scholarly journals Hypoxia-inducible factor-1 alpha expression is induced by IL-2 via the PI3K/mTOR pathway in hypoxic NK cells and supports effector functions in NKL cells and ex vivo expanded NK cells

Author(s):  
Emily Cluff ◽  
Carina C. Magdaleno ◽  
Emyly Fernandez ◽  
Trenton House ◽  
Srividya Swaminathan ◽  
...  

AbstractNatural killer (NK) cells are cytotoxic innate lymphocytes that are specialized to kill tumor cells. NK cells are responsive to the primary cytokine IL-2 in the tumor microenvironment (TME), to activate its effector functions against tumors. Despite their inherent ability to kill tumor cells, dysfunctional NK cells observed within advanced solid tumors are associated with poor patient survival. Hypoxia in the TME is a major contributor to immune evasion in solid tumors that could contribute to impaired NK cell function. HIF-1α is a nodal regulator of hypoxia in driving the adaptive cellular responses to changes in oxygen concentrations. Whether HIF-1α is expressed in hypoxic NK cells in the context of IL-2 and whether its expression regulates NK cell effector function are unclear. Here, we report that freshly isolated NK cells from human peripheral blood in hypoxia could not stabilize HIF-1α protein coincident with impaired anti-tumor cytotoxicity. However, ex vivo expansion of these cells restored HIF-1α levels in hypoxia to promote antitumor cytotoxic functions. Similarly, the human NK cell line NKL expressed HIF-1α upon IL-2 stimulation in hypoxia and exhibited improved anti-tumor cytotoxicity and IFN-γ secretion. We found that ex vivo expanded human NK cells and NKL cells required the concerted activation of PI3K/mTOR pathway initiated by IL-2 signaling in combination with hypoxia for HIF-1α stabilization. These findings highlight that HIF-1α stabilization in hypoxia maximizes NK cell effector function and raises the prospect of NK cells as ideal therapeutic candidates for solid tumors.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Berenice Mbiribindi ◽  
Josselyn K. Pena ◽  
Matthew P. Arvedson ◽  
Claudia Moreno Romero ◽  
Sarah R. McCarthy ◽  
...  

AbstractNatural killer (NK) cells control viral infection through the interaction between inhibitory receptors and human leukocyte antigen (HLA) ligands and bound peptide. NK cells expressing the inhibitory receptor NKG2A/CD94 recognize and respond to autologous B cells latently infected with Epstein–Barr virus (EBV). The mechanism is not yet understood, thus we investigated peptides derived from seven latent proteins of EBV in the interaction of NKG2A and its ligand HLA-E. Functional analysis demonstrated that EBV peptides can bind to HLA-E and block inhibition of NK cell effector function. Moreover, analysis of DNA from 79 subjects showed sequence variations in the latent protein, LMP1, which alters NK responses to EBV. We provide evidence that peptides derived from EBV latent cycle proteins can impair the recognition of NKG2A despite being presented by HLA-E, resulting in NK cell activation.


1999 ◽  
Vol 190 (3) ◽  
pp. 435-444 ◽  
Author(s):  
Erika Cretney ◽  
Mariapia A. Degli-Esposti ◽  
Eloise H. Densley ◽  
Helen E. Farrell ◽  
Nick J. Davis-Poynter ◽  
...  

Until now, it has been unclear whether murine cytomegalovirus (MCMV)-encoded protein m144 directly regulates natural killer (NK) cell effector function and whether the effects of m144 are only strictly evident in the context of MCMV infection. We have generated clones of the transporter associated with antigen processing (TAP)-2–deficient RMA-S T lymphoma cell line and its parent cell line, RMA, that stably express significant and equivalent levels of m144. In vivo NK cell–mediated rejection of RMA-S-m144 lymphomas was reduced compared with rejection of parental or mock-transfected RMA-S clones, indicating the ability of m144 to regulate NK cell–mediated responses in vivo. Significantly, the accumulation of NK cells in the peritoneum was reduced in mice challenged with RMA-S-m144, as was the lytic activity of NK cells recovered from the peritoneum. Expression of m144 on RMA-S cells also conferred resistance to cytotoxicity mediated in vitro by interleukin 2–activated adherent spleen NK cells. In summary, the data demonstrate that m144 confers some protection from NK cell effector function mediated in the absence of target cell class I expression, but that in vivo the major effect of m144 is to regulate NK cell accumulation and activation at the site of immune challenge.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A566-A566
Author(s):  
Tram Dao ◽  
Sandro Matosevic ◽  
Sagar Utturkar ◽  
Nadia Lanman

