γδ T cell-mediated individualized immunotherapy for hepatocellular carcinoma considering clinicopathological characteristics and immunosuppressive factors
- Authors:
- Published online on: February 12, 2018 https://doi.org/10.3892/ol.2018.8026
- Pages: 5433-5442
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Copyright: © Tian et al. This is an open access article distributed under the terms of Creative Commons Attribution License.
Abstract
Introduction
Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and the third and fifth main cause of cancer-associated mortality in men and women respectively in China, 2015 (1). In previous years, γδ T cells have been revealed to be feasible candidates for immunotherapy in the treatment of various types of cancer, including melanoma, breast cancer and lung cancer. In addition, a number of studies have demonstrated that γδ T cells may recognize and lyse numerous types of HCC cell and are involved in the immunotherapeutic mechanism against HCC (2–7). Zoledronate may activate and induce the selective amplification of Vγ9Vδ2 T cells in vitro from peripheral blood mononuclear cells (PBMCs) taken from patients, making it suitable for clinical adoptive immunotherapy (8,9). However, the use of this type of cell in clinical trials has revealed that numerous challenges to be overcome remain (10).
Human Vγ9Vδ2 T cells comprise 50–95% of peripheral blood γδ T cells and may be divided into four subsets: CD45RA+CD27+ naïve (Tnaïve) cells, CD45RA−CD27+ central memory cells, CD45RA−CD27− effector memory (TEM) cells and CD45RA+ CD27− effector memory (TEMRA) cells (11). Furthermore, Vγ9Vδ2 T cells may express natural killer receptor group 2, member D (NKG2D) and recognize major histocompatibility complex (MHC) class I-related chain A/B and UL16-binding proteins, which are induced or upregulated on the surface of numerous types of tumor cell (10). A number of studies have suggested that γδ T cells may be activated and regulated by NKG2D (10,12).
Vγ9Vδ2 T cells also exert marked cytotoxic effects through the perforin/granzyme signaling pathway dependent on cell-to-cell contact, resulting in the release of interferon (IFN)-γ and tumor necrosis factor (TNF)-α which enhance antitumor activity (2–4). A number of studies have demonstrated that the cytotoxicity of Vγ9Vδ2 T cells primarily depends on the perforin/granzyme signaling pathway (13,14). Therefore, the expression levels of perforin and granzyme B, which are essential in this signaling pathway, may indirectly reflect the cytotoxicity of Vγ9Vδ2 T cells.
CD4+, CD25+ and FoxP3+ regulatory T cells (Tregs), which are involved in the formation of the immunosuppressive network, suppress antitumor immunity and are the main obstacles faced by cancer immunotherapy. In vivo and in vitro studies have revealed that Tregs may suppress the proliferation and function of cytotoxic T cells (15–17), and impair the function of HCC-infiltrating γδ T cells (18). Wu et al (19) demonstrated that the main innate source of interleukin (IL)-17A was γδ T17 cells and that these cells may also suppress antitumor immunity in human colorectal cancer. Furthermore, Ma et al (20) suggested that IL-17A produced by γδ T cells promoted tumor growth in HCC. However, the effect of in vitro amplification of circulating γδ T cells in patients with HCC on the levels of Tregs, γδ T17 cells and IL-17A have yet to be fully clarified.
On the basis of previous research, the association between the change in immunosuppressive factors during in vitro γδ T cell amplification and factors determining the suitability of patients for immunotherapy remains unclear. Therefore, the aim of the present study was to characterize the proportions and functions of circulating γδ T cells, and levels of immunosuppressive factors in patients with HCC prior to and following amplification in vitro using zoledronate with IL-2. In addition, the association between the amplification ability of γδ T cells and the clinicopathological characteristics of patients with HCC was investigated.
