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.

SP-A1 and SP-A2 variants differentially enhance association ofPseudomonas aeruginosawith rat alveolar macrophages

2005 ◽  
Vol 288 (1) ◽  
pp. L150-L158 ◽  
Author(s):  
Anatoly N. Mikerov ◽  
Todd M. Umstead ◽  
Weixiong Huang ◽  
Wenlei Liu ◽  
David S. Phelps ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Single Gene ◽  
Protein A ◽  
Surfactant Protein ◽  
Phagocytic Index ◽  
Dependent Manner ◽  
Gene Products ◽  
Concentration Dependent Manner ◽  
Cell Association

Chronic airway inflammation caused by Pseudomonas aeruginosa is an important feature of cystic fibrosis (CF). Surfactant protein A (SP-A) enhances phagocytosis of P. aeruginosa. Two genes, SP-A1 and SP-A2, encode human SP-A. We hypothesized that genetically determined differences in the activity of SP-A1 and SP-A2 gene products exist. To test this, we studied association of a nonmucoid P. aeruginosa strain (ATCC 39018) with rat alveolar macrophages in the presence or absence of insect cell-expressed human SP-A variants. We used two trios, each consisting of SP-A1, SP-A2, and their coexpressed SP-A1/SP-A2 variants. We tested the 6A2and 6A4alleles (for SP-A1), the 1A0and 1A alleles (for SP-A2), and their respective coexpressed SP-A1/SP-A2 gene products. After incubation of alveolar macrophages with P. aeruginosa in the presence of the SP-A variants at 37°C for 1 h, the cell association of bacteria was assessed by light microscopy analysis. We found 1) depending on SP-A concentration and variant, SP-A2 variants significantly increased the cell association more than the SP-A1 variants (the phagocytic index for SP-A1 was ∼52–95% of the SP-A2 activity); 2) coexpressed variants at certain concentrations were more active than single gene products; and 3) the phagocytic index for SP-A variants was ∼18–41% of the human SP-A from bronchoalveolar lavage. We conclude that human SP-A variants in vitro enhance association of P. aeruginosa with rat alveolar macrophages differentially and in a concentration-dependent manner, with SP-A2 variants having a higher activity compared with SP-A1 variants.

Surfactant protein A, but not surfactant protein D, is an opsonin for influenza A virus phagocytosis by rat alveolar macrophages

1997 ◽  
Vol 27 (4) ◽  
pp. 886-890 ◽  
Author(s):  
Cornelis A. Benne ◽  
Barry Benaissa-Trouw ◽  
Jos A. G. Van Strijp ◽  
Cornelis A. Kraaijeveld ◽  
J. Freek F. Van Iwaarden
Keyword(s):  
Influenza A Virus ◽  
Alveolar Macrophages ◽  
Influenza A ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Surfactant Protein D

scholarly journals Human surfactant protein A with two distinct oligomeric structures which exhibit different capacities to interact with alveolar type II cells

1996 ◽  
Vol 317 (3) ◽  
pp. 939-944 ◽  
Author(s):  
Akiko HATTORI ◽  
Yoshio KUROKI ◽  
Hitoshi SOHMA ◽  
Yoshinori OGASAWARA ◽  
Toyoaki AKINO
Keyword(s):  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Dependent Manner ◽  
Type Ii ◽  
Concentration Dependent Manner ◽  
Lower Affinity ◽  
Alveolar Proteinosis