BackgroundNatural killer (NK) cells are part of the innate immune system, but are capable of participating in both innate and adaptive immune responses due to their wide range of cytolytic activities, from degranulation, secretion of cytokines to antibody-dependent cell-mediated cytotoxicity. These are possible due to the cells’ ability to recognize self and non-self-entities via the net signal generated from their activating and inhibitory receptors upon engagement. TIM-3 is a part of the NK receptor repertoire, expressed commonly on different lymphocytes. In T cells, TIM-3 is established as an inhibitory marker. However, in NK cells, the role of TIM-3 could be agonistic or antagonistic to NK cytotoxicity based on the disease type and activation status, though limited information is known about its role in cancer and its correlation to NK cell effector functions.MethodsWe measured TIM-3 expression upon activation of human NK cells under various conditions. NK cells were isolated from peripheral blood of healthy donors and expanded either in K562-based feeder media or feeder-free OpTmizerTM media. After expansion, they were co-cultured for 4 hours with patient-derived glioblastoma multiforme cells (GBM43) at effector:target ratios of 2.5:1 and 10:1. To evaluate the effect of TIM-3 expression on NK cells, 7AAD/CFSE killing assays, CD107a degranulation and IFNγ secretion assays were carried out while blocking TIM-3 with neutralizing antibodies. Bioinformatics analysis of GBM patient RNAseq data was carried out to correlate TIM-3 expression with in vivo function, and this analysis is supplemented by phenotyping TIM-3 on NK cells isolated from patient samples in order to infer the role of this receptor in GBM.ResultsWe found that TIM-3 was downregulated on OpTmizerTM -cultured NK cells once exposed to cancer targets, and this correlated to a decreased in NK killing capacity when compared to feeder media-cultured NK cells, where the downregulation was not observed. Culturing NK cells in different derivatives of both media suggested that a combination of serum and cytokines can induce TIM-3 expression change to cancer targets. Flow cytometric assays revealed that while degranulation remained the same, the decreased in cytotoxicity corresponded to a decrease in IFNγ secretion. In GBM patient datasets, TIM-3 expression correlates to high IFN-γ levels and associates with both pro- and anti-tumorigenic functions. Here, we report a new role of TIM-3 in modulating NK functionality by correlating its loss to a loss in NK cell effector functions, and how its expression can be modified by ex vivo activation.ConclusionsTIM-3 expression on NK cells can be induced by ex vivo expansion, and this change in expression could influence NK cytotoxicity and cytokine secretion. Our data suggested that TIM-3 is not necessarily an inhibitory marker in GBM, and more likely to be a status marker or an activation limiter, working in conjunction with other receptors to modulate NK cell anti-tumor responses.Ethics ApprovalThis study was approved by Purdue Intuition’s Ethics Board, approval number [1804020540].


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 314-314 ◽  
Author(s):  
Katrin M. Baltz ◽  
Matthias Krusch ◽  
Tina Baessler ◽  
Anita Bringmann ◽  
Lothar Kanz ◽  
...  

Abstract Glucocorticoid-induced TNF-related protein (GITR) and its ligand (GITRL) are members of the TNF/TNF receptor (TNFR) superfamily, which mediates multiple cellular functions including proliferation, differentiation, and cell death. Recently we reported that NK cells express GITR while tumor cells express GITRL, and GITR-GITRL interaction downregulates NK cell-mediated anti-tumor immunity (Baltz et al., FASEB J 2007). Many TNF family members are released as soluble forms, which affects cell-cell interactions by reduction of ligand density and distally modulates effector cells bearing the respective receptor. Here we report that human tumor cells spontaneously release a soluble form of GITRL (sGITRL), which can be detected in tumor cell culture supernatants by ELISA (detection limit 0.01ng/ml). We demonstrated that NK cell cytotoxicity and IFN-γ production in cocultures with the tumor cell lines SK-Mel (Melanoma), PC-3 (prostate), HCT116 (colon), and LX-1 (lung) were significantly (both p<0.01, Mann-Whitney U-test) and concentration dependently reduced (up to 50%) by tumor-derived sGITRL, and NK cell effector functions could be restored by neutralization of sGITRL using a GITR-Fc fusion protein. While tumor-derived GITRL did not induce apoptosis in NK cells, it diminished nuclear localized RelB indicating that sGITRL negatively modulates NK cell NF-κB activity. Furthermore, we demonstrate that significantly elevated sGITRL levels (mean 0.4ng/ml, range from 0.01 to 3.5ng/ml) were contained in 40 out of 50 sera of patients with various cancers (colon, lung and germ line), while sera of healthy volunteers (n=8) contained no detectable levels of sGITRL. Addition of sGITRL containing patient sera to cocultures of NK cells and GITRL-negative tumor cells significantly reduced NK cell cytotoxicity and IFN-γ production about 30% and 45%, respectively (both p<0.05, Mann-Whitney U-test). Again the inhibitory effects of sGITRL on NK cell effector functions could be completely restored by neutralization of sGITRL with GITR-Fc. The strong correlation of tumor incidence and elevated sGITRL levels clearly suggests that sGITRL is released at significant amounts from malignant cells in vivo and may reduce immune surveillance of human tumors. Our data indicate that determination of sGITRL levels may be implemented as an immunological diagnostic marker in tumor patients, and GITRL-neutralization may be employed in therapeutic strategies like adoptive NK cell transfer.


