Ingested (oral) SST inhibits EAE.

Background: Ingested immunoactive proteins type I interferon, soluble immune response suppressor peptide 1-21 and melanocyte-stimulating hormone inhibit clinical attacks and inflammation in acute experimental autoimmune encephalomyelitis (EAE). Objective: We examined whether another immunoactive protein, somatostatin (SST), would have similar anti-inflammatory effects on EAE after oral administration. Design/methods: B6 mice were immunized with MOG peptide 35-55 and gavaged with control saline or SST during ongoing disease. Splenocytes from mock-fed or SST-fed mice were adoptively transferred into active MOG peptide 35-55-immunized recipient mice during ongoing disease. Results: In actively fed mice, increased Th2-like cytokines in both the spleen and the central nervous system (CNS) inhibited active disease. In recipients of donor cells from SST-fed donors, reduction of Th1 and Th17 and induction of Th2-like IL-4 cytokines in both the spleen and CNS inhibited disease. T_reg cells were increased threefold in actively fed spleen cells that are responsible for protection against disease after adoptive transfer. Conclusions: Ingested (orally administered) SST can inhibit clinical disease, inhibit CNS inflammation by decreasing Th17 and Th1-like cytokines and increasing Th2-like cytokines in the CNS via induction of T_reg cells. [ABSTRACT FROM AUTHOR]