Materials and methods
Patients and peripheral blood specimens
Written informed consent was obtained from all patients prior to the study. Peripheral blood samples (10 ml) from 83 patients with HCC and from 15 healthy donors used as the control group were collected in the present study. The present study was approved by the Ethics Committee of Shanxi Medical University (Taiyuan, China). The inclusion and exclusion criteria of the patients were as follows: i) patients having a confirmed diagnosis of HCC according to the National Comprehensive Cancer Network clinical practice guidelines in Oncology: Hepatobiliary Cancers (version 2; https://www.nccn.org/professionals/physician_gls/default.aspx); and ii) patients without other malignancies, autoimmune diseases or other immune-associated diseases. The clinicopathological characteristics of the patients are presented in Table I. The clinical stage of the tumors was confirmed according to the Barcelona-Clinic Liver Cancer system (21).
 | Table I.Univariate analyses of the quality of amplification associated with clinicopathological characteristics and a number of suppressive factors. |
Isolation and amplification of γδ T cells and culture of HCC cell lines
PBMCs were isolated from the fresh peripheral blood of patients and healthy donors using Ficoll density gradient to centrifuge at 453 × g for 15 min at room temperature (GE Healthcare, Chicago, IL, USA). As described previously (5), in order to amplify γδ T cells from fresh PBMCs (mean viability: 94.4%), 5 µM zoledronate (Zometa; Novartis International AG, Basel, Switzerland) was added to GT-T551 medium (Takara Bio, Inc., Otsu, Japan) supplemented with 10% heat-inactivated autologous plasma, 80 U/ml gentamicin and 1,000 IU/ml recombinant human IL-2 (Proleukin®; Chiron Therapeutics, Suresnes, France) at the onset of cultivation. Every 3 days, 10 ml GT-T551 and 1,000 IU/ml IL-2 were added to the cultures. After 12–14 days, γδ T cells were harvested (mean viability, 96.83±6.81%) which were cultured at 37°C in a 5% CO2 humidified incubator during this period. The human HCC cell lines HuH7, PLC, and SMMC-7721 supplied by Shanghai Institutes for Biological Sciences (Chinese Academy of Sciences, Shanghai, China) were cultured at 37°C in a 5% CO2 humidified incubator.
Flow cytometry
Prior to and following amplification, normal mouse serum (cat. no. S-I-000004, EarthOx Life Sciences, Millbrae, CA, USA) was diluted using PBS (1:50 dilution; cat. no. 10010023, eBioscience; Thermo Fisher Scientific, Inc. Waltham, MA, USA) and mixed with cells for 1 min at room temperature in order to block non-specific binding. Following this, cells were stained (either intracellularly or on the surface) at 4°C in dark with fluorochrome-conjugated monoclonal antibodies for 20 min in order to analyze the proportion, phenotype, tumor-killing capacity and cytokine secretion of Tregs and γδ T17 cells. Anti-NKG2D-fluorescein isothiocyanate-FITC (cat. no. 11-5878-41), anti-cluster of differentiation (CD)3-phycoerythrin (PE)-cyanine (Cy)5, (cat. no. 15-0038-42), anti-CD27-PE-Cy7, (cat. no. 25-0279-41), anti-TNF-α-FITC (cat. no. 11-7349-82), anti-forkhead box P3 (FoxP3)-PE (cat. no. 12-4777-42) and anti-IL-17A-PE antibodies (cat. no. 14-7179-82) were purchased from eBioscience; Thermo Fisher Scientific, Inc.; anti-Vγ9TCR-PE (cat. no. 555733), anti-perforin-FITC (cat. no. 556577), anti-granzyme B-FITC (cat. no. 560211) and anti-CD107a-FITC (cat. no. 555800) antibodies were purchased from BD Biosciences (Franklin Lakes, NJ, USA); and anti-IFN-γ-FITC (cat. no. IM2716U), anti-T cell receptor (TCR) -pan-γδ-FITC (cat. no. IM1571U), anti-CD45-proprotein convertase subtilisin/kexin type (PC) 7 (cat. no. IM3548U), anti-CD25-PC5 (cat. no. IM2646U), anti-CD4-FITC (cat. no. 6603862) and anti-CD45RA-FITC (cat. no. IM0584U) antibodies were purchased from Beckman Coulter, Inc. (Brea, CA, USA). The dilutions used for different experiments are detailed in the relevant protocols. Prior to staining for CD107a, cells were stimulated using phorbol 12-myristate 13-acetate (50 ng/ml) and ionomycin (500 ng/ml) for 4–6 h in incubator at 37°C. Immunofluorescence was determined using a Cytomics FC500 flow cytometer with CXP software (version 2.1; Beckman Coulter, Inc.).
