title: Streptococcal erythrogenic toxin B abrogates fibronectin-dependent internalization of Streptococcus pyogenes by cultured mammalian cells.
abstract: Streptococcus pyogenes secretes several proteins that influence host-pathogen interactions. A tissue-culture model was used to study the influence of the secreted cysteine protease streptococcal erythrogenic toxin B (SPE B) on the interaction between S. pyogenes strain NZ131 (serotype M49) and mammalian cells. Inactivation of the speB gene enhanced fibronectin-dependent uptake of the pathogen by Chinese hamster ovary (CHO-K1) cells compared to that in the isogenic wild-type strain. Preincubation of the NZ131 speB mutant with purified SPE B protease significantly inhibited fibronectin-dependent uptake by both CHO-K1 and CHO-pgs745 cells. The effect was attributed to an abrogation of fibronectin binding to the surface of the bacteria that did not involve either the M49 protein or the streptococcal fibronectin-binding protein SfbI. In contrast, pretreatment of the NZ131 speB mutant with SPE B did not influence sulfated polysaccharide-mediated uptake by CHO-pgs745 cells. The results indicate that the SPE B protease specifically alters bacterial cell surface proteins and thereby influences pathogen uptake.
authors.affiliation: Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA. mchaussee@nih.gov
authors.forename: M S
authors.initials: MS
authors.lastname: Chaussee
authors.forename: R L
authors.initials: RL
authors.lastname: Cole
authors.forename: J P
authors.initials: JP
authors.lastname: van Putten
mesh_terms: D018829:Adhesins, Bacterial; D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects; D001426:Bacterial Proteins / Q000378:metabolism; D016466:CHO Cells; D002352:Carrier Proteins / Q000378:metabolism; D006224:Cricetinae; D003546:Cysteine Endopeptidases / Q000494:pharmacology*; D005098:Exotoxins / Q000494:pharmacology*; D005353:Fibronectins; D008565:Membrane Proteins; D013297:Streptococcus pyogenes / Q000472:pathogenicity*
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D005098:Exotoxins; D005353:Fibronectins; D008565:Membrane Proteins; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin; C078635:fibronectin-binding proteins, bacterial; D003546:Cysteine Endopeptidases