Calcium Dependent Association of Surfactant Protein A with Pulmonary Surfactant: Application to Simple Surfactant Protein A Purification

Suwabe, Akira; Mason, Robert J.; Voelker, Dennis R.

doi:10.1006/abbi.1996.0123

Cited by 50 publications

(39 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, this is consistent with the C-type lectin DC-SIGN, which also does not overlap the specific 2G12 or CVN epitopes, despite its mannose-dependent binding (35). The neutralization effect by SP-A was similar to that observed for the structurally homologous collectin MBL (16). When used in our competition studies, MBL also blocked the binding of gp120 to CD4 (data not shown), although not as effectively as SP-A.…”

Section: Discussionsupporting

confidence: 80%

See 1 more Smart Citation

Surfactant Protein A Binds to HIV and Inhibits Direct Infection of CD4+ Cells, but Enhances Dendritic Cell-Mediated Viral Transfer

Gaiha

Dong

Palaniyar

et al. 2008

The Journal of Immunology

View full text Add to dashboard Cite

The identification of surfactant protein A (SP-A) as an important innate immune factor of the lungs, amniotic fluid, and the vaginal tract suggests that it could play an important role during various stages of HIV disease progression and transmission. Therefore, we examined whether SP-A could bind to HIV and also had any effect on viral infectivity. Our data demonstrate that SP-A binds to HIV in a calcium-dependent manner that is inhibitable by mannose and EDTA. Affinity capture of the HIV viral lysate reveals that SP-A targets the envelope glycoprotein of HIV (gp120), which was confirmed by ELISA using recombinant gp120. Digestion of gp120 with endoglycosidase H abrogates the binding of SP-A, indicating that the high mannose structures on gp120 are the target of the collectin. Infectivity studies reveal that SP-A inhibits the infection of CD4+ T cells by two strains of HIV (BaL, IIIB) by >80%. Competition assays with CD4 and mAbs F105 and b12 suggest that SP-A inhibits infectivity by occlusion of the CD4-binding site. Studies with dendritic cells (DCs) demonstrate that SP-A enhances the binding of gp120 to DCs, the uptake of viral particles, and the transfer of virus from DCs to CD4+ T cells by >5-fold at a pH representative of the vaginal tract. Collectively, these results suggest that SP-A acts as a dual modulator of HIV infection by protecting CD4+ T cells from direct infection but enhancing the transfer of infection to CD4+ T cells mediated by DCs.

show abstract

Section: Discussionsupporting

confidence: 80%

“…SP-A was purified from therapeutic lung lavage obtained from alveolar proteinosis patients as described previously (16). Recombinant soluble DC-SIGN was produced as described previously (17).…”

Section: Proteinsmentioning

confidence: 99%

Surfactant Protein A Binds to HIV and Inhibits Direct Infection of CD4+ Cells, but Enhances Dendritic Cell-Mediated Viral Transfer

Gaiha

Dong

Palaniyar

et al. 2008

The Journal of Immunology

View full text Add to dashboard Cite

show abstract

“…Rat SP-D was purified from the BAL of silica-pretreated rats by calciumdependent adsorption of the 12,000-g supernatant to maltose-Sepharose columns. Human SP-A was isolated from the lung washings of patients with the lung disease alveolar proteinosis by a modification of the method of Suwabe et al (23). Briefly, hSP-A was purified from the cell-free surfactant pellet of BAL by serial sedimentation and resuspension (five times) in buffer containing 10 mM Tris, 150 mM NaCl, and 1 mM CaCl 2 , release by incubation with 10 mM Tris, 150 mM NaCl, and 2 mM EDTA, and adsorption of the recalcified supernatant to mannose-Sepharose affinity columns.…”

Section: Purification Of Native Sp-a and Sp-dmentioning

confidence: 99%

Surfactant proteins A and D inhibit the growth of Gram-negative bacteria by increasing membrane permeability

