scholarly journals Activation of Human γδ T Cells: Modulation by Toll-Like Receptor 8 Ligands and Role of Monocytes

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 713 ◽  
Author(s):  
Ruben Serrano ◽  
Daniela Wesch ◽  
Dieter Kabelitz

Background: Human Vγ9Vδ2 γδ T cells can kill a variety of cancer cells and have attracted substantial interest for cancer immunotherapy. Toll-like receptor (TLR) ligands are promising adjuvants for cancer immunotherapy, but TLR7/8 ligand Resiquimod has been shown to inhibit CD4 T-cell activation in a monocyte-dependent manner. Therefore, we studied the modulation of human γδ T-cell activation by TLR7/8 ligands. Methods: Peripheral blood mononuclear cells (PBMC) or purified γδ T cells together with purified monocytes were stimulated with zoledronic acid or phosphoantigens in the absence or presence of various imidazoquinoline TLR7 or TLR8 agonists. Read-out systems included interferon-γ induction and cellular expansion of γδ T cells, as well as viability, cell surface antigen modulation, and IL-1β and TNF-α production of monocytes. Results: TLR8 ligand TL8-506 and TLR7/8 ligand Resiquimod (but not TLR7 ligands) rapidly induced IFN-γ expression in γδ T cells within PBMC, and co-stimulated phosphoantigen-induced IFN-γ expression in γδ T cells. On the other hand, TLR8 ligands potently suppressed γδ T-cell expansion in response to zoledronic acid and phosphoantigen. Purified monocytes secreted large amounts of IL-1β and TNF-α when stimulated with TLR8 ligands but simultaneously underwent substantial cell death after 24 h. Conclusions: TLR8 ligand-activated monocytes potently co-stimulate early γδ T-cell activation but failed to provide accessory cell function for in vitro expansion of γδ T cells.

Author(s):  
Yan Yan ◽  
Wei Zhao ◽  
Wei Liu ◽  
Yan Li ◽  
Xu Wang ◽  
...  

Abstract Background Chemokine (C–C motif) ligand 19 (CCL19) is a leukocyte chemoattractant that plays a crucial role in cell trafficking and leukocyte activation. Dysfunctional CD8+ T cells play a crucial role in persistent HBV infection. However, whether HBV can be cleared by CCL19-activated immunity remains unclear. Methods We assessed the effects of CCL19 on the activation of PBMCs in patients with HBV infection. We also examined how CCL19 influences HBV clearance and modulates HBV-responsive T cells in a mouse model of chronic hepatitis B (CHB). In addition, C–C chemokine-receptor type 7 (CCR7) knockdown mice were used to elucidate the underlying mechanism of CCL19/CCR7 axis-induced immune activation. Results From in vitro experiments, we found that CCL19 enhanced the frequencies of Ag-responsive IFN-γ+ CD8+ T cells from patients by approximately twofold, while CCR7 knockdown (LV-shCCR7) and LY294002 partially suppressed IFN-γ secretion. In mice, CCL19 overexpression led to rapid clearance of intrahepatic HBV likely through increased intrahepatic CD8+ T-cell proportion, decreased frequency of PD-1+ CD8+ T cells in blood and compromised suppression of hepatic APCs, with lymphocytes producing a significantly high level of Ag-responsive TNF-α and IFN-γ from CD8+ T cells. In both CCL19 over expressing and CCR7 knockdown (AAV-shCCR7) CHB mice, the frequency of CD8+ T-cell activation-induced cell death (AICD) increased, and a high level of Ag-responsive TNF-α and low levels of CD8+ regulatory T (Treg) cells were observed. Conclusions Findings in this study provide insights into how CCL19/CCR7 axis modulates the host immune system, which may promote the development of immunotherapeutic strategies for HBV treatment by overcoming T-cell tolerance.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A119-A119
Author(s):  
Lu Bai ◽  
Kevin Nishimoto ◽  
Mustafa Turkoz ◽  
Marissa Herrman ◽  
Jason Romero ◽  
...  

