Induction of cell death in malignant cells and regulatory T cells in the tumor microenvironment by targeting CD137

Regulatory T cells (Tregs) contribute significantly to the immunosuppressive nature of the tumor microenvironment which is a main barrier for immunotherapies of solid cancers. Reducing Treg numbers enhances anti-tumor immune responses but current depletion strategies also impair effector T cells (Te...

Full description

Saved in:
Bibliographic Details
Main Authors: Rui Sun, Kang Yi Lee, Yu Mei, Emily Nickles, Jia Le Lin, Runze Xia, Haiyan Liu, Herbert Schwarz
Format: Article
Language:English
Published: Taylor & Francis Group 2025-12-01
Series:OncoImmunology
Subjects:
Online Access:https://www.tandfonline.com/doi/10.1080/2162402X.2024.2443265
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Regulatory T cells (Tregs) contribute significantly to the immunosuppressive nature of the tumor microenvironment which is a main barrier for immunotherapies of solid cancers. Reducing Treg numbers enhances anti-tumor immune responses but current depletion strategies also impair effector T cells (Teffs), potentially leading to reduced anti-tumor immunity and/or autoimmune diseases. CD137 has been identified as the most differentially expressed gene between peripheral Tregs and intratumoral Tregs in virtually all solid cancers. Further, CD137 is expressed by malignant cells of certain cancers, making it a potential target for tumor immunotherapy. Here, we report the development of a fully human anti-human CD137 antibody of the IgG1 isotype, clone P1A1, that induces antibody-dependent cell-mediated cytotoxicity (ADCC) in CD137+ Tregs and cancer cells. P1A1 cross-reacts with murine CD137 which allowed testing murine chimeric P1A1 in syngeneic murine tumor models where P1A1 significantly reduced the number of CD137+ Tregs and inhibited tumor growth in a murine hepatocellular carcinoma (HCC) and a melanoma lung metastasis model. P1A1 can also be internalized thus enabling it as a carrier for drugs to target CD137+ Tregs and cancer cells. These anti-cancer properties suggest a translation of P1A1 to human immunotherapy.
ISSN:2162-402X