Adhärenz von Streptokokken der Gruppe A an Zellen des Mund-Rachen-Raumes: Lipoteicholsäure-Adhäsin und Fibronectin-Rezeptor

Abstract

The attachment of group A streptococci to oropharyngeal epithelial cells is mediated by adhesive molecules (adhesins) on the surfaces of the micro-organisms that interact with receptor molecules on the epithelial cells. The evidence that the adhesin is composed of lipoteichoic acid (LTA) complexed with bacterial cell surface proteins is as follows: (a) Among the purified cell wall substances tested, only LTA was able to inhibit attachment; (b) treatment of streptococci with anti LTA but not with antibody against other surface substances blocks attachment; (c) LTa forms complexes with purified M protein, the most abundant protein on the surface of virulent streptococci; (d) the lipid moieties of LTA, which mediate attachment, remain free in the M protein-LTA complexes to interact with receptor analogues, such as serum albumin. The evidence that the receptor for the LTA mediated binding of streptococci resides in fibronectin molecules on oropharyngeal cells is as follows: (a) the addition ot adhesion test mixtures of fibronection inhibits binding; (b) the number of streptococci capable of attaching is directly proportional to the amount of fibronectin present on epithelial cells; (c) purified fibronectin immobilized on latex beads agglutinates suspensions of streptococci; (d) radiolabeled fibronectin binds to group A streptococci; (e) both the agglutination of fibronectin-beads and the binding of fibronectin to streptococci is blocked by LTA, the streptococcal adhesin.

Multiple binding of type 3 streptococcal M protein to human fibrinogen, albumin and fibronectin

“…Lipoteichoic acid was first described to be involved in streptococcal adherence to epithelial ceils and in binding to Fn [3,7,39]. However, more recent reports and our results provide evidence that fibronectin binds with a higher affinity to proteins of group A streptococci [6,11,24,31,33].…”

Cloning and expression of the gene for a fibronectin-binding protein from Staphylococcus aureus.

“…Several different cell surface components have been implicated as fibronectin receptors on Gram-positive bacteria including lipotechioc acid (Beachey and Simpson, 1982;Courtney et al, 1986) and protein (Ryden et al, 1983). In previous studies, a fibronectin-binding protein (FNBP) with a Mr of 197-210 kd has been isolated from S. aureus strain Newman (Espersen and Clemmensen, 1982;Froman et al, 1987) and tentatively identified as a fibronectin receptor.…”

A New Model of Pneumococcal Lipoteichoic Acid Structure Resolves Biochemical, Biosynthetic, and Serologic Inconsistencies of the Current Model

“…LTA is also important for bacterial growth since LTA can inhibit autolysin, which is critical for cell wall remodeling and necessary for replication (22). In addition, LTA is critical in pathogenesis as it is involved in bacterial adhesion to host cells (2,7,9) and initiates inflammatory cascades by activating complement (24), Tolllike receptor 2 (12,19,41), and/or CD36, a C-type lectin (21,36). In fact, a monoclonal antibody to LTA has been shown to protect animals from experimental infections (46,49,51).…”

“…1A). The polymer would then be linked to a cytoplasmic membrane lipid anchor: Glc(␤133)AATGal(␤133)Glc(␣133)-acyl 2 Gro. The lipid anchor is critical for attaching LTA to the cytoplasmic membrane (3,13,17,30).…”