ELISA
Culture supernatants from γδ T cells were collected on days 3, 7, 10 and 14. The IL-17A content in the supernatants were determined using a direct ELISA. Briefly, 200 µl 0.25% gelatin (Sigma Aldrich; Merck KGaA, Darmstadt, Germany) was added to each well, and the plates were incubated for 2 h at room temperature. Then each well of a 96-well plate was coated with 50 ml supernatants from patients with HCC or healthy donor cells overnight at 4°C. Following washing with PBS with Tween-20 (PBST; Beijing Solarbio Science & Technology Co., Ltd., Beijing, China), 50 µl primary anti-IL-17A antibodies were diluted by a factor of 1:100 and added to the wells. The plates were then incubated for 1 h at room temperature and washed with PBST to remove excess primary antibodies. A 50 µl volume of horseradish peroxidase (HRP) -labeled secondary antibody (rabbit anti-mouse IgG; cat. no. 61-6520; eBioscience-Thermo Fisher Scientific, Inc.) was added to the wells and plates were further incubated for 45 min at 37°C. Excess secondary antibodies were removed and HRP enzyme activity was determined by adding o-phenylenediamine for o-phenylenediamine dihydrochloride reaction at room temperature for 20–30 min in darkness, which was terminated by adding 1 M H2SO4 after 10 min at room temperature. The concentration of IL-17A was calculated using CurveExpert 1.4 software (Hyams Development; https://www.curveexpert.net/).
In vitro cytotoxicity assay
The in vitro cytotoxicity of γδ T cells from patients with HCC following amplification was determined using an MTT assay (Sigma Aldrich; Merck KGaA). Briefly, exponentially growing target cells (HuH7, PLC and SMMC-7721 cells) were prepared at a density of 5×103 cells/well and seeded in 96-well plates with γδ T cells at effector/target ratios of 0:1, 5:1, 10:1 or 20:1. HCC cells and γδ T cells were simultaneously seeded as two control groups and were incubated at 37°C in an atmosphere containing 5% CO2 for 48 h. Subsequently, 20 µl MTT (5 mg/ml; Sigma-Aldrich; Merck KGaA) was added to each well, and cells were cultured at 37°C in incubator for an additional 4 h, and subsequently 100 µl dimethylsulfoxide (Sigma Aldrich; Merck KGaA) was added to each well. Cells were shocked for 10 min in the dark at room temperature, and the optical density (OD) of each well was determined using a microplate reader at 570 nm. The cytotoxicity was calculated according to the following formula: Cytotoxicity (%)=(control OD-experimental OD)/control ODx100%. The assay was repeated three times.
Statistical analysis
SPSS software (version 17.0; SPSS, Inc., Chicago, IL, USA) was used for statistical analyses. Data are expressed as the mean ± standard deviation (SD). Paired or non-paired Student's t-tests were performed as appropriate. One-way analysis of variance was used to analyze the differences among three HCC cell lines at different effector/target ratios. Further comparison of the differences between two groups was performed using least-significance difference test or Student-Newman-Keuls. Univariate analyses were performed using χ2 tests. Multivariate analyses for factors affecting the quality of amplification were performed using logarithmic regression analysis. Spearman's correlation was used to analyze the associations between α-fetoprotein (AFP) in 10% autologous plasma and the absolute numbers of γδ T cells following amplification. P<0.05 was considered to indicate a statistically significant difference.
Results
Proliferation of γδ T cells derived from patients with HCC and healthy controls
γδ T cells derived from healthy donors and patients with HCC were cultured in vitro in a humidified atmosphere at 37°C. Following culture for 240 h, the γδ T cells were amplified to form a cell mass. The morphology of the cell mass from patients with HCC and healthy donors were similar (Fig. 1A-D).
