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

Figure 1

IL-21 mRNA expression in the small intestine from patients with Crohn’s disease. In situ hybridization for IL-21 mRNA expression using the IL-21as (a, b, c, d, e, f) and IL-21s (g, h) probes on the small intestine from patients with CD (patient 1 (a–d), patient 2 (e-f)). IL-21 mRNA expressions are seen as white and black granules, in few isolated cells within the IEL compartment in (a) and (b) (white and black arrowheads, resp.). IL-21 mRNA-expressing cells are seen as white and black granules in lymphoid aggregates in the mucosa (white and black arrows in (a) and (b), resp.), in isolated lymphoid follicles in the submucosa (white and black arrows in (c) and (d), resp.), and in the muscularis externa (white and black arrows in (e) and (f), resp.). No specific reaction was observed with the IL-21s probe (g, h). The sections were counterstained with haematoxylin/eosin. Bars: 50 μm (a–e).