IL17A and colitis: Severe colitis in HSD-fed mice was accompanied by a massive increase in neutrophils in colon tissue (Figure 2B), increased anti-CD3/anti-CD28-stimulated production of IL-17 in mesenteric lymph nodes (Figure 2C), and increased Tnfa expression (Figure 2D) and IL-6 and IL-1β production (Figure 2E) in the colonic tissue.