BackgroundAutologous chimeric antigen receptor (CAR) T cells have been shown to be efficacious for the treatment of B cell malignancies; however, widespread adoption and application of CAR T cell products still face a number of challenges. To overcome these challenges, Adicet Bio is developing an allogeneic γδ T cell-based CAR T cell platform, which capitalizes on the intrinsic abilities of Vδ1 γδ T cells to recognize and kill transformed cells in an MHC-unrestricted manner, to migrate to epithelial tissues, and to function in hypoxic conditions. To gain a better understanding of the requirements for optimal intratumoral CAR Vδ1 γδ T cell activation, proliferation, and differentiation, we developed a three-dimensional (3D) tumor spheroid assay, in which tumor cells acquire the structural organization of a solid tumor and establish a microenvironment that has oxygen and nutrient gradients. Moreover, through the addition of cytokines and/or tumor stromal cell types, the spheroid microenvironment can be modified to reflect hot or cold tumors. Here, we report on the use of a 3D CD20+ Raji lymphoma spheroid assay to evaluate the effects of IL-2 and IL-15, positive regulators of T cell homeostasis and differentiation, on the proliferative and antitumor capacities of CD20 CAR Vδ1 γδ T cells.MethodsMolecular, phenotypic, and functional profiling were performed to characterize the in vitro dynamics of the intraspheroid CD20 CAR Vδ1 γδ T cell response to target antigen in the presence of IL-2, IL-15, or no added cytokine.ResultsWhen compared to no added cytokine, the addition of IL-2 or IL-15 enhanced CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and cytokine production in a dose-dependent manner but were only able to alter the kinetics of Raji cell killing at low effector to target ratios. Notably, differential gene expression analysis using NanoString nCounter® Technology confirmed the positive effects of IL-2 or IL-15 on CAR-activated Vδ1 γδ T cells as evidenced by the upregulation of genes involved in activation, cell cycle, mitochondrial biogenesis, cytotoxicity, and cytokine production.ConclusionsTogether, these results not only show that the addition of IL-2 or IL-15 can potentiate CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation into antitumor effectors but also highlight the utility of the 3D spheroid assay as a high throughput in vitro method for assessing and predicting CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation in hot and cold tumors.


Blood ◽  
2009 ◽  
Vol 114 (20) ◽  
pp. 4422-4431 ◽  
Author(s):  
Georg Gruenbacher ◽  
Hubert Gander ◽  
Andrea Rahm ◽  
Walter Nussbaumer ◽  
Nikolaus Romani ◽  
...  

Abstract CD56+ human dendritic cells (DCs) have recently been shown to differentiate from monocytes in response to GM-CSF and type 1 interferon in vitro. We show here that CD56+ cells freshly isolated from human peripheral blood contain a substantial subset of CD14+CD86+HLA-DR+ cells, which have the appearance of intermediate-sized lymphocytes but spontaneously differentiate into enlarged DC-like cells with substantially increased HLA-DR and CD86 expression or into fully mature CD83+ DCs in response to appropriate cytokines. Stimulation of CD56+ cells containing both DCs and abundant γδ T cells with zoledronate and interleukin-2 (IL-2) resulted in the rapid expansion of γδ T cells as well as in IFN-γ, TNF-α, and IL-1β but not in IL-4, IL-10, or IL-17 production. IFN-γ, TNF-α, and IL-1β production were almost completely abolished by depleting CD14+ cells from the CD56+ subset before stimulation. Likewise, depletion of CD14+ cells dramatically impaired γδ T-cell expansion. IFN-γ production could also be blocked by neutralizing the effects of endogenous IL-1β and TNF-α. Conversely, addition of recombinant IL-1β, TNF-α, or both further enhanced IFN-γ production and strongly up-regulated IL-6 production. Our data indicate that CD56+ DCs from human blood are capable of stimulating CD56+ γδ T cells, which may be harnessed for immunotherapy.


2021 ◽  
Vol 12 ◽  
Author(s):  
Supansa Pata ◽  
Sirirat Surinkaew ◽  
Nuchjira Takheaw ◽  
Witida Laopajon ◽  
Kantinan Chuensirikulchai ◽  
...  

