There are studies reporting food sensitization in infancy increases the risk of sensitization to inhalants later in life. We performed a study to evaluate whether cosensitization with buckwheat (BW) has an effect on the production of house dust mite-IgE. C3H/HeJ mice (4 weeks, female) were sensitized with house dust mite (HDM)/Al (OH)3, intraperitoneally on day 0, followed by 4 intranasal sensitizations (on days 14, 15, 16, and 21). Group 1 was cosensitized intragastrically with BW/cholera toxin (CT) (on days 0, 1, 2, 7, and 18) during sensitization with HDM, group 2 was cosensitized intragastrically with CT only (on days 0, 1, 2, 7, and 18), and group 3 was used as controls. HDM- and BW-IgE and antigen-specific T-cell proliferation and cytokine production were evaluated. In Group 1, BW-IgE levels were highest at week 4, and the HDM-IgE at week 3 (98.45+/-64.37 ng/mL and 169.86+/-55.54 ng/mL, respectively). In Group 2, HDM-IgE levels reached a peak at week 3, remarkably higher (810.52+/-233.29 ng/mL) compared to those of Group 1 (169.86+/-55.54 ng/mL). The interleukin (IL)-4 and interferon (IFN)-gamma in the HDM-stimulated culture supernatants of splenocytes were not significantly different among groups. We postulate that the cosensitization with BW may down-regulate the specific IgE response to HDM.
Pyroglyphidae/*immunology ; Plant Extracts/adverse effects ; Mice, Inbred C3H ; Mice ; Immunoglobulin E/*immunology ; Immunization/*methods ; Food Hypersensitivity/*immunology ; Flour/*adverse effects ; Female ; Fagopyrum/*adverse effects ; Disease Models, Animal ; Dermatitis, Atopic/*immunology ; Animals

Food allergies affect about 4% of the Korean population, and buckwheat allergy is one of the most severe food allergies in Korea. The purpose of the present study was to develop a murine model of IgE-mediated buckwheat hypersensitivity induced by intragastric sensitization. Young female C3H/HeJ mice were sensitized and challenged intragastricly with fresh buckwheat flour (1, 5, 25 mg/dose of proteins) mixed in cholera toxin, followed by intragastric challenge. Anaphylactic reactions, antigen-specific antibodies, splenocytes proliferation assays and cytokine productions were evaluated. Oral buckwheat challenges of sensitized mice provoked anaphylactic reactions such as severe scratch, perioral/periorbital swellings, or decreased activity. Reactions were associated with elevated levels of buckwheatspecific IgE antibodies. Splenocytes from buckwheat allergic mice exhibited significantly greater proliferative responses to buckwheat than non-allergic mice. Buckwheat-stimulated IL-4, IL-5, and INF-gamma productions were associated with elevated levels of buckwheat-specific IgE in sensitized mice. In this model, 1 mg and 5 mg dose of sensitization produced almost the same degree of Th2-directed immune response, however, a 25 mg dose showed blunted antibody responses. In conclusion, we developed IgE-mediated buckwheat allergy by intragastric sensitization and challenge, and this model could provide a good tool for future studies.
Anaphylaxis/blood/immunology ; Animals ; Cell Proliferation/drug effects ; Comparative Study ; Disease Models, Animal ; Dose-Response Relationship, Drug ; Enzyme-Linked Immunosorbent Assay ; Fagopyrum/*immunology ; Female ; *Flour ; Food Hypersensitivity/blood/*immunology ; Immunoglobulin E/blood/immunology ; Immunoglobulin G/blood/immunology ; Interferon Type II/biosynthesis ; Interleukin-4/biosynthesis ; Interleukin-5/biosynthesis ; Mice ; Mice, Inbred C3H ; Plant Extracts/administration & dosage/immunology ; Research Support, Non-U.S. Gov't ; Spleen/cytology/drug effects/metabolism ; Stomach/drug effects/*immunology ; T-Lymphocytes/cytology/drug effects/metabolism ; Time Factors