Zoledronate and IL-2 may efficiently expand the γδ T cells from PBMCs of patients with HCC
Prior to amplification, the numbers of γδ T cells from patients with HCC and healthy donors were (2.12±1.15)×104 and (1.78±0.91)×105, respectively, and the proportion of γδ T cells out of the total number of T cells was significantly decreased in patients with HCC compared with healthy donors (3.32±1.67 vs. 5.06±1.91%, respectively; P<0.05; Fig. 2A and B). Prior to and following amplification, the proportion of Vγ9Vδ2 T cells out of the total number of γδ T cells was not significantly decreased compared with healthy donors (P>0.05; Fig. 2C and D). However, following amplification, the numbers of γδ T cells from patients with HCC and healthy donors were (1.68±0.92)×107 and (1.05±0.65)×108, respectively, and the proportion of γδ T cells out of the total number of T cells (3.32±1.67 vs. 30.27±15.25%, respectively; P<0.05) and Vγ9Vδ2 T cells out of the total number of γδ T cells (60.26±19.31% vs. 93.14±12.87%, prior to and following amplification, respectively; P<0.05) were significantly increased in patients with HCC.
In terms of phenotype, there were also significant differences in patients with HCC prior to and following amplification. Following amplification, the proportions and numbers of Tnaïve (24.88±13.17 vs. 6.52±4.43% prior to and following amplification, respectively; P<0.05) and TEMRA (34.18±18.45 vs. 13.38±5.81% prior to and following amplification, respectively; P<0.05) cells were significantly decreased. The proportion of TEM cells was significantly increased following amplification (6.76±4.07 vs. 63.16±11.16% prior to and following amplification, respectively; P<0.05). As presented in Fig. 2E and F, prior to amplification, γδ T cells were generally positive for NKG2D in healthy donors (6.93±2.89 vs. 27.93±13.48% for patients and healthy donors, respectively; P<0.05). Following amplification, numbers of NKG2D+ γδ T cells were significantly increased compared with healthy donors.
Amplification capacity of γδ T cells is correlated with the clinicopathological characteristics of patients
Notably, γδ T cells from all patients did not expand equally as well. Therefore, the aim of the present study was to elucidate the factors underlying this phenomenon. The results of the univariate analysis, presented in Table I, demonstrate that the quality of amplification was significantly associated with clinical stage, levels of AFP and albumin, duration of disease (DOD), size and number of tumors, numbers of Tregs and γδ T17 cells and levels of IL-17A. The results of the multivariate analysis revealed that the levels of AFP and the proportions of Tregs and γδ T17 cells were independent factors associated with low-quality amplification, whereas DOD was an independent factor associated with high-quality amplification (Table II). There was no correlation between AFP in 10% autologous plasma and the amplification ability of γδ T cells (rs=−0.396; P=0.379), indicating that exogenous AFP did not affect the amplification of γδ T cells in vitro.
| Table II.Multivariate analyses of the quality of amplification associated with clinicopathological characteristics and a number of suppressive factors. |
These data indicated that amplification with zoledronate and IL-2 may increase the proportion of γδ T cells and promote the effective phenotype. However, the amplification ability was not the same in all patients, varying depending on the clinicopathological characteristics of the patients with HCC and the presence of specific suppressive factors.
Secretion and cytotoxic activity of γδ T cells
Prior to amplification, the proportion of perforin+ γδ T cells in patients with HCC was not significantly decreased compared with healthy donors (P>0.05; Fig. 3A and B). However, following amplification, the proportion in patients with HCC decreased (66.61±20.87 vs. 49.97±15.97% prior to and following amplification, respectively; P<0.05), becoming significantly lower when compared with healthy donors (71.25±14.06%; P<0.05). The proportion of granzyme B+ γδ T cells in patients with HCC significantly increased following amplification (2.17±1.62 vs. 9.96±6.22% prior to and following amplification, respectively; P<0.05; Fig. 3C and D); however, there was no significant difference when compared with that in healthy donors (P>0.05). Amplification also did not significantly affect CD107a (26.41±15.66 vs. 41.52±26.17% prior to and following amplification, respectively; P>0.05) and IFN-γ (50.61±15.25 vs. 48.07±25.10% prior to and following amplification, respectively; P>0.05; Figs. 3E and F, 4A and B). In addition, prior to amplification, the proportion of TNF-α+ γδ T cells was higher in patients compared with healthy controls (56.70±16.43 vs. 15.74±5.71%, respectively; P<0.05; Fig. 4C and D), and amplification had almost no effect on this parameter (56.70±16.43 vs. 51.62±30.67% prior to and following amplification, respectively; P>0.05).