CD147, a member of the immunoglobulin (Ig) superfamily, is widely expressed in several cell types. CD147 molecules have multiple cellular functions, such as migration, adhesion, invasion, energy metabolism and T cell activation. In particular, recent studies have demonstrated the potential application of CD147 as an effective therapeutic target for cancer, as well as autoimmune and inflammatory diseases. In this study, we elucidated the functional epitopes on CD147 extracellular domains in T cell regulation using specific monoclonal antibodies (mAbs). Upon T cell activation, the anti-CD147 domain 1 mAbs M6-1E9 and M6-1D4 and the anti-CD147 domain 2 mAb MEM-M6/6 significantly reduced surface expression of CD69 and CD25 and T cell proliferation. To investigate whether functional epitopes of CD147 are differentially expressed on distinct leukocyte subsets, PBMCs, monocyte-depleted PBMCs and purified T cells were activated in the presence of anti-CD147 mAbs. The mAb M6-1E9 inhibited T cell functions via activation of CD147 on monocytes with obligatory cell-cell contact. Engagement of the CD147 epitope by the M6-1E9 mAb downregulated CD80 and CD86 expression on monocytes and IL-2, TNF-α, IFN-γ and IL-17 production in T cells. In contrast, the mAb M6-1D4 inhibited T cell function via activation of CD147 on T cells by downregulating IL-2, TNF-α and IFN-γ. Herein, we demonstrated that certain epitopes of CD147, expressed on both monocytes and T cells, are involved in the regulation of T cell activation.


Science ◽  
2020 ◽  
Vol 367 (6478) ◽  
pp. eaay5516 ◽  
Author(s):  
Marc Rigau ◽  
Simone Ostrouska ◽  
Thomas S. Fulford ◽  
Darryl N. Johnson ◽  
Katherine Woods ◽  
...  

Gamma delta (γδ) T cells are essential to protective immunity. In humans, most γδ T cells express Vγ9Vδ2+ T cell receptors (TCRs) that respond to phosphoantigens (pAgs) produced by cellular pathogens and overexpressed by cancers. However, the molecular targets recognized by these γδTCRs are unknown. Here, we identify butyrophilin 2A1 (BTN2A1) as a key ligand that binds to the Vγ9+ TCR γ chain. BTN2A1 associates with another butyrophilin, BTN3A1, and these act together to initiate responses to pAg. Furthermore, binding of a second ligand, possibly BTN3A1, to a separate TCR domain incorporating Vδ2 is also required. This distinctive mode of Ag-dependent T cell activation advances our understanding of diseases involving pAg recognition and creates opportunities for the development of γδ T cell–based immunotherapies.


2022 ◽  
Author(s):  
Linjie Yuan ◽  
Xianqiang Ma ◽  
Yunyun Yang ◽  
Xin Li ◽  
Weiwei Ma ◽  
...  

Tumor cells and pathogen-infected cells are presented to human γδ T cells based on "inside-out" signaling in which metabolites called phosphoantigens (pAgs) inside target cells are recognized by the intracellular domain of a butyrophilin protein (BTN3A1), leading to an extracellular conformational change. Here, we report that pAgs function as molecular "glues" that initiate a heteromeric association between the intracellular domains of BTN3A1 and the structurally similar BTN2A1. Working with both exogenous and endogenous pAgs, we used x-ray crystallography, mutational studies, cellular assays, synthetic probe as well as molecular dynamics investigations to determine how pAgs glue intracellular BTN3A1 and BTN2A1 together for the "inside-out" signaling that triggers γδ T cell activation. This γδ T cell-specific mode of antigen sensing creates opportunities for the development of alternative immunotherapies against cancer and infectious diseases that do not involve αβ T cells.


2021 ◽  
Vol 9 (4) ◽  
pp. e002051
Author(s):  
Ryan Michael Reyes ◽  
Yilun Deng ◽  
Deyi Zhang ◽  
Niannian Ji ◽  
Neelam Mukherjee ◽  
...  

