goat s cheese. She tolerated cow s milk, dairy products, and sheep cheese but her skin tests were positive for goat s milk and goat s cheese (Tavares et al. 2007). 

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