Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody

Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody

In order to treat Toll like receptor 4 (TLR4)-mediated diseases, we generated a potent antagonistic antibody directed against human TLR4, Hu 15C1. This antibody's potency can be modulated by engaging not only TLR4 but also Fcγ receptors (FcγR), a mechanism that is driven by avidity and not cell...

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Main Authors: Loyau, Jérémy, Malinge, Pauline, Daubeuf, Bruno, Shang, Limin, Elson, Greg, Kosco-Vilbois, Marie, Fischer, Nicolas, Rousseau, François
Format: Online
Language:English
Published: Taylor & Francis 2014
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4622919/
id pubmed-4622919
recordtype oai_dc
spelling pubmed-46229192015-11-12 Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody Loyau, Jérémy Malinge, Pauline Daubeuf, Bruno Shang, Limin Elson, Greg Kosco-Vilbois, Marie Fischer, Nicolas Rousseau, François Reports In order to treat Toll like receptor 4 (TLR4)-mediated diseases, we generated a potent antagonistic antibody directed against human TLR4, Hu 15C1. This antibody's potency can be modulated by engaging not only TLR4 but also Fcγ receptors (FcγR), a mechanism that is driven by avidity and not cell signaling. Here, using various formats of the antibody, we further dissect the relative contributions of the Fv and Fc portions of Hu 15C1, discovering that the relationship to potency of the different antibody arms is not linear. First, as could be anticipated, we observed that Hu 15C1 co-engages up to 3 receptors on the same plasma membrane, i.e., 2 TLR4 molecules (via its variable regions) and either FcγRI or FcγRIIA (via the Fc). The Kd of these interactions are in the nM range (3 nM of the Fv for TLR4 and 47 nM of the Fc for FcγRI). However, unexpectedly, neutralization experiments revealed that, due to the low level of cell surface TLR4 expression, the avidity afforded by engagement through 2 Fv arms was significantly limited. In contrast, the antibody's neutralization capacity increases by 3 logs when able to exploit Fc-FcγR interactions. Taken together, these results demonstrate an unforeseen level of contribution by FcγRs to an antibody's effectiveness when targeting a cell surface protein of relatively low abundance. These findings highlight an exploitable mechanism by which FcγR-bearing cells may be more powerfully targeted, envisioned to be broadly applicable to other reagents aimed at neutralizing cell surface targets on cells co-expressing FcγRs. Taylor & Francis 2014-10-30 /pmc/articles/PMC4622919/ /pubmed/25484053 http://dx.doi.org/10.4161/19420862.2014.975098 Text en © 2014 The Author(s). Published with license by Taylor & Francis Group, LLC http://creativecommons.org/licenses/by-nc/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The moral rights of the named author(s) have been asserted.
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
author Loyau, Jérémy
Malinge, Pauline
Daubeuf, Bruno
Shang, Limin
Elson, Greg
Kosco-Vilbois, Marie
Fischer, Nicolas
Rousseau, François
spellingShingle Loyau, Jérémy
Malinge, Pauline
Daubeuf, Bruno
Shang, Limin
Elson, Greg
Kosco-Vilbois, Marie
Fischer, Nicolas
Rousseau, François
Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody
author_facet Loyau, Jérémy
Malinge, Pauline
Daubeuf, Bruno
Shang, Limin
Elson, Greg
Kosco-Vilbois, Marie
Fischer, Nicolas
Rousseau, François
author_sort Loyau, Jérémy
title Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody
title_short Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody
title_full Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody
title_fullStr Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody
title_full_unstemmed Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors: Fc-mediated avidity enhances the potency of an anti-TLR4 antibody
title_sort maximizing the potency of an anti-tlr4 monoclonal antibody by exploiting proximity to fcγ receptors: fc-mediated avidity enhances the potency of an anti-tlr4 antibody
description In order to treat Toll like receptor 4 (TLR4)-mediated diseases, we generated a potent antagonistic antibody directed against human TLR4, Hu 15C1. This antibody's potency can be modulated by engaging not only TLR4 but also Fcγ receptors (FcγR), a mechanism that is driven by avidity and not cell signaling. Here, using various formats of the antibody, we further dissect the relative contributions of the Fv and Fc portions of Hu 15C1, discovering that the relationship to potency of the different antibody arms is not linear. First, as could be anticipated, we observed that Hu 15C1 co-engages up to 3 receptors on the same plasma membrane, i.e., 2 TLR4 molecules (via its variable regions) and either FcγRI or FcγRIIA (via the Fc). The Kd of these interactions are in the nM range (3 nM of the Fv for TLR4 and 47 nM of the Fc for FcγRI). However, unexpectedly, neutralization experiments revealed that, due to the low level of cell surface TLR4 expression, the avidity afforded by engagement through 2 Fv arms was significantly limited. In contrast, the antibody's neutralization capacity increases by 3 logs when able to exploit Fc-FcγR interactions. Taken together, these results demonstrate an unforeseen level of contribution by FcγRs to an antibody's effectiveness when targeting a cell surface protein of relatively low abundance. These findings highlight an exploitable mechanism by which FcγR-bearing cells may be more powerfully targeted, envisioned to be broadly applicable to other reagents aimed at neutralizing cell surface targets on cells co-expressing FcγRs.
publisher Taylor & Francis
publishDate 2014
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4622919/
_version_ 1613493824908165120

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