BackgroundAnti-programmed death-ligand 1 (αPD-L1) immunotherapy is approved to treat bladder cancer (BC) but is effective in <30% of patients. Interleukin (IL)-2/αIL-2 complexes (IL-2c) that preferentially target IL-2 receptor β (CD122) augment CD8+ antitumor T cells known to improve αPD-L1 efficacy. We hypothesized that the tumor microenvironment, including local immune cells in primary versus metastatic BC, differentially affects immunotherapy responses and that IL-2c effects could differ from, and thus complement αPD-L1.MethodsWe studied mechanisms of IL-2c and αPD-L1 efficacy using PD-L1+ mouse BC cell lines MB49 and MBT-2 in orthotopic (bladder) and metastatic (lung) sites.ResultsIL-2c reduced orthotopic tumor burden and extended survival in MB49 and MBT-2 BC models, similar to αPD-L1. Using antibody-mediated cell depletions and genetically T cell-deficient mice, we unexpectedly found that CD8+ T cells were not necessary for IL-2c efficacy against tumors in bladder, whereas γδ T cells, not reported to contribute to αPD-L1 efficacy, were indispensable for IL-2c efficacy there. αPD-L1 responsiveness in bladder required conventional T cells as expected, but not γδ T cells, altogether defining distinct mechanisms for IL-2c and αPD-L1 efficacy. γδ T cells did not improve IL-2c treatment of subcutaneously challenged BC or orthotopic (peritoneal) ovarian cancer, consistent with tissue-specific and/or tumor-specific γδ T cell contributions to IL-2c efficacy. IL-2c significantly altered bladder intratumoral γδ T cell content, activation status, and specific γδ T cell subsets with antitumor or protumor effector functions. Neither IL-2c nor αPD-L1 alone treated lung metastatic MB49 or MBT-2 BC, but their combination improved survival in both models. Combination treatment efficacy in lungs required CD8+ T cells but not γδ T cells.ConclusionsMechanistic insights into differential IL-2c and αPD-L1 treatment and tissue-dependent effects could help develop rational combination treatment strategies to improve treatment efficacy in distinct cancers. These studies also provide insights into γδ T cell contributions to immunotherapy in bladder and engagement of adaptive immunity by IL-2c plus αPD-L1 to treat refractory lung metastases.


Cell ◽  
2020 ◽  
Vol 183 (4) ◽  
pp. 1134-1136
Author(s):  
Donnele Daley ◽  
Constantinos Pantelis Zambirinis ◽  
Lena Seifert ◽  
Neha Akkad ◽  
Navyatha Mohan ◽  
...  

Cell ◽  
2016 ◽  
Vol 166 (6) ◽  
pp. 1485-1499.e15 ◽  
Author(s):  
Donnele Daley ◽  
Constantinos Pantelis Zambirinis ◽  
Lena Seifert ◽  
Neha Akkad ◽  
Navyatha Mohan ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3948
Author(s):  
Kazumasa Oya ◽  
Yoshiyuki Nakamura ◽  
Zhu Zhenjie ◽  
Ryota Tanaka ◽  
Naoko Okiyama ◽  
...  

The exact mechanisms of the imiquimod (IMQ)-induced antitumor effect have not been fully understood. Although both topical IMQ treatment and anti-PD-1 antibody may be used for primary skin lesions or skin metastases of various cancers, the efficacy of each monotherapy for these lesions is insufficient. Using a murine tumor model and human samples, we aimed to elucidate the detailed mechanisms of the IMQ-induced antitumor effect and analyzed the antitumor effect of combination therapy of topical IMQ plus anti-PD-1 antibody. Topical IMQ significantly suppressed the tumor growth of MC38 in wildtype mice. IMQ upregulated interferon γ (IFN-γ) expression in CD8+ T cells in both the lymph nodes and the tumor, and the antitumor effect was abolished in both Rag1-deficient mice and IFN-γ-deficient mice, indicating that IFN-γ produced by CD8+ T cells play a crucial role in the IMQ-induced antitumor effect. IMQ also upregulated PD-1 expression in T cells as well as PD-L1/PD-L2 expression in myeloid cells, suggesting that IMQ induces not only T-cell activation but also T-cell exhaustion by enhanced PD-1 inhibitory signaling. Combination therapy of topical IMQ plus anti-PD-1 antibody exerted a significantly potent antitumor effect when compared with each single therapy, indicating that the combination therapy is a promising therapy for the skin lesions of various cancers.


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