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Monoclonal antibodies (mAbs) constitute the most rapidly growing class of human therapeutics and the second largest class of drugs after vaccines. The treatment of B-cell malignancies and HER2/Neu+ breast cancer has benefited considerably from the use of therapeutic mAbs, either alone or in combination with standard chemotherapy. Frequent relapses, however, demonstrate that the bioactivity of these mAbs is still suboptimal. The concept of improving the anti-tumor activity of mAbs is well established and potentiating the cytotoxicity induced by anticancer mAbs can be achieved by strategies that target the downstream cytolytic effector cells. The recruitment of Fcγ receptor-dependent functions appears well suited in this regard, because several lines of evidence suggest that enhancing antibody-dependent cellular cytotoxicity (ADCC) induced by therapeutic mAbs may directly improve their clinical efficacy. The cytolytic effector cells involved in ADCC are Fcγ-Rexpressing natural killer (NK) cells, but also γδ T cells can be amplified and finetuned for stronger ADCC activity. γδ T cells are raising a considerable interest in the immunotherapy community given their intrinsic antitumor activity that can be boosted by stimulation with synthetic phosphoantigens (PAgs), or with drugs that cause their accumulation into target cells, like aminobisphosphonates (N-BPs), and low doses interleukin (IL)-2. The field is interesting, and several papers have already explored this approach in solid and haematological malignancies. Thus, we propose that enhancing the efficacy of mAbs by combination with γδ T cell activation may have considerable therapeutic potential for a variety of malignancies, most especially for patients whose FcγR alleles impair ADCC.

Monoclonal antibodies (mAbs) constitute the most rapidly growing class of human therapeutics and the second largest class of drugs after vaccines. The treatment of B-cell malignancies and HER2/Neu breast cancer has benefited considerably from the use of therapeutic mAbs, either alone or in combination with standard chemotherapy. Frequent relapses, however, demonstrate that the bioactivity of these mAbs is still suboptimal. The concept of improving the anti-tumor activity of mAbs is well established and potentiating the cytotoxicity induced by anticancer mAbs can be achieved by strategies that target the downstream cytolytic effector cells. The recruitment of Fc receptor-dependent functions appears well suited in this regard, because several lines of evidence suggest that enhancing antibody-dependent cellular cytotoxicity (ADCC) induced by therapeutic mAbs may directly improve their clinical efficacy. The cytolytic effector cells involved in ADCC are Fc-Rexpressing natural killer (NK) cells, but also T cells can be amplified and finetuned for stronger ADCC activity. T cells are raising a considerable interest in the immunotherapy community given their intrinsic antitumor activity that can be boosted by stimulation with synthetic phosphoantigens (PAgs), or with drugs that cause their accumulation into target cells, like aminobisphosphonates (N-BPs), and low doses interleukin (IL)-2. The field is interesting, and several papers have already explored this approach in solid and haematological malignancies. Thus, we propose that enhancing the efficacy of mAbs by combination with T cell activation may have considerable therapeutic potential for a variety of malignancies, most especially for patients whose FcR alleles impair ADCC.

The broad antimicrobial and antitumoral reactivity of V9Vδ2 T cells, their ability to produce inflammatory cytokines involved in protective immunity against intracellular pathogens and tumors and their strong cytolytic and bactericidal activities suggest their direct involvement in immune control of cancers and infections. δ T cells can be selectively activated by naturally occurring or synthetic phosphoantigens, and drugs that enhance their accumulation into stressed cells, offering new avenues for the development of δ T cell-based immunotherapies. The recent development of small drugs selectively activating V9Vδ2 T lymphocytes, which upregulate endogenous phosphoantigens, has enabled investigators to design experimental approaches of cancer immunotherapies; several ongoing phase I and II clinical trials are focused on the role of direct bioactivity of drugs and of adoptive cell therapies involving phosphoantigen-activated V9Vδ2 T lymphocytes in humans. In this review, we focus on the recent advances of the activation/expansion of δ T cells in vitro and in vivo that may represent a promising target for the design of novel and highly innovative immunotherapy in patients with different types of cancer.

The broad antimicrobial and antitumoral reactivity of Vγ9Vδ2 T cells, their ability to produce inflammatory cytokines involved in protective immunity against intracellular pathogens and tumors and their strong cytolytic and bactericidal activities suggest their direct involvement in immune control of cancers and infections. γδ T cells can be selectively activated by naturally occurring or synthetic phosphoantigens, and drugs that enhance their accumulation into stressed cells, offering new avenues for the development of γδ T cell-based immunotherapies. The recent development of small drugs selectively activating Vγ9Vδ2 T lymphocytes, which upregulate endogenous phosphoantigens, has enabled investigators to design experimental approaches of cancer immunotherapies; several ongoing phase I and II clinical trials are focused on the role of direct bioactivity of drugs and of adoptive cell therapies involving phosphoantigen-activated Vγ9Vδ2 T lymphocytes in humans. In this review, we focus on the recent advances of the activation/expansion of γδ T cells in vitro and in vivo that may represent a promising target for the design of novel and highly innovative immunotherapy in patients with different types of cancer.

In this study we have evaluated the in vitroeffects of four different aminobisphosphonates, alendronate, risedronate, neridronate and zoledronate, on Vγ9Vδ2 T cell activation and differentiation. All tested aminobisphosphonates induce an IL-2-dependent activation and expansion of Vγ9Vδ2 T lymphocytes in primary PBMC cultures of healthy donors. Most notably, they also determine a different distribution of Vγ9Vδ2 T cell subsets, with decrease of Tnaiveand TCMcells and increase of TEMand TEMRAVγ9Vδ2 cells, indicating that in vitrotreatment with aminobisphosphonates induces Vγ9Vδ2 T lymphocytes to differentiate towards an effector/cytotoxic phenotype. Accordingly, Vγ9Vδ2 T lymphocytes cultured with aminobisphosphonates and IL-2 showed a major content of IFN-γ and acquired the ability to kill tumor target cells.

ABSTRACTγδ T cells usually infiltrate many different types of cancer, but it is unclear whether they inhibit or promote tumor progression. Moreover, properties of tumor-infiltrating γδ T cells and those in the corresponding normal tissue remain largely unknown. Here we have studied features of γδ T cells in colorectal cancer, normal colon tissue and peripheral blood, and correlated their levels with clinicopathologic hallmarks. Flow cytometry and transcriptome analyses showed that the tumor comprised a highly variable rate of TILs (5–90%) and 4% γδ T cells on average, with the majority expressing Vδ1. Most Vδ1 and Vδ2 T cells showed a predominant effector memory phenotype and had reduced production of IFN- γ which was likely due to yet unidentified inhibitory molecules present in cancer stem cell secretome. Transcriptome analyses revealed that patients containing abundant γδ T cells had significantly longer 5-year disease free survival rate, suggesting their efficacy in controlling tumor at very early stage.