The results of the MTT assay, as presented in Fig. 3G, revealed that γδ T cells exerted significant cytotoxic effects on four HCC cell lines at differing effector/target ratios. In addition, for the PLC cells, cytotoxicity was significantly increased when the effector/target ratio was increased.
γδ T17 cells, Tregs and IL-17A were not altered during amplification
Immunosuppressive cells and factors were examined during amplification. Amplification had almost no effect on the levels of Tregs and γδ T17 cells (P>0.05; Fig. 5A-D). The levels of IL-17A in the supernatants were assessed using an ELISA. As presented in Fig. 5E, the levels were not significantly altered on days 3, 7, 10 and 14 (P>0.05).
Discussion
Previously, numerous immunotherapeutic methods have been developed in an attempt to induce tumor-specific adaptive immune responses. Adaptive immunotherapy with γδ T cells represents a novel, safe and effective approach to inducing immunological and clinical responses (22–24). However, few studies have examined these parameters in HCC. In the present study, it was concluded that circulating γδ T cells in patients with HCC expanded by the use of zoledronate and IL-2 in vitro, and may lyse HCC cells effectively, without increasing immunosuppressive factors during amplification. Additionally, the amplification ability of γδ T cells was associated with the clinicopathological features of patients with HCC.
A γδ T-cell proliferation of at ≥70% was considered the threshold for therapy (25). A real-time cell analyzer may be used for monitoring the absolute cell numbers and cytotoxicity of circulating γδ T cells from patients with cancer, in order to provide a more comprehensive assessment for personalized tumor treatment (26). In the present study, the absolute numbers and proportion of γδ T cells in patients with HCC increased significantly following amplification; however, this was not consistently observed in all patients, and this effect may be associated with various clinicopathological characteristics and suppressive factors. It was revealed that the quality of amplification was negatively associated with the serum AFP level, proportion of γδ T17 cells and proportion of Tregs, but positively associated with the DOD. These results suggested that optimized immunotherapy of γδ T cells in patients with HCC should be individualized.
In order to further explore the feasibility and efficacy of immunotherapy, the phenotype, secretion and cytotoxicity of Vγ9Vδ2 T cells were examined. Encouragingly, the results of the present study suggested that there was substantial differentiation of Vγ9Vδ2 T cells towards the effective phenotype of secretion and lysis following amplification, which was consistent with other studies (24,27). Previous studies have revealed that activated Vγ9Vδ2 T cells are a primary source of IFN-γ and TNF-α, which have direct cytotoxic activity against tumor cells and indirect cytotoxic activity via the stimulation of macrophages and dendritic cells (28–30). In the present study, although the proportions of IFN-γ+ and TNF-α+ γδ T cells were not significantly altered, the absolute numbers and proportions of TEM cells were significantly increased following amplification. It was revealed that the secretion of γδ T cells was increased following amplification. Collectively, the results of the present study revealed that the cytotoxic activity of γδ T cells was also increased following amplification.
Immunosuppressive factors are the main obstacles for the anticancer immunity effects of γδ T cells in vivo. The accumulation of Tregs in a number of tumors mediate tumor-promoting effects through the suppression of antitumor immunity (31). Furthermore, IL-17A has been revealed to promote metastasis and is associated with a poor prognosis in patients with HCC (32). Immunosuppressive cells and factors should not be expanded during the amplification of effective cells. To the best of our knowledge, the present study is the first to explore the changes in Tregs, γδ T17 cells and IL-17A during the amplification of circulating γδ T cells in patients with HCC in vitro. The results of the present study revealed that these immunosuppressive cells and factors were not increased following amplification, which suggested that γδ T cells expanded by zoledronate and IL-2 in vitro may be safe for immunotherapy in patients with HCC.
