Activation Patterns of Murine T Cells after Oral Administration of an Enterocoated Soluble Antigen

An orally administered soluble protein antigen, ovalbumin (OVA), enterocoated with an acid-resistant acrylic polymer, induced a strong humoral immune response in BDF1mice, exhibiting Th2 cell phenotype, typified by increased OVA-specific IgA, IgG1, and IgE antibody responses. This antibody response was accompanied by OVA-specific T cell proliferation response and IL-4 cytokine production. Mice fed enterocoated OVA and administered anti-IL-4 mAb showed a shift of the immune response toward the Th1 cell phenotype as evidenced by increased IFN-γ production and anti-OVA IgG2a isotype antibody response. Additionally, in mice fed OVA solution and simultaneously administered anti-IL-4, we saw a slight but significant expression of Th1 cell phenotype. In conclusion, our data indicate that the dominance of Th2 cell phenotype in oral immunity is strongly influenced by the production and presence of IL-4.