Hazelnut Allergy: evidence that hazelnut can directly elicit specific IgE antibody response via activating type 2 cytokines in mice.
BACKGROUND
Hazelnut is one of the major tree nuts that causes potentially fatal food allergy, with underlying mechanisms that are unclear at present. One suggestion is that hazelnut allergy results from immune crossreactivity of IgE antibodies produced against certain aeroallergens. We tested the hypothesis that hazelnut is intrinsically capable of eliciting an allergic response using a mouse model.


METHODS
Groups of mice were injected intraperitoneally with hazelnut/filbert protein extract with or without alum as an adjuvant, and hazelnut-specific antibody (IgE, IgG1) responses were examined using optimized enzyme-linked immunosorbent assay. Hazelnut-specific type 2 and type 1 cytokine responses were evaluated by ex vivo antigen-mediated activation of spleen cells.


RESULTS
Hazelnut elicited robust IgE and IgG1 antibody responses. Timecourse and dose-response analyses further provided evidence for memory type 2-dependent antibody responses to hazelnuts. Hazelnut-specific IgE response in two strains of mice with different MHC haplotypes and IgE response to hazelnut without the use of alum adjuvant asserted that hazelnut is intrinsically an allergenic food. The type 2 cytokine analyses revealed that hazelnut sensitization results from activation of IL-4 and IL-5, thus providing a mechanistic basis for hazelnut-specific IgE response.


CONCLUSIONS
Our data argue that hazelnut - a widely consumed food - is intrinsically an allergenic food capable of directly eliciting hazelnut-binding specific IgE antibodies viaactivation of type 2 cytokines in mice.
Birmingham
Neil
N
Nutritional Immunology Program, Food Allergy and Immunology Laboratory, Department of Food Science and Human Nutrition, East Lansing, MI 48824, USA.
Gangur
Venu
V
Samineni
Sridhar
S
Navuluri
Lalitha
L
Kelly
Caleb
C
D000818:Animals; D031211:Corylus / Q000009:adverse effects / Q000276:immunology*; D016207:Cytokines / Q000276:immunology; D005512:Food Hypersensitivity / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology*; D015848:Interleukin-5 / Q000276:immunology*; D051379:Mice; D023421:Models, Animal
D016207:Cytokines; D007074:Immunoglobulin G; D015848:Interleukin-5; D015847:Interleukin-4; D007073:Immunoglobulin E