A Novel Allogeneic Rituximab-Conjugated Gamma Delta T Cell Therapy for the Treatment of Relapsed/Refractory B-Cell Lymphoma

SIMPLE SUMMARY: CD20-targeting CAR T cells have shown remarkable clinical outcomes in patients with B-cell malignancies. However, the manufacturing processes usually involved in autologous cell collection and gene editing limit their usage and development across the board. Here, we developed an allogenic cell product ACE1831, Vγ9Vδ2 T (γδ2 T) cells equipped with anti-CD20 antibody, using antibody–cell conjugation (ACC) technology. ACE1831 elicits a specific and potent anti-tumor activity against CD20-expressing cancer cells in vitro and in vivo with no abnormal clinical observation. We further found that the ACC-linked antibody/receptor complex stimulated T cell activation upon recognizing the antigen on cancer cells. To summarize, our data show the promise of a novel combination of an ACC platform with γδ2 T cells in allogenic immunotherapy against relapsed/refractory B-cell lymphoma. ABSTRACT: Chimeric antigen receptor T cell (CAR-T) therapy has been applied in the treatment of B-cell lymphoma; however, CAR-T manufacturing requires virus- or non-virus-based genetic modification, which causes high manufacturing costs and potential safety concerns. Antibody–cell conjugation (ACC) technology, which originated from bio-orthogonal click chemistry, provides an efficient approach for arming immune cells with cancer-targeting antibodies without genetic modification. Here, we applied ACC technology in Vγ9Vδ2 T (γδ2 T) cells to generate a novel off-the-shelf CD20-targeting cell therapy ACE1831 (rituximab-conjugated γδ2 T cells) against relapsed/refractory B-cell lymphoma. ACE1831 exhibited superior cytotoxicity against B-cell lymphoma cells and rituximab-resistant cells compared to γδ2 T cells without rituximab conjugation. The in vivo xenograft study demonstrated that ACE1831 treatment strongly suppressed the aggressive proliferation of B-cell lymphoma and prolonged the survival of tumor-bearing mice with no observed toxicity. Mass spectrometry analysis indicated that cell activation receptors including the TCR complex, integrins and cytokine receptors were conjugated with rituximab. Intriguingly, the antigen recognition of the ACC-linked antibody/receptor complex stimulated NFAT activation and contributed to ACE1831-mediated cytotoxicity against CD20-expressing cancer cells. This study elucidates the role of the ACC-linked antibody/receptor complex in cytotoxicity and supports the potential of ACE1831 as an off-the-shelf γδ2 cell therapy against relapsed/refractory B-cell lymphoma.