Targeted Activation of Human Vγ9Vδ2-T Cells Controls Epstein-Barr Virus-Induced B Cell Lymphoproliferative Disease

Abstract

Epstein-Barr virus-induced lymphoproliferative disease (EBV-LPD) after transplantation remains a serious and life-threatening complication. Herein we showed that the aminobisphosphonate pamidronate-expanded human Vγ9Vδ2-T cells efficiently killed EBV-transformed autologous lymphoblastoid B cell lines (EBV-LCL) through γ/δ-TCR and NKG2D receptor triggering and Fas and TRAIL engagement. By inoculation of EBV-LCL in Rag2(-/-)γc(-/-) mice and humanized mice, we established lethal EBV-LPD with characteristics close to those of the human disease. Adoptive transfer of pamidronate-expanded Vγ9Vδ2-T cells alone effectively prevented EBV-LPD in Rag2(-/-)γc(-/-) mice and induced EBV-LPD regression in EBV(+) tumor-bearing Rag2(-/-)γc(-/-) mice. Pamidronate treatment inhibited EBV-LPD development in humanized mice through selective activation and expansion of Vγ9Vδ2-T cells. This study provides proof-of-principle for a therapeutic approach using pamidronate to control EBV-LPD through Vγ9Vδ2-T cell targeting.

T-Cell Responses to EBV

“…The Vδ1 subset of γδ T cells can directly recognise and lyse EBV-transformed LCLs in vitro (Hacker et al 1992) and high frequencies of these cells have been described in transplant recipients who have previously experienced EBV reactivation (Fujishima et al 2007;Farnault et al 2013). The Vγ2 Vδ9 subset of γδ T cells can also recognise and lyse LCLs in vitro, but efficiency is low unless the cells are activated with pamidronate and then positively selected using anti-γδ-TCR-specific beads (thus delivering a TCR signal to the cells) (Xiang et al 2014). However in mice reconstituted with human immune system components, pamidronate administration was sufficient to significantly reduce EBV-positive lymphoproliferative disease and this control was dependent upon Vγ2 Vδ2 T cells (Xiang et al 2014).…”

Adoptively transferred Vγ9Vδ2 T cells show potent antitumor effects in a preclinical B cell lymphomagenesis model

“…Thus, in addition to supporting the potential clinical utility of in vitro-expanded Vδ2 + T cells, our analysis suggests that a key area for future investigation will be to understand in detail the regulation of PD-1 expression on human γδ T cells that are to be used for cellular immunotherapy. A study by Xiang et al recently established that similar in vitro-expanded human Vδ2 + T cells can control the growth in vivo of human B lymphoblastoid cell lines that were first transformed by EBV in vitro and then transferred into NSG mice (32). While providing a powerful demonstration that high doses of Vδ2 + T cells are sufficient to kill EBV-transformed B lymphoblastoid cells in vivo, the analysis by Xiang et al did not address the more physiological scenario that we have created in our model, where we have tested the antitumor impact of a comparatively small number of adoptively transferred γδ T cells in the presence of a much larger number of autologous T cells that are functionally suppressed.…”

“…However, a challenge to modeling the actions of human Vδ2 + T cells in vivo is that rodents do not possess a similar isoprenoid-reactive γδ T cell subset, and lack the BTN3A1 isoform (25,26). Prior studies have thus xenografted established human tumors into immune-deficient mice in the presence or absence of human Vδ2 + T cells to evaluate their effects in vivo (27)(28)(29)(30)(31)(32). These studies have provided important demonstrations of the antitumor potential of human Vδ2 + T cells.…”

How I treat posttransplant lymphoproliferative disorders

“…[82][83][84][85] In addition, recent studies in mice have shown that adoptive transfer of pamidronate-expanded Vg9Vd2 T cells and tacrolimus-resistant engineered CTLs might become potential therapies in PTLD without the need for reducing immune-suppressive therapy. 86,87 To improve the positive predictive value of EBV viral load, different approaches have been described that combine EBV PCR with measurements of diminished T-cell immunity (absolute lymphocyte count, absence of EBV-specific CD8 1 T cells) or cytokine polymorphisms. [88][89][90] Other potential candidates allowing preventive or prophylactic interventions include measurements of interleukin-6, interleukin-10, and chemokine (C-X-C motif) ligand 13.…”