Hemato ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 167-181
Author(s):  
Marie Thérèse Rubio ◽  
Adèle Dhuyser ◽  
Stéphanie Nguyen

Myeloma tumor cells are particularly dependent on their microenvironment and sensitive to cellular antitumor immune response, including natural killer (NK) cells. These later are essential innate lymphocytes implicated in the control of viral infections and cancers. Their cytotoxic activity is regulated by a balance between activating and inhibitory signals resulting from the complex interaction of surface receptors and their respective ligands. Myeloma disease evolution is associated with a progressive alteration of NK cell number, phenotype and cytotoxic functions. We review here the different therapeutic approaches that could restore or enhance NK cell functions in multiple myeloma. First, conventional treatments (immunomodulatory drugs-IMids and proteasome inhibitors) can enhance NK killing of tumor cells by modulating the expression of NK receptors and their corresponding ligands on NK and myeloma cells, respectively. Because of their ability to kill by antibody-dependent cell cytotoxicity, NK cells are important effectors involved in the efficacy of anti-myeloma monoclonal antibodies targeting the tumor antigens CD38, CS1 or BCMA. These complementary mechanisms support the more recent therapeutic combination of IMids or proteasome inhibitors to monoclonal antibodies. We finally discuss the ongoing development of new NK cell-based immunotherapies, such as ex vivo expanded killer cell immunoglobulin-like receptors (KIR)-mismatched NK cells, chimeric antigen receptors (CAR)-NK cells, check point and KIR inhibitors.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A163-A163
Author(s):  
Yui Harada ◽  
Yoshikazu Yonemitsu

BackgroundCancer immunotherapy has been established as a new therapeutic category since the recent success of immune checkpoint inhibitors and a type of adoptive immunotherapy, namely chimeric antigen receptor-modified T cells (CAR-T). Although CAR-T demonstrated impressive clinical results, serious adverse effects (cytokine storm and on-target off-tumor toxicity) and undefined efficacy on solid tumors are important issues to be solved. We’ve developed a cutting-edge, simple, and feeder-free method to generate highly activated and expanded human NK cells from peripheral blood (US9404083, PCT/JP2019/012744, PCT/JP2020/012386), and have been conducting further investigation why our new type of NK cells, named as GAIA-102, are so effective to kill malignant cells.MethodsCryopreserved PBMCs purchased from vendors were mixed and processed by using LOVO and CliniMACS® Prodigy (automated/closed systems). CD3+ and CD34+ cells were depleted, and the cells were cultured with high concentration of hIL-2 and 5% UltraGRO® for 14 days in our original closed system. Then, we confirmed the expression of surface markers, CD107a mobilization and cell-mediated cytotoxicity against various tumor cells and normal cells with or without monoclonal antibody drugs in vitro and antitumor effects against peritoneal dissemination model using SKOV3 in vivo.ResultsImportantly, we’ve found that our GAIA-102 exhibited CD3-/CD56bright/CD57- immature phenotype that could kill various tumor cells efficiently from various origins, including Raji cells that was highly resistant to NK cell killing. More importantly, massive accumulation, retention, infiltration and sphere destruction by GAIA-102 were affected neither by myeloid-derived suppressor cells nor regulatory T-lymphocytes. GAIA-102 was also effective in vivo to murine model of peritoneal dissemination of human ovarian cancer; thus, these findings indicate that GAIA-102 has a potential to be an ‘upward compatible’ modality over CAR-T strategy, and would be a new and promising candidate for adoptive immunotherapy against solid tumors.ConclusionsWe now just started GMP/GCTP production of this new and powerful NK cells and first-in-human clinical trials in use of GAIA-102 will be initiated on 2021.Ethics ApprovalThe animal experiments were reviewed and approved by the Institutional Animal Care and Use Committee of Kyushu University (approval nos. A30-234-0 and A30-359-0).


