Extended Data Fig. 5: CCL17 and CCL22 promote TFH cell–GC B cell encounters without changing contact duration.
From: Affinity-coupled CCL22 promotes positive selection in germinal centres
a, Duration of contact between TFH cells and wild-type or CCL17/22-DKO B cells in follicles. See corresponding Supplementary Videos 1, 2 and Fig. 2a, b. b, Duration of contact between wild-type or CCR4-KO TFH cells and B cells in follicles. See corresponding Supplementary Videos 3, 4 and Fig. 2d, e. c–h, Interacting OT-II T cells and MD4 B cells in GCs 120 h post-immunization. c, Time-lapse images highlighting one CFP-expressing CCL17/22-DKO (blue arrowheads) and one GFP-expressing wild-type (green arrowheads) MD4 B cells being contacted by dsRed-expressing OT-II T cells (red arrowheads), with each incidence of contact marked by a broken white line between the two cells. Also see corresponding Supplementary Video 5. d, Time-lapse images of CFP- and GFP-expressing wild-type MD4 B cells contacted by OT-II T cells, colour-coded as in c. Also see corresponding Supplementary Video 6. e, Summary NHRB statistics. Each dot is one field imaged, red lines denote means. f, Time-lapse images highlighting dsRed-expressing CCR4-KO (red arrowhead) and GFP-expressing wild-type (green arrowheads) OT-II T cells being contacted by CFP-expressing MD4 B cells (blue arrowheads), with each incidence of contact marked by a broken white line between the two cells. Also see corresponding Supplementary Video 7. g, Time-lapse images of dsRed- and GFP-expressing wild-type OT-II T cells contacted by CFP-expressing MD4 B cells, colour-configured as in f. Also see corresponding Supplementary Video 8. h, Summary NHRB statistics. Each dot is one field imaged, red lines denote means. Data are pooled from 5 mice for WT–WT mix and 5 mice for DKO–WT mix or KO–WT mix, imaged in 3 independent experiments. P values by two-tailed t-tests. Scale bars, 20 μm. i, Durations of contacts between TFH cells and wild-type or DKO B cells in GCs, as measured in intravital imaging sessions represented by c, d and Supplementary Videos 5, 6. j, Durations of contacts between wild-type or CCR4KO TFH cells and MD4 B cells in GCs, as measured in intravital imaging sessions represented by f, g and Supplementary Videos 7, 8. Each symbol is one incidence of a T cell–B cell contact, and red lines denote means. Data are pooled from three independent experiments. P values by two-tailed t-tests.
