Establishment of a novel NFAT-GFP reporter platform useful for the functional avidity maturation of HLA class II-restricted TCRs

• DOI: 10.1007/s00262-023-03420-8
• Publication Date: 2023-03-20T07:02:55Z
• Authors: Fumihiro Fujiki; Soyoko Morimoto; Yuya Nishida; Satoe Tanii; Nao Aoyama; Miki Inatome; Kento Inoue; Akiko Katsuhara; Hiroko Nakajima; Jun Nakata; Sumiyuki Nishida; Akihiro Tsuboi; Yoshihiro Oka; Yusuke Oji; Shinji Sogo; Haruo Sugiyama
• Keywords: CD4-Positive T-Lymphocytes; Antigens, Neoplasm; Research; Neoplasms; Receptors, Antigen, T-Cell; Humans; Immunotherapy, Adoptive; 3. Good health

AbstractCD4+ T cells that recognize antigenic peptides presented on HLA class II are essential for inducing an optimal anti-tumor immune response, and adoptive transfer of tumor antigen-specific TCR-transduced CD4+ T cells with high responsiveness against tumor is a promising strategy for cancer treatment. Whereas a precise evaluation method of functional avidity, an indicator of T cell responsiveness against tumors, has been established for HLA class I-restricted TCRs, it remains unestablished for HLA class II-restricted TCRs. In this study, we generated a novel platform cell line, CD4-2D3, in which GFP reporter was expressed by NFAT activation via TCR signaling, for correctly evaluating functional avidity of HLA class II-restricted TCRs. Furthermore, using this platform cell line, we succeeded in maturating functional avidity of an HLA class II-restricted TCR specific for a WT1-derived helper peptide by substituting amino acids in complementarity determining region 3 (CDR3) of the TCR. Importantly, we demonstrated that transduction of an avidity-maturated TCR conferred strong cytotoxicity against WT1-expressing leukemia cells on CD4+ T cells, compared to that of its original TCR. Thus, CD4-2D3 cell line should be useful not only to evaluate TCR functional avidity in HLA class II-restricted TCRs but also to screen appropriate TCRs for clinical applications such as cancer immunotherapy.