Cancer exosomes and natural killer cells dysfunction: biological roles, clinical significance and implications for immunotherapy

AbstractTumor-derived exosomes (TDEs) play pivotal roles in several aspects of cancer biology. It is now evident that TDEs also favor tumor growth by negatively affecting anti-tumor immunity. As important sentinels of immune surveillance system, natural killer (NK) cells can recognize malignant cells very early and counteract the tumor development and metastasis without a need for additional activation. Based on this rationale, adoptive transfer of ex vivo expanded NK cells/NK cell lines, such as NK-92 cells, has attracted great attention and is widely studied as a promising immunotherapy for cancer treatment. However, by exploiting various strategies, including secretion of exosomes, cancer cells are able to subvert NK cell responses. This paper reviews the roles of TDEs in cancer-induced NK cells impairments with mechanistic insights. The clinical significance and potential approaches to nullify the effects of TDEs on NK cells in cancer immunotherapy are also discussed.

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Durable natural killer cell responses after heterologous two-dose Ebola vaccination

npj Vaccines ◽

10.1038/s41541-021-00280-0 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Helen R. Wagstaffe ◽

Giada Susannini ◽

Rodolphe Thiébaut ◽

Laura Richert ◽

Yves Lévy ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Cell Activation ◽

Ebola Virus ◽

Nk Cell ◽

Ex Vivo ◽

Killer Cell ◽

Post Dose ◽

Vaccine Regimen ◽

Cell Responses

AbstractNatural killer (NK) cells are implicated among immune effectors after vaccination against viral pathogens, including Ebola virus. The two-dose heterologous Ebola virus vaccine regimen, adenovirus type 26.ZEBOV followed by modified vaccinia Ankara-BN-Filo (EBOVAC2 consortium, EU Innovative Medicines Initiative), induces NK cell activation and anti-Ebola glycoprotein (GP) antibody-dependent NK cell activation post-dose 1, which is further elevated post-dose 2. Here, in a multicentre, phase 2 clinical trial (EBL2001), we demonstrate durable ex vivo NK cell activation 180 days after dose 2, with responses enriched in CD56bright NK cells. In vitro antibody-dependent responses to immobilised Ebola GP increased after dose 1, and remained elevated compared to pre-vaccination levels in serum collected 180 days later. Peak NK cell responses were observed post-dose 2 and NK cell IFN-γ responses remained significantly elevated at 180 days post-dose 2. Individual variation in NK cell responses were influenced by both anti-Ebola GP antibody concentrations and intrinsic interindividual differences in NK cell functional capacity. In summary, this study demonstrates durable NK cell responses after Ad26.ZEBOV, MVA-BN-Filo Ebola virus vaccination and could inform the immunological evaluation of future iterations of the vaccine regimen and vaccination schedules.

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The m15 Locus of Murine Cytomegalovirus Modulates Natural Killer Cell Responses to Promote Dissemination to the Salivary Glands and Viral Shedding

Pathogens ◽

10.3390/pathogens10070866 ◽

2021 ◽

Vol 10 (7) ◽

pp. 866

Author(s):

Baca Chan ◽

Maja Arapović ◽

Laura Masters ◽

Francois Rwandamuiye ◽

Stipan Jonjić ◽

...

Keyword(s):

Nk Cells ◽

Salivary Glands ◽

Natural Killer ◽

Nk Cell ◽

Acute Infection ◽

Killer Cell ◽

Viral Escape ◽

Murine Cytomegalovirus ◽

Viral Shedding ◽

Cell Responses

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.

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Fibronectin maintains survival of mouse natural killer (NK) cells via CD11b/Src/β-catenin pathway

Blood ◽

10.1182/blood-2009-05-219881 ◽

2009 ◽

Vol 114 (19) ◽

pp. 4081-4088 ◽

Cited By ~ 22

Author(s):

Ting Zhang ◽

Shuxun Liu ◽

Pengyuan Yang ◽

Chaofeng Han ◽

Jianli Wang ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Nuclear Translocation ◽

