title: Expression and functional properties of the Streptococcus intermedius surface protein antigen I/II.
abstract: Streptococcus intermedius is associated with deep-seated purulent infections. In this study, we investigated expression and functional activities of antigen I/II in S. intermedius. The S. intermedius antigen I/II appeared to be cell surface associated, with a molecular mass of approximately 160 kDa. Northern blotting indicated that the S. intermedius NCTC 11324 antigen I/II gene was transcribed as a monocistronic message. Maximum expression was seen during the early exponential phase. Insertional inactivation of the antigen I/II gene resulted in reduced hydrophobicity during early exponential phase, whereas no effect was detected during mid- and late exponential phases. Binding to human fibronectin and laminin was reduced in the isogenic mutant, whereas binding to human collagen types I and IV and to rat collagen type I was not significant for either the wild type or the mutant. Compared to the wild type, the capacity of the isogenic mutant to induce interleukin 8 (IL-8) release by THP-1 monocytic cells was significantly reduced. The results indicate that the S. intermedius antigen I/II is involved in adhesion to human receptors and in IL-8 induction.
authors.affiliation: Department of Oral Biology, Dental Faculty, University of Oslo, Blindern, N0372 Oslo, Norway. cpaiva@odont.uio.no
authors.forename: F C
authors.initials: FC
authors.lastname: Petersen
authors.forename: S
authors.initials: S
authors.lastname: Pasco
authors.forename: J
authors.initials: J
authors.lastname: Ogier
authors.forename: J P
authors.initials: JP
authors.lastname: Klein
authors.forename: S
authors.initials: S
authors.lastname: Assev
authors.forename: A A
authors.initials: AA
authors.lastname: Scheie
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D003094:Collagen / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D008562:Membrane Glycoproteins; D008856:Microscopy, Fluorescence; D016296:Mutagenesis; D051381:Rats; D013291:Streptococcus
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D016209:Interleukin-8; D008562:Membrane Glycoproteins; C055764:S-layer proteins; D003094:Collagen