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17:30 Dr Erzsébet Szabó: Identification of Major Allergens of Cereal Proteins by Electrophoretic Methods. Department of Nutrition, Central Food Research Institute, Hungary.17:45 MSc Andras Nagy: Studies on immunomodulative effect of selected food(probiotics). Central Food Research Institute, Budapest, Hungary 18:00 Discussion 19:00 Bonfire SATURDAY 31st August 2002 Session B: Possibilities of the reduction of food allergenic propertiesChairpersons: Dr Ronald van Ree (University of Amsterdam, The Netherlands), Prof. Lucjan Jędrychowski (Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland). LECTURES09:00 Dr Jean Michel Wal: Food allergens -general considerations on the structural and molecular basis of allergenicity illustrated by examples essentially from cow's milk allergens. Laboratoire d’Immuno-Allergie Alimentaire, Service de Pharmacologie et immuno-logie (SPI) INRA-CEA Saclay, France 09:40 Dr Gyongyi Hajos: Enzymatic modification as a tool for alteration of allergenic character of food proteins.Central Food Research Institute, Budapest, Hungary SHORT PRESENTATIONS10:20 Dr Urszula Pytasz The effect of proteolysis on the gliadin immunogenicity. Clinic of Endocrynology. Research Institute of Polish Mothers Memorial Hospital in Łódź, Poland 10:35 Dr Cristiana Berti: Effects on celiac activity of gluten proteins modified by chemical deamidation DISTAM - Nutrition Unit University of Milan, Italy 10:50 Discussion 11:00 Coffee and tea break LECTURES 11:20 Dr Barbara Wróblewska: Influence of technological and biotechnological processes on immunoreactivity of cow milk proteins. Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland SHORT PRESENTATION12:00 Dr M. Carbonaro, S. Iametti: Sensitivity of food allergens to proteolysis: in vivo and in vitro approaches. Istituto Nazionale di Ricerca per gli Alimenti e la Nutrizione, Italy. Dipartimento di Scienze Molecolari Agroalimentari, Università degli Studi di Milano, Milan, Italy 12:15 Dr Cristiana Berti, Iametti S., Porrini M., Bonomi F.: Chenopodium quinoa may represent a viable alternative for gluten-free products Nutrition Unit University of Milan, Italy12:30 Discussion 13:00 LUNCH SATURDAY 31st.August 2002 Session C: Production of hypoallergenic foodChairpersons: Dr. Clare Mills (Institute of Food Research, Norwich, UK) Dr Barbara Wróblewska (Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland). LECTURES15:00 Dr Marianne Polgar: Clinical background of food allergy. Children Gastrointestinal Centre, Madarasz Children's Hospital , Budapest, Hungary 15:40 Dr Ronald van Ree: Lipid transfer proteins as allergens. Department of Allergy, University of Amsterdam, The Netherlands 16:20 Coffee and tea break 16:40 Prof. Lucjan Jędrychowski: Food and nutrition in food allergy. Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland. SHORT PRESENTATIONS17:20 Dr Wanda: Karwowska: Human milk IgA antibodies isolated from atopic andhealth mothers''. Agricultural University of Warsaw (SGGW –AR Warszawa), Poland17:35 Discussion18:00 Conclusions and closing of the workshop SUNDAY 1st September 2002 08:30 Breakfeast 05:30 Departure of the participants (I group) 12:30 Departure of the participants (II group) SESSION A ALLERGENICITY OF FOODS OF PLANT AND ANIMAL ORIGIN PLANT ALLERGEN PROTEIN FAMILIES – STRUCTURAL ATTRIBUTES AND ALLERGENICITY E.N. Clare Mills1, John A Jenkins1. Institute of Food Research, Norwich Research Park, Colney Lane, Norwich, NR4 In order to formulate means of predicting the allergenicity of food proteins, efforts have been made to define the physicochemical properties common to known allergens and to elucidate structural features, which are recognised by IgE antibodies. One approach has been to protein sequence comparisons to identify allergens but such an approach will only identify close homologues. In order to improve this aspect of allergenic risk assessment Protall, an EU-funded network of plant biochemists, food scientists and clinicians, is focussing on the need to identify structures and activities which are common to food allergens using plant food allergens as an example. A large proportion of food allergens are of plant origin and a number of these have been characterised, notably from pollen (e.g. birch), seeds (e.g. peanut, mustard, soya, rice, wheat) and fruits/vegetables (e.g. apples, plums and celery). Many of these are low molecular weight proteins (10-20,000 daltons), which are thermostable and have biological activities which include conferring resistance to pests and pathogens. Some act as inhibitors of the proteases and carbohydrases secreted by the pathogens to break down plant cell structures, while others display lipid-binding activity and may destabilise the cell membranes of pathogens. Almost all allergens are either involved in pathogen resistance or have a seed storage function. An overview of the structures and properties common to these types of allergens will be presented illustrated by the
These common properties will be discussed in terms of their influence on the stability of allergens to processing and the digestive processes, both factors thought to be important in contributing to the allergenic potential of a food protein. PLANT FOOD ALLERGENS - THEIR STRUCTURAL AND BIOLOGICAL RELATIONSHIPS John Jenkins1, Sam Griffiths-Jones2 and Clare Mills1 1Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney, Norwich NR4 7UA, UK. 2Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK Are plant food allergens different from other plant proteins in either sequence or 3-dimensional structure? If so, what are the characteristics of allergens and potential allergens? We are attempting to answer these questions by assembling lists of allergens and by classifying them and comparing them with other plant proteins. An online database of plant food allergens (http://www.ifrn.bbsrc.ac.uk/protall/) has been created which is aimed at including entries for all plant food allergens for which any molecular data has been published. Using this and other databases gives us lists of both food and aero allergens. These protein allergens can be classified into families based on their amino acid sequences following the methods of the PFAM database (Bateman A, Birney E, Cerruti L, Durbin R, Etwiller L, Eddy SR, Griffiths-Jones S, Howe KL, Marshall M, Sonnhammer EL. Nucleic Acids Research 30: 276-280, 2002). Allergens are found to cluster in a small number of families and the distribution is different from that seen in the proteins of the two sequenced plant genomes. The stability of the allergens to both denaturation and proteolysis seems important as is the concentration in the food. However, neither accounts completely for the observed allergens. Cross-reactivity with latex and pollen allergens is also a major factor in allergenicity. Lipid binding and a potential for aggregation may also be linked with allergenicity. This research was supported by the BBSRC (UK), the Welcome Trust and by the EU grants FAIR-CT98-4356, QLK1-CT-2000-01394 and QLRT-2000-02139. IMMUNE RESPONSES TO DIETARY ANTIGENS: ORAL TOLERANCE E. Gelencser Central Food Research Institute, H-1022 Budapest, Herman Ottó út 15., Hungary Foreign antigens are plentiful in the gut and the general immunological tone of the GI tract is one of suppression (oral tolerance). Such mucosal tolerance mechanisms apparently explains why most individuals show no adverse immune reactions despite persistent contact with large amounts of food proteins and, it probably also contributes to the host’s adaptation to the indigenous intestinal microbiota. Three principal immune mechanisms have been implicated in oral tolerance: clonal deletion, clonal anergy and Ag driven suppression. Perturbation or dysfunction of the GI immune system is associated with diseases as allergies. The precise immune basis remains controversial, but probably reflects complex interactions between digestion, specialized antigen uptake and a variety of immune regulatory mechanism. Well known studies have shown that oral adjuvant (e.g. Cholera toxin, plant lectins, probiotic bacteria) are excellent manipulators of systemic and mucosal responses. Oral adjuvant have also been developed to facilitate powerful mucosal secretory antibody responses to an unrelated, but anatomically co-localized, Ag. Keywords: oral tolerance, food allergy, mucosal adjuvant To whom correspondence should be addressed. Tel.: 36 1 225 3343; Fax: 36 1 225 3342; E-mail: e.gelencser@cfri.hu ANIMAL MODELS FOR POTENTIAL IMMUNOTOXICITY TESTING OF NOVEL FOOD PROTEINS: POSSIBILITIES AND LIMITATIONS |