title: Glycolipid-based TLR4 Modulators and Fluorescent Probes: Rational Design, Synthesis, and Biological Properties.
abstract: The cationic glycolipid IAXO-102, a potent TLR4 antagonist targeting both MD-2 and CD14 co-receptors, has been used as scaffold to design new potential TLR4 modulators and fluorescent labels for the TLR4 receptor complex (membrane TLR4.MD-2 dimer and CD14). The primary amino group of IAXO-102, not involved in direct interaction with MD-2 and CD14 receptors, has been exploited to covalently attach a fluorescein (molecules 1 and 2) or to link two molecules of IAXO-102 through diamine and diammonium spacers, obtaining 'dimeric' molecules 3 and 4. The structure-based rational design of compounds 1-4 was guided by the optimization of MD-2 and CD14 binding. Compounds 1 and 2 inhibited TLR4 activation, in a concentration-dependent manner, and signaling in HEK-Blue TLR4 cells. The fluorescent labeling of murine macrophages by molecule 1 was inhibited by LPS and was also abrogated when cell surface proteins were digested by trypsin, thus suggesting an interaction of fluorescent probe 1 with membrane proteins of the TLR4 receptor system.
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Ciaramelli
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Calabrese
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy.
authors.forename: Stefania E
authors.initials: SE
authors.lastname: Sestito
authors.affiliation: Department of Chemistry and Biochemistry, Universidad CEU San Pablo, 28668-Boadilla del Monte, Madrid, Spain.|Department of Chemical and Physical Biology, Center for Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors.forename: Lucia
authors.initials: L
authors.lastname: Pérez-Regidor
authors.affiliation: Department of Chemistry and Biochemistry, Universidad CEU San Pablo, 28668-Boadilla del Monte, Madrid, Spain.|Department of Chemical and Physical Biology, Center for Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Klett
authors.affiliation: Department of Biotechnology, National Institute of Chemistry Ljubljana and EN-FIST Center of Excellence, Hajdrihova 19, SI-1001, Ljubljana, Slovenia.
authors.forename: Alja
authors.initials: A
authors.lastname: Oblak
authors.affiliation: Department of Biotechnology, National Institute of Chemistry Ljubljana and EN-FIST Center of Excellence, Hajdrihova 19, SI-1001, Ljubljana, Slovenia.
authors.forename: Roman
authors.initials: R
authors.lastname: Jerala
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Piazza
authors.affiliation: Department of Chemistry and Biochemistry, Universidad CEU San Pablo, 28668-Boadilla del Monte, Madrid, Spain.|Department of Chemical and Physical Biology, Center for Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors.forename: Sonsoles
authors.initials: S
authors.lastname: Martín-Santamaría
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milano, Italy.
authors.forename: Francesco
authors.identifier: 0000-0002-3417-8224
authors.initials: F
authors.lastname: Peri
mesh_terms: D000818:Animals; D002460:Cell Line; D015195:Drug Design; D005456:Fluorescent Dyes / Q000737:chemistry*; D006017:Glycolipids / Q000737:chemistry*; D006801:Humans; D051379:Mice; D051197:Toll-Like Receptor 4 / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D006017:Glycolipids; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4
keywords: HEK-TLR4 cells; MD-2; TLR4; antagonists; computational chemistry; fluorescent chemical probes; glycolipids; medicinal chemistry