Nk Cell ◽

Ex Vivo ◽

Interleukin 12 ◽

Erk Phosphorylation ◽

Extracellular Signal ◽

B Cell Leukemia

Abstract Tissue microenvironment and stroma-derived extracellular matrix (ECM) molecules play important roles in the survival and differentiation of cells. Mouse natural killer (NK) cells usually die within 24 hours once isolated ex vivo. Exogenous cytokines such as interleukin-12 (IL-12) and IL-15 are required to maintain the survival and activity of mouse NK cells cultured in vitro. Whether and how ECM molecules such as fibronectin can support the survival of NK cells remain unknown. We demonstrate that fibronectin, just like IL-15, can maintain survival of mouse NK cells in vitro. Furthermore, we show that fibronectin binds to the CD11b on NK cells, and then CD11b recruits and activates Src. Src can directly interact with β-catenin and trigger nuclear translocation of β-catenin. The activation of β-catenin promotes extracellular signal-related kinase (ERK) phosphorylation, resulting in the increased expression of antiapoptotic protein B-cell leukemia 2 (Bcl-2), which may contribute to the maintenance of NK-cell survival. Consistently, fibronectin cannot maintain the survival of CD11b− NK cells and β-catenin–deficient NK cells in vitro, and the number of NK cells is dramatically decreased in the β-catenin–deficient mice. Therefore, fibronectin can maintain survival of mouse NK cells by activating ERK and up-regulating Bcl-2 expression via CD11b/Src/β-catenin pathway.

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An Anti-MICA/B Antibody and IL-15 Rescue Altered NKG2D-Dependent NK Cell Responses in Hepatocellular Carcinoma

Cancers ◽

10.3390/cancers12123583 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3583

Author(s):

Stefania Mantovani ◽

Stefania Varchetta ◽

Dalila Mele ◽

Matteo Donadon ◽

Guido Torzilli ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Protein A ◽

Ligand Interaction ◽

Cell Responses ◽

Hcc Cells

Natural killer (NK) cells play a pivotal role in cancer immune surveillance, and activating the receptor/ligand interaction may contribute to control the development and evolution of hepatocellular carcinoma (HCC). We investigated the role of the natural killer group 2 member D (NKG2D) activating receptor and its ligand, the major histocompatibility complex class I chain-related protein A and B (MICA/B) in patients with cirrhosis and HCC subjected to surgical resection, patients with cirrhosis and no HCC, and healthy donors (HD). The NKG2D-mediated function was determined in peripheral blood (PB), in tumor-infiltrating lymphocytes (NK-TIL), and in matched surrounding liver tissue (NK-LIL). A group of patients treated with sorafenib because of clinically advanced HCC was also studied. A humanized anti-MICA/B monoclonal antibody (mAb) was used in in vitro experiments to examine NK cell-mediated antibody-dependent cellular cytotoxicity. Serum concentrations of soluble MICA/B were evaluated by ELISA. IL-15 stimulation increased NKG2D-dependent activity which, however, remained dysfunctional in PB NK cells from HCC patients, in line with the reduced NKG2D expression on NK cells. NK-TIL showed a lower degranulation ability than NK-LIL, which was restored by IL-15 stimulation. Moreover, in vitro IL-15 stimulation enhanced degranulation and interferon-γ production by PB NK from patients at month one of treatment with sorafenib. Anti-MICA/B mAb associated with IL-15 was able to induce PB NK cytotoxicity for primary HCC cells in HD and patients with HCC, who also showed NK-TIL degranulation for autologous primary HCC cells. Our findings highlight the key role of the NKG2D-MICA/B axis in the regulation of NK cell responses in HCC and provide evidence in support of a potentially important role of anti-MICA/B mAb and IL-15 stimulation in HCC immunotherapy.

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Slaying the Trojan Horse: Natural Killer Cells Exhibit Robust Anti-HIV-1 Antibody-Dependent Activation and Cytolysis against Allogeneic T Cells

Journal of Virology ◽

10.1128/jvi.02461-14 ◽

2014 ◽

Vol 89 (1) ◽

pp. 97-109 ◽

Cited By ~ 31

Author(s):

Shayarana L. Gooneratne ◽

Jonathan Richard ◽

Wen Shi Lee ◽

Andrés Finzi ◽

Stephen J. Kent ◽

...

Keyword(s):

T Cells ◽

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Target Cells ◽

Dependent Manner ◽

Inhibitory Receptors ◽

Cell Responses ◽

Anti Hiv ◽

Hiv 1

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.

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TIM-3 Expression Is Downregulated on Human NK Cells in Response to Cancer Targets in Synergy with Activation

Cancers ◽

10.3390/cancers12092417 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2417 ◽

Cited By ~ 1

Author(s):

Tram N. Dao ◽

Sagar Utturkar ◽

Nadia Atallah Lanman ◽

Sandro Matosevic

Keyword(s):

T Cell ◽

Nk Cells ◽

Natural Killer ◽

Interferon Gamma ◽

Nk Cell ◽

Ex Vivo ◽

Cell Dysfunction ◽

Nk Cell Receptors ◽

Ifn Γ

Among natural killer (NK) cell receptors, the T-cell immunoglobulin and mucin-containing domain (TIM-3) has been associated with both inhibitory and activating functions, depending on context and activation pathway. Ex vivo and in vitro, expression of TIM-3 is inducible and depends on activation stimulus. Here, we report that TIM-3 expression can be downregulated on NK cells under specific conditions. When NK cells are exposed to cancer targets, they synergize with stimulation conditions to induce a substantial decrease in TIM-3 expression on their surface. We found that such downregulation occurs following prior NK activation. Downregulated TIM-3 expression correlated to lower cytotoxicity and lower interferon gamma (IFN-γ) expression, fueling the notion that TIM-3 might function as a benchmark for human NK cell dysfunction.

