SEB/OVA Facilitated TIM4 Expression in Intestinal Antigen Presenting Cells via Acetylation of Histone H3

Background: Various animal models have been established to dictate the pathogenesis of food allergy and each one has its own limitation. This study aimed to investigate the detailed molecular mechanisms underlying Staphylococcal enterotoxin B (SEB)/ovalbumin (OVA)-induced allergic reaction in mouse intestine. Methods: Using SEB/OVA-sensitized food allergic model, the effect of SEB/OVA on Th1/Th2 cytokine production was determined by ELISA. Mean while, the gene and protein expression of TIM4 in intestinal antigen presenting cells (APCs) was evaluated by PCR and Western blot, respectively. The inducible effect of SEB/OVA-primed APCs on TIM1 expression of CD4+ T cell was also investigated. Finally, the acetylation of histones induced by SEB/OVA was analyzed by Western blot. Results: We demonstrated that SEB/OVA showed dual effect on Th1/Th2 responses. The mRNA and protein expression of TIM4 in intestinal APCs was significantly elevated by SEB/OVA sensitization, which could further induce TIM1 expression on CD4+ T cell. The enhancement of TIM4 was mediated by acetylation of histone H3. Conclusion: The present study demonstrated that the effect of SEB/OVA on Th0 cell differentiation is dependent on its concentration. Furthermore, SEB/OVA induced TIM4 up-regulation may be via acetylation of histone H3.