FIGURE 4.

The early phase of lymphatic vessels remodeling is dependent on IL-7. (A) Quantitative RT-PCR analysis of mRNA transcript for il-7 in wt mice at days 0, 2, 5, 8, 15, and 23 p.c. Transcripts were normalized to housekeeping gene pdgfrß. The RQ expression values were calibrated with day 0 p.c. salivary gland values. Data are representative means ± SEM of three to four experiments with six to four glands analyzed per group. *p < 0.05, **p < 0.01. (B) Histogram showing IL-7Rα expression (black) and isotype control (gray) on LECs in salivary glands at day 5 p.c. (C) Graph showing flow cytometry analysis of percentage of LEC in wt mice treated with isotype Ab (black bars) as compared with IL-7Ra blocking Ab–treated mice (gray bars) mice. Data are represented as mean ± SEM. *p < 0.05. (D) Graph showing flow cytometry analysis of absolute number of LEC in wt mice treated with isotype Ab (black bars) as compared with IL-7Ra blocking Ab–treated mice (gray bars) mice. Data are represented as mean ± SEM. (E and F) Graphs summarizing image analysis results showing differences observed in the number of lymphatic vessels/mm² of tissue area and average vessel area (mm²) in wt mice treated with IL-7Rα blocking Ab (gray bars) compared with isotype treated mice (black bars). Data are representative of two independent experiments with four to six glands analyzed per group. Data are shown as mean ± SEM. *p < 0.05, unpaired t test. (G) Representative photomicrograph of lymphatic vessels in infected salivary glands (day 5 p.c.) from IL-7Rα blocking Ab–treated mice (i and ii) in comparison with wt mice treated with isotype (iii and iv) stained for LYVE-1 (green). Scale bars, 100 μm. (H) Graphs showing summary of analysis for percentage of proliferating (BrdU⁺) gp38⁺CD31⁺ LEC within the CD45⁻EpCAM⁻ stromal fraction in wt mice treated with isotype Ab (black bars) as compared with IL-7Rα blocking Ab–treated mice (gray bars) mice. Data are represented as mean ± SEM. *p < 0.05.