To discover TCRs capable of recognizing B cell malignancies, Meeuwsen et al. first identified HLA-expressed peptides derived from genes highly expressed in B cell cancers, but not healthy tissues. Through tetramer binding, T cells recognizing these peptides were sorted from HLA-mismatched donor PBMCs, and following screening for specificity, recognition of endogenously presentated peptide, and normal cell cross-reactivity, three TCRs were used to engineer CD8+ T cells. The engineered cells specifically lysed B cell malignancy lines in vitro, and one was tested and temporarily regressed HLA-transfected tumors in a xenograft model.
Contributed by Alex Najibi
ABSTRACT: CAR T-cell therapy has shown great promise for the treatment of B-cell malignancies. However, antigen-negative escape variants often cause disease relapse necessitating the development of multi-antigen-targeting approaches. We propose that a TCR-based strategy would increase the number of potential antigenic targets as peptides from both intracellular and extracellular proteins can be recognized. Here, we aimed to isolate a broad range of promising TCRs targeting multiple antigens for treatment of B-cell malignancies. As a first step, 28 target genes for B-cell malignancies were selected based on gene expression profiles. Twenty target peptides presented in either HLA-A*01:01, A*24:02, B*08:01 or B*35:01 were identified from the immunopeptidome of B-cell malignancies and used to form peptide-HLA-tetramers for T-cell isolation. Target-peptide specific CD8 T cells were isolated from HLA-mismatched healthy donors and subjected to a stringent stepwise selection procedure to ensure potency and eliminate cross-reactivity. In total, five T-cell clones specific for FCRL5 in HLA-A*01:01, VPREB3 in HLA-A*24:02 and BOB1 in HLA-B*35:01 recognized B-cell malignancies. For all three specificities, TCR gene transfer into CD8 T cells resulted in cytokine production and efficient killing of multiple B-cell malignancies. In conclusion, using this systematic approach we successfully identified three promising TCRs for T-cell therapy against B-cell malignancies.
Author Info: (1) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands;. Electronic address: m.h.meeuwsen@lumc.nl. (2) Department of Hematology, Leiden Uni
Author Info: (1) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands;. Electronic address: m.h.meeuwsen@lumc.nl. (2) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (3) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands;; Department of Immunology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA. (4) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (5) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (6) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (7) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (8) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (9) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (10) Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (11) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (12) Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (13) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands. (14) Department of Hematology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands;. Electronic address: m.h.m.heemskerk@lumc.nl.