A number of studies have demonstrated that Tregs express immune checkpoint proteins, including programmed cell death-1 (PD-1) and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) (33,34), and impair the function of HCC-infiltrating γδ T cells (18). Additionally, activated T cells upregulate CTLA-4 and PD-1, which act to increase T-cell responses, and antibody blockade of immune checkpoints enhances T-cell responses (35). Adoptive γδ T-cell immunotherapy combined with checkpoint inhibitors may be a promising therapeutic strategy for the treatment of HCC.
In summary, circulating γδ T cells from patients with HCC expanded using zoledronate and IL-2 in vitro may be used for immunotherapy in patients with HCC without increasing immunosuppressive factors. However, this immunotherapy should be individualized according to the specific clinicopathological features of the patients.
Acknowledgements
The present study was supported by the Scientific and Technological Project of Shanxi Province (grant no. 130313021–17).
References
|
Chen W, Zheng R, Baade PD, Zhang S, Zeng H, Bray F, Jemal A, Yu XQ and He J: Cancer statistics in China, 2015. CA Cancer J Clin. 66:115–132. 2016. View Article : Google Scholar : PubMed/NCBI | |
|
Braza MS and Klein B: Anti-tumour immunotherapy with Vγ9Vδ2 T lymphocytes: From the bench to the bedside. Br J Haematol. 160:123–132. 2013. View Article : Google Scholar : PubMed/NCBI | |
|
Dhar S and Chiplunkar SV: Lysis of aminobisphosphonate-sensitized MCF-7 breast tumor cells by Vγ9Vδ2 T cells. Cancer Immun. 10:102010.PubMed/NCBI | |
|
Wu YL, Ding YP, Tanaka Y, Shen LW, Wei CH, Minato N and Zhang W: γδ T cells and their potential for immunotherapy. Int J Biol Sci. 10:119–135. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Bouet-Toussaint F, Cabillic F, Toutirais O, Le Gallo M, Thomas de la Pintière C, Daniel P, Genetet N, Meunier B, Dupont-Bierre E, Boudjema K and Catros V: Vgamma9Vdelta2 T cell-mediated recognition of human solid tumors. Potential for immunotherapy of hepatocellular and colorectal carcinomas. Cancer Immunol Immunother. 57:531–539. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Toutirais O, Cabillic F, Le Friec G, Salot S, Loyer P, Le Gallo M, Desille M, de La Pintière CT, Daniel P, Bouet F and Catros V: DNAX accessory molecule-1 (CD226) promotes human hepatocellular carcinoma cell lysis by Vgamma9Vdelta2 T cells. Eur J Immunol. 39:1361–1368. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Cabillic F, Toutirais O, Lavoué V, de La Pintière CT, Daniel P, Rioux-Leclerc N, Turlin B, Mönkkönen H, Mönkkönen J, Boudjema K, et al: Aminobisphosphonate-pretreated dendritic cells trigger successful Vgamma9Vdelta2 T cell amplification for immunotherapy in advanced cancer patients. Cancer Immunol Immunother. 59:1611–1619. 2010. View Article : Google Scholar : PubMed/NCBI | |
|
Kondo M, Sakuta K, Noguchi A, Ariyoshi N, Sato K, Sato S, Sato K, Hosoi A, Nakajima J, Yoshida Y, et al: Zoledronate facilitates large-scale ex vivo expansion of functional gammadelta T cells from cancer patients for use in adoptive immunotherapy. Cytotherapy. 10:842–856. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Nicol AJ, Tokuyama H, Mattarollo SR, Hagi T, Suzuki K, Yokokawa K and Nieda M: Clinical evaluation of autologous gamma delta T cell-based immunotherapy for metastatic solid tumours. Br J Cancer. 105:778–786. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