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A834-A834
Author(s):  
Xue Yao ◽  
Sandro Matosevic

BackgroundThe effectiveness of natural killer (NK) cell-based immunotherapy against solid tumors is limited by the lack of specific antigens and the immunosuppressive tumor microenvironment (TME). Glioblastoma multiforme (GBM) is one such heavily immunosuppressive tumor that has been particularly hard to target and remains without a viable treatment. The development of novel approaches to enhance the efficacy of NK cells against GBM is urgently needed. NK cell engagers (NKCE) have been developed to enhance the efficacy of NK cell therapy.MethodsTo improve the clinical efficacy of NK cell therapy, we are developing a new generation of multi-specific killer engagers, which consists of a neoantigen-targeting moiety, together with cytokine and chemokine-producing domains. Neoantigens are new antigens formed specifically in tumor cells due to genome mutations, making them highly specific tools to target tumor cells. Our engager has been designed to target Wilms' tumor-1 (WT-1), a highly specific antigen overexpressed in GBM among other solid tumors. This is done through the generation of an scFv specific targeting the complex of WT-1126-134/HLA-A*02:01 on the surface of GBM. On the NK cell side, the engager is designed to target the activating receptor NKp46. Incorporation of the cytokine IL-15 within the engager supports the maturation, persistence, and expansion of NK cells in vivo while favoring their proliferation and survival in the tumor microenvironment. Additionally, our data indicated that the chemokine CXCL10 plays an important role in the infiltration of NK cells into GBM, however, GBM tumors produce low levels of this chemokine. Incorporation of a CXCL10-producing function into our engager supports intratumoral NK cell trafficking by promoting, through their synthetic production, increased levels of CXCL10 locally in the tumor microenvironment.ResultsCollectively, this has resulted in a novel multifunctional NK cell engager, combining neoantigen-cytokine-chemokine elements fused to an activating domain-specific to NK cells, and we have investigated its ability to support and enhance NK cell-mediated cytotoxicity against solid tumors in vitro and in vivo against patient-derived GBM models. The multi-specific engager shows both high tumor specificity, as well as the ability to overcome NK cell dysfunction encountered in the GBM TME.ConclusionsWe hypothesize that taking advantage of our multi-functional engager, NK cells will exhibit superior ex vivo expansion, infiltration, and antitumor activity in the treatment of GBM and other solid tumors.


2020 ◽  
Vol 8 (2) ◽  
pp. e001849
Author(s):  
Isobel Okoye ◽  
Lai Xu ◽  
Melika Motamedi ◽  
Pallavi Parashar ◽  
John W Walker ◽  
...  

BackgroundWe have previously reported that the upregulation of galectin-9 (Gal-9) on CD4+ and CD8+ T cells in HIV patients was associated with impaired T cell effector functions. Gal-9 is a ligand for T cell immunoglobulin and mucin domain-3, and its expression on T cells in cancer has not been investigated. Therefore, we aimed to investigate the expression level and effects of Gal-9 on T cell functions in patients with virus-associated solid tumors (VASTs).Methods40 patients with VASTs through a non-randomized and biomarker-driven phase II LATENT trial were investigated. Peripheral blood mononuclear cells and tumor biopsies were obtained and subjected to immunophenotyping. In this trial, the effects of oral valproate and avelumab (anti-PD-L1) was investigated in regards to the expression of Gal-9 on T cells.ResultsWe report the upregulation of Gal-9 expression by peripheral and tumor-infiltrating CD4+ and CD8+ T lymphocytes in patients with VASTs. Our results indicate that Gal-9 expression is associated with dysfunctional T cell effector functions in the periphery and tumor microenvironment (TME). Coexpression of Gal-9 with PD-1 or T cell immunoglobulin and ITIM domain (TIGIT) exhibited a synergistic inhibitory effect and enhanced an exhausted T cell phenotype. Besides, responding patients to treatment had lower Gal-9 mRNA expression in the TME. Translocation of Gal-9 from the cytosol to the cell membrane of T cells following stimulation suggests persistent T cell receptor (TCR) stimulation as a potential contributing factor in Gal-9 upregulation in patients with VASTs. Moreover, partial colocalization of Gal-9 with CD3 on T cells likely impacts the initiation of signal transduction via TCR as shown by the upregulation of ZAP70 in Gal-9+ T cells. Also, we found an expansion of Gal-9+ but not TIGIT+ NK cells in patients with VASTs; however, dichotomous to TIGIT+ NK cells, Gal-9+ NK cells exhibited impaired cytotoxic molecules but higher Interferon gamma (IFN-γ) expression.ConclusionOur data indicate that higher Gal-9-expressing CD8+ T cells were associated with poor prognosis following immunotherapy with anti-Programmed death-ligand 1 (PD-L1) (avelumab) in our patients’ cohort. Therefore, for the very first time to our knowledge, we report Gal-9 as a novel marker of T cell exhaustion and the potential target of immunotherapy in patients with VASTs.


2020 ◽  
Vol 8 (3) ◽  
pp. 356-367 ◽  
Author(s):  
Juming Yan ◽  
Xian-Yang Li ◽  
Amelia Roman Aguilera ◽  
Christos Xiao ◽  
Celia Jacoberger-Foissac ◽  
...  

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