Journal: iScience
Article Title: TLR ligand sensing by lymph node FRCs directs intranodal lymphocyte accumulation to promote immune responses
doi: 10.1016/j.isci.2025.113734
Figure Lengend Snippet: LPS directs intranodal lymphocyte accumulation via increased CCL19/CCL21 expression (A–C) Lymphocyte numbers in the popliteal LNs of WT (A), Tlr4 −/− (B) or Myd88 −/− (C) mice 6 h after s.c. injection of PBS or LPS. n = 12 WT mice/group, 9–10 Tlr4 −/− mice/group, 6–8 Myd88 −/− mice/group. Unpaired t test. Numbers at the top of the graphs indicate fold changes in cellularity as compared to PBS injections. (D) Representative FACS plots, number of de novo accumulating lymphocytes, and competitive B and T cell ratios between CD45.1 + WT and CD45.2 + Tlr4 −/− lymphocytes recovered from the popliteal lymph nodes of CD45.1 + CD45.2 + WT recipients 6 h after i.v cell injection, and PBS or LPS s.c administration. n = 7 mice/group. two-way ANOVA with Sidak’s multiple comparisons post-test (left) and unpaired t test (right). (E) Number of de novo accumulating CD45.1 + WT B cells and T cells recovered from the popliteal lymph nodes of WT: Tlr4 −/− chimeric mice 6 h after i.v cell injection and LPS s.c administration. n = 9 mice/group. one-way ANOVA with Tukey’s multiple comparisons post-test. (F) Representative immunofluorescence images and quantification of intranodal PNAd, CCL21, CXCL13 and VCAM1 expression on lymph node stromal cells, 6 h after PBS or LPS administration to WT mice. Signals are depicted in a divergent scale of red to yellow. Scale bar, 200 μm; insets = 50 μm. n = 4 mice/group. Two-way ANOVA with Sidak’s multiple comparisons post-test. Numbers at the top of the graphs indicate fold changes in MFI expression as compared to PBS injections. (G) Intranodal CCL19, CCL21, and CXCL13 expression as quantified by ELISA, 6 h after PBS or LPS administration to WT, Tlr4 −/− or Myd88 −/− mice. n = 3–4 mice/group. Two-way ANOVA with Sidak’s multiple comparisons post-test. (H) Representative FACS plots and number of de novo accumulating CD45.1 + WT and CD45.2 + Ccr7 −/− lymphocytes recovered from the popliteal lymph nodes of CD45.1 + CD45.2 + WT recipients 6 h after i.v cell injection, and PBS or LPS s.c administration. n = 5 mice/group. Two-way ANOVA with Sidak’s multiple comparisons post-test. (I) Representative FACS plots and number of de novo accumulating CD45.1 + WT lymphocytes recovered from the popliteal lymph nodes of CD45.2 + WT recipients 6 h after i.v donor cell injection, and PBS, recombinant CCL19 or recombinant CCL21 s.c administration. n = 5 mice/group. one-way ANOVA with Dunn’s multiple comparisons post-test. Data represent the mean ± SD with superimposed individual data points. n.s, not significant; ∗, p < 0.05; ∗∗, p < 0.01; ∗∗∗, p < 0.001; ∗∗∗∗, p < 0.0001.
Article Snippet: In some experiments, lymphocyte migration to and from lymph nodes was manipulated with anti-CD62L antibodies (BioXcell – clone Mel14; 100ug/mouse i.p ) or FTY720 (Cayman Chemicals; 10ug/mouse i.p ): in others experiments, 0.25ug of recombinant CCL19 or recombinant CCL21 proteins (R&D Systems) were injected subcutaneously in the footpad.
Techniques: Expressing, Injection, Immunofluorescence, Enzyme-linked Immunosorbent Assay, Recombinant