Characterization of a TNFR2-Selective Agonistic TNF-α Mutant and Its Derivatives as an Optimal Regulatory T Cell Expander

Abstract

Regulatory T cells (Tregs) are a subpopulation of lymphocytes that play a role in suppressing and regulating immune responses. Recently, it was suggested that controlling the functions and activities of Tregs might be applicable to the treatment of human diseases such as autoimmune diseases, organ transplant rejection, and graft-versus-host disease. TNF receptor type 2 (TNFR2) is a target molecule that modulates Treg functions. In this study, we investigated the role of TNFR2 signaling in the differentiation and activation of mouse Tregs. We previously reported the generation of a TNFR2-selective agonist TNF mutant, termed R2agoTNF, by using our unique cytokine modification method based on phage display. R2agoTNF activates cell signaling via mouse TNFR2. In this study, we evaluated the efficacy of R2agoTNF for the proliferation and activation of Tregs in mice. R2agoTNF expanded and activated mouse CD4+CD25+ Tregs ex vivo. The structural optimization of R2agoTNF by internal cross-linking or IgG-Fc fusion selectively and effectively enhanced Treg expansion in vivo. Furthermore, the IgG-Fc fusion protein suppressed skin-contact hypersensitivity reactions in mice. TNFR2 agonists are expected to be new Treg expanders.

Targeting TNFR2 in Cancer: All Roads Lead to Rome

“…Other TNFR family members, such as 4-1BB, GITR, and DR3, but not OX40, can also increase Tregs' proliferation and survival through canonical NF-kB; TNFR2 is the most efficient among them, and the transcriptome feature of each group seems to be similar (44). Tsunoda et al reported the generation of a new TNFR2-selective agonist TNFa mutant, termed R2gaoTNF; it could expand and activate mouse CD4+ CD25+ Tregs ex vivo, which makes it a new candidate for Treg expansion (45). Another novel TNFR2 agonist antibody developed by Faustman can also expand highly potent Tregs (25,46).…”

“…Tsunoda et al. reported the generation of a new TNFR2-selective agonist TNFα mutant, termed R2gaoTNF; it could expand and activate mouse CD4+CD25+ Tregs ex vivo , which makes it a new candidate for Treg expansion ( 45 ). Another novel TNFR2 agonist antibody developed by Faustman can also expand highly potent Tregs ( 25 , 46 ).…”

Tregs in Autoimmunity: Insights Into Intrinsic Brake Mechanism Driving Pathogenesis and Immune Homeostasis

“…TNFR2 DARPins showed increased i-κB degradation in human primary Tregs and increased NF-κB activation in a Jurkat reporter cell line, which could lead to decreased suppressive functions. However, conflicting literature exists showing TNFR2 agonistic antibody or TNF-α mutant protein selectively binding to TNFR2, expand highly potent regulatory Tregs ( 43 , 44 ). Moreover, TNF-α together with IL-6 enables human Treg proliferation with sustained function and stability ex vivo ( 45 ).…”

Development of a 1:1-binding biparatopic anti-TNFR2 antagonist by epitope selection

“…In contrast, anti-TNFR2 signal-inducing antibodies (agonists) are pursued as therapeutic strategies to expand Tregs in autoimmunity, organ transplant rejection, and graft-versus-host disease. (9,10,(13)(14)(15). Bivalency of conventional antibody (cIgG) could produce dimer formation-related unwanted cellular responses (16).…”

“…In contrast, anti-TNFR2 signal-inducing antibodies (agonists) are pursued as therapeutic strategies to expand T regs in autoimmunity, organ transplant rejection, and graft-versus-host disease. ( 9,10,13-15 ).…”