Leucine‐rich repeat 2 of human Toll‐like receptor 4 contains the binding site for inhibitory monoclonal antibodies. Issue 24 (19th November 2015)

• Record Type: Journal Article
• Authors: Tsukamoto, Hiroki; Ukai, Ippo; Yamagata, Yuki; Takeuchi, Shino; Kubota, Kanae; Kozakai, Sao; Suzuki, Naoto; Kimoto, Masao; Tomioka, Yoshihisa
• Is Part Of: FEBS letters. Volume 589:Issue 24(2015) Part B
• Page Start: 3893
• Page End: 3898
• Publication Date: 2015-11-19
• Subjects: Bio- -- biotinylated -- IP -- immunoprecipitation -- LPS -- lipopolysaccharide -- LRR -- leucine-rich repeat -- mAb -- monoclonal antibody -- sTLR4F -- C-terminal FLAG-tagged secreted form of TLR4 -- stv -- streptavidin -- TLR -- Toll-like receptor -- WB -- western blotting -- Toll-like receptor 4 -- MD-2 -- Inhibitory monoclonal antibody -- Lipopolysaccharide -- Epitope; Biochemistry -- Periodicals; Biophysics -- Periodicals; Molecular biology -- Periodicals; Biochimie -- Périodiques; Biochemistry; Biophysics; Molecular biology; Periodicals; 572.05
• DOI: 10.1016/j.febslet.2015.11.018
• Languages: English
• ISSNs: 0014-5793

Abstract

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. Abstract : A novel anti‐TLR4 mAb HTB2 was obtained by cross‐block screening against HT52. HTB2 inhibits LPS‐induced TLR4 activation. HT52 and HTB2 epitopes were identified on the LRR2 of TLR4. Inhibitory and non‐inhibitory antibodies have distinct binding specificities on TLR4.