OBJECTIVETo establish WZS miniature swine model of beta-conglycinin (7 S) allergy for evaluating the potential allergenicity of genetically modified food.

METHODSTwelve 45-day-old WZS miniature swines from three litters were randomly divided into three groups (control group; 4% 7 S group and 8% 7 S group, n = 4), which were respectively gastric sensitized (day 0 - 10) and oral challenged (day 6 - 18, 31) to induce anaphylactic reactions. Clinical symptoms, skin prick reactions were recorded. At day 10, 19 and 32, serum IgG, IgE, histamine and cytokines levels were measured by ELISA.

RESULTSDiarrhea at different degrees were observed in 4% and 8% 7 S groups. The skin erythema reactions in grade "-", "+/-", "+", "++" of control group respectively were 2/4, 2/4, 0/4, 0/4, of 4% 7 S group were 0/4, 0/4, 2/4, 2/4 and of 8% 7 S group were 0/4, 0/4, 1/4, 3/4. The serum IgE and histamine levels of day 11, 19 and 32 were all significantly and positively correlated (Pearson coefficients = 1, P = 0.000). The serum IgG, IgE and histamine levels all reached the peak after 7 S groups were oral challenged at day 19.Compared with the control group, serum IgG (lg IgG: 2.95 +/- 0.31 vs 2.29 +/- 0.25, t = 3.19, P = 0.011), IgE (lg IgE: 2.45 +/- 0.30 vs 1.77 +/- 0.23, t = 3.31, P = 0.009) and histamine levels(lg histamine:2.13 +/- 0.30 vs 1.45 +/- 0.23, t = 3.34, P = 0.009) of 4% 7 S group at day 19 were all significantly higher, while the serum IFN-gamma content [(35.78 +/- 6.42) pg/ml vs (51.10 +/- 9.67) pg/ml, t = -2.33, P = 0.045] of 4%7 S group was significantly lower.

CONCLUSIONThe WZS miniature swine model orally induced by soybean beta-conglycinin is type I hypersensitivity mediated by IgE, which can be used to predict the potential allergenicity of genetically modified food.