title: Revisiting the CD14: epitope mapping by Phage Display.
abstract: The cluster of differentiation antigen 14 (CD14) is a key molecule of the innate immunity. This pattern recognition receptor binds mainly to lipopolysaccharide (LPS), lipotechoic acid (LTA), arachidonic acid, and thus induces the releases various cytokines, as a defense mechanism. Several studies suggest that different regions of the amino-terminal portion of the molecule may be involved in the LPS binding; however, controversial results on the recognition sequence still persist. In this work, functional epitopes of the CD14 molecule were mapped through Phage Display by using a 7-mer conformational constrained random peptide library against a monoclonal antibody anti-soluble CD14-fraction ST and a polyclonal anti-CD14. In silico and empirical analyses were performed to map the selected peptides into the CD14 3D structure. Immunoreactivity tests of peptides against bacterial components of Gram+ and Gram- bacteria were performed in order to demonstrate their functional recognition. All peptides strongly reacted against all bacteria, and besides the recognition of the amino-terminal region, we were able to demonstrate a second epitope site in the middle of the receptor. Additional in silico analysis suggests a possible role of CD14 epitopes as natural antimicrobial peptides.
authors.affiliation: Laboratory of Nanobiotechnology, Institute of Genetics and Biochemistry, Federal University of Uberlandia, Uberlandia, MG, Brazil. Electronic address: patriciaterraalves@yahoo.com.br.
authors.forename: Patrícia Terra
authors.initials: PT
authors.lastname: Alves
authors.affiliation: Laboratory of Nanobiotechnology, Institute of Genetics and Biochemistry, Federal University of Uberlandia, Uberlandia, MG, Brazil. Electronic address: tiemebr@yahoo.com.br.
authors.forename: Patrícia Tiemi
authors.initials: PT
authors.lastname: Fujimura
authors.affiliation: Laboratory of Nanobiotechnology, Institute of Genetics and Biochemistry, Federal University of Uberlandia, Uberlandia, MG, Brazil. Electronic address: leaduarte8@yahoo.com.br.
authors.forename: Léa Duarte da Silva
authors.initials: LD
authors.lastname: Morais
authors.affiliation: Laboratory of Nanobiotechnology, Institute of Genetics and Biochemistry, Federal University of Uberlandia, Uberlandia, MG, Brazil; Department of Medical Microbiology and Immunology, University of California Davis, Davis, CA, USA. Electronic address: lrgoulart@ufu.br.
authors.forename: Luiz Ricardo
authors.initials: LR
authors.lastname: Goulart
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000276:immunology; D061505:Cell Surface Display Techniques; D019295:Computational Biology; D018604:Epitope Mapping / Q000379:methods; D006801:Humans; D007113:Immunity, Innate; D018950:Lipopolysaccharide Receptors / Q000737:chemistry / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D008958:Models, Molecular; D018716:Molecular Mimicry; D008969:Molecular Sequence Data; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D011487:Protein Conformation
chemical_list: D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D019151:Peptide Library; D010455:Peptides
keywords: CD14; Epitope mapping; LPS receptor; Phage Display