Expansion of human γδ T cells for adoptive immunotherapy using a bisphosphonate prodrug

Abstract

Cancer immunotherapy with human γδ T cells expressing Vγ2Vδ2 T cell receptor (also termed Vγ9Vδ2) has shown promise because of their ability to recognize and kill most types of tumors in a major histocombatibility complex (MHC) ‐unrestricted fashion that is independent of the number of tumor mutations. In clinical trials, adoptive transfer of Vγ2Vδ2 T cells has been shown to be safe and does not require preconditioning. In this report, we describe a method for preparing highly enriched human Vγ2Vδ2 T cells using the bisphosphonate prodrug, tetrakis‐pivaloyloxymethyl 2‐(thiazole‐2‐ylamino)ethylidene‐1,1‐bisphosphonate (PTA). PTA stimulated the expansion of Vγ2Vδ2 cells to purities up to 99%. These levels were consistently higher than those observed after expansion with zoledronic acid, the most commonly used stimulator for clinical trials. Cell numbers also averaged more than those obtained with zoledronic acid and the expanded Vγ2Vδ2 cells exhibited high cytotoxicity against tumor cells. The high purity of Vγ2Vδ2 cells expanded by PTA increased engraftment success in immunodeficient NOG mice. Even low levels of contaminating αβ T cells resulted in some mice with circulating human αβ T cells rather than Vγ2Vδ2 cells. Vγ2Vδ2 cells from engrafted NOG mice upregulated CD25 and secreted tumor necrosis factor‐α and interferon‐γ in response to PTA‐treated tumor cells. Thus, PTA expands Vγ2Vδ2 T cells to higher purity than zoledronic acid. The high purities allow the successful engraftment of immunodeficient mice without further purification and may speed up the development of allogeneic Vγ2Vδ2 T cell therapies derived from HLA‐matched normal donors for patients with poor autologous Vγ2Vδ2 T cell responses.

Contribution of Macrophages and T Cells in Skeletal Metastasis

“…Despite positive effects in a few patients, there were some significant side effects [316,317]. Therefore, current studies are attempting to further increase the anti-cancer effect of γδT cells using analogs of bisphosphonates that could be more efficient in patients [318,319].…”

Determination of human γδ T cell–mediated cytotoxicity using a non-radioactive assay system

“…In order to validate the non-radioactive cellular cytotoxicity assay system for the measurement of tumoricidal activity exhibited by human Vγ2Vδ2 + γδ T cells, peripheral blood samples were obtained from healthy adult volunteers and peripheral blood mononuclear cells (PBMCs) were purified. As previously described, tetrakis-pivaloyloxymethyl 2-(thiazole-2ylamino)ethylidene-1,1-bisphosphonate (PTA) was used for the expansion of Vγ2Vδ2 + γδ T cells (Matsumoto et al, 2016;Tanaka et al, 2017;Tanaka et al, 2018). After stimulation of PBMCs with PTA and IL-2 for 11 days, Vδ2 + cells occupied 98% or more of the lymphocyte gate in three healthy adult PBMCs (HD01: 99.7%, HD02: 99.3% and HD3: 98.4%).…”

Protective Role ofγδT Cells in Different Pathogen Infections and Its Potential Clinical Application

“…It can get inside the cells where it is converted into acid enzymes with activity by intracellular esterases [ 173 ]. PTA could activate the expansion of peripheral blood V γ 9 δ 2 T cells which are separated from cancer patients (prostate and breast cancer) [ 174 ]. Compared with Zol, PTA activates γδ T cell expansion more effectively and produces more cytokines (TNF- α and IFN- γ ) [ 173 ].…”