Cholera toxin and Salmonella typhimurium induce different cytokine profiles in the gastrointestinal tract

Salmonella infection of the gastrointestinal tract (GT) results in fluid secretion and inflammation. In contrast, cholera toxin (CT) induces fluid secretion but no inflammation. Using a murine ligated intestinal loop model, we investigated cytokine production (interleukin-1 [IL-1], IL-2, IL-4, IL-6, IL-10, gamma interferon, and tumor necrosis factor alpha) in the GT following exposure to these agents. Salmonella typhimurium induced a Th1-like cytokine profile in loops obtained from either nonimmune mice or Salmonella-immunized mice. CT induced only IL-6 and IL-10 production in ligated loops from nonimmune mice but induced a Th2-like cytokine profile in ligated loops obtained from CT-immunized mice. These results show that CT and S. typhimurium induce very different cytokine profiles in the GT.