title: Leucine-rich repeat 2 of human Toll-like receptor 4 contains the binding site for inhibitory monoclonal antibodies.
abstract: Excessive activation of Toll-like receptor 4 (TLR4)/MD-2 by lipopolysaccharide (LPS) causes septic shock. We previously produced an inhibitory antibody, HT52, against LPS-induced human TLR4 activation independently of LPS binding of MD-2. Consistent with the hypothesis that HT52 recognizes the epitopes inherent to inhibitory antibodies, we generated an HT52-crossblockable antibody and revealed the relationship between its inhibitory activity and the anti-TLR4 antibody epitope. Leucine-rich repeat 2 was identified as an inhibitory epitope, and Phe(75), Ser(76) and Pro(79) as antigenic determinants. These findings provide a way to design therapeutic antibodies targeted to TLR4 that are distinct from LPS analog antagonists targeting MD-2.
authors.affiliation: Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Sendai 980-8578, Japan; Department of Immunology, Saga Medical School, 5-1-1 Nabeshima, Saga 849-8501, Japan. Electronic address: tsukamoh@m.tohoku.ac.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tsukamoto
authors.affiliation: Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Sendai 980-8578, Japan.
authors.forename: Ippo
authors.initials: I
authors.lastname: Ukai
authors.affiliation: Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Sendai 980-8578, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yamagata
authors.affiliation: Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Sendai 980-8578, Japan.
authors.forename: Shino
authors.initials: S
authors.lastname: Takeuchi
authors.affiliation: Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Sendai 980-8578, Japan.
authors.forename: Kanae
authors.initials: K
authors.lastname: Kubota
authors.affiliation: Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Sendai 980-8578, Japan.
authors.forename: Sao
authors.initials: S
authors.lastname: Kozakai
authors.affiliation: Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Sendai 980-8578, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Suzuki
authors.affiliation: Department of Immunology, Saga Medical School, 5-1-1 Nabeshima, Saga 849-8501, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Kimoto
authors.affiliation: Laboratory of Oncology, Pharmacy Practice and Sciences, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Sendai 980-8578, Japan. Electronic address: ytomioka@m.tohoku.ac.jp.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Tomioka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001665:Binding Sites; D018604:Epitope Mapping; D006801:Humans; D007114:Immunization; D007930:Leucine; D051379:Mice; D008969:Molecular Sequence Data; D020449:Repetitive Sequences, Amino Acid; D051197:Toll-Like Receptor 4 / Q000737:chemistry* / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D007930:Leucine
keywords: Epitope; Inhibitory monoclonal antibody; Lipopolysaccharide; MD-2; Toll-like receptor 4