Allergic and anaphylactic response to sesame seeds in mice: identification of Ses i 3 and basic subunit of 11s globulins as allergens.
BACKGROUND
Allergy to sesame seeds is an emerging food allergy of a serious nature due to a high risk of systemic anaphylaxis. Although a mouse model to study sesame anaphylaxis is desirable, currently it is not available. Here, using a transdermal exposure model system, we tested the hypothesis that sesame seed elicits IL-4-associated IgE antibody response with consequent clinical sensitization in mice.


METHODS
Groups of BALB/c mice were exposed to sesame seed extract or saline or a control food (vanilla bean extract) by transdermal applications. Systemic IgE, IgG1 and IgG2a antibody responses were examined using preoptimized ELISA. Type 2 and type 1 cytokine responses were evaluated by ex vivo antigen-mediated activation of spleen cells. Clinical response to oral sesame challenge was studied. Western blot and N-terminal amino acid sequence analyses were performed to identify the sesame allergens.


RESULTS
Transdermal exposure to sesame elicited robust IgE and IgG1 but very little IgG2a antibody responses. IgE response to transdermal exposure in two high-IgE responder mice strains with disparate MHC confirmed the intrinsic allergenicity of sesame seed. Transdermal sensitization was associated with activation of IL-4 but not IFN-gamma. Furthermore, oral exposure to sesame resulted in clinical signs of systemic anaphylaxis. Western blot and sequence analysis identified four allergens including Ses i 3 and the basic subunit of 11s globulins.


CONCLUSIONS
These data argue that transdermal exposure to sesame seed can result in IL-4 activation, IgE response and clinical sensitization for systemic anaphylaxis.
Navuluri
Lalitha
L
Food Allergy and Immunology Laboratory, Department of Food Science and Human Nutrition, Nutritional Immunology Program, Michigan State University, East Lansing, Mich. 48824, USA.
Parvataneni
Sitaram
S
Hassan
Hanem
H
Birmingham
Neil P
NP
Kelly
Caleb
C
Gangur
Venu
V
D000279:Administration, Cutaneous; D000595:Amino Acid Sequence; D000707:Anaphylaxis / Q000209:etiology / Q000276:immunology*; D000818:Animals; D015153:Blotting, Western; D016207:Cytokines / Q000032:analysis; D005512:Food Hypersensitivity / Q000276:immunology*; D005916:Globulins / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D021122:Protein Subunits; D012639:Seeds / Q000009:adverse effects / Q000276:immunology; D017422:Sequence Analysis, DNA; D031685:Sesamum / Q000009:adverse effects* / Q000276:immunology; D013154:Spleen / Q000276:immunology
D016207:Cytokines; D005916:Globulins; D007074:Immunoglobulin G; D010940:Plant Proteins; D021122:Protein Subunits; D007073:Immunoglobulin E