Figure 2: LN-like vasculature supports naive T-cell infiltration.

(a) Representative plots and summary data (n=3) for naive T-cell infiltration. Naive Thy1.1⁺ OT-I cells (4 × 10⁶) were injected i.v. into WT mice with established i.p. B16-OVA tumours. One or 18 h after transfer, tumours were harvested and infiltrating naive T cells were enumerated by flow cytometry. Numbers indicate the percentage of naive OT-I cells out of the live singlet CD45⁺ CD8⁺ parent gate. (b) WT mice with i.p. B16-OVA tumours received a 50:50 mix of Cell Trace Violet (CTV)-labelled naive Thy1.1⁺ OT-I cells and CD44^lo naive T cells from C57BL/6 mice i.v. (4 × 10⁶ total cells). Infiltration into tissues was determined after 18 h. (c) Homing efficiency (number of T cells per mg tissue) of naive OT-I cells to i.p. tumours and iLN. n=7. Naive OT-I cells pretreated with pertussis toxin (PTX) (d) or antibodies against L-selectin (CD62L), CCR7 or LFA-1 (CD11a) (e–g) were transferred into tumour-bearing mice. Infiltration into iLN (d,e), i.p. (d,f) or s.c. (g) B16-OVA tumours was determined after 18 h. n=10–17 per group (tumours) or 4 per group (iLN). Naive OT-I cells were transferred into WT mice with i.p. B16-OVA tumours pre-treated with anti-MAdCAM-1 antibody or Rat IgG isotype control (h), or anti-PNAd antibody or Rat IgM isotype control (i). Infiltration into tissues was determined 1 h after T-cell transfer. n=5 (h) or 3(i). PP, Peyer’s patches; iLN, inguinal lymph node. Data (mean+s.e.m.) are pooled from two independent experiments. ns: P>0.05, *P<0.05, **P<0.01, ***P<0.001 by unpaired t-test (a,c,h,i) or one-way analysis of variance with Dunnett’s post test (e–g).