Treatment with IL-28A reduces neutrophil recruitment in the air pouch model of acute inflammation by limiting neutrophil migratory capacity. (a) Schematic timeline of the air pouch model showing subcutaneous air injections, treatment with IL-28A or PBS, and challenge with zymosan. (b) Total number of neutrophils per milliliter of wash recovered from the air pouches of mice that had been treated with IL-28A or PBS control before inflammatory challenge. The data are mean and SEM from 12 mice treated with IL-28A and 12 mice treated with PBS from 2 independent experiments. (c) Center-zeroed tracks of air pouch neutrophilic infiltrate in an EZ-Taxiscan migrating toward LTB4; scale is shown in micrometers. (d) The tracks presented in c were analyzed to show the Euclidean distance each cell traveled in a 45-min time period. Data shown are the average and SEM of three independent experiments, each including 9–20 movies per treatment. (e) Percentage of cells infiltrating into the air pouch staining positive for PI and Annexin V. The data are mean and SEM using 12 mice treated with IL-28A and 12 treated with PBS, from 2 independent experiments. (f) Percentage of neutrophils that were positive for pro–IL-1β and infiltrated into the air pouch space of mice. (g) Levels of IL-1β secreted into the air pouch after challenge with zymosan. (h) Percentage of neutrophils or macrophages lining the air pouch membrane that were positive for pro-IL-1β. (i) Expression of IL28RA mRNA in cells infiltrating into the air pouch space compared with cells lining the air pouch, as well as in Percoll-purified neutrophils. (f–i) The data are mean and SEM derived from six mice treated with IL-28A and six mice treated with PBS, in a representative out of two experiments. Statistical analysis was performed by two-tailed Mann-Whitney U test. *, P < 0.05; **, P < 0.01; ***, P < 0.001.