Fig. 7: Capsule fibrosis constrains late lymph node expansion.
From: Multitier mechanics control stromal adaptations in the swelling lymph node
a, Representative images from in vivo laser cut experiments of subcapsular sinus LECs before (t = −1s), directly after (t = 0 s) and late after (t = 10.2 s) cutting (scale bars, 5 µm), with corresponding kymograph along the recoil axis (scale bar, x = 1 s and y = 2 µm). The scissor and line indicate the location of the cut and arrows indicate the recoiling cell. Dashed lines in the kymograph indicate slopes and the vertical white line shows the cut. b, Quantification of experiments as in a during homeostasis (day 0) and inflammation (days 2, 4, 8 and 14; n = 11, 12, 20, 25 and 22). c, UV laser cut experiment on TAMRA-labeled capsule ECM of explanted LNs in homeostasis (day 0) and inflammation (day 2, 4, 8 and 14), which recapitulate ECM from scanning electron microscopy (SEM) imaging. Recoil displacement is depicted by orange vectors. Scale bars, SEM image = 1 µm and fluorescence image = 20 µm. d, Quantification of recoil velocities in c (n = 20, 14, 18, 24 and 14). e, Representative examples of LN capsules from Prox1-GFP mice in homeostasis (day 0) and inflammation (day 14), stained for PDGFR-β (only shown on right) and counterstained with DAPI. Scale bars, 200 µm. f, Quantification of capsule thickness as in e (n = 6, 6, 8, 7 and 5). g, Capsule stiffness measurements of homeostatic (day 0) and inflamed (days 2, 4, 8 and 14) explanted popliteal LNs labeled with ERT-R7 antibody. Scale bar, 50 µm. h, Quantification of capsule stiffness as in g (n = 8, 9, 9, 4 and 6). i, Quantification of passive tension (n = 6, 6, 8, 7 and 5). Data from b, d, f, h and i are shown as the mean ± s.e.m. Datapoints in b and d represent independent cuts, and data in f, h and i show independently measured LNs. Statistical analysis was performed using the Kruskal-Wallis test (b, f, h and i) and one-way ANOVA (d). All experiments were repeated independently (≥4 lymph nodes from ≥4 mice and ≥2 experiments) and data from b and d was pooled for each condition. For statistical details, see Supplementary Table 1. *P < 0.05, **P < 0.01, ***P < 0.001.
