Establishment of novel anti-TIM-3 antibodies interfering with its binding to ligands

Zhuohong Yan; Teng Ma; Xiaojue Wang; Ling Yi; Panjian Wei; Hongtao Zhang; Jinghui Wang

doi:10.1016/j.heliyon.2024.e28126

Establishment of novel anti-TIM-3 antibodies interfering with its binding to ligands

Heliyon. 2024 Mar 18;10(7):e28126. doi: 10.1016/j.heliyon.2024.e28126. eCollection 2024 Apr 15.

Authors

Zhuohong Yan¹, Teng Ma¹, Xiaojue Wang¹, Ling Yi¹, Panjian Wei¹, Hongtao Zhang¹, Jinghui Wang^{1

2}

Affiliations

¹ Cancer Research Center, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, 101149, China.
² Department of Medical Oncology, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, 101149, China.

Abstract

The T cell immunoglobulin and mucin-domain containing-3 (TIM-3) receptor has gained significant attention as a promising target for cancer immunotherapy. The inhibitory effect of T cells by TIM-3 is mediated through the interaction between TIM-3 and its ligands. Ligand-blocking anti-TIM-3 antibodies possess the potential to reactivate antigen-specific T cells and augment anti-tumor immunity. However, the precise ligand-receptor interactions disrupted by the administration of TIM-3 blocking Abs have yet to be fully elucidated. In this study, we have developed a panel of monoclonal antibodies targeting human TIM-3, namely MsT001, MsT065, MsT229, and MsT286. They exhibited high sensitivities (10 pg/mL) and affinities (3.70 × 10^-9 to 4.61 × 10^-11 M) for TIM-3. The TIM-3 antibodies recognized distinct epitopes, including linear epitopes (MsT001 and MsT065), and a conformational epitope (MsT229 and MsT286). Additionally, the MsT229 and MsT286 displayed reactivity towards cynomolgus TIM-3. The interactions between TIM-3/Gal-9, TIM-3/HMGB-1, and TIM-3/CEACAM-1 disrupt the binding of MsT229 and MsT286, while leaving the binding of MsT001 and MsT065 unaffected. The inhibitory effect on the interaction between Gal-9 and TIM-3 was found to be dose-dependently in the presence of either MsT229 or MsT286. The findings suggested that the involvement of conformational epitopes in TIM-3 is crucial for its interaction with ligands, and we successfully generated novel anti-TIM-3 Abs that exhibit inhibitory potential. In conclusion, our finding offers valuable insights -on the comprehension and targeting of human TIM-3.

Keywords: CEACAM-1; Conformational epitope; Galectin-9; HMGB-1; Monoclonal antibody; TIM-3.