title: Identification of a high-molecular-mass Lactobacillus epithelium adhesin (LEA) of Lactobacillus crispatus ST1 that binds to stratified squamous epithelium.
abstract: Lactobacilli belong to the normal gastrointestinal and genital tract microbiota of human and animal hosts. Adhesion is important for bacterial colonization; however, only a few Lactobacillus adhesins have been identified so far. We studied extracted surface proteins from an adhesive Lactobacillus crispatus strain, ST1, which efficiently colonizes the chicken alimentary tract, for their binding to tissue sections of the chicken crop, and identified a novel high-molecular-mass repetitive surface protein that shows specific binding to stratified squamous epithelium. The adhesin binds to both crop epithelium and epithelial cells from human vagina, and was named Lactobacillus epithelium adhesin (LEA). Expression of LEA is strain-specific among L. crispatus strains and corresponds directly to in vitro bacterial adhesion ability. The partial sequence of the lea gene predicts that the LEA protein carries an N-terminal YSIRK signal sequence and a C-terminal LPxTG anchoring motif, as well as a highly repetitive region harbouring 82 aa long repeats with non-identical sequences that show similarity to Lactobacillus Rib/alpha-like repeats. LEA-mediated epithelial adherence may improve bacterial colonization in the chicken crop and the human vagina, which are the natural environments for L. crispatus.
authors.affiliation: Division of General Microbiology, Department of Biosciences, PO Box 56, University of Helsinki, FI-00014, Finland.
authors.forename: Sanna M
authors.initials: SM
authors.lastname: Edelman
authors.affiliation: Division of General Microbiology, Department of Biosciences, PO Box 56, University of Helsinki, FI-00014, Finland.
authors.forename: Timo A
authors.initials: TA
authors.lastname: Lehti
authors.affiliation: Division of General Microbiology, Department of Biosciences, PO Box 56, University of Helsinki, FI-00014, Finland.
authors.forename: Veera
authors.initials: V
authors.lastname: Kainulainen
authors.affiliation: Division of General Microbiology, Department of Biosciences, PO Box 56, University of Helsinki, FI-00014, Finland.
authors.forename: Jenni
authors.initials: J
authors.lastname: Antikainen
authors.affiliation: Division of General Microbiology, Department of Biosciences, PO Box 56, University of Helsinki, FI-00014, Finland.
authors.forename: Riikka
authors.initials: R
authors.lastname: Kylväjä
authors.affiliation: Protein Chemistry and Proteomics Unit, Biomedicum Helsinki, PO Box 63, University of Helsinki, FI-00014, Finland.
authors.forename: Marc
authors.initials: M
authors.lastname: Baumann
authors.affiliation: Division of General Microbiology, Department of Biosciences, PO Box 56, University of Helsinki, FI-00014, Finland.
authors.forename: Benita
authors.initials: B
authors.lastname: Westerlund-Wikström
authors.affiliation: Division of General Microbiology, Department of Biosciences, PO Box 56, University of Helsinki, FI-00014, Finland.
authors.forename: Timo K
authors.initials: TK
authors.lastname: Korhonen
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D001422:Bacterial Adhesion; D002478:Cells, Cultured; D002645:Chickens; D004847:Epithelial Cells / Q000382:microbiology*; D005243:Feces; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology; D006801:Humans; D007778:Lactobacillus / Q000235:genetics* / Q000472:pathogenicity*; D020449:Repetitive Sequences, Amino Acid; D020539:Sequence Analysis, Protein; D014621:Vagina / Q000382:microbiology
chemical_list: D018829:Adhesins, Bacterial; C062777:adhesin, Lactobacillus