scholarly journals Inhibitory Receptors and Immune Checkpoints Regulating Natural Killer Cell Responses to Cancer

Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4263
Author(s):  
Irina Buckle ◽  
Camille Guillerey

The discovery of immune checkpoints provided a breakthrough for cancer therapy. Immune checkpoints are inhibitory receptors that are up-regulated on chronically stimulated lymphocytes and have been shown to hinder immune responses to cancer. Monoclonal antibodies against the checkpoint molecules PD-1 and CTLA-4 have shown early clinical success against melanoma and are now approved to treat various cancers. Since then, the list of potential candidates for immune checkpoint blockade has dramatically increased. The current paradigm stipulates that immune checkpoint blockade therapy unleashes pre-existing T cell responses. However, there is accumulating evidence that some of these immune checkpoint molecules are also expressed on Natural Killer (NK) cells. In this review, we summarize our latest knowledge about targetable NK cell inhibitory receptors. We discuss the HLA-binding receptors KIRS and NKG2A, receptors binding to nectin and nectin-like molecules including TIGIT, CD96, and CD112R, and immune checkpoints commonly associated with T cells such as PD-1, TIM-3, and LAG-3. We also discuss newly discovered pathways such as IL-1R8 and often overlooked receptors such as CD161 and Siglecs. We detail how these inhibitory receptors might regulate NK cell responses to cancer, and, where relevant, we discuss their implications for therapeutic intervention.

2021 ◽  
Author(s):  
Yanlin Du ◽  
Da Zhang ◽  
Yiru Wang ◽  
Ming Wu ◽  
Cuilin Zhang ◽  
...  

A highly stable multifunctional aptamer was prepared for strengthening antitumor immunity through a dual immune checkpoint blockade of CTLA-4 and PD-L1.


Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 866
Author(s):  
Baca Chan ◽  
Maja Arapović ◽  
Laura Masters ◽  
Francois Rwandamuiye ◽  
Stipan Jonjić ◽  
...  

As the largest herpesviruses, the 230 kb genomes of cytomegaloviruses (CMVs) have increased our understanding of host immunity and viral escape mechanisms, although many of the annotated genes remain as yet uncharacterised. Here we identify the m15 locus of murine CMV (MCMV) as a viral modulator of natural killer (NK) cell immunity. We show that, rather than discrete transcripts from the m14, m15 and m16 genes as annotated, there are five 3′-coterminal transcripts expressed over this region, all utilising a consensus polyA tail at the end of the m16 gene. Functional inactivation of any one of these genes had no measurable impact on viral replication. However, disruption of all five transcripts led to significantly attenuated dissemination to, and replication in, the salivary glands of multiple strains of mice, but normal growth during acute infection. Disruption of the m15 locus was associated with heightened NK cell responses, including enhanced proliferation and IFNγ production. Depletion of NK cells, but not T cells, rescued salivary gland replication and viral shedding. These data demonstrate the identification of multiple transcripts expressed by a single locus which modulate, perhaps in a concerted fashion, the function of anti-viral NK cells.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii106-ii106
Author(s):  
Bryan Iorgulescu ◽  
Prafulla Gokhale ◽  
Maria Speranza ◽  
Benjamin Eschle ◽  
Michael Poitras ◽  
...  

Abstract BACKGROUND Dexamethasone, a uniquely potent corticosteroid, is frequently administered to brain tumor patients to decrease tumor-associated edema, but limited data exist describing how dexamethasone affects the immune system systemically and intratumorally in glioblastoma patients – particularly in the context of immunotherapy. METHODS We evaluated the dose-dependent effects of dexamethasone when administered with anti-PD-1 and/or radiotherapy in immunocompetent C57BL/6 mice with syngeneic GL261 or CT-2A glioblastoma tumors, including analyses of intracranial tumors, draining lymph nodes, and spleen. Clinically, the effect of dexamethasone on survival was additionally evaluated in 181 consecutive IDH-wildtype glioblastoma patients treated with anti-PD-(L)1, with adjustment for relevant prognostic factors. RESULTS Despite the inherent responsiveness of GL261 to immune checkpoint blockade, concurrent dexamethasone administration with anti-PD-1 therapy decreased survival in a dose-dependent fashion and decreased survival following anti-PD-1 plus radiotherapy in both GL261 and immunoresistant CT-2A models. Dexamethasone quantitatively decreased T lymphocytes by reducing the proliferation while increasing apoptosis. Dexamethasone also decreased lymphocyte functional capacity. Myeloid and NK cell populations were also generally reduced. Thus, dexamethasone negatively affects both the adaptive and innate immune responses. As a clinical correlate, a retrospective analysis of 181 consecutive IDH-wildtype glioblastoma patients treated with PD-(L)1 blockade revealed worse survival among those on baseline dexamethasone. Upon multivariable adjustment with relevant prognostic factors, baseline dexamethasone use – regardless of dose – was the strongest predictor of poor survival (reference no dexamethasone; < 2mg HR 2.28, 95%CI=1.41–3.68, p=0.001; ≥2mg HR 1.97, 95%CI=1.27–3.07, p=0.003). CONCLUSIONS Our preclinical and clinical data indicate that concurrent dexamethasone therapy may be detrimental to immunotherapeutic approaches for glioblastoma patients. Our preclinical analyses also suggest that dexamethasone’s detrimental effects are dose-dependent, suggesting that the lowest possible dose should be used for patients when dexamethasone use is unavoidable. Careful evaluation of dexamethasone use is warranted for neuro-oncology patients undergoing immunotherapy clinical trials.


