HERA-GITRL activates T cells and promotes anti-tumor efficacy independent of FcγR-binding functionality

Autor: Oliver Hill, Christian Merz, Meinolf Thiemann, Christian Gieffers, David M. Richards, Julian P. Sefrin, Katharina Billian-Frey, Mauricio Redondo Müller, Karl Heinonen, Harald Fricke, Jaromir Sykora, Matthias Schröder, Viola Marschall
Rok vydání: 2019
Předmět:
0301 basic medicine
Cancer Research
TNFSF
Recombinant Fusion Proteins
T cell
HERA
Agonist
Immunology
Lymphocyte Activation
T-Lymphocytes
Regulatory
lcsh:RC254-282
Receptors
Tumor Necrosis Factor
Mice
03 medical and health sciences
0302 clinical medicine
Immune system
Cell Line
Tumor
CD357
medicine
Animals
Humans
Immunology and Allergy
GITR
Receptor
Pharmacology
TNFRSF18
biology
Chemistry
Biological activity
lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens
In vitro
Immunoglobulin Fc Fragments
Cell biology
Macaca fascicularis
030104 developmental biology
medicine.anatomical_structure
Oncology
030220 oncology & carcinogenesis
Tumor Necrosis Factors
biology.protein
Single-chain GITRL
Molecular Medicine
Antibody
scGITRL-RBD
CD8
Research Article
Signal Transduction
Single-Chain Antibodies
Zdroj: Journal for ImmunoTherapy of Cancer, Vol 7, Iss 1, Pp 1-13 (2019)
Journal for Immunotherapy of Cancer
ISSN: 2051-1426
Popis: Background Glucocorticoid-induced TNFR-related protein (TNFRSF18, GITR, CD357), expressed by T cells, and its ligand (TNFSF18, GITRL), expressed by myeloid populations, provide co-stimulatory signals that boost T cell activity. Due to the important role that GITR plays in regulating immune functions, agonistic stimulation of GITR is a promising therapeutic concept. Multiple strategies to induce GITR signaling have been investigated. The limited clinical efficacy of antibody-based GITR agonists results from structural and functional characteristics of antibodies that are unsuitable for stimulating the well-defined trimeric members of the TNFRSF. Methods To overcome limitations of antibody-based TNFRSF agonists, we have developed HERA-GITRL, a fully human hexavalent TNF receptor agonist (HERA) targeting GITR and mimicking the natural signaling concept. HERA-GITRL is composed of a trivalent but single-chain GITRL-receptor-binding-domain (scGITRL-RBD) unit fused to an IgG1 derived silenced Fc-domain serving as dimerization scaffold. A specific mouse surrogate, mmHERA-GITRL, was also generated to examine in vivo activity in respective mouse tumor models. Results For functional characterization of HERA-GITRL in vitro, human immune cells were isolated from healthy-donor blood and stimulated with anti-CD3 antibody in the presence of HERA-GITRL. Consistently, HERA-GITRL increased the activity of T cells, including proliferation and differentiation, even in the presence of regulatory T cells. In line with these findings, mmHERA-GITRL enhanced antigen-specific clonal expansion of both CD4+ (OT-II) and CD8+ (OT-I) T cells in vivo while having no effect on non-specific T cells. In addition, mmHERA-GITRL showed single-agent anti-tumor activity in two subcutaneous syngeneic colon cancer models (CT26wt and MC38-CEA). Importantly, this activity is independent of its FcγR-binding functionality, as both mmHERA-GITRL with a functional Fc- and a silenced Fc-domain showed similar tumor growth inhibition. Finally, in a direct in vitro comparison to a bivalent clinical benchmark anti-GITR antibody and a trivalent GITRL, only the hexavalent HERA-GITRL showed full biological activity independent of additional crosslinking. Conclusion In this manuscript, we describe the development of HERA-GITRL, a true GITR agonist with a clearly defined mechanism of action. By clustering six receptor chains in a spatially well-defined manner, HERA-GITRL induces potent agonistic activity without being dependent on additional FcγR-mediated crosslinking. Electronic supplementary material The online version of this article (10.1186/s40425-019-0671-4) contains supplementary material, which is available to authorized users.
Databáze: OpenAIRE
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