Mucosal immune responses to b-lactoglobuin (βLG)-immunized mice are altered following colitis challenge

Abstract

Abstract Food allergens induce mucosal immune responses, and their continual exposure to sensitive hosts leads to health problems, e.g. intestinal inflammation. We tested dextran sodium sulfate (DSS) to disrupt intestinal homeostasis in mice immunized with βLG. BALB/c mice were ip. sensitised with βLG/PBS, thereafter orally challenged with βLG. DSS was delivered in drinking water et libitum. Humoral response and T cell profile were monitored for differences in immune response between groups. The highest level of Ag-specific serum IgG was observed in the i.p. immunized group without dependence on DSS presence. The level of Ag-specific IgA in sera and fecal extracts was low in each group. We found the greatest amount of CD4+ and FoxP3+CD25+CD4+ T cells in the spleens, mesenteric and peripheral lymph nodes obtained from mice orally immunized with βLG and receiving DSS treatment. DSS also induced a subset of CD4+ T cells producing a high amount of IFN-γ in all experimental groups. An elevated number IFN-γ+ CD4+ T cells was found in the lymphoid tissues of βLG-immunized mice (ip and orally) and treated with DSS. The profile of peripheral blood lymphocytes showed a two-fold increase in FoxP3+CD25+CD4+ T cells after DSS stimulation. The proposed experimental model of the inflamed intestine provoked with allergens showed differences in humoral responses and lymphocyte profiles, demonstrating that this regimen can be used to monitor immunoreactivity to food compounds.