Evaluating IL-21 as a Potential Therapeutic Target in Crohn’s Disease

Figure 9

Prophylactic treatment with anti-IL-21 mAb reduces colonic transformation and neutrophil infiltration. All images are from animals representing mean values of the individual analyses. (a), (d), and (g) show the colon of AdTr mice treated with anti-IL-21 mAb, and (b), (e), and (h) show animals treated with the control mIgG1 antibody. (a, b) HE staining showing the hyperplasia of the mucosa significantly reduced () by treatment with anti-IL-21 as seen in the histopathological analysis (c). (d, e) Immunohistochemical demonstration of CD3-positive T cells (in brown) in the mucosa and submucosa. (f) The density- (in %) positive T cells quantified by digital image analysis did not reach significance. (g, h) Immunohistochemical demonstration of calprotectin-positive neutrophils (in brown). (i) The density (in %) calprotectin-positive neutrophils and macrophages quantified by digital image analysis were significantly reduced () by treatment with anti-IL-21. Nuclei (in blue) were counterstained with haematoxylin. Bars: 200 μm (a, b, d, e, g, h).