The lung lavage fluids from patients with pulmonary alveolar proteinosis have been generally used as a source for human surfactant protein A (SP-A). We have recently found that a multimerized form of SP-A oligomer (alveolar proteinosis protein-I, APP-I) exists besides the normal-sized octadecamer (APP-II) in SP-As isolated from the patients. When analysed by Bio-Gel A15m column chromatography in 5 mM Tris buffer (pH 7.4), the apparent molecular masses of APP-I and APP-II were 1.65 MDa and 0.93 MDa, respectively. Gel-filtration analysis also revealed that APP-II is clearly separated from APP-I in the presence of 2 mM Ca2+ and 150 mM NaCl. We investigated the abilities of both SP-A oligomers to regulate phospholipid secretion and to bind to alveolar type II cells. Although APP-I inhibited lipid secretion, it was clearly a less effective inhibitor than APP-II. IC50 for inhibition of lipid secretion was apparently 0.23±0.08 µg/ml (0.14±0.05 nM) and 0.055±0.019 µg/ml (0.059±0.020 nM) for APP-I and APP-II, respectively. Both proteins bound to monolayers of type II cells in a concentration-dependent manner; however, APP-I clearly had a lower affinity to bind to type II cells. The apparent dissociation contants were, Kd = 2.31±0.70 µg/ml (1.40±0.43 nM) and 0.89±0.22 µg/ml (0.95±0.24 nM) for APP-I and APP-II, respectively. Excess unlabelled rat SP-A replaced 45% of 125I-APP-I and 77% of 125I-APP-II for type II cell binding. Although 125I-APP-II competed with excess unlabelled APP-I or APP-II, 125I-APP-I failed to compete and instead its binding rather increased in the presence of unlabelled APPs. The biotinylated APP-I bound to APP-I and APP-II coated on to microtitre wells in a concentration-dependent manner, indicating that APP-I interacts with APPs. This study demonstrates that the multimerized form of human SP-A oligomer exhibits the following attributes: (1) the reduced capacity to regulate phospholipid secretion from type II cells, and (2) lower affinity to bind to type II cells, and that the integrity of a flower-bouquet-like octadecameric structure of SP-A oligomer is important for the expression of full activity of this protein, indicating the importance of the oligomeric structure of mammalian lectins with collagenous domains.

Pulmonary surfactant protein A stimulates chemotaxis of alveolar macrophage

1993 ◽  
Vol 264 (4) ◽  
pp. L338-L344 ◽  
Author(s):  
J. R. Wright ◽  
D. C. Youmans
Keyword(s):  
Pulmonary Surfactant ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Macrophage Migration ◽  
Dependent Manner ◽  
Directed Movement ◽  
Concentration Dependent Manner ◽  
Pulmonary Surfactant Protein ◽  
Checker Board

Pulmonary surfactant modulates several functions of alveolar macrophages including phagocytosis, killing, and chemotaxis. We hypothesized that the reported stimulatory effect of surfactant on macrophage migration was mediated by one of the surfactant proteins, SP-A. We found that macrophage migration was stimulated by SP-A in a concentration-dependent manner. A concentration of 105 micrograms SP-A/ml enhanced migration approximately 10-fold. Heat treatment or reduction and alkylation of SP-A reduced its stimulatory effect. A checker-board analysis showed that SP-A stimulated migration primarily by enhancing chemotaxis (directed movement) rather than chemokinesis (random movement). The interaction of SP-A with macrophages may be mediated at least partly by the collagen-like domain of SP-A. We speculate that SP-A may play a multifunctional role in regulating pulmonary immune response by stimulating multiple macrophage functions.

Surfactant protein A enhances the binding and deacylation ofE. coliLPS by alveolar macrophages

1999 ◽  
Vol 276 (3) ◽  
pp. L540-L547 ◽  
Author(s):  
Cordula Stamme ◽  
Jo Rae Wright
Keyword(s):  
Alveolar Macrophages ◽  
Protein A ◽  
Surfactant Protein ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cell Surface Molecule ◽  
Molar Ratios ◽  
A Cell ◽  
First Time ◽  
Lps Binding

Surfactant protein (SP) A and SP-D are involved in multiple immunomodulatory functions of innate host defense partly via their interaction with alveolar macrophages (AMs). In addition, both SP-A and SP-D bind to bacterial lipopolysaccharide (LPS). To investigate the functional significance of this interaction, we first tested the ability of SP-A and SP-D to enhance the binding of tritium-labeled Escherichia coli LPS to AMs. In contrast to SP-D, SP-A enhanced the binding of LPS by AMs in a time-, temperature-, and concentration-dependent manner. Coincubation with surfactant-like lipids did not affect the SP-A-mediated enhancement of LPS binding. At SP-A-to-LPS molar ratios of 1:2–1:3, the LPS binding by AMs reached 270% of control values. Second, we investigated the role of SP-A in regulating the degradation of LPS by AMs. In the presence of SP-A, deacylation of LPS by AMs increased by ∼2.3-fold. Pretreatment of AMs with phosphatidylinositol-specific phospholipase C had no effect on the SP-A-enhanced LPS binding but did reduce the amount of serum-enhanced LPS binding by 50%, suggesting that a cell surface molecule distinct from CD14 mediates the effect of SP-A. Together the results for the first time provide direct evidence that SP-A enhances LPS binding and degradation by AMs.

