Leucine-rich repeat 2 of human Toll-like receptor 4 contains the binding site for inhibitory monoclonal antibodies

FEBS Lett. 2015 Dec 21;589(24 Pt B):3893-8. doi: 10.1016/j.febslet.2015.11.018. Epub 2015 Nov 19.

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.

Keywords: Epitope; Inhibitory monoclonal antibody; Lipopolysaccharide; MD-2; Toll-like receptor 4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology*
  • Binding Sites
  • Epitope Mapping*
  • Humans
  • Immunization
  • Leucine*
  • Mice
  • Molecular Sequence Data
  • Repetitive Sequences, Amino Acid*
  • Toll-Like Receptor 4 / chemistry*
  • Toll-Like Receptor 4 / immunology*

Substances

  • Antibodies, Monoclonal
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • Leucine