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Novel engagement of CD14 and multiple toll-like receptors by group B streptococci.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2001 Dec 15; Vol. 167 (12), pp. 7069-76. - Publication Year :
- 2001
-
Abstract
- Group B streptococcus (GBS) imposes a major health threat to newborn infants. Little is known about the molecular basis of GBS-induced sepsis. Both heat-inactivated whole GBS bacteria and a heat-labile soluble factor released by GBS during growth (GBS-F) induce nuclear translocation of NF-kappaB, the secretion of TNF-alpha, and the formation of NO in mouse macrophages. Macrophages from mice with a targeted disruption of MyD88 failed to secrete TNF-alpha in response to both heat-inactivated whole bacteria and GBS-F, suggesting that Toll-like receptors (TLRs) are involved in different aspects of GBS recognition. Immune cell activation by whole bacteria differed profoundly from that by secreted GBS-F. Whole GBS activated macrophages independently of TLR2 and TLR6, whereas a response to the secreted GBS-F was not observed in macrophages from TLR2-deficient animals. In addition to TLR2, TLR6 and CD14 expression were essential for GBS-F responses, whereas TLR1 and TLR4 or MD-2 did not appear to be involved. Heat lability distinguished GBS-F from peptidoglycan and lipoproteins. GBS mutants deficient in capsular polysaccharide or beta-hemolysin had GBS-F activity comparable to that of wild-type streptococci. We suggest that CD14 and TLR2 and TLR6 function as coreceptors for secreted microbial products derived from GBS and that cell wall components of GBS are recognized by TLRs distinct from TLR1, 2, 4, or 6.
- Subjects :
- Animals
Antigens, Surface physiology
Biological Factors metabolism
CHO Cells
Carrier Proteins genetics
Carrier Proteins physiology
Cells, Cultured
Cricetinae
Humans
Inflammation Mediators metabolism
Lymphocyte Antigen 96
Membrane Glycoproteins genetics
Membrane Glycoproteins physiology
Mice
Mice, Knockout
Models, Immunological
Receptors, Cell Surface genetics
Receptors, Cell Surface physiology
Sepsis immunology
Streptococcal Infections immunology
Toll-Like Receptor 1
Toll-Like Receptor 2
Toll-Like Receptor 4
Toll-Like Receptor 6
Toll-Like Receptors
Transfection
Tumor Necrosis Factor-alpha biosynthesis
Drosophila Proteins
Lipopolysaccharide Receptors metabolism
Macrophages immunology
Membrane Glycoproteins metabolism
Receptors, Cell Surface metabolism
Receptors, Interleukin-1
Streptococcus agalactiae physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1767
- Volume :
- 167
- Issue :
- 12
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 11739528
- Full Text :
- https://doi.org/10.4049/jimmunol.167.12.7069