scholarly journals Surfactant protein A enhances alveolar macrophage phagocytosis of a live, mucoid strain ofP. aeruginosa

1999 ◽  
Vol 277 (4) ◽  
pp. L777-L786 ◽  
Author(s):  
William I. Mariencheck ◽  
Jordan Savov ◽  
Qun Dong ◽  
Michael James Tino ◽  
Jo Rae Wright
Keyword(s):  
Outer Membrane ◽  
Fluorescent Microscopy ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Macrophage Phagocytosis ◽  
Live Bacteria ◽  
Membrane Components

In this study, we investigate the interaction between surfactant protein A (SP-A) and a live, mucoid strain of Pseudomonas aeruginosa and identify a mechanism of clearance of this organism by alveolar macrophages.125I-labeled SP-A bound live, but not heat-killed, P. aeruginosaorganisms in a concentration-dependent manner. Unlabeled SP-A bound live bacteria, protein isolated from whole organisms, and specific proteins of the P. aeruginosa outer membrane. The binding of SP-A to P. aeruginosa and outer membrane components was inhibited by either EDTA or mannose. Phagocytosis assays with fluorescent microscopy demonstrated that the percentage of macrophages with internalized FITC-labeled P. aeruginosa was increased 1.8-fold (19 vs. 35%) by pretreating the live bacteria with SP-A. This finding was confirmed by direct visualization of ingested bacteria by electron microscopy. Adhering macrophages to SP-A-coated surfaces attenuated the increased uptake of P. aeruginosa pretreated with SP-A, suggesting that SP-A acts as an opsonin to stimulate macrophage phagocytosis of this strain of P. aeruginosa.

scholarly journals Regulation of Protein Phosphorylation and Pathogen Phagocytosis by Surfactant Protein A

1999 ◽  
Vol 67 (9) ◽  
pp. 4693-4699 ◽  
Author(s):  
Trista L. Schagat ◽  
Michael James Tino ◽  
Jo Rae Wright
Keyword(s):  
Protein Phosphorylation ◽  
Alveolar Macrophages ◽  
Actin Polymerization ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein A ◽  
Sodium Dodecyl ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Dependent Manner ◽  
Cell Functions

ABSTRACT Surfactant protein A (SP-A), a pulmonary member of the collectin family of proteins, facilitates the rapid clearance of pathogens by upregulating immune cell functions in the lungs. SP-A binds to bacteria and targets them for rapid phagocytosis by alveolar macrophages, but the mechanism by which this stimulation occurs is not clear. To characterize the intracellular events that may be involved, we examined the roles of protein phosphorylation and cytoskeletal polymerization in SP-A-stimulated phagocytosis. In rat alveolar macrophages, SP-A stimulated rapid tyrosine phosphorylation of specific proteins in a dose- and time-dependent manner. The pattern of proteins that were phosphorylated in response to SP-A, as resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was similar to that observed for immunoglobulin G (IgG)-stimulated macrophages. Both SP-A and IgG stimulated increases in phagocytosis of Streptococcus pneumoniae above levels in the absence of added protein by 394% ± 81% and 200% ± 25%, respectively. Phagocytosis in both cases was dependent on tyrosine kinases, protein kinase C, and actin polymerization but not on microtubule activity. These studies show that SP-A utilizes pathways similar to those used by IgG to increase macrophage phagocytosis of bacteria.

