T-cell killing of primary follicular lymphoma cells is dramatically potentiated by GA101, a type II glycoengineered anti-CD20 monoclonal antibody

Abstract

BackgroundAnti-CD20 monoclonal antibodies are major therapeutic agents for patients with follicular lymphoma and work through complement-mediated cytotoxicity and antibody-dependent cellular cytotoxicity. Optimization of antibody-dependent cellular cytotoxicity, in particular by amplifying its effectors, could further increase the efficacy of anti-CD20 monoclonal antibodies. Design and MethodsWe investigated the cytotoxic activity of Vγ9Vδ2 T cells against follicular lymphoma cells and whether this killing could be increased by promoting antibody-dependent cellular cytotoxicity with anti-CD20 monoclonal antibodies, in particular a type-II glycoengineered anti-CD20. Vγ9Vδ2 T cells were expanded in vitro in the presence of bromohydrin pyrophosphate (Phosphostim) and interleukin-2 and their ability to kill follicular lymphoma primary cells or cell lines was evaluated by flow cytometry cytotoxic T-lymphocyte assays in the presence or absence of three anti-CD20 monoclonal antibodies: the afucosylated GA101, the chimeric rituximab or the humanized ofatumumab. The ability of these cells to release perforin/granzyme and secrete interferon-γ when co-cultured with follicular lymphoma primary cells or cell lines in the presence or not of the three anti-CD20 monoclonal antibodies was also evaluated by CD107a staining and Elispot assays. ResultsPhosphostim and interleukin-2 expanded Vγ9Vδ2 T cells were cytotoxic to primary follicular lymphoma cells and their cytotoxic potential was dramatically increased by GA101, a type II glycoengineered anti-CD20 monoclonal antibody, and to a lesser extent, by rituximab and ofatumumab. The increased cytotoxicity was associated with increased secretion of perforin/granzyme and interferon-γ. ConclusionsIn-vitro expanded Vγ9Vδ2 T cells efficiently kill primary follicular lymphoma cells and express CD16; anti-CD20 monoclonal antibodies, in particular GA101, dramatically increase the cytotoxic activity of expanded Vγ9Vδ2 T cells. These preclinical results prompt the development of clinical trials using this antibody dependent cellular cytotoxicity property of Vγ9Vδ2 T cells and anti-CD20 monoclonal antibodies.Key words: γδ T-Lymphocytes, follicular lymphoma, anti-CD20 monoclonal antibody, rituximab, ofatumumab. GA101, a type II glycoengineered anti-CD20 monoclonal antibody. Haematologica 2011;96(3):400-407. doi:10.3324/haematol.2010 γδ T-cell killing of primary follicular lymphoma cells is dramatically potentiated by GA101, a type II glycoengineered anti-CD20 monoclonal antibody Citation: Braza MS, Klein B, Fiol G, and Rossi J-F,. γδ T-cell killing of primary follicular lymphoma cells is dramatically potentiated by

Targeting immune effector cells to promote antibody-induced cytotoxicity in cancer immunotherapy

“…These CD16 high gd T cells have specific phenotypic features that distinguish them from the CD16 low subset: they constitutively express several natural killer receptors (NKG2A/CD94) and high amounts of perforin, but express low levels of chemokine receptors (CXCR3, CCR6) and IFN-g [46]. They specifically respond to activation via CD16 and their ability to perform ADCC against tumor cells has been proven in vitro with several therapeutic antitumor mAbs: rituximab [48][49][50], trastuzumab [49,50], alemtuzumab [49], ofatumumab [48] and GA101 [48]. Surprisingly, the level of tumor cell cytotoxicity obtained by gd T cells through CD16 stimulation with these therapeutic mAbs is sometimes higher than the cytotoxicity obtained through natural TCR stimulation alone [48,50].…”

“…They specifically respond to activation via CD16 and their ability to perform ADCC against tumor cells has been proven in vitro with several therapeutic antitumor mAbs: rituximab [48][49][50], trastuzumab [49,50], alemtuzumab [49], ofatumumab [48] and GA101 [48]. Surprisingly, the level of tumor cell cytotoxicity obtained by gd T cells through CD16 stimulation with these therapeutic mAbs is sometimes higher than the cytotoxicity obtained through natural TCR stimulation alone [48,50]. One explanation for these results could be that CD16 high gd T cells have weaker responses to PAgs than the CD16 low subset [46].…”

Low Counts of γδ T Cells in Peritumoral Liver Tissue are Related to More Frequent Recurrence in Patients with Hepatocellular Carcinoma after Curative Resection

“…Recent date showed that these cells not only served as guards in the innate immune system but also acted as a bridge between innate and adaptive immune responses by performing multiple functions (Bonneville et al, 2010). γδ T cells also played a prominent role in innate defenses against tumor formation by directly recognizing molecules expressed on cancer cells without antigen processing and presentation (Braza et al, 2011). Liver, largely accepted as an immune organ, is one of the richest source of γδ T cells.…”

Combination Strategies to Enhance Antitumor ADCC

“…CD16 high γδ T cells constitutively express several NK cell receptors including NKG2A–CD94 and express high amounts of perforin, but low levels of IFN-γ [36]. They specifically respond to activation via CD16 and are capable of lysing tumors following exposure to mAbs including RTX [38–40], TRAST [39,40], alemtuzumab [39], ofatumumab [38] and GA101 [38], and may facilitate NK cell function [41]. The synergy between γδ T cells and NK cells relies on an interaction between the CD137 ligand and CD137; activated γ9γ2 T cells enhance antitumor cytotoxicity of NK cells through CD137 engagement [42].…”