Purification, biochemical, and immunological characterisation of a major food allergen: different immunoglobulin E recognition of the apo- and calcium-bound forms of carp parvalbumin.
نویسندگان
چکیده
BACKGROUND Almost 4% of the population suffer from food allergy which is an adverse reaction to food with an underlying immunological mechanism. AIMS To characterise one of the most frequent IgE defined food allergens, fish parvalbumin. METHODS Tissue and subcellular distribution of carp parvalbumin was analysed by immunogold electron microscopy and cell fractionation. Parvalbumin was purified to homogeneity, analysed by mass spectrometry and circular dichroism (CD) spectroscopy, and its allergenic activity was analysed by IgE binding and basophil histamine release tests. RESULTS The isoelectric point (pI) 4.7 form of carp parvalbumin, a three EF-hand calcium-binding protein, was purified to homogeneity. CD analysis revealed a remarkable stability and refolding capacity of calcium-bound parvalbumin. This may explain why parvalbumin, despite cooking and exposure to the gastrointestinal tract, can sensitise patients. Purified parvalbumin reacted with IgE of more than 95% of individuals allergic to fish, induced dose-dependent basophil histamine release and contained, on average, 83% of the IgE epitopes present in other fish species. Calcium depletion reduced the IgE binding capacity of parvalbumin which, according to CD analysis, may be due to conformation-dependent IgE recognition. CONCLUSIONS Purified carp parvalbumin represents an important cross reactive food allergen. It can be used for in vitro and in vivo diagnosis of fish-induced food allergy. Our finding that the apo-form of parvalbumin had a greatly reduced IgE binding capacity indicates that this form may be a candidate for safe immunotherapy of fish-related food allergy.
منابع مشابه
A recombinant hypoallergenic parvalbumin mutant for immunotherapy of IgE-mediated fish allergy.
IgE-mediated allergy to fish is a frequent cause of severe anaphylactic reactions. Parvalbumin, a small calcium-binding protein, is the major fish allergen. We have recently isolated a cDNA coding for carp parvalbumin, Cyp c 1, and expressed in Escherichia coli a recombinant Cyp c 1 molecule, which contained most IgE epitopes of saltwater and freshwater fish. In this study, we introduced mutati...
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Background: Aflatoxin contamination is a common natural phenomenon that is difficult to avoid or control and it can occur during pre and post-harvest periods under high humidity and temperature conditions, and are potentially dangerous to fish. In the present study, a feeding trial evaluated the effects of diets contaminated with aflatoxin on certain immunological parameters of common carp. Me...
متن کاملBlocking antibodies induced by immunization with a hypoallergenic parvalbumin mutant reduce allergic symptoms in a mouse model of fish allergy
BACKGROUND Fish is a frequent elicitor of severe IgE-mediated allergic reactions. Beside avoidance, there is currently no allergen-specific therapy available. Hypoallergenic variants of the major fish allergen, parvalbumin, for specific immunotherapy based on mutation of the 2 calcium-binding sites have been developed. OBJECTIVES This study sought to establish a mouse model of fish allergy re...
متن کاملHistamine and Food Allergy
Histamine is synthesized via histidine decarboxylase (HDC) in wide types of immune cells and is involved in abundant physiologic and pathologic processes. Histamine is a mediator released during inflammatory reactions, such as food allergy. Food allergy is immunological reactions to 'fight off' specific allergens within food in susceptible individuals. The aim of this study is investigation of ...
متن کاملHistamine and Food Allergy
Histamine is synthesized via histidine decarboxylase (HDC) in wide types of immune cells and is involved in abundant physiologic and pathologic processes. Histamine is a mediator released during inflammatory reactions, such as food allergy. Food allergy is immunological reactions to 'fight off' specific allergens within food in susceptible individuals. The aim of this study is investigation of ...
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ورودعنوان ژورنال:
- Gut
دوره 46 5 شماره
صفحات -
تاریخ انتشار 2000