Anti-γδ TCR antibody-expanded γδ T cells: a better choice for the adoptive immunotherapy of lymphoid malignancies

Cell-based immunotherapy for lymphoid malignancies has gained increasing attention as patients develop resistance to conventional treatments. γδ T cells, which have major histocompatibility complex (MHC)-unrestricted lytic activity, have become a promising candidate population for adoptive cell transfer therapy. We previously established a stable condition for expanding γδ T cells by using anti-γδ T-cell receptor (TCR) antibody. In this study, we found that adoptive transfer of the expanded γδ T cells to Daudi lymphoma-bearing nude mice significantly prolonged the survival time of the mice and improved their living status. We further investigated the characteristics of these antibody-expanded γδ T cells compared to the more commonly used phosphoantigen-expanded γδ T cells and evaluated the feasibility of employing them in the treatment of lymphoid malignancies. Slow but sustained proliferation of human peripheral blood γδ T cells was observed upon stimulation with anti-γδ TCR antibody. Compared to phosphoantigen-stimulated γδ T cells, the antibody-expanded cells manifested similar functional phenotypes and cytotoxic activity towards lymphoma cell lines. It is noteworthy that the anti-γδ TCR antibody could expand both the Vδ1 and Vδ2 subsets of γδ T cells. The in vitro-expanded Vδ1 T cells displayed comparable tumour cell-killing activity to Vδ2 T cells. Importantly, owing to higher C-C chemokine receptor 4 (CCR4) and CCR8 expression, the Vδ1 T cells were more prone to infiltrate CCL17- or CCL22-expressing lymphomas than the Vδ2 T cells. Characterizing the peripheral blood γδ T cells from lymphoma patients further confirmed that the anti-γδ TCR antibody-expanded γδ T cells could be a more efficacious choice for the treatment of lymphoid malignancies than phosphoantigen-expanded γδ T cells.