Figure 3.

IL-22 is produced by conventional lymphocytes such as NK cells. Multiple lymphocyte subsets including NK cells are able to produce IL-22. Representative confocal images of tracheal sections of mice infected with influenza virus (PR8) were stained for NCR1 (azure), NK1.1 (blue), and IL-22 (red). Scale bars in the images represent 20 μM. The number of NK cells producing IL-22 steadily increased in the later stages (7-12 days) of influenza virus infection, when epithelial cell layer repair was underway.