Novel TCR-like CAR-T cells targeting an HLA∗0201-restricted SSX2 epitope display strong activity against acute myeloid leukemia

ABSTRACT: Summary The synovial sarcoma X breakpoint 2 (SSX2) belongs to a multigene family of cancer-testis antigens and can be found overexpressed in multiple malignancies. Its restricted expression in immune-privileged normal tissues suggest that SSX2 may be a relevant target antigen for chimeric antigen receptor (CAR) therapy. We have developed a T cell receptor (TCR)-like antibody (Fab/3) that binds SSX2 peptide 41-49 (KASEKIFYV) in the context of HLA-A∗-0201. The sequence of Fab/3 was utilized to engineer a CAR with the CD3 zeta intra-cellular domain along with either a CD28 or 4-1BB costimulatory endodomain. Human T cells from HLA-A2+ donors were transduced to mediate anti-tumor activity against acute myeloid leukemia (AML) tumor cells. Upon challenge with HLA-A2+/SSX2+ AML tumor cells, CAR-expressing T cells released interferon-γ and eliminated the tumor cells in a long-term co-culture assay. Using the HLA-A2+ T2 cell line, we demonstrated a strong specificity of the single-chain variable fragment (scFv) for SSX2 p41-49 and the closely related SSX3 p41-49, with no response against the others SSX-homologous peptides or unrelated homologous peptides. Since SSX3 has not been observed in tumor cells and expression cannot be induced by pharmacological intervention, SSX241-49 represents an attractive target for CAR-based cellular therapy to treat multiple types of cancer. Graphical abstract The TCR-like antibody engineered as a chimeric antigen receptor (CAR) is able to target the cancer-testis antigen (CTA) SSX2 peptide 41-49 in an HLA-A∗0201 context. Because of the SSX2 expression pattern in cancers, a cell-therapy approach using T cells expressing the SSX241-49 CAR can be readily deployed to treat patients.

SUBMITTER: Raskin S 

PROVIDER: S-EPMC8526777 | biostudies-literature |

REPOSITORIES: biostudies-literature