Extended Data Fig. 1: PbTII cells localise to T cell zones, B cell follicles and GCs during infection.

a, Representative FACS plots for surface CXCR6 and CXCR5 expression on PbTII cells at various timepoints during infection. Graphs showing proportion of CXCR6⁺ or CXCR5⁺ PbTII cells over time. Data are pooled from 3 independent experiments (n=5 mice per group, per individual timepoint for each independent experiment) and presented as mean +/- SEM. Statistical analysis was performed between saline and IAT groups for each individual timepoint using two-tailed Mann-Whitney test. p-values where indicated are **p< 0.01, ***p<0.001, ****p<0.0001. b, eGFP⁺ PbTII cells were distributed throughout splenic B cell follicles and T cell zones at D7 p.i. (n=4). Graph showing proportion of PbTII cells localised within B cell (IgD) or T cell (CD3) zones. Scale bar, 2mm. c, Standard microanatomical structures observed in saline-treated mice at D21 p.i. White arrows indicate eGFP⁺ PbTII cells. Scale bar, 100µm. d, Localisation of PbTII cells within GCs and IgD⁺ naive B cell follicle regions of mice at D21 p.i. in the presence or absence of IAT. Graph showing proportion of PbTII cells localised within GCs or follicular regions of saline- (n=6) or IAT- (n=5) treated mice. Scale bar, 2mm. Images were acquired on an Aperio FL slide scanner (b, d) or a Zeiss 780-NLO point scanning confocal microscope (c).