Rincon-Orozco B, Kunzmann V, Wrobel P, Kabelitz D, Steinle A and Herrmann T: Activation of V gamma 9V delta 2 T cells by NKG2D. J Immunol. 175:2144–2151. 2005. View Article : Google Scholar : PubMed/NCBI | |
|
Pang DJ, Neves JF, Sumaria N and Pennington DJ: Understanding the complexity of γδ T-cell subsets in mouse and human. Immunology. 136:283–290. 2012. View Article : Google Scholar : PubMed/NCBI | |
|
Bauer S, Groh V, Wu J, Steinle A, Phillips JH, Lanier LL and Spies T: Activation of NK cells and T cells by NKG2D, a receptor for stress-inducible MICA. Science. 285:727–729. 1999. View Article : Google Scholar : PubMed/NCBI | |
|
Kunzmann V and Wilhelm M: Anti-lymphoma effect of gammadelta T cells. Leuk Lymphoma. 46:671–680. 2005. View Article : Google Scholar : PubMed/NCBI | |
|
Todaro M, D'Asaro M, Caccamo N, Iovino F, Francipane MG, Meraviglia S, Orlando V, La Mendola C, Gulotta G, Salerno A, et al: Efficient killing of human colon cancer stem cells by gammadelta T lymphocytes. J Immunol. 182:7287–7296. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Yang ZZ, Novak AJ, Ziesmer SC, Witzig TE and Ansell SM: Attenuation of CD8(+) T-cell function by CD4(+)CD25(+) regulatory T cells in B-cell non-Hodgkin's lymphoma. Cancer Res. 66:10145–10152. 2006. View Article : Google Scholar : PubMed/NCBI | |
|
Mempel TR, Pittet MJ, Khazaie K, Weninger W, Weissleder R, von Boehmer H and von Andrian UH: Regulatory T cells reversibly suppress cytotoxic T cell function independent of effector differentiation. Immunity. 25:129–141. 2006. View Article : Google Scholar : PubMed/NCBI | |
|
Fu J, Xu D, Liu Z, Shi M, Zhao P, Fu B, Zhang Z, Yang H, Zhang H, Zhou C, et al: Increased regulatory T cells correlate with CD8 T-cell impairment and poor survival in hepatocellular carcinoma patients. Gastroenterology. 132:2328–2339. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Yi Y, Hong WH, Wang JX, Cai XY, Li YW, Zhou J, Cheng YF, Jin JJ, Fan J and Qiu SJ: The functional impairment of HCC-infiltrating γδ T cells, partially mediated by regulatory T cells in a TGFβ- and IL-10-dependent manner. J Hepatol. 58:977–983. 2013. View Article : Google Scholar : PubMed/NCBI | |
|
Wu P, Wu D, Ni C, Ye J, Chen W, Hu G, Wang Z, Wang C, Zhang Z and Xia W: γδT17 cells promote the accumulation and expansion of myeloid-derived suppressor cells in human colorectal cancer. Immunity. 40:785–800. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Ma S, Cheng Q, Cai Y, Gong H, Wu Y, Yu X, Shi L, Wu D, Dong C and Liu H: IL-17A produced by γδ T cells promotes tumor growth in hepatocellular carcinoma. Cancer Res. 74:1969–1982. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Llovet JM, Di Bisceglie AM, Bruix J, Kramer BS, Lencioni R, Zhu AX, Sherman M, Schwartz M, Lotze M, Talwalkar J, et al: Design and endpoints of clinical trials in hepatocellular carcinoma. J Natl Cancer Inst. 100:698–711. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Wilhelm M, Kunzmann V, Eckstein S, Reimer P, Weissinger F, Ruediger T and Tony HP: Gammadelta T cells for immune therapy of patients with lymphoid malignancies. Blood. 102:200–206. 2003. View Article : Google Scholar : PubMed/NCBI | |
|
