title: Pulmonary surfactant suppresses the immune lung injury response to inhaled antigen in guinea pigs.
abstract: Pulmonary surfactant (PS) has been shown to regulate the function of macrophages, T cells, B cells, and NK cells in vitro. We designed this study to explore the immunoregulatory role of PS in vivo. Guinea pigs were immunized to complete Freund's adjuvant (CFA) and 2 weeks later were subjected to an aerosol challenge with purified protein derivative (PPD) to induce immune lung injury (group I). Group II and group III were subjected to lung lavage by tracheostomy just before aerosol challenge. Group II was lavaged with 0.9% NaCl, which depleted PS by 32%. Group III was lavaged with 0.9% NaCl containing bovine surfactant, which did not alter total PS content. Control animals for each condition were not presensitized to CFA. All guinea pigs were killed 24 hours after the aerosol challenge; for each group n = 10 +/- 2. Bronchoalveolar lavage (BAL) protein and mononuclear leukocyte counts, as well as lung histopathologic grading, were performed. Group I animals showed evidence of mild immune lung injury by these parameters. Animals partially depleted of PS (group II) showed more severe lung injury with greater abnormalities in BAL leukocytes and histopathology compared with group I. Guinea pigs lavaged with fluid containing bovine surfactant (group III) were nearly identical to group I with respect to these two parameters. BAL protein levels were not related to PS depletion. This study suggests that surfactant may have an in vivo role in modulating the inflammatory response that accompanies immune lung injury in this model.
authors.affiliation: Department of Medicine, University of California, San Diego Medical Center.
authors.forename: P S
authors.initials: PS
authors.lastname: Richman
authors.forename: S
authors.initials: S
authors.lastname: Batcher
authors.forename: A
authors.initials: A
authors.lastname: Catanzaro
mesh_terms: D000336:Aerosols; D000542:Alveolitis, Extrinsic Allergic / Q000276:immunology; D000818:Animals; D000941:Antigens / Q000276:immunology*; D001992:Bronchoalveolar Lavage Fluid; D004195:Disease Models, Animal; D006168:Guinea Pigs; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008168:Lung / Q000276:immunology* / Q000473:pathology; D011663:Pulmonary Surfactants / Q000276:immunology*
chemical_list: D000336:Aerosols; D000941:Antigens; D011663:Pulmonary Surfactants