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The human surfactant protein A (SP-A) locus consists of two functional genes (SP-A1, SP-A2) with gene-specific products exhibiting qualitative and quantitative differences. The aim here was twofold: 1) generate SP-A1 genespecific antibody, and 2) use this to assess gene-specific SP-A content in the bronchoalveolar lavage fluid (BALF). An SP-A1-specific polyclonal antibody (hSP-Al_[Ab.sup.68-88]_Col) was raised in chicken, and its specificity was determined by immunoblot and ELISA using mammalian Chinese hamster ovary (CHO) cell-expressed SP-A1 and SP-A2 variants and by immunofluorescence with stably transfected CHO cell lines expressing SP-A1 or SP-A2 variants. SP-A1 content was evaluated according to age and lung status. A gradual decrease (P < 0.05) in SP-A1/SP-A ratio was observed in healthy subjects (HS) with increased age, although no significant change was observed in total SP-A content among age groups. Total SP-A and SP-A1 content differed significantly between alveolar proteinosis (AP) patients and HS, with no significant difference observed in SP-A1/SP-A ratio between AP and HS. The cystic fibrosis (CF) ratio was significantly higher compared with AP, HS, and noncystic fibrosis (NCF), even though SP-A1 and total SP-A were decreased in CF compared with most of the other groups. The ratio was higher in culture-positive vs. culture-negative samples from CF and NCF (P = 0.031). A trend of an increased ratio was observed in culture-positive CF (0.590 [+ or -] 0.10) compared with culture-positive NCF (0.368 [+ or -] 0.085). In summary, we developed and characterized an SP-A1 gene-specific antibody and used it to identify gene-specific SP-A content in BALFs as a function of age and lung health. alveolar proteinosis; bronchoalveolar lavage fluid; cystic fibrosis; peptide antibody; surfactant protein A doi:10.1152/ajplung.00249.2006

Bonfield, Tracey L., Baisakhi Raychaudhuri, Anagha Malur, Susamma Abraham, Bruce C. Trapnell, Mani S. Kavuru, and Mary Jane Thomassen. PU.1 regulation of human alveolar macrophage differentiation requires granulocyte-macrophage colony-stimulating factor. Am J Physiol Lung Cell Mol Physiol 285: L1132-L1136, 2003. First published August 1, 2003; 10.1152/ajplung.00216.2003.--Granulocyte-macrophage colony-stimulating factor (GM-CSF) is critically implicated in lung homeostasis in the GM-CSF knockout mouse model. These animals develop an isolated lung lesion reminiscent of pulmonary alveolar proteinosis (PAP) seen in humans. The development of the adult form of human alveolar proteinosis is not due to the absence of a GM-CSF gene or receptor defect but to the development of an anti-GM-CSF autoimmunity. The role of GM-CSF in the development of PAP is unknown. Studies in the GM-CSF knockout mouse have shown that lack of PU.1 protein expression in alveolar macrophages is correlated with decreased maturation, differentiation, and surfactant catabolism. This study investigates PU. 1 expression in vitro and in vivo in human PAP alveolar macrophages as well as the regulation of PU.1 by GM-CSF. We show for the first time that PU.1 mRNA expression in PAP bronchoalveolar lavage cells is deficient compared with healthy controls. PU.1-dependent terminal differentiation markers CD32 (FC[gamma]II), mannose receptor, and macrophage colony-stimulating factor receptor (M-CSFR) are decreased in PAP alveolar macrophages. In vitro studies demonstrate that exogenous GM-CSF treatment upregulated PU.1 and M-CSFR gene expression in PAP alveolar macrophages. Finally, in vivo studies showed that PAP patients treated with GM-CSF therapy have higher levels of PU.1 and M-CSFR expression in alveolar macrophages compared with healthy control and PAP patients before GM-CSF therapy. These observations suggest that PU.1 is critical in the terminal differentiation of human alveolar macrophages. PU-1; c-fms; alveolar proteinosis

Transplanting gene-corrected macrophage cells directly into the lungs of mice has been shown to effectively treat their pulmonary alveolar proteinosis, a hereditary lung disease also found in humans. See Article [...]

Normal and asthmatic human pulmonary epithelial cells were analyzed to determine the mechanisms of respiratory antioxidant response to chronic oxidant stress in the bronchial epithelial cells. The pulmonary epithelial cells of asthmatics exhibited lower superoxide dismutase activity during chronic oxidant stress compared to normal bronchial epithelial cells. The asthmatic airway epithelium also exhibited impaired Cu, Zn-superoxide dismutase (SOD) activity due to the inactivation of the Cu, Zn-SOD protein.

Surfactants play an important regulatory role in lung fibroblasts, especially during lung injury in humans. Surfactants downregulate DNA and secondary inflammatory mediator synthesis in the adult respiratory distress syndrome. Synthetic and natural surfactants inhibit the incorporation of fibroblast labeled thymidine. The antioxidant, N-acetyl-l-cysteine also inhibits labeled thymidine incorporation. Surfactant inhibits the stimulatory action of menadione on labeled thymidine incorporation, and the interleukin (IL)-1-stimulated secretion of IL-6 and prostaglandin.

Abstract Background Although granulomatous inflammation is a central feature of many disease processes, cellular mechanisms of granuloma formation and persistence are poorly understood. Carbon nanoparticles, which can be products of manufacture or the environment, have been associated with granulomatous disease. This paper utilizes a previously described carbon nanoparticle granuloma model to address the issue of whether peroxisome proliferator-activated receptor gamma (PPARγ), a nuclear transcription factor and negative regulator of inflammatory cytokines might play a role in granulomatous lung disease. PPARγ is constitutively expressed in alveolar macrophages from healthy individuals but is depressed in alveolar macrophages of patients with sarcoidosis, a prototypical granulomatous disease. Our previous study of macrophage-specific PPARγ KO mice had revealed an intrinsically inflammatory pulmonary environment with an elevated pro-inflammatory cytokines profile as compared to wild-type mice. Based on such observations we hypothesized that PPARγ expression would be repressed in alveolar macrophages from animals bearing granulomas induced by MWCNT instillation. Methods Wild-type C57Bl/6 and macrophage-specific PPARγ KO mice received oropharyngeal instillations of multiwall carbon nanotubes (MWCNT) (100 μg). Bronchoalveolar lavage (BAL) cells, BAL fluids, and lung tissues were obtained 60 days post-instillation for analysis of granuloma histology and pro-inflammatory cytokines (osteopontin, CCL2, and interferon gamma [IFN-γ] mRNA and protein expression. Results In wild-type mice, alveolar macrophage PPARγ expression and activity were significantly reduced in granuloma-bearing animals 60 days after MWCNT instillation. In macrophage-specific PPARγ KO mice, granuloma formation was more extensive than in wild-type at 60 days after MWCNT instillation. PPARγ KO mice also demonstrated elevated pro-inflammatory cytokine expression in lung tissue, laser-microdissected lung granulomas, and BAL cells/fluids, at 60 days post MWCNT exposure. Conclusions Overall, data indicate that PPARγ deficiency promotes inflammation and granuloma formation, suggesting that PPARγ functions as a negative regulator of chronic granulomatous inflammation.