Fig. 1: The reactive lymph node resists swelling.
From: Multitier mechanics control stromal adaptations in the swelling lymph node
a, Volumes of swelling LNs calculated from 2D side views over the course of 2 weeks after immunization (n = 46). Means are connected (blue line) and a linear regression line (dashed) has been fitted to the data. b, Measured geometrical parameters annotated on 2D side images during a measurement (25% strain). Force is measured on the top plate. Scale bar, 300 µm. H0, LN height before compression; L, LN length before compression; Heq, LN height at equilibrium. R1, R2 and R3 indicate measured radii. c, Stress relaxation curve from the measured force over time (left) and the corresponding force fit (right). Colored arrows indicate short-, medium- and long-term relaxations. Force is fitted with a double exponential equation (blue line). The arrow (black) indicates force at equilibrium (Feq). d–f, Quantification of the effective resistance (d; n = 8, 11, 8, 9 and 10), viscosity (e; n = 8, 11, 7, 6 and 10) and Young’s modulus (f; n = 8, 11, 8, 9 and 10). g–j, Stress relaxation measurements in LNs of wild-type (WT) mice during homeostasis (day 0; g and h) and in LNs of wild-type or OT-II mice during inflammation (day 4; i and j) following treatment with PBS or CD62L antibody intravenously injected 24 h before measurements at day 0 or injected at immunization for measurements at day 4. g,i, Representative side views of explanted and measured LNs. Scale bars, 300 µm (g) and 400 µm (i). h, Quantification of LN volume (left, n = 11 and 9) and quantification of effective resistance (right, n = 11 and 9). j, Quantification of LN volume (n = 13, 16, 8 and 12) and effective resistance (n = 13, 16, 8 and 11). Data from a, d–f, h and j are shown as the mean ± s.e.m. and individual datapoints represent independent measurements of single popliteal LNs. Statistical analysis was performed using Kruskal-Wallis test (d–f), unpaired two-tailed t-test (h; left), two-tailed Mann-Whitney test (j; left; y = (y0.8–1)/0.8 transformed) and two-way analysis of variance (ANOVA; h, right, j, right; y = ln(y) transformed). All experiments were repeated independently (≥5 mice and ≥3 experiments). For statistical details, see Supplementary Table 1. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.
