The University of Southampton
University of Southampton Institutional Repository

Fc-null anti-PD-1 monoclonal antibodies deliver optimal checkpoint blockade in diverse immune environments

Fc-null anti-PD-1 monoclonal antibodies deliver optimal checkpoint blockade in diverse immune environments
Fc-null anti-PD-1 monoclonal antibodies deliver optimal checkpoint blockade in diverse immune environments
Background: Despite extensive clinical use, the mechanisms that lead to therapeutic resistance to anti-programmed cell-death (PD)-1 monoclonal antibodies (mAbs) remain elusive. Here, we sought to determine how interactions between the Fc region of anti-PD-1 mAbs and Fcγ receptors (FcγRs) affect therapeutic activity and how these are impacted by the immune environment.

Methods: Mouse and human anti-PD-1 mAbs with different Fc binding profiles were generated and characterized in vitro. The ability of these mAbs to elicit T-cell responses in vivo was first assessed in a vaccination setting using the model antigen ovalbumin. The antitumor activity of anti-PD-1 mAbs was investigated in the context of immune ‘hot’ MC38 versus ‘cold’ neuroblastoma tumor models, and flow cytometry performed to assess immune infiltration.

Results: Engagement of activating FcγRs by anti-PD-1 mAbs led to depletion of activated CD8 T cells in vitro and in vivo, abrogating therapeutic activity. Importantly, the extent of this Fc-mediated modulation was determined by the surrounding immune environment. Low FcγR-engaging mouse anti-PD-1 isotypes, which are frequently used as surrogates for human mAbs, were unable to expand ovalbumin-reactive CD8 T cells, in contrast to Fc-null mAbs. These results were recapitulated in mice expressing human FcγRs, in which clinically relevant hIgG4 anti-PD-1 led to reduced endogenous expansion of CD8 T cells compared with its engineered Fc-null counterpart. In the context of an immunologically ‘hot’ tumor however, both low-engaging and Fc-null mAbs induced long-term antitumor immunity in MC38-bearing mice. Finally, a similar anti-PD-1 isotype hierarchy was demonstrated in the less responsive ‘cold’ 9464D neuroblastoma model, where the most effective mAbs were able to delay tumor growth but could not induce long-term protection.

Conclusions: Our data collectively support a critical role for Fc:FcγR interactions in inhibiting immune responses to both mouse and human anti-PD-1 mAbs, and highlight the context-dependent effect that anti-PD-1 mAb isotypes can have on T-cell responses. We propose that engineering of Fc-null anti-PD-1 mAbs would prevent FcγR-mediated resistance in vivo and allow maximal T-cell stimulation independent of the immunological environment.

antibodies, immunotherapy, neoplasm, programmed cell death 1 receptor
Willoughby, Jane
aa6969bd-3830-4e1b-83ac-6369b5711e1f
Gray, Juliet
12d5e17c-97bb-4d6d-8fc4-3914b730ed42
Beers, Stephen
a02548be-3ffd-41ab-9db8-d6e8c3b499a2
Moreno vicente, Julia
38e74775-04e8-42e3-a0b8-50c6f1c140a0
Willoughby, Jane
aa6969bd-3830-4e1b-83ac-6369b5711e1f
Willoughby, Jane
aa6969bd-3830-4e1b-83ac-6369b5711e1f
Gray, Juliet
12d5e17c-97bb-4d6d-8fc4-3914b730ed42
Beers, Stephen
a02548be-3ffd-41ab-9db8-d6e8c3b499a2
Moreno vicente, Julia
38e74775-04e8-42e3-a0b8-50c6f1c140a0
Willoughby, Jane
aa6969bd-3830-4e1b-83ac-6369b5711e1f

Willoughby, Jane, Gray, Juliet, Beers, Stephen, Moreno vicente, Julia and Willoughby, Jane (2022) Fc-null anti-PD-1 monoclonal antibodies deliver optimal checkpoint blockade in diverse immune environments. Journal for Immunotherapy of Cancer, 10 (1), [e003735]. (doi:10.1136/jitc-2021-003735).

Record type: Article

Abstract

Background: Despite extensive clinical use, the mechanisms that lead to therapeutic resistance to anti-programmed cell-death (PD)-1 monoclonal antibodies (mAbs) remain elusive. Here, we sought to determine how interactions between the Fc region of anti-PD-1 mAbs and Fcγ receptors (FcγRs) affect therapeutic activity and how these are impacted by the immune environment.

Methods: Mouse and human anti-PD-1 mAbs with different Fc binding profiles were generated and characterized in vitro. The ability of these mAbs to elicit T-cell responses in vivo was first assessed in a vaccination setting using the model antigen ovalbumin. The antitumor activity of anti-PD-1 mAbs was investigated in the context of immune ‘hot’ MC38 versus ‘cold’ neuroblastoma tumor models, and flow cytometry performed to assess immune infiltration.

Results: Engagement of activating FcγRs by anti-PD-1 mAbs led to depletion of activated CD8 T cells in vitro and in vivo, abrogating therapeutic activity. Importantly, the extent of this Fc-mediated modulation was determined by the surrounding immune environment. Low FcγR-engaging mouse anti-PD-1 isotypes, which are frequently used as surrogates for human mAbs, were unable to expand ovalbumin-reactive CD8 T cells, in contrast to Fc-null mAbs. These results were recapitulated in mice expressing human FcγRs, in which clinically relevant hIgG4 anti-PD-1 led to reduced endogenous expansion of CD8 T cells compared with its engineered Fc-null counterpart. In the context of an immunologically ‘hot’ tumor however, both low-engaging and Fc-null mAbs induced long-term antitumor immunity in MC38-bearing mice. Finally, a similar anti-PD-1 isotype hierarchy was demonstrated in the less responsive ‘cold’ 9464D neuroblastoma model, where the most effective mAbs were able to delay tumor growth but could not induce long-term protection.

Conclusions: Our data collectively support a critical role for Fc:FcγR interactions in inhibiting immune responses to both mouse and human anti-PD-1 mAbs, and highlight the context-dependent effect that anti-PD-1 mAb isotypes can have on T-cell responses. We propose that engineering of Fc-null anti-PD-1 mAbs would prevent FcγR-mediated resistance in vivo and allow maximal T-cell stimulation independent of the immunological environment.

Text
Fc-null anti-PD-1 monoclonal antibodies deliver optimal checkpoint blockade in diverse immune environments - Accepted Manuscript
Restricted to Repository staff only
Request a copy
Text
e003735.full - Version of Record
Available under License Creative Commons Attribution.
Download (3MB)

More information

Accepted/In Press date: 8 December 2021
Published date: 11 January 2022
Keywords: antibodies, immunotherapy, neoplasm, programmed cell death 1 receptor

Identifiers

Local EPrints ID: 455797
URI: http://eprints.soton.ac.uk/id/eprint/455797
PURE UUID: d8e597a0-f094-413a-8c0f-373352e4bfb6
ORCID for Juliet Gray: ORCID iD orcid.org/0000-0002-5652-4722
ORCID for Stephen Beers: ORCID iD orcid.org/0000-0002-3765-3342

Catalogue record

Date deposited: 05 Apr 2022 16:32
Last modified: 06 Apr 2022 01:37

Export record

Altmetrics

Contributors

Author: Jane Willoughby
Author: Juliet Gray ORCID iD
Author: Stephen Beers ORCID iD
Author: Julia Moreno vicente
Author: Jane Willoughby

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×