The safety assessment of genetically modified crops involves the evaluation of the potential allergenicity of novel proteins by using several
in silico and
in vitro endpoints. In this publication, ...the variables and questions associated with the development of
in vivo models are examined and several unpublished results are presented. Both rodent and non-rodent (dog and pig) models have been investigated using various routes of administration with purified proteins or food extracts, with or without the use of an adjuvant. The ideal model should be simple, reproducible across laboratories over time, specific and sensitive enough for distinguishing a threshold beyond which relevant allergenicity would be predicted and, for ranking proteins correlated with the allergic responses in humans, and acceptable under animal care. Preliminary data suggest that a few appear promising; however, further evaluation of these models is required. In particular, more extensive validation testing with additional allergenic and non-allergenic material should be performed before using them in the safety assessment of genetically modified crops.
Very few traditional foods that are consumed have been subjected to systematic toxicological and nutritional assessment, yet because of their long history and customary preparation and use and ...absence of evidence of harm, they are generally regarded as safe to eat. This ‘history of safe use’ of traditional foods forms the benchmark for the comparative safety assessment of novel foods, and of foods derived from genetically modified organisms. However, the concept is hard to define, since it relates to an existing body of information which describes the safety profile of a food, rather than a precise checklist of criteria. The term should be regarded as a working concept used to assist the safety assessment of a food product. Important factors in establishing a history of safe use include: the period over which the traditional food has been consumed; the way in which it has been prepared and used and at what intake levels; its composition and the results of animal studies and observations from human exposure. This paper is aimed to assist food safety professionals in the safety evaluation and regulation of novel foods and foods derived from genetically modified organisms, by describing the practical application and use of the concept of ‘history of safe use’.
Food processing and allergenicity Verhoeckx, Kitty C.M.; Vissers, Yvonne M.; Baumert, Joseph L. ...
Food and chemical toxicology,
06/2015, Letnik:
80
Journal Article
Recenzirano
Odprti dostop
•Peanuts, tree nuts, cows' milk, hens' eggs, soy, wheat and mustard were reviewed.•Processing may influence, but does not abolish, the allergenic potential of proteins.•Reduction of allergenicity by ...fermentation and hydrolysis are the best characterised.•The effect of processing on the ability to induce sensitisation is poorly studied.•A need remains to develop robust methods for food allergenicity risk assessment.
Food processing can have many beneficial effects. However, processing may also alter the allergenic properties of food proteins. A wide variety of processing methods is available and their use depends largely on the food to be processed.
In this review the impact of processing (heat and non-heat treatment) on the allergenic potential of proteins, and on the antigenic (IgG-binding) and allergenic (IgE-binding) properties of proteins has been considered. A variety of allergenic foods (peanuts, tree nuts, cows' milk, hens' eggs, soy, wheat and mustard) have been reviewed.
The overall conclusion drawn is that processing does not completely abolish the allergenic potential of allergens. Currently, only fermentation and hydrolysis may have potential to reduce allergenicity to such an extent that symptoms will not be elicited, while other methods might be promising but need more data. Literature on the effect of processing on allergenic potential and the ability to induce sensitisation is scarce. This is an important issue since processing may impact on the ability of proteins to cause the acquisition of allergic sensitisation, and the subject should be a focus of future research. Also, there remains a need to develop robust and integrated methods for the risk assessment of food allergenicity.
The construction and first proton beam tests of a demonstrator dedicated to the beam ballistic control in hadrontherapy cancer treatments are described. This cost-effective demonstrator, called large ...area pixelized detector, is a PET-like detector used for in-beam ballistic control. It was built to test the feasibility of monitoring in real time, during irradiation, the ion range in the patient through the measurement of the beam-induced β + activity distribution. Achieving this goal necessitates to overcome several challenges. One of them is the rejection of the beam-induced background. Another one is the definition of fast event selection and reconstruction techniques so that real time monitoring is possible. Strategies employed to tackle these problems are presented and tested with the 65 MeV Medicyc proton beam of the cancer treatment center in Nice, France. In particular, an original fast reconstruction technique is presented. First performances obtained during irradiation of polymethyl methacrylate targets are described.
Some of the proteins expressed in the soybean (Glycine max) seed are allergenic to humans and animals; however, the concentration of these allergens and their variability in expression across ...germplasms is presently unknown.
The ILSI Health and Environmental Sciences Institute Protein Allergenicity Technical Committee organized an international workshop in June 2006 in Estoril, Portugal, co-sponsored by the ILSI Research ...Foundation, ILSI International Food Biotechnology Committee and ILSI Europe. The objective was to discuss the effects of food processing on the allergenic potential of proteins and foods. The impact of food processing on the sensitization/induction phases of food allergy, and the bioavailability of allergens to the immune system were presented. Studies evaluating the stability, digestibility, and allergenicity of processed food allergens were identified, and their complexity and limitations discussed. Participants agreed that investigating food allergy mechanisms, validating appropriate methods for identifying allergenic proteins, and refining strategies to assess and manage the risks from food allergy were important before processing considerations are integrated into public-health decision-making for novel proteins. Other factors may also play a role in food allergy and include: food matrix; multiplicity of epitopes; geographic variation in patterns/prevalence of food allergies; and genetic factors, but required further exploration. Food processing may increase or decrease the intrinsic allergenicity of a protein, but current data do not facilitate the identification of specific variables that could be used to reliably determine how processing will influence protein allergenicity.
One component of the safety assessment of agricultural products produced through biotechnology is evaluation of the safety of newly expressed proteins. The ILSI International Food Biotechnology ...Committee has developed a scientifically based two-tiered, weight-of-evidence strategy to assess the safety of novel proteins used in the context of agricultural biotechnology. Recommendations draw upon knowledge of the biological and chemical characteristics of proteins and testing methods for evaluating potential intrinsic hazards of chemicals. Tier I (potential hazard identification) includes an assessment of the biological function or mode of action and intended application of the protein, history of safe use, comparison of the amino acid sequence of the protein to other proteins, as well as the biochemical and physico-chemical properties of the proteins. Studies outlined in Tier II (hazard characterization) are conducted when the results from Tier I are not sufficient to allow a determination of safety (reasonable certainty of no harm) on a case-by-case basis. These studies may include acute and repeated dose toxicology studies and hypothesis-based testing. The application of these guidelines is presented using examples of transgenic proteins applied for agricultural input and output traits in genetically modified crops along with recommendations for future research considerations related to protein safety assessment.
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