Hapten Facilitates Food Allergen-Related Intestinal Hypersensitivity

Background: Haptens can bind to proteins to elicit antigenicity. Whether haptens play a role in the pathogenesis of food allergy remains to be investigated. This article aims to elucidate the role a hapten plays in food antigen-related T helper 2 (T(h)2) pattern inflammation in the intestine. Methods: The effect of trinitrobenzene sulfonic acid (TNBS; as a hapten) on the properties of dendritic cells was assessed by a cell culture model. BALB/c mice were sensitized with a mixture of TNBS and ovalbumin (OVA; as a model antigen). Intestinal T(h)2 response, OVA-specific immunoglobulin E and histamine were analyzed with the mouse model. In addition to the infiltration of the intestinal inflammatory cells, cytokine expression profiles were determined. Results: TNBS increased the expression of T-cell immunoglobulin and mucin domain-4 and CD80 and decreased the levels of interleukin-12 in dendritic cells. Higher serum levels of OVA-specific immunoglobulin E, histamine expression and skewed antigen-specific T(h)2 polarization in the intestinal tissue were detected in mice sensitized with TNBS + OVA as compared with those treated with either OVA or TNBS alone. In addition, the TNBS-OVA-treated mice also showed an increased number of inflammatory cells, high levels of interleukin-4 and a decreased expression of interferon-gamma in the lamina propria mononuclear cells. Conclusions: Hapten TNBS can facilitate the initiation of food antigen-related T(h)2 pattern inflammation, such as food allergy, in the intestine.