2021 ◽  
Vol 9 (1) ◽  
pp. e001460 ◽  
Author(s):  
Xiuting Liu ◽  
Graham D Hogg ◽  
David G DeNardo

The clinical success of immune checkpoint inhibitors has highlighted the central role of the immune system in cancer control. Immune checkpoint inhibitors can reinvigorate anti-cancer immunity and are now the standard of care in a number of malignancies. However, research on immune checkpoint blockade has largely been framed with the central dogma that checkpoint therapies intrinsically target the T cell, triggering the tumoricidal potential of the adaptive immune system. Although T cells undoubtedly remain a critical piece of the story, mounting evidence, reviewed herein, indicates that much of the efficacy of checkpoint therapies may be attributable to the innate immune system. Emerging research suggests that T cell-directed checkpoint antibodies such as anti-programmed cell death protein-1 (PD-1) or programmed death-ligand-1 (PD-L1) can impact innate immunity by both direct and indirect pathways, which may ultimately shape clinical efficacy. However, the mechanisms and impacts of these activities have yet to be fully elucidated, and checkpoint therapies have potentially beneficial and detrimental effects on innate antitumor immunity. Further research into the role of innate subsets during checkpoint blockade may be critical for developing combination therapies to help overcome checkpoint resistance. The potential of checkpoint therapies to amplify innate antitumor immunity represents a promising new field that can be translated into innovative immunotherapies for patients fighting refractory malignancies.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A888-A888
Author(s):  
Laura Ridgley ◽  
Angus Dalgleish ◽  
Mark Bodman-Smith

BackgroundVγ9Vδ2 T-cells are a subset of cells with a crucial role in immunosurveillance which can be activated and expanded by multiple means to stimulate effector responses, often exploited in cancer immunotherapy. Little is known about the expression of checkpoint molecules on this cell population and whether the ligation of these molecules can regulate their activity. The aim of this study was to assess the expression of activatory and inhibitory markers on Vγ9Vδ2 T-cells to assess potential avenues of regulation to target with immunotherapy.MethodsPBMCs were isolated from healthy donors and the expression of activatory and inhibitory receptors was assessed on Vγ9Vδ2 T-cells by flow cytometry at baseline, following 24 hours activation and 14 days expansion using zoledronic acid (ZA) and Bacillus Calmette-Guerin (BCG), both with IL-2. Activation and expansion of Vδ2 cells was assessed by expression of CD69 and by frequency of Vδ2 cells, respectively. Production of effector molecules was also assessed following coculture with various tumour cell targets. The effect of immune checkpoint blockade on Vγ9Vδ2 T-cells was also assessed.ResultsVγ9Vδ2 T-cells constitutively expressed high levels of NK-associated activatory markers NKG2D and DNAM1 which remained high following stimulation with ZA and BCG. Vγ9Vδ2 T-cells expressed variable levels of checkpoint inhibitor molecules at baseline with high levels of BTLA, KLRG1 and NKG2A and intermediate levels of PD1, TIGIT and VISTA. Expression of checkpoint receptors were modulated following activation and expansion with ZA and BCG with decreased expression of BTLA and upregulation of numerous markers including PD1, TIGIT, TIM3, LAG3 and VISTA. Expression of these markers is further modulated upon coculture with tumour cell lines with changes reflecting activation of these cells with Vγ9Vδ2 T-cells expressing inhibitory receptors PD1 and NKG2A producing the highest level of TNF.ConclusionsOur data reveals unique characteristics of Vδ2 in terms of their expression of immune checkpoints, which provide a mechanism which may be utilised by tumour cells to subvert Vγ9Vδ2 T-cell cytotoxicity. Our work suggests different profiles of immune checkpoints dependent on the method of stimulation. This highlights importance of expansion method in the function of Vγ9Vδ2 T-cells. Furthermore, this work suggests important candidates for blockade by immune checkpoint therapy in order to increase the successful use of Vγ9Vδ2 T-cells in cancer immunotherapy.


Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3504
Author(s):  
Silvia Pesce ◽  
Sara Trabanelli ◽  
Clara Di Vito ◽  
Marco Greppi ◽  
Valentina Obino ◽  
...  

Immune checkpoints refer to a plethora of inhibitory pathways of the immune system that play a crucial role in maintaining self-tolerance and in tuning the duration and amplitude of physiological immune responses to minimize collateral tissue damages. The breakdown of this delicate balance leads to pathological conditions, including cancer. Indeed, tumor cells can develop multiple mechanisms to escape from immune system defense, including the activation of immune checkpoint pathways. The development of monoclonal antibodies, targeting inhibitory immune checkpoints, has provided an immense breakthrough in cancer therapy. Immune checkpoint inhibitors (ICI), initially developed to reverse functional exhaustion in T cells, recently emerged as important actors in natural killer (NK)-cell-based immunotherapy. Moreover, the discovery that also helper innate lymphoid cells (ILCs) express inhibitory immune checkpoints, suggests that these molecules might be targeted on ILCs, to modulate their functions in the tumor microenvironment. Recently, other strategies to achieve immune checkpoint blockade have been developed, including miRNA exploiting systems. Herein, we provide an overview of the current knowledge on inhibitory immune checkpoints on NK cells and ILCs and we discuss how to target these innate lymphocytes by ICI in both solid tumors and hematological malignancies.


2014 ◽  
Vol 89 (1) ◽  
pp. 97-109 ◽  
Author(s):  
Shayarana L. Gooneratne ◽  
Jonathan Richard ◽  
Wen Shi Lee ◽  
Andrés Finzi ◽  
Stephen J. Kent ◽  
...  

ABSTRACTMany attempts to design prophylactic human immunodeficiency virus type 1 (HIV-1) vaccines have focused on the induction of neutralizing antibodies (Abs) that block infection by free virions. Despite the focus on viral particles, virus-infected cells, which can be found within mucosal secretions, are more infectious than free virus bothin vitroandin vivo. Furthermore, assessment of human transmission couples suggests infected seminal lymphocytes might be responsible for a proportion of HIV-1 transmissions. Although vaccines that induce neutralizing Abs are sought, only some broadly neutralizing Abs efficiently block cell-to-cell transmission of HIV-1. As HIV-1 vaccines need to elicit immune responses capable of controlling both free and cell-associated virus, we evaluated the potential of natural killer (NK) cells to respond in an Ab-dependent manner to allogeneic T cells bearing HIV-1 antigens. This study presents data measuring Ab-dependent anti-HIV-1 NK cell responses to primary and transformed allogeneic T-cell targets. We found that NK cells are robustly activated in an anti-HIV-1 Ab-dependent manner against allogeneic targets and that tested target cells are subject to Ab-dependent cytolysis. Furthermore, the educated KIR3DL1+NK cell subset from HLA-Bw4+individuals exhibits an activation advantage over the KIR3DL1−subset that contains both NK cells educated through other receptor/ligand combinations and uneducated NK cells. These results are intriguing and important for understanding the regulation of Ab-dependent NK cell responses and are potentially valuable for designing Ab-dependent therapies and/or vaccines.IMPORTANCENK cell-mediated anti-HIV-1 antibody-dependent functions have been associated with protection from infection and disease progression; however, their role in protecting from infection with allogeneic cells infected with HIV-1 is unknown. We found that HIV-1-specific ADCC antibodies bound to allogeneic cells infected with HIV-1 or coated with HIV-1 gp120 were capable of activating NK cells and/or trigging cytolysis of the allogeneic target cells. This suggests ADCC may be able to assist in preventing infection with cell-associated HIV-1. In order to fully utilize NK cell-mediated Ab-dependent effector functions, it might also be important that educated NK cells, which hold the highest activation potential, can become activated against targets bearing HIV-1 antigens and expressing the ligands for self-inhibitory receptors. Here, we show that with Ab-dependent stimulation, NK cells expressing inhibitory receptors can mediate robust activation against targets expressing the ligands for those receptors.


Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1689 ◽  
Author(s):  
Edoardo Giannini ◽  
Andrea Aglitti ◽  
Mauro Borzio ◽  
Martina Gambato ◽  
Maria Guarino ◽  
...  

Despite progress in our understanding of the biology of hepatocellular carcinoma (HCC), this tumour remains difficult-to-cure for several reasons, starting from the particular disease environment where it arises—advanced chronic liver disease—to its heterogeneous clinical and biological behaviour. The advent, and good results, of immunotherapy for cancer called for the evaluation of its potential application also in HCC, where there is evidence of intra-hepatic immune response activation. Several studies advanced our knowledge of immune checkpoints expression in HCC, thus suggesting that immune checkpoint blockade may have a strong rationale even in the treatment of HCC. According to this background, initial studies with tremelimumab, a cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitor, and nivolumab, a programmed cell death protein 1 (PD-1) antibody, showed promising results, and further studies exploring the effects of other immune checkpoint inhibitors, alone or with other drugs, are currently underway. However, we are still far from the identification of the correct setting, and sequence, where these drugs might be used in clinical practice, and their actual applicability in real-life is unknown. This review focuses on HCC immunobiology and on the potential of immune checkpoint blockade therapy for this tumour, with a critical evaluation of the available trials on immune checkpoint blocking antibodies treatment for HCC. Moreover, it assesses the potential applicability of immune checkpoint inhibitors in the real-life setting, by analysing a large, multicentre cohort of Italian patients with HCC.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuqing Cao ◽  
Xiaoyu Wang ◽  
Tianqiang Jin ◽  
Yu Tian ◽  
Chaoliu Dai ◽  
...  

Abstract Recent studies have demonstrated the potential of natural killer (NK) cells in immunotherapy to treat multiple types of cancer. NK cells are innate lymphoid cells that play essential roles in tumor surveillance and control that efficiently kill the tumor and do not require the major histocompatibility complex. The discovery of the NK’s potential as a promising therapeutic target for cancer is a relief to oncologists as they face the challenge of increased chemo-resistant cancers. NK cells show great potential against solid and hematologic tumors and have progressively shown promise as a therapeutic target for cancer immunotherapy. The effector role of these cells is reliant on the balance of inhibitory and activating signals. Understanding the role of various immune checkpoint molecules in the exhaustion and impairment of NK cells when their inhibitory receptors are excessively expressed is particularly important in cancer immunotherapy studies and clinical implementation. Emerging immune checkpoint receptors and molecules have been found to mediate NK cell dysfunction in the tumor microenvironment; this has brought up the need to explore further additional NK cell-related immune checkpoints that may be exploited to enhance the immune response to refractory cancers. Accordingly, this review will focus on the recent findings concerning the roles of immune checkpoint molecules and receptors in the regulation of NK cell function, as well as their potential application in tumor immunotherapy.


2010 ◽  
Vol 06 (01) ◽  
pp. 86
Author(s):  
Norbert Vey ◽  
Daniel Olive ◽  
◽  

Treatment with anti-killer-cell immunoglobulin-like receptor (KIR) monoclonal antibody (mAb) is a new approach aimed at harnessing the antileukaemic potential of natural killer (NK) cells for the treatment of acute myeloid leukaemia (AML). NK cell antitumour activity is regulated by a balance between activating and inhibitory receptors (KIR). 1-7F9/IPH2101 is a fully human immunoglobulin G4 (IgG4) mAb that binds to inhibitory KIR and blocks binding with its ligand (human leukocyte antigen C [HLA-C] molecule) on leukaemic cells.In vitro,and in a surrogatein vivomodel in mice, treatment with 1-7F9/IPH2101 was able to induce NK cell activation and cytotoxicity against leukaemic cells. Patients with AML often display abnormal NK cell function, while evidence of an impact of NK cell status on AML outcome has been reported in allogeneic transplantation. 1-7F9/IPH2101 is currently under clinical investigation in patients with AML. This article reviews the mechanisms of NK cell antileukaemic activity and its role and defects in AML. Currently available data on the pre-clinical and clinical development of 1-7F9/IPH2101 are presented, and the rationale for its future use as a single agent or in combination is discussed.


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