(A) Recipient monocytes (CD45.2⁺CD11b⁺Ly6C^hi) were isolated from the bone marrow or lung grafts in resting mice or 2 hours after transplantation of B6 CD45.1⁺ lungs into B6 CD45.2⁺ recipients, and their expression levels of Il1b, Tnfa, Cxcl1, Cxcl2, and Cxcl5 were analyzed by quantitative PCR. n = 4 each compartment with 1 statistical outlier for Cxcl1 and 1 statistical outlier for Cxcl5 in the lung excluded from analysis. *P < 0.05, Mann-Whitney U test. (B) Expression levels of IL1B in human donor grafts at conclusion of cold ischemia and 2 hours after reperfusion, assessed by quantitative PCR. n = 5. **P < 0.01, paired t test. (C) Arterial blood oxygenation was assessed and absolute numbers of recipient (D) monocytes and (E) neutrophils were determined in lung grafts 24 hours after transplantation of B6 CD45.1⁺ lungs into splenectomized congenic B6 CD45.2⁺ recipients that received either B6 WT or B6 IL-1β–deficient monocytes. Data are expressed as median with interquartile range. n = 6 per group. **P < 0.01, Mann-Whitney U test. (F) Representative contour plots of extravascular vs. intravascular neutrophils and quantification of the percentage of graft-infiltrating neutrophils in lung grafts and (G) number of neutrophils in BALF 24 hours after transplantation of B6 CD45.1⁺ lungs into splenectomized B6 CD45.2⁺ recipients that received B6 WT or B6 IL-1β–deficient monocytes. Data are expressed as median with interquartile range. n = 6 per group. *P < 0.05; **P < 0.01, Mann-Whitney U test. (H) Representative intravital 2-photon microscopy of B6 WT or B6 IL-1R–KO lung grafts 2 hours after transplantation into syngeneic B6 LysM-GFP mice and quantification of neutrophil extravasation. Qdot 655 labeled the vessels red. Recipient neutrophils are green. Scale bar: 50 μm. Data are expressed as median with interquartile range. n = 4 per group. *P < 0.05, Mann-Whitney U test.