Research Article

TRAIL-Dependent Resolution of Pulmonary Fibrosis

Figure 2

Gr-1+ myeloid cells were recruited in a temporal manner to the lung and their depletion exacerbated bleomycin-induced fibrosis. Bleomycin-challenged mice were killed at days 14, 21, and 42 and their lungs were isolated for analysis. (a) Lungs were digested to generate a cellular suspension; the cells were stained with the following antibodies for flow cytometry: Gr-1, CD11b, CD11c, F4/80, and CD80. (b) Mice were unchallenged (i.e., naïve) or received bleomycin 14 or 21 days previously. Other groups of mice (n = 5–10/group) were treated with control IgG or anti-Gr-1 mAb at day 21 and were subsequently analyzed at day 42 after bleomycin. Whole lungs were fixed, paraffin-embedded, sectioned, and Masson’s trichrome-stained to visualize ECM. Shown are representative images taken at 200x magnification (naïve, day 14, and day 21) or 40x magnification (day 42 and day 42 + αGr-1). (c) Quantitative PCR analysis of procollagen 3 and fibronectin 1 in whole lung samples. Data are mean ± SEM, n = 5–10/group, compared with IgG control group.
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