Aflatoxin B1 can aggravate BALB/c mice allergy to ovalbumin through changing their Th2 cells immune responses

Abstract

Foods contaminated by Aflatoxin B₁ (AFB₁) frequently happen in the world and can cause a lot healthy damages to human beings, meanwhile, some of these foods are easily irritate food allergy. To investigate the effect of AFB₁ exposure on food allergy, three doses of AFB₁ were set, including 0.3 μg/kg · bw (LDAF), 7.5 μg/kg · bw (MDAF), and 100.0 μg/kg · bw (HDAF), respectively; food allergy model was constructed by the BALB/c mice allergy to ovalbumin (OVA). The changes of titer in OVA-specific immunoglobulin E (IgE), IgG, IgG1, IgG2a, as well as level of the mMCP-1 in sera were determined by enzyme linked immunosorbent assay (ELISA), respectively; the levels of interleukin (IL-4, IL-5, IL-13) and interferon (IFN)-γ in spleen were separately assessed using ELISA kits, and their relative genes expression were verified by Real-time fluorescence quantitative PCR (Q-PCR); the population of Th1/Th2/Treg cells were analyzed by flow cytometry. Results showed that when OVA-allergic mice were exposed to AFB₁, the production of OVA-specific IgE, IL-4, IL-5 and IL-13, and mMCP-1 were all increased, whereas the level of IFN-γ was decreased; the Th1/Th2 balance was disrupted and the development of Th cells tilted to the Th2 phenotype. The study would contribute to further understand the risk of fungal toxins in food allergy.

Keywords: Aflatoxin B(1); Cytokine; Food allergy; IgE; Oral ministration; Ovalbumin.