Fig. 5. Macrophages are a significant IL-10 source after lung priming.
Alveolar cells from primed and non-primed WT mice were isolated at day +1 after i.t. LPS (3 mg/kg) challenge, and then restimulated, and stained for macrophage, neutrophil, and lymphocyte flow markers as well as intracellular cytokine production. IC IL-10 production (A) and IC TNF-α production (B) were quantified by mean fluorescence intensity (MFI) in F4-80+ alveolar macrophages collected from primed and non-primed WT mice; a representative flow cytometry histogram is shown for each, and for IL-10 includes alveolar macrophages from primed IL-10−/− mice (dashed line). (C) Among F4-80+ CD11b+ alveolar cells from primed (black) and non-primed (gray) mice, a dot plot demonstrating individual cell IC production demonstrates a predominant increase in dual cytokine production from primed alveolar cells. (D) Alveolar macrophages were isolated 7 days after o.p. LPS or o.p. water (control), and stimulated with LPS (100 ng/mL); IL-10 secretion was quantified by ELISA after 18 hours of stimulation. Values expressed as mean ± SEM; *paired t-test against other group at same time point, p<0.05. (n=4-5 animals or wells per group per time point)