Fig. 5

Lack of EBI2 leads to a lower number of lymphoid structures in the colon. Colonic lymphoid structures of 12 weeks old female EBI2^−/− and wild-type littermate mice were assessed using complementary approaches. (a) B220 B cell staining in a whole mounted colon of wild-type and EBI2^−/− mice (B220: white). (b) Quantification of B cell follicles in B220-stained whole mounted colons. (c) Stratification of B220⁺ structures from (b) by size (area). ## = p < 0.01 and #### = p < 0.0001 comparing structures < 20’000 µm² and < 100’000 µm² respectively with a multivariate Poisson regression using model-based t-tests. (d) Classification of B220⁺ structures from (b) by presence or absence of multiple follicles per structure. (e) HE-stained colon Swiss rolls (left) and representative SILT and CLP structures stained with HE (middle) and B220 and αSMA (right); scale bars: 200 µm. (f) Lymphoid structures were quantified and categorized according to their location in 20 HE-stained colon Swiss roll sections per mouse. Scale bars: 200 µm. Data shown as mean ± SEM. Statistical analysis: Mann–Whitney U test; *p < 0.05