Fig. 4

Histopathology from IMP co-administration study. Mice were exposed to silica or vehicle weekly for the first four weeks, while receiving IMP or PBS by osmotic pump for entire six week duration. Light photomicrographs are H&E-stained lung tissue sections from mice treated with (a) vehicle, (b) IMP, (c) silica, and (d) silica + IMP. Silica-induced histopathology included alveolar proteinosis (asterisk), microgranuloma (solid arrow), perivascular and peribronchioloar ectopic lymphoid tissue (dashed arrow; lymphoplasmacytic infiltrate). IMP treatment reduced severity of silica-related lesions, with minimal alveolar proteinosis and a small microgranuloma. Abbreviations: a = alveolar parenchyma; b = bronchiolar airway; v = blood vessel. Tissue was observed from n ≥ 3 mice per treatment condition