scholarly journals Effects of endotoxin on surfactant protein A and D stimulation of NO production by alveolar macrophages

1999 ◽  
Vol 276 (4) ◽  
pp. L650-L658 ◽  
Author(s):  
Jo Rae Wright ◽  
Daniel F. Zlogar ◽  
Julie C. Taylor ◽  
Thomas M. Zlogar ◽  
Clara I. Restrepo
Keyword(s):  
Alveolar Macrophages ◽  
Protein A ◽  
Surfactant Protein ◽  
Optimal Recovery ◽  
Surfactant Protein A ◽  
No Production ◽  
Nitrite Production ◽  
Endotoxin Contamination ◽  
Nitric Oxide Metabolites ◽  
Endotoxin Content

Surfactant protein (SP) A and SP-D affect numerous functions of immune cells including enhancing phagocytosis of bacteria and production of reactive species. Previous studies have shown that SP-A and SP-D bind to a variety of bacteria and to the lipopolysaccharide (LPS) components of their cell walls. In addition, purified preparations of SPs often contain endotoxin. The goals of this study were 1) to evaluate the effects of SP-A and SP-D and complexes of SPs and LPS on the production of nitric oxide metabolites by rat alveolar macrophages and 2) to evaluate methods for the removal of endotoxin with optimal recovery of SP. Incubation of SP-A or SP-D with polymyxin, 100 mM N-octyl-β-d-glucopyranoside, and 2 mM EDTA followed by dialysis was the most effective method of those tested for reducing endotoxin levels. Commonly used storage buffers for SP-D, but not for SP-A, inhibited the detection of endotoxin. There was a correlation between the endotoxin content of the SP-A and SP-D preparations and their ability to stimulate production of nitrite by alveolar macrophages. SP-A and SP-D treated as described above to remove endotoxin did not stimulate nitrite production. These studies suggest that the functions of SP-A and SP-D are affected by endotoxin and illustrate the importance of monitoring SP preparations for endotoxin contamination.

Surfactant protein A mediates mycoplasmacidal activity of alveolar macrophages

1998 ◽  
Vol 274 (2) ◽  
pp. L270-L277 ◽  
Author(s):  
Judy M. Hickman-Davis ◽  
J. Russell Lindsey ◽  
S. Zhu ◽  
S. Matalon
Keyword(s):  
Nitric Oxide ◽  
Alveolar Macrophages ◽  
Protein A ◽  
Surfactant Protein ◽  
No Production ◽  
Nitric Oxide Synthase Inhibitor ◽  
Nitrite Production ◽  
Ifn Γ ◽  
Synthase Inhibitor ◽  
Nitrate And Nitrite

Mycoplasma pneumoniae is a leading cause of pneumonia and exacerbates other respiratory diseases in humans. We investigated the potential role of surfactant protein (SP) A in antimycoplasmal defense using alveolar macrophages (AMs) from C57BL/6NCr (C57BL) mice, which are highly resistant to infections of Mycoplasma pulmonis. C57BL AMs, activated with interferon (IFN)-γ and incubated with SP-A (25 μg/ml) at 37°C, produced significant amounts of nitric oxide (⋅ NO; nitrate and nitrite production = 1.1 μM ⋅ h−1⋅ 105AMs−1) and effected an 83% decrease in mycoplasma colony-forming units (CFUs) by 6 h postinfection. Preincubation of AMs with the inducible nitric oxide synthase inhibitor NG-monomethyl-l-arginine abolished ⋅ NO production and SP-A-mediated killing of mycoplasmas. No decrease in CFUs was seen when IFN-γ-activated macrophages were infected with mycoplasmas in the absence of SP-A despite significant ⋅ NO production (nitrate and nitrite production = 0.6 μM ⋅ h−1⋅ 105AMs−1). These results demonstrate that SP-A mediates killing of mycoplasmas by AMs, possibly through an ⋅ NO-dependent mechanism.

scholarly journals A novel procedure for the rapid isolation of surfactant protein A with retention of its alveolar-macrophage-stimulating properties

1995 ◽  
Vol 309 (2) ◽  
pp. 551-555 ◽  
Author(s):  
J F van Iwaarden ◽  
F Teding van Berkhout ◽  
J A Whitsett ◽  
R S Oosting ◽  
L M G van Golde
Keyword(s):  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Normal Rat ◽  
Normal Human ◽  
Novel Method ◽  
Alveolar Proteinosis ◽  
Simplex Virus

Previous studies have shown that surfactant protein A (SP-A) derived from alveolar-proteinosis patients activates rat alveolar macrophages. However, it is not known if normal rat, dog and human SP-A can also stimulate alveolar macrophages. As alveolar-proteinosis SP-A has a slightly different structure from ordinary SP-A, it would be possible that the ascribed alveolar-macrophage-stimulating properties of SP-A are restricted to alveolar-proteinosis SP-A. To clarify this issue, we isolated SP-A from normal rat and dog pulmonary surfactants, using the same isolation technique commonly used for the isolation of alveolar-proteinosis SP-A, i.e. by butanol precipitation. In contrast with human alveolar-proteinosis SP-A, rat and dog SP-A obtained thus could not activate rat alveolar macrophages to produce oxygen radicals or enhance the phagocytosis of fluorescein isothiocyanate-labelled herpes simplex virus. However, rat, dog and normal human SP-A isolated by a novel method, involving extraction from pulmonary surfactant by using n-octyl beta-D-glucopyranoside and subsequent purification by cation-exchange chromatography, were able to elicit an oxidative burst in rat as well as normal human alveolar macrophages. In addition, dog and rat SP-A obtained thus stimulated the phagocytosis of herpes simplex virus by rat alveolar macrophages. These findings indicate that normal human, rat and dog SP-A have the same alveolar-macrophage-stimulating properties as human alveolar proteinosis SP-A. Dog and rat SP-A isolated by this novel method had the same Ca(2+)-dependent self-aggregation and lipid-aggregation properties as SP-A isolated by butanol precipitation. The new and milder isolation procedure yielded SP-A of high purity, as judged by SDS/PAGE and ELISA.