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Natural Killer Cell Responses in Hepatocellular Carcinoma: Implications for Novel Immunotherapeutic Approaches

Cancers ◽

10.3390/cancers12040926 ◽

2020 ◽

Vol 12 (4) ◽

pp. 926 ◽

Cited By ~ 5

Author(s):

Stefania Mantovani ◽

Barbara Oliviero ◽

Stefania Varchetta ◽

Dalila Mele ◽

Mario U. Mondelli

Keyword(s):

Hepatocellular Carcinoma ◽

T Cells ◽

Nk Cells ◽

Natural Killer ◽

Immune Escape ◽

Nk Cell ◽

Ex Vivo ◽

Killer Cell ◽

Current Status ◽

Tumor Immune Escape

Hepatocellular carcinoma (HCC) still represents a significant complication of chronic liver disease, particularly when cirrhosis ensues. Current treatment options include surgery, loco-regional procedures and chemotherapy, according to specific clinical practice guidelines. Immunotherapy with check-point inhibitors, aimed at rescuing T-cells from exhaustion, has been applied as second-line therapy with limited and variable success. Natural killer (NK) cells are an essential component of innate immunity against cancer and changes in phenotype and function have been described in patients with HCC, who also show perturbations of NK activating receptor/ligand axes. Here we discuss the current status of NK cell treatment of HCC on the basis of existing evidence and ongoing clinical trials on adoptive transfer of autologous or allogeneic NK cells ex vivo or after activation with cytokines such as IL-15 and use of antibodies to target cell-expressed molecules to promote antibody-dependent cellular cytotoxicity (ADCC). To this end, bi-, tri- and tetra-specific killer cell engagers are being devised to improve NK cell recognition of tumor cells, circumventing tumor immune escape and efficiently targeting NK cells to tumors. Moreover, the exciting technique of chimeric antigen receptor (CAR)-engineered NK cells offers unique opportunities to create CAR-NK with multiple specificities along the experience gained with CAR-T cells with potentially less adverse effects.

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Cord Blood Derived Natural Killer Cells Engineered with a Chimeric Antigen Receptor Targeting CD19 and Expressing IL-15 Have Long Term Persistence and Exert Potent Anti-Leukemia Activity

Blood ◽

10.1182/blood.v126.23.3091.3091 ◽

2015 ◽

Vol 126 (23) ◽

pp. 3091-3091 ◽

Cited By ~ 2

Author(s):

Enli Liu ◽

Yijiu Tong ◽

Gianpietro Dotti ◽

Barbara Savoldo ◽

Muharrem Muftuoglu ◽

...

Keyword(s):

