HLA-A2.1/MAGEA1 Specific TCRs Transduced Human T cells Induced Killing and IFN-γ Production
Most MAGEA1-HLA-A2.1 specific TCRs transduced human T cells showed killing and IFN-γ production in MAGEA1-HLA-A2.1 positive cell lines A375, U2OS, and U266B1.
RenTCR™ platform-derived TCRs exhibit higher peptide sensitivity than human donor-derived TCRs
IFN-γ production by TCR-transduced human T cells in response to stimulation with MAGEA1 peptide-loaded T2 cells. Human donor-derived TCRs include those in clinical development or reported in the literature. Data are normalized to maximum IFN-γ release and fitted to a four-parameter logistic model.
Candidate TCRs Demonstrated No Off-target Reactivity
(A) IFN-γ production by TCR-T cells was measured after stimulation with T2 cells loaded with peptides from a mutational cross-reactivity (X-scan) library. Heat maps show recognition motifs (threshold: 5% relative IFN-γ), which were used to screen a human proteome database. (B) Only peptides with predicted HLA-A*02:01 binding, as identified by X-scan, were retained for further analysis. T2 cells loaded with these peptide pools (10⁻⁶ M each) were used to stimulate TCR-T cells, and recognition was assessed via IFN-γ ELISA. (C) Recognized off-target peptides were validated in dose-response assays. (D) TCR-T cells were co-cultured with tumor cell lines overexpressing the genes encoding the putative off-target proteins (E:T=5:1, 18h). (E) TCR-T cells were co-cultured with HLA-A*02:01⁺/MAGEA1⁻, HLA-A*02:01-/MAGEA1⁻ or HLA-A*02:01⁻/MAGEA1+ cell lines (E:T=1.5:1) for 18h. TCR molecule tested in clinical-stage served as the positive control (pos ctrl). IFN-γ secretion of experiments was quantified by ELISA.
HLA-A2.1/MAGEA1-Specific TCRs Suppress Tumor Growth In Vivo
NDG immunodeficient mice were implanted with human HLA-A*02:01+ tumor cell lines U266B1 and NCI-H1703, both of which endogenously express MAGEA1. Once the tumors reached 100 mm3, T cells expressing MAGEA1-specific TCRs or mock T cells were administered (n = 6 mice/group). S.C.: subcutaneous injection; I.V.: intravenous injection; TIW: three times a week.