Wu¹,

Kuzmenko²,

Wan³

et al. 2003

J. Clin. Invest.

130

154

View full text Add to dashboard Cite

The pulmonary collectins, surfactant proteins A (SP-A) and D (SP-D), have been reported to bind lipopolysaccharide (LPS), opsonize microorganisms, and enhance the clearance of lung pathogens. In this study, we examined the effect of SP-A and SP-D on the growth and viability of Gram-negative bacteria. The pulmonary clearance of Escherichia coli K12 was reduced in SP-A–null mice and was increased in SP-D–overexpressing mice, compared with strain-matched wild-type controls. Purified SP-A and SP-D inhibited bacterial synthetic functions of several, but not all, strains of E. coli, Klebsiella pneumoniae, and Enterobacter aerogenes. In general, rough E. coli strains were more susceptible than smooth strains, and collectin-mediated growth inhibition was partially blocked by coincubation with rough LPS vesicles. Although both SP-A and SP-D agglutinated E. coli K12 in a calcium-dependent manner, microbial growth inhibition was independent of bacterial aggregation. At least part of the antimicrobial activity of SP-A and SP-D was localized to their C-terminal domains using truncated recombinant proteins. Incubation of E. coli K12 with SP-A or SP-D increased bacterial permeability. Deletion of the E. coli OmpA gene from a collectin-resistant smooth E. coli strain enhanced SP-A and SP-D–mediated growth inhibition. These data indicate that SP-A and SP-D are antimicrobial proteins that directly inhibit the proliferation of Gram-negative bacteria in a macrophage- and aggregation-independent manner by increasing the permeability of the microbial cell membrane

show abstract

“…Native human SP-D and native human SP-A were purified from bronchiolar lavage fluid (BALF) obtained from alveolar proteinosis patients as described previously (Suwabe et al, 1996;Strong et al, 1998). Purity of the proteins was verified by SDS-PAGE analysis and was > 95%.…”

Section: Protein Purificationmentioning

confidence: 99%

Surface-bound myeloperoxidase is a ligand for recognition of late apoptotic neutrophils by human lung surfactant proteins A and D

et al. 2010

View full text Add to dashboard Cite

Surfactant proteins A (SP-A) and D (SP-D), both members of the collectin family, play a well established role in apoptotic cell recognition and clearance. Recent in vitro data show that SP-A and SP-D interact with apoptotic neutrophils in a distinct manner. SP-A and SP-D bind in a Ca 2+ -dependent manner to viable and early apoptotic neutrophils whereas the much greater interaction with late apoptotic neutrophils is Ca 2+ -independent. Cell surface molecules on the apoptotic target cells responsible for these interactions had not been identified and this study was done to find candidate target molecules. Myeloperoxidase (MPO), a specific intracellular defense molecule of neutrophils that becomes exposed on the outside of the cell upon apoptosis, was identified by affinity purification, mass-spectrometry and western blotting as a novel binding molecule for SP-A and SP-D. To confirm its role in recognition, it was shown that purified immobilised MPO binds SP-A and SP-D, and that MPO is surface-exposed on late apoptotic neutrophils. SP-A and SP-D inhibit binding of an anti-MPO monoclonal Ab to late apoptotic cells. Fluorescence microscopy confirmed that anti-MPO mAb and SP-A/SP-D colocalise on late apoptotic neutrophils. Desmoplakin was identified as a further potential ligand for SP-A, and neutrophil defensin as a target for both proteins.

show abstract

Calcium Dependent Association of Surfactant Protein A with Pulmonary Surfactant: Application to Simple Surfactant Protein A Purification

Cited by 50 publications

References 0 publications

Surfactant Protein A Binds to HIV and Inhibits Direct Infection of CD4+ Cells, but Enhances Dendritic Cell-Mediated Viral Transfer

Surfactant Protein A Binds to HIV and Inhibits Direct Infection of CD4+ Cells, but Enhances Dendritic Cell-Mediated Viral Transfer

Surfactant proteins A and D inhibit the growth of Gram-negative bacteria by increasing membrane permeability

Surface-bound myeloperoxidase is a ligand for recognition of late apoptotic neutrophils by human lung surfactant proteins A and D

Contact Info

Product

Resources

About