Role of complement S protein (vitronectin) in adherence of Streptococcus dysgalactiae to bovine epithelial cells.
The binding of bovine complement S protein (vitronectin) to Streptococcus dysgalactiae isolates from cattle with mastitis and the S protein's role in streptococcal adherence to bovine epithelial cells were investigated. All 25 clinical isolates of S dysgalactiae interacted with bovine S protein. None of the other streptococcal species tested bound to bovine S protein. The S protein-binding sites were saturable and highly sensitive to trypsin. The binding of bovine S protein to S dysgalactiae isolates was specific and could not be inhibited by other plasma proteins, such as fibronectin, albumin, fibrinogen, alpha 2-macroglobulin, or IgG. Similarly, streptococcal binding of bovine S protein was not influenced by the synthetic peptide Gly-Arg-Gly-Asp-Ser, which constituted the host cell attachment sequence of S protein. In adherence experiments, prior binding of bovine S protein to S dysgalactiae enhanced streptococcal adherence to bovine epithelial cells. The enhancing effects by bovine S protein were abolished when the respective binding sites on the streptococci were digested by trypsin. Thus, bovine S protein could be an important mediator of adherence of S dysgalactiae to bovine epithelial cells.
Institute of Bacteriology and Immunology, Faculty of Veterinary Medicine, Justus-Liebig-Universität, Giessen, Federal Republic of Germany.
L F
LF
Filippsen
P
P
Valentin-Weigand
H
H
Blobel
K T
KT
Preissner
G S
GS
Chhatwal
D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004847:Epithelial Cells; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D006023:Glycoproteins / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D008414:Mastitis, Bovine / Q000382:microbiology; D009061:Mouth Mucosa / Q000166:cytology; D011485:Protein Binding / Q000502:physiology; D013045:Species Specificity; D013291:Streptococcus / Q000378:metabolism* / Q000502:physiology; D013861:Thiocyanates; D019096:Vitronectin
D005452:Fluoresceins; D006023:Glycoproteins; D013861:Thiocyanates; D019096:Vitronectin; D016650:Fluorescein-5-isothiocyanate