Next-generation CD179a-CAR-T cells demonstrate potent and sustained anti-tumor activity in preclinical B-cell malignancies

Abstract

Background: Chimeric Antigen Receptor (CAR) T-cell therapy has transformed the treatment landscape for B-cell malignancies, particularly in relapsed and refractory leukemia. However, conventional CAR constructs targeting CD19 or CD20 often result in off-tumor toxicity due to shared antigen expression on healthy B-cells. CD179a, a novel leukemia-associated antigen with limited expression on normal tissues, presents a promising alternative target for safer and more specific immunotherapy.

Methods: A 5th-generation CAR construct targeting CD179a was engineered and transfected into human T-cells to assess its antileukemic efficacy. Functional characterization was performed using the JM1-VRL-10,423 B-cell leukemia cell line. Post-transfection, cytotoxic activity, apoptosis induction, gene expression, and tumor cell viability were quantified. To evaluate safety, CD179a-CAR T-cells were also co-cultured with normal human peripheral blood mononuclear cells (PBMCs). Additionally, the in vivo efficacy of CD179a-directed CAR T-cells was tested in a xenograft model of B-cell leukemia, using mice transplanted with CD179a+ tumor cells.

Results: In vitro, CD179a-targeted CAR T-cells demonstrated potent cytotoxicity, reducing leukemia cell viability to 44.22% after 72 h, superior to both CD3/CD28-activated T-cells and 5-Fluorouracil (5-FU). Apoptosis assays confirmed early apoptotic induction in 54.3% of leukemia cells. Importantly, negligible cytotoxic effects were observed in PBMCs, indicating selective targeting. In the xenograft model, CD179a-CAR T-cells significantly reduced the expression of CD179a in leukemic cells compared to controls. Gene expression profiling further validated apoptosis pathway activation.

Conclusion: These findings highlight the promising antileukemic potential of CD179a-directed CAR T-cells, combining high specificity with a favorable safety profile. This in vitro and in vivo study supports the advancement of CD179a-CAR T-cell therapy as a next-generation immunotherapeutic strategy for B-cell leukemias, warranting further preclinical and clinical development.