Title

Novel engagement of CD14 and multiple toll-like receptors by group B streptococci

UMMS Affiliation

Department of Medicine, Division of Infectious Diseases and Immunology

Publication Date

12-12-2001

Document Type

Article

Subjects

Animals; Antigens, CD14; Antigens, Surface; Biological Factors; CHO Cells; Carrier Proteins; Cells, Cultured; Cricetinae; *Drosophila Proteins; Humans; Inflammation Mediators; Lymphocyte Antigen 96; Macrophages; Membrane Glycoproteins; Mice; Mice, Knockout; Models, Immunological; Receptors, Cell Surface; *Receptors, Interleukin-1; Sepsis; Streptococcal Infections; Streptococcus agalactiae; Toll-Like Receptor 1; Toll-Like Receptor 2; Toll-Like Receptor 4; Toll-Like Receptor 6; Toll-Like Receptors; Transfection; Tumor Necrosis Factor-alpha

Disciplines

Life Sciences | Medicine and Health Sciences

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.

Rights and Permissions

Citation: J Immunol. 2001 Dec 15;167(12):7069-76.

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

Journal of immunology (Baltimore, Md. : 1950)

PubMed ID

11739528