Dieli F, Vermijlen D, Fulfaro F, Caccamo N, Meraviglia S, Cicero G, Roberts A, Buccheri S, D'Asaro M, Gebbia N, et al: Targeting human{gamma}delta} T cells with zoledronate and interleukin-2 for immunotherapy of hormone-refractory prostate cancer. Cancer Res. 67:7450–7457. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Santini D, Martini F, Fratto ME, Galluzzo S, Vincenzi B, Agrati C, Turchi F, Piacentini P, Rocci L, Manavalan JS, et al: In vivo effects of zoledronic acid on peripheral T lymphocytes in early breast cancer patients. Cancer Immunol Immunother. 58:31–38. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Bennouna J, Bompas E, Neidhardt EM, Rolland F, Philip I, Galéa C, Salot S, Saiagh S, Audrain M, Rimbert M, et al: Phase-I study of innacell gammadelta, an autologous cell-therapy product highly enriched in gamma9delta2 T lymphocytes, in combination with IL-2, in patients with metastatic renal cell carcinoma. Cancer Immunol Immunother. 57:1599–1609. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
Oberg HH, Kellner C, Peipp M, Sebens S, Adam-Klages S, Gramatzki M, Kabelitz D and Wesch D: Monitoring circulating γδ T cells in cancer patients to optimize γδ T cell-based immunotherapy. Front Immunol. 5:6432014. View Article : Google Scholar : PubMed/NCBI | |
|
Dieli F, Gebbia N, Poccia F, Caccamo N, Montesano C, Fulfaro F, Arcara C, Valerio MR, Meraviglia S, Di Sano C, et al: Induction of gammadelta T-lymphocyte effector functions by bisphosphonate zoledronic acid in cancer patients in vivo. Blood. 102:2310–2311. 2003. View Article : Google Scholar : PubMed/NCBI | |
|
Ismaili J, Olislagers V, Poupot R, Fournie JJ and Goldman M: Human gammadelta T cells induce dendritic cell maturation. Clin Immunol. 103:296–302. 2002. View Article : Google Scholar : PubMed/NCBI | |
|
Conti L, Casetti R, Cardone M, Varano B, Martino A, Belardelli F, Poccia F and Gessani S: Reciprocal activating interaction between dendritic cells and pamidronate-stimulated gammadelta T cells: Role of CD86 and inflammatory cytokines. J Immunol. 174:252–260. 2005. View Article : Google Scholar : PubMed/NCBI | |
|
Devilder MC, Maillet S, Bouyge-Moreau I, Donnadieu E, Bonneville M and Scotet E: Potentiation of antigen-stimulated V Gamma 9V delta 2 T cell cytokine production by immature dendritic cells (DC) and reciprocal effect on DC maturation. J Immunol. 176:1386–1393. 2006. View Article : Google Scholar : PubMed/NCBI | |
|
Nishikawa H and Sakaguchi S: Regulatory T cells in tumor immunity. Int J Cancer. 127:759–767. 2010.PubMed/NCBI | |
|
Li J, Lau GK, Chen L, Dong SS, Lan HY, Huang XR, Li Y, Luk JM, Yuan YF and Guan XY: Interleukin 17A promotes hepatocellular carcinoma metastasis via NF-kB induced matrix metalloproteinases 2 and 9 expression. PLoS One. 6:e218162011. View Article : Google Scholar : PubMed/NCBI | |
|
Hodi FS, O'Day SJ, McDermott DF, Weber RW, Sosman JA, Haanen JB, Gonzalez R, Robert C, Schadendorf D, Hassel JC, et al: Improved survival with ipilimumab in patients with metastatic melanoma. N Engl J Med. 363:711–723. 2010. View Article : Google Scholar : PubMed/NCBI | |
|
Topalian SL, Hodi FS, Brahmer JR, Gettinger SN, Smith DC, McDermott DF, Powderly JD, Carvajal RD, Sosman JA, Atkins MB, et al: Safety, activity and immune correlates of anti-PD-1 antibody in cancer. N Engl J Med. 366:2443–2454. 2012. View Article : Google Scholar : PubMed/NCBI | |
|
Sharma P and Allison JP: The future of immune checkpoint therapy. Science. 348:56–61. 2015. View Article : Google Scholar : PubMed/NCBI |
