Figure 3.

Effects of inhibition of angiopoietin-2 (Ang2) and/or tumor necrosis factor (TNF) on lymphatic sprouting during Mycoplasma pulmonis infection (7 days). A–E: Confocal microscopic images of lymphatic vessels [red, lymphatic vessel endothelial hyaluronan receptor (LYVE-1)] in the mucosa over cartilage rings of tracheal whole mounts. Lymphatic sprouts are absent in the pathogen-free mouse (A) but appear as abundant tapered, finger-like sprouts (arrowheads) after infection (B). Lymphatic sprouts are less numerous after treatment with anti-Ang2 antibody (C) or anti-TNF antibody (D) and absent after treatment with both antibodies (E). F: Lymphatic sprouts, expressed per mm² of mucosa, are rare in pathogen-free mice (1 ± 0.3 per mm²) but are 50 times as abundant after infection for 7 days (55 ± 10 per mm²). Lymphatic sprouts reduce by treatment with anti-Ang2 antibody (30 ± 7 per mm²) or anti-TNF antibody (15 ± 5 per mm²) and are nearly absent with both antibodies (1.3 ± 0.4 per mm²). Data are given as means ± SEM (F). N = 7 to 10 mice per group (F). ^∗P < 0.05 versus pathogen-free group; ^†P < 0.05 versus infected vehicle group treated with phosphate-buffered saline vehicle. Scale bar = 50 μm (E, applies to A–E).