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

Figure 3

IL-21 and IL-21R protein expression in the intestine from patients with Crohn’s disease. Immunohistochemical staining of IL-21 (a, c, e) and IL-21R (b, d, f) in the colon from patients with CD. IgG1 isotype-specific control antibody is shown in (g) and (h). IL-21⁺ cells (arrows in (a), (c), and (e)) and IL-21R⁺ cells (arrows in (b), (d), and (f)) are seen as solitary cells in the lamina propria of the mucosa (a, b), lymphoid aggregates of the submucosa (c and d), and muscularis externa (e, f), respectively. No reaction was observed with the IgG1 control antibody (g, h). Nuclei (in blue) were counterstained with haematoxylin. Bars: 50 μm (a–h).