Effects of Ccr7 inhibition on leukocyte trafficking via pulmonary lymphatics. (A) Rosa26 ^mTmG mice were given either isotype-matched control antibody or anti-Ccr7 by o.a. together with LPS. (B–D) Leukocytes continued to flow through lung lymphatics in anti-Ccr7–treated mice, quantified in C, but these leukocytes formed intralymphatic multicell clusters, quantified in D. (E) Separate mice were administered LPS, and 18 h later were randomized to receive navarixin (5 mg/kg by oral gavage [p.o.]) or vehicle control. (F–I) At 24 h after LPS administration, treatment with navarixin reduced leukocyte flow through pulmonary lymphatics, quantified in G. This navarixin dosing strategy did not alter the extent of lung inflammation readouts of BAL fluid: (H) cell content or (I) protein concentration. White arrowheads in B and F point to intralymphatic leukocytes (also circled in white), and white arrows in B point to multicell intralymphatic leukocyte clusters. P values are from unpaired, two-tailed t tests on log₁₀-transformed datasets. Group sizes: (C and D) n = 4; (G) n = 4-6; (H and I) n = 5.