scholarly journals Rat surfactant protein D enhances the production of oxygen radicals by rat alveolar macrophages

1992 ◽  
Vol 286 (1) ◽  
pp. 5-8 ◽  
Author(s):  
J F Van Iwaarden ◽  
H Shimizu ◽  
P H M Van Golde ◽  
D R Voelker ◽  
L M G Van Golde
Keyword(s):  
Alveolar Macrophages ◽  
Oxygen Radicals ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Surfactant Protein D ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Oxygen Radical Production ◽  
Stimulation Of

Rat surfactant protein D (SP-D) was shown to enhance the production of oxygen radicals by rat alveolar macrophages. This enhancement, which was determined by a lucigenin-dependent chemiluminescence assay, was maximal after 18 min at an SP-D concentration of 0.2 micrograms/ml. Surfactant lipids did not influence the stimulation of alveolar macrophages by SP-D, whereas the oxygen-radical production of these cells induced by surfactant protein A was inhibited by the lipids in a concentration-dependent manner.

Pathways for clearance of surfactant protein A from the lung

2005 ◽  
Vol 289 (6) ◽  
pp. L1011-L1018 ◽  
Author(s):  
Deepika Jain ◽  
Chandra Dodia ◽  
Aron B. Fisher ◽  
Sandra R. Bates
Keyword(s):  
Alveolar Macrophages ◽  
Protein A ◽  
Surfactant Protein ◽  
Cytochalasin D ◽  
Surfactant Protein A ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Space ◽  
Alveolar Cells ◽  
Specific Inhibitors

Uptake and degradation of 125I-surfactant protein A (SP-A) over a 1-h period was studied in alveolar cells in culture and in isolated perfused lungs to elucidate the mechanism for clearance of the protein from the alveolar space. Specific inhibitors of clathrin- and actin-dependent endocytosis were utilized. In type II cells, uptake of SP-A, compared with controls, was decreased by 60% on incubation with clathrin inhibitors (amantadine and phenylarsine oxide) or with the actin inhibitor cytochalasin D. All agents reduced SP-A metabolism by alveolar macrophages. Untreated rat isolated perfused lungs internalized 36% of instilled SP-A, and 56% of the incorporated SP-A was degraded. Inhibitors of clathrin and actin significantly reduced SP-A uptake by ∼54%, whereas cytochalasin D inhibited SP-A degradation. Coincubation of agents did not produce an additive effect on uptake of SP-A by cultured pneumocytes or isolated perfused lungs, indicating that all agents affected the same pathway. Thus SP-A clears the lung via a clathrin-mediated pathway that requires the polymerization of actin.

scholarly journals Surfactant protein A enhances the phagocytosis of C1q-coated particles by alveolar macrophages

2002 ◽  
Vol 283 (5) ◽  
pp. L1011-L1022 ◽  
Author(s):  
Wendy T. Watford ◽  
Molly B. Smithers ◽  
Michael M. Frank ◽  
Jo Rae Wright
Keyword(s):  
Alveolar Macrophages ◽  
Solid Phase ◽  
Protein A ◽  
Surfactant Protein ◽  
Protective Role ◽  
Innate Immune ◽  
Multiple Roles ◽  
Surfactant Protein A ◽  
Complement Protein ◽  
Functional Consequences

Surfactant protein-A (SP-A) plays multiple roles in pulmonary host defense, including stimulating bacterial phagocytosis by innate immune cells. Previously, SP-A was shown to interact with complement protein C1q. Our goal was to further characterize this interaction and elucidate its functional consequences. Radiolabeled SP-A bound solid-phase C1q but not other complement proteins tested. The lectin activity of SP-A was not required for binding to C1q. Because C1q is involved in bacterial clearance but alone does not efficiently enhance the phagocytosis of most bacteria, we hypothesize that SP-A enhances phagocytosis of C1q-coated antigens. SP-A enhanced by sixfold the percentage of rat alveolar macrophages in suspension that phagocytosed C1q-coated fluorescent beads. Furthermore, uptake of C1q-coated beads was enhanced when either beads or alveolar macrophages were preincubated with SP-A. In contrast, SP-A had no significant effect on the uptake of C1q-coated beads by alveolar macrophages adhered to plastic slides. We conclude that SP-A may serve a protective role in the lung by interacting with C1q to enhance the clearance of foreign particles.

scholarly journals Surfactant Protein A Prevents IFN-γ/IFN-γ Receptor Interaction and Attenuates Classical Activation of Human Alveolar Macrophages

2016 ◽  
Vol 197 (2) ◽  
pp. 590-598 ◽  
Author(s):  
Carlos M. Minutti ◽  
Belén García-Fojeda ◽  
Alejandra Sáenz ◽  
Mateo de las Casas-Engel ◽  
Raquel Guillamat-Prats ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Receptor Interaction ◽  
Classical Activation ◽  
Human Alveolar Macrophages ◽  
Ifn Γ
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