Nk Cells ◽

Natural Killer ◽

Research Funding ◽

Nk Cell ◽

Ex Vivo ◽

Phase 1 ◽

Leukemia Cell ◽

Antigen Presenting Cells ◽

Caspase 9 ◽

Antigen Presenting

Abstract Natural killer (NK) cells are a major component of the innate immune system, possessing the ability to lyse their targets without the need for prior sensitization or specificity for antigen. Besides their classical role in providing potent antitumor and antiviral immunity, NK cells can reduce the risk of graft-versus-host disease (GVHD) by targeting host antigen-presenting cells, as well as activated alloreactive donor T cells, indicating that NK-mediated graft-versus-leukemia (GVL) responses may occur in the absence of GVHD. Although most groups have relied on autologous or adult peripheral blood donor-derived NK cells, we have studied umbilical CB as a potential source of NK cells because of their availability as an "off-the-shelf" frozen product and their potent preclinical activity against leukemia cells. To overcome the obstacle of limited numbers of NK cells in a single CB unit, we have established GMP-compliant conditions for the ex vivo expansion of clinically relevant doses of such cells. By using GMP grade K562-based artificial antigen-presenting cells (aAPCs), which express membrane-bound IL-21 (clone 9.mbIL21), to numerically expand highly functional and mature CB-derived NK cells. To further enhance the GVL effect independent of KIR-ligand mismatch, we have genetically modified human CB-derived NK cells with a retroviral vector, CAR19-CD28-zeta-2A-IL15 (CAR19/IL15), which incorporates the genes for CAR-CD19, IL-15 to enhance proliferation and survival, and the inducible caspase-9 molecule. CB-NK cells could be stably transduced with CAR19/IL15, proliferated efficiently in vitro and maintained superior effector function against CD19-expressing leukemia cell lines and primary CLL cells. Moreover, the effector functions of both NK-CAR and nontransduced NK cells against K562 were comparable, indicating that the genetic modification of CB-NK cells does not alter their intrinsic cytotoxicity against NK-sensitive targets. Because of concerns over autonomous, uncontrolled NK cell growth due to autocrine production of IL15, we also incorporated into our construct a suicide gene based on the inducible caspase-9 (IC9) gene. The addition of as little as 10 nM of the small molecule dimerizer CID AP20187 to cultures of iC9/CAR19/IL15+ NK cells induced apoptosis/necrosis of >60% of transgenic cells within 4 hours as assessed by annexin-V-7AAD staining. The infusion of CAR.CD19.IL15-transduced CB-NK cells into a NOD-SCID-gamma null model of lymphoblastic lymphoma (Raji model) resulted in impressive anti-tumor responses (Fig. 1). Moreover, adoptively infused CAR-transduced CB NK persisted for up to 70 days post-infusion (Fig. 2), supporting our hypothesis that IL-15 enhances the proliferation and survival of the engineered CB-NK cells. Based on these promising data, we now propose to manufacture a GMP-grade CAR19-CD28-zeta-2A-IL15 vector for a phase 1 dose escalation trial in patients with high risk B-cell leukemia. Disclosures Wierda: Celgene Corp.: Consultancy; Glaxo-Smith-Kline Inc.: Research Funding. Rezvani:Pharmacyclics: Research Funding.

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Engineering lymph node homing of ex vivo–expanded human natural killer cells via trogocytosis of the chemokine receptor CCR7

Blood ◽

10.1182/blood-2011-11-389924 ◽

2012 ◽

Vol 119 (22) ◽

pp. 5164-5172 ◽

Cited By ~ 56

Author(s):

Srinivas S. Somanchi ◽

Anitha Somanchi ◽

Laurence J. N. Cooper ◽

Dean A. Lee

Keyword(s):

Lymph Node ◽

Nk Cells ◽

Natural Killer ◽

Chemokine Receptor ◽

Chemokine Receptors ◽

Nk Cell ◽

Ex Vivo ◽

Ccr7 Expression ◽

Lymph Node Homing

Natural killer (NK) cells have gained significant attention in adoptive immunotherapy for cancer. Consequently, novel methods of clinical-grade expansion of NK cells have emerged. Subsets of NK cells express a variety of chemokine receptors. However, to expand the scope of adoptively transferred NK cell homing to various malignancies, expression of corresponding chemokine receptors on NK cells is essential. Here, we have explored the use of trogocytosis as a tool to transiently express the chemokine receptor CCR7 on expanded human NK cells with the aim to enhance their homing to lymph nodes. We generated a K562-based “donor” cell line expressing CCR7, Clone9.CCR7, to transfer CCR7 onto NK cells via trogocytosis. CCR7 expression occurred in 80% of expanded NK cells within 1 hour after coculture with Clone9.CCR7. After removal of the donor cells from the coculture, the CCR7 expression on NK cells steadily declined to baseline levels by 72 hours. The acquired CCR7 receptors mediated in vitro migration of NK cells toward CCL19 and CCL21 and increased the lymph node homing by 144% in athymic nude mice. This is the first report on exploiting trogocytosis to rapidly and transiently modify lymphocytes, without direct genetic interven-tion, for adoptive transfer.

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Human natural killer cells

Blood ◽

10.1182/blood-2007-09-077438 ◽

2008 ◽

Vol 112 (3) ◽

pp. 461-469 ◽

Cited By ~ 1040

Author(s):

Michael A. Caligiuri

Keyword(s):

Immune System ◽

Nk Cells ◽

Natural Killer ◽

Nk Cell ◽

Immune Surveillance ◽

Cell Receptor ◽

Human Malignancy ◽

Human Natural Killer Cells ◽

Receptor Biology ◽

Granular Lymphocytes

Abstract Natural killer (NK) cells were discovered more than 30 years ago. NK cells are large granular lymphocytes that belong to the innate immune system because unlike T or B lymphocytes of the adaptive or antigen-specific immune system, NK cells do not rearrange T-cell receptor or immunoglobulin genes from their germline configuration. During the past 2 decades there has been a substantial gain in our understanding of what and how NK-cells “see,” lending important insights into their functions and purpose in normal immune surveillance. The most recent discoveries in NK-cell receptor biology have fueled translational research that has led to remarkable results in treating human malignancy.

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