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 Surfactant protein D binding to alveolar macrophages

1994 ◽  
Vol 300 (1) ◽  
pp. 237-242 ◽  
Author(s):  
K Miyamura ◽  
L E A Leigh ◽  
J Lu ◽  
J Hopkin ◽  
A López Bernal ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Serum Proteins ◽  
Specific Binding ◽  
Lectin Binding ◽  
Protein A ◽  
Direct Interaction ◽  
Surfactant Protein ◽  
Lung Epithelial Cells ◽  
Surfactant Protein D ◽  
Apparent Dissociation Constant

Surfactant protein D (SP-D) is a lung-specific protein, synthesized and secreted by lung epithelial cells. It belongs to group III of the family of C-type lectins; each member of this group has an unusual overall structure consisting of multiple globular ‘head’ regions (which contain the C-type lectin domains) linked by triple-helical, collagen-like, strands. This group includes the surfactant protein A (SP-A) and the serum proteins mannan-binding protein, conglutinin and collectin-43, all of which have been shown to bind to the C1q receptor found on a wide variety of cells, including macrophages. Both SP-D and SP-A have been shown to enhance oxygen radical production by alveolar macrophages. Although this strongly suggests a direct interaction between SP-D and a specific receptor on alveolar macrophages, it is still unclear whether SP-D binds to the same receptor used by SP-A and/or C1q. Human SP-D was isolated from amniotic fluid and was radiolabelled using 125I. Alveolar macrophages were isolated from human bronchioalveolar lavage fluid, and also from bovine lung washings, by differential adhesion to 24-well tissue-culture plates. The study was carried out using EDTA-containing buffers, to eliminate Ca(2+)-dependent C-type lectin binding, and was also carried out at 4 degrees C to eliminate possible internalization by the cells. 125I-SP-D showed specific binding to alveolar macrophages in both a time- and concentration-saturable manner. The binding was inhibited, by approx. 90%, on addition of a 200-fold excess of unlabelled SP-D. The apparent dissociation constant (Kd) was (3.6 +/- 1.3) x 10(-11) M, based on the assumption that native SP-D is assembled as a dodecamer of 12 identical polypeptides of 43 kDa to yield a protein of 516 kDa. C1q was also shown to bind alveolar macrophages (Kd 3 x 10(-6) M), but addition of C1q did not show inhibition of the binding of 125I-SP-D to the macrophages. We conclude that SP-D binds specifically to alveolar macrophages and the receptor involved is different from that utilized by C1q.

scholarly journals Role of the PI3-kinase signaling pathway in trafficking of the surfactant protein A receptor P63 (CKAP4) on type II pneumocytes

2010 ◽  
Vol 299 (6) ◽  
pp. L794-L807 ◽  
Author(s):  
Altaf S. Kazi ◽  
Jian-Qin Tao ◽  
Sheldon I. Feinstein ◽  
Li Zhang ◽  
Aron B. Fisher ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Protein A ◽  
Surfactant Protein ◽  
Pi3 Kinase ◽  
Surfactant Protein A ◽  
Type Ii Cells ◽  
Type Ii ◽  
Type Ii Pneumocytes ◽  
Kinase Signaling Pathway ◽  
Stimulation Of

Surfactant protein A (SP-A) plays an important role in the maintenance of lung lipid homeostasis. Previously, an SP-A receptor, P63 (CKAP4), on type II pneumocyte plasma membranes (PM) was identified by chemical cross-linking techniques. An antibody to P63 blocked the specific binding of SP-A to pneumocytes and the ability of SP-A to regulate surfactant secretion. The current report shows that another biological activity of SP-A, the stimulation of surfactant uptake by pneumocytes, is inhibited by P63 antibody. cAMP exposure resulted in enrichment of P63 on the cell surface as shown by stimulation of SP-A binding, enhanced association of labeled P63 antibody with type II cells, and promotion of SP-A-mediated liposome uptake, all of which were inhibited by competing P63 antibody. Incubation of A549 and type II cells with SP-A also increased P63 localization on the PM. The phosphatidylinositol 3-kinase (PI3-kinase) signaling pathway was explored as a mechanism for the transport of this endoplasmic reticulum (ER)-resident protein to the PM. Treatment with LY-294002, an inhibitor of the PI3-kinase pathway, prevented the SP-A-induced PM enrichment of P63. Exposure of pneumocytes to SP-A or cAMP activated Akt (PKB). Blocking either PI3-kinase or Akt altered SP-A-mediated lipid turnover. The data demonstrate an important role for the PI3-kinase-Akt pathway in intracellular transport of P63. The results add to the growing body of evidence that P63 is critical for SP-A receptor-mediated interactions with type II pneumocytes and the resultant regulation of surfactant turnover.

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