TLR4 signaling contributes to macrophage trafficking to the draining lymphatic vessels. The diaphragms were analyzed at 4 and 24 hours after intraperitoneal injection of LPS (0.5 mg/kg) and transfer of approximately 2 × 10⁷ of CFSE-tagged peritoneal macrophages (green) into the peritoneal cavity. (A) Whole diaphragms were harvested and then immunostained with LYVE-1; LYVE-1⁺ diaphragmatic lymphatic vessels (red) and injected cells (green) were visualized. Scale bars indicate 200 μm. (B) The number of transferred cells (green) along the lymphatic vessel (red) was divided by the total area of LYVE-1⁺ lymphatic vessel in a given area (1 mm²). (C) At 3 days after intraperitoneal injection of PBS, CL (50 mg/kg), or CDL (50 mg/kg) into HeN and HeJ mice, LPS (0.5 mg/kg) and approximately 2 × 10⁷ of CFSE-tagged peritoneal macrophages were injected intraperitoneally. After 4 hours, whole diaphragms were harvested. The number of transferred cells along the lymphatic vessel was divided by the total area of the LYVE-1⁺ lymphatic vessel in a given area (1 mm²). The values are presented as arbitrary units (AU) compared with the value from HeN mice as 1. Bars represent means plus or minus SD (n = 4). *P < .05 versus HeN.