Characterization of the antigenic specificity of soybean protein beta-conglycinin and its effects on growth and immune function in rats.
The objective of the present study was to characterize the antigenic specificity of purified soybean beta-conglycinin and to investigate its effects on the growth and immune responses of rats. Thirty-two Brown Norway rats, 3 weeks of age, were randomly allotted to one of four treatments and individually fed casein-cornstarch based diets. Rats were sensitised by means of intragastric gavage with purified beta-conglycinin (0, 5, 10 or 20 mg protein/ml in phosphate buffered saline at pH 7.4) on day 0, 7, 14, and 21 (1 ml/animal). On day 28, rats received a double dose of beta-conglycinin. Blood was obtained at weekly intervals after initiation of challenge. Growth declined linearly with increasing the concentration of soybean beta-conglycinin (p < 0.05). Both the total IgE and beta-conglycinin-specific IgE levels in serum increased while passive cutaneous anaphylactic reactions were induced in the rats. Lymphocyte proliferation response to concanavalin A in plasma and spleen was increased linearly with increased levels of soybean (p < 0.01) beta-conglycinin. The percentage of CD4+ lymphocyte subset linearly increased (p < 0.001). As a result, the concentrations of cytokines in plasma and spleen, including interleukin-4 (p < 0.01), interleukin-5 (p < 0.01), and tumour necrosis factor-alpha (p < 0.01) increased linearly with increasing level of purified beta-conglycinin. Our results indicate that purified beta-conglycinin possesses intrinsic immune-stimulating capacity and can induce an allergic reaction. Therefore, dietary soybean beta-conglycinin has negative effects on growth and both cell-mediated and humoral immune function in rats.
Guo
Pengfei
P
National Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, PR China.
Piao
Xiangshu
X
Ou
Deyuan
D
Li
Defa
D
Hao
Yue
Y
D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects* / Q000502:physiology; D052179:Antigens, Plant; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005916:Globulins / Q000008:administration & dosage / Q000276:immunology*; D007111:Immunity, Cellular / Q000187:drug effects* / Q000502:physiology; D007073:Immunoglobulin E / Q000097:blood; D009753:Nutritive Value; D011897:Random Allocation; D051381:Rats / Q000254:growth & development* / Q000276:immunology*; D055314:Seed Storage Proteins; D030262:Soybean Proteins / Q000008:administration & dosage / Q000276:immunology*; D015430:Weight Gain / Q000187:drug effects
D052179:Antigens, Plant; D005916:Globulins; D055314:Seed Storage Proteins; D030262:Soybean Proteins; C013894:beta-conglycinin protein, Glycine max; D007073:Immunoglobulin E