title: Chlamydia trachomatis OmcB protein is a surface-exposed glycosaminoglycan-dependent adhesin.
abstract: The OmcB protein of Chlamydia trachomatis is a cysteine-rich outer membrane polypeptide with important functional, structural and antigenic properties. The entire gene encoding the OmcB protein from C. trachomatis serovar LGV1 was cloned and expressed in Escherichia coli and the full-length protein used to raise polyclonal antibodies. Recombinant OmcB was used to show that OmcB is a surface-exposed protein that functions as a chlamydial adhesin. Infectivity inhibition assays carried out using HeLa cells with serovar LGV1 in the presence of purified anti-OmcB serum showed inhibition of infectivity, suggesting that some of the OmcB was surface exposed. Moreover, using recombinant OmcB in infectivity inhibition assays resulted in 70% inhibition of infectivity, confirming that OmcB plays a role as an adhesin in C. trachomatis. Furthermore, recombinant OmcB protein bound to the surface of HeLa and Hec1B cells, but binding to glycosaminoglycan (GAG)-deficient cells (pgsA-745 and pgsD-677) was markedly reduced, indicating that OmcB binds to GAG-like receptors on host cells.
authors.affiliation: Henry Wellcome Laboratories for Medical Research, Division of Genomic Medicine, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX, UK.
authors.forename: Sanaa
authors.initials: S
authors.lastname: Fadel
authors.affiliation: Henry Wellcome Laboratories for Medical Research, Division of Genomic Medicine, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX, UK.
authors.forename: Adrian
authors.initials: A
authors.lastname: Eley
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D016466:CHO Cells; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002692:Chlamydia trachomatis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D011485:Protein Binding; D011817:Rabbits; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology
chemical_list: D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D006025:Glycosaminoglycans; D007106:Immune Sera; C436968:OmcB protein, bacteria; D011994:Recombinant Proteins