title: Human salivary proteins with affinity to lipoteichoic acid of Enterococcus faecalis.
abstract: Enterococcus faecalis is associated with refractory apical periodontitis and its lipoteichoic acid (Ef.LTA) is considered as a major virulence factor. Although the binding proteins of Ef.LTA may play an important role for mediating infection and immunity in the oral cavity, little is known about Ef.LTA-binding proteins (Ef.LTA-BPs) in saliva. In this study, we identified salivary Ef.LTA-BPs with biotinylated Ef.LTA (Ef.LTA-biotin) through mass spectrometry. The biotinylation of Ef.LTA was confirmed by binding capacity with streptavidin-FITC on CHO/CD14/TLR2 cells. The biological activity of Ef.LTA-biotin was determined based on the induction of nitric oxide and macrophage inflammatory protein-1α in a macrophage cell-line, RAW 264.7. To identify salivary Ef.LTA-BPs, the Ef.LTA-biotin was mixed with a pool of human saliva obtained from nine healthy subjects followed by precipitation with a streptavidin-coated bead. Ef.LTA-BPs were then separated with 12% SDS-PAGE and subjected to the mass spectrometry. Six human salivary Ef.LTA-BPs including short palate lung and nasal epithelium carcinoma-associated protein 2, zymogen granule protein 16 homolog B, hemoglobin subunit α and β, apolipoprotein A-I, and lipocalin-1 were identified with statistical significance (P<0.05). Ef.LTA-BPs were validated with lipocalin-1 using pull-down assay. Hemoglobin inhibited the biofilm formation of E. faecalis whereas lipocalin-1 did not show such effect. Collectively, the identified Ef.LTA-BPs could provide clues for our understanding of the pathogenesis of E. faecalis and host immunity in oral cavity.
authors.affiliation: Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Baik
authors.affiliation: Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Hyuk-Il
authors.initials: HI
authors.lastname: Choe
authors.affiliation: Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Sun Woong
authors.initials: SW
authors.lastname: Hong
authors.affiliation: Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Seok-Seong
authors.initials: SS
authors.lastname: Kang
authors.affiliation: Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Ki Bum
authors.initials: KB
authors.lastname: Ahn
authors.affiliation: Biomedical Omics Group, Korea Basic Science Institute, Ochang 28119, Republic of Korea.
authors.forename: Kun
authors.initials: K
authors.lastname: Cho
authors.affiliation: Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Cheol-Heui
authors.initials: CH
authors.lastname: Yun
authors.affiliation: Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul 08826, Republic of Korea. Electronic address: shhan-mi@snu.ac.kr.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Han
mesh_terms: D013293:Enterococcus faecalis / Q000276:immunology / Q000378:metabolism / Q000472:pathogenicity*; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology / Q000378:metabolism*; D012463:Saliva / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D013682:Teichoic Acids / Q000276:immunology / Q000378:metabolism*; D037521:Virulence Factors / Q000276:immunology / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D012471:Salivary Proteins and Peptides; D013682:Teichoic Acids; D037521:Virulence Factors; C009900:lipoteichoic acid
keywords: Enterococcus faecalis; Innate immunity; Lipoteichoic acid; Saliva