Nanobody-based canine PD-L1-targeting immune checkpoint inhibitors for cancer therapy in dogs.
Publisher DOI
PubMed ID
41199882
Abstract
Although the demand for novel immunotherapies to treat companion dogs with spontaneously developing cancer is increasing in high-income countries, most options remain inaccessible. Dogs host a complete and functional immune system reacting to the presence of their tumor. As for humans, many canine neoplasms were shown to overexpress programmed death-ligand 1 (PD-L1), an immune checkpoint inhibitor (ICI) known to downregulate cytotoxic T cell activity upon interaction with its ligand PD-1. In this study, we used alpaca-derived single domain antibodies (sdAbs), also known as nanobodies (Nbs), to develop new ICI targeting canine PD-L1. We selected several clones binding to both recombinant soluble and cell membrane-anchored cPD-L1 forms. Next, their cPD-L1-binding affinities, cPD-1/cPD-L1-blocking abilities and epitope relationships were determined. Most effective Nbs binding to non-overlapping epitopes were combined as biparatopic Fc fusions to provide additional functionalities and improve their efficacy. Remarkably, all engineered Nb constructs efficiently interfered with the cPD-1/cPD-L1-induced signaling pathway, with some multivalent molecules displaying inhibitory concentrations reaching low picomolar range. Moreover, Fc-competent Nb constructs were also shown to induce tumor cell death by antibody-dependent cell-mediated cytotoxicity using human or canine models. Finally, using donor canine peripheral blood mononuclear cells (PBMCs), best candidates were favorably compared with atezolizumab in a Staphylococcal enterotoxin B (SEB)-based interferon-γ (IFNγ) secretion assay.
Date Issued
2025-09-18
Publication Type
Article
Subject(s)
Subjects
canine PD-L1
•
checkpoint inhibitors
•
dog cancers
•
multivalent constructs
•
single-domain antibody
Language(s)
en
Author(s)
Taskoparan, Betül | |
Maheswaran, Mathischan | |
Berg, Johannes Vom | |
Chames, Patrick |
Journal
Molecular Therapy - Oncology
Publisher
Cell Press
ISSN
2950-3299
2372-7705
Access(Rights)
open.access