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A Novel Role for the Bactericidal/Permeability Increasing Protein in Interactions of Gram-Negative Bacterial Outer Membrane Blebs with Dendritic Cells
- Source :
- The Journal of Immunology. 179:2477-2484
- Publication Year :
- 2007
- Publisher :
- The American Association of Immunologists, 2007.
-
Abstract
- The bactericidal/permeability-increasing protein (BPI) is thought to play an important role in killing and clearance of Gram-negative bacteria and the neutralization of endotoxin. A possible role for BPI in clearance of cell-free endotoxin has also been suggested based on studies with purified endotoxin aggregates and blood monocytes. Because the interaction of BPI with cell-free endotoxin, during infection, occurs mainly in tissue and most likely in the form of shed bacterial outer membrane vesicles (“blebs”), we examined the effect of BPI on interactions of metabolically labeled ([14C]-acetate) blebs purified from Neisseria meningitidis serogroup B with either human monocyte-derived macrophages or monocyte-derived dendritic cells (MDDC). BPI produced a dose-dependent increase (up to 3-fold) in delivery of 14C-labeled blebs to MDDC, but not to monocyte-derived macrophages in the presence or absence of serum. Both, fluorescently labeled blebs and BPI were internalized by MDDC under these conditions. The closely related LPS-binding protein, in contrast to BPI, did not increase association of the blebs with MDDC. BPI-enhanced delivery of the blebs to MDDC did not increase cell activation but permitted CD14-dependent signaling by the blebs as measured by changes in MDDC morphology, surface expression of CD80, CD83, CD86, and MHC class II and secretion of IL-8, RANTES, and IP-10. These findings suggest a novel role of BPI in the interaction of bacterial outer membrane vesicles with dendritic cells that may help link innate immune recognition of endotoxin to Ag delivery and presentation.
- Subjects :
- Bacterial outer membrane vesicles
Immunology
Biological Transport, Active
Neisseria meningitidis, Serogroup B
Microbiology
Antigens, CD
Humans
Immunology and Allergy
Secretion
Cells, Cultured
CD86
Antigen Presentation
Antigens, Bacterial
Membrane Glycoproteins
Innate immune system
biology
Macrophages
Cell Membrane
Histocompatibility Antigens Class II
Membrane Proteins
Blood Proteins
Dendritic Cells
Bactericidal/permeability-increasing protein
Immunity, Innate
humanities
Endotoxins
biology.protein
Chemokines
Carrier Proteins
Bacterial outer membrane
Cell activation
CD80
Acute-Phase Proteins
Antimicrobial Cationic Peptides
Protein Binding
Signal Transduction
Subjects
Details
- ISSN :
- 15506606 and 00221767
- Volume :
- 179
- Database :
- OpenAIRE
- Journal :
- The Journal of Immunology
- Accession number :
- edsair.doi.dedup.....c491b0bfdd34e31758a98e7848ada418