Role of NOTCH1 in Aggressive NK-Cell Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4231-4231
Author(s):  
Hideki Makishima ◽  
Masao Ota ◽  
Takefumi Suzuki ◽  
Kozo Nakayama ◽  
Fumihiro Ishida
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
Nk Cells ◽  
Cell Lines ◽  
Western Blotting ◽  
Nk Cell ◽  
Cell Leukemia ◽  
Expression Levels ◽  
Healthy Donors ◽  
Enhanced Expression

Abstract Back ground: Aggressive NK-cell leukemia (ANKL) is a malignant NK-cell proliferative disorder resistant to most chemotherapies and frequently shows rapidly progressive clinical course. ANKL is characterized with hepatosplenomegaly, hemophagocytic syndrome, and strong association with EBV, and is mostly observed among Asian populations. Oncogenic mechanism of ANKL is not clear. NOTCH1 is a gene encoding a transmembrane receptor that regulates T-cell development and is a major oncogene in T-cell lymphoblastic leukemia (T-ALL). Recently, the potential involvement of NOTCH signaling in the development of NK-cells has been reported. We discuss here that the NOTCH1 protein might play a significant role in the pathogenesis of ANKL. Patients, materials, and methods: 6 ANKL cases, 7 Chronic NK-cell lymphocytosis (CNKL) cases, and 3 NK tumor cell lines (NKL, NK-92, and KHYG) derived from ANKL patients were enrolled. Chromosomal translocation (7;9) was not found in any subjects. The expression levels of NOTCH1 intracellular subunit (NOTCH-IC) were examined with flowcytometry and western blotting. NK-cell lines were cultured with g-secretase inhibitor (GSI) (L-685,458) for evaluation of the effect. Cell proliferation and apoptosis were measured with XTT assay and annexinV positivity, respectively. The mutation analysis of NOTCH1 genome was performed with nested PCR and direct sequencing. mRNA expression of NOTCH1 gene was measured with real time PCR using the corresponding TaqMan probes. Results: NOTCH-IC was detected in CD2+CD3− fractions from healthy donors, CNKL patients, ANKL patients, NK-cell lines, and Cos7 cells transfected with NOTCH1 gene coding NOTCH-IC, but not in CD2-CD3− fractions. The expression levels were significantly high in ANKL patients, compared to healthy donors (P < 0.05). With western blotting, cleaved form (110kDa) of NOTCH1 protein was recognized in all NK-cell lines. NOTCH-IC expression was reduced with the treatment of GSI in NKL and NK-92, but not in KHYG. Cell proliferation was inhibited with GSI in NKL and NK-92, whereas the inhibitory effect was not seen in KHYG. There was no significant difference in the increase ratio of apoptotic cells after the treatment of GSI among 3 NK-cell lines. Mutations in HD, TAD, or PEST domain, where frequent mutations are detected in T-ALL, were not found in NK-cell lines, and no enhanced expression of NOTCH1 mRNA in ANKL cells, compared with healthy donor NK-cells. Conclusion: These results indicate that NOTCH-IC was increased in ANKL cells and might be an important role in the proliferation. Genomic or transcriptional dysregulation would not be the cause for enhanced expression of NOTCH1 in ANKL contrast with T-ALL. Further investigation is required for the relationship with NOTCH1 ligands. In the future, NOTCH1 might be a novel therapeutic target in ANKL.

KIR-LIGAND Mismatched Natural Killer Cells Effectively Kill Primary Myeloma and Myeloma Cell Lines.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2449-2449
Author(s):  
Frits van Rhee ◽  
Susann M. Szmania ◽  
JuMei Shi ◽  
Michele Cottler-Fox ◽  
Justin W. Dyniewski ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
Cell Lines ◽  
Nk Cell ◽  
Allogeneic Transplantation ◽  
Myeloma Cell ◽  
Myeloma Cells

Abstract Recent observations in haplo-identical, T-cell-depleted allogeneic transplantation have focused attention on the rapid and remarkable anti-tumor effect mediated by Killer Inhibitory Receptor (KIR) ligand mismatched natural killer (NK) cells. Most data are confined to the role of KIR-ligand mismatched NK cells for acute leukemia after allogeneic transplantation. In this study, we report both the ability of KIR mismatched NK cells to kill primary myeloma cells, and the effects of interleukin (IL)2 and IL15 on NK cells in vitro. NK cells were prepared from healthy donor PBMCs by depletion of T-lymphocytes using immunomagnetic beads conjugated to anti-CD3 followed by depletion of monocytes using a simple adherence step. After overnight incubation in cytokines (IL2/IL15 as indicated) standard chromium release assays determined the cytotoxicity of NK cells against target cells and 3H-thymidine incorporation assessed NK cell proliferation. KIR-ligand mismatched NK cells incubated overnight in 300 IU/ml IL2 killed primary MM cells from four individuals (76, 64,60,48% lysis) as well as MM lines U266, NCI H929, and the NK sensitive line K562 (95, 86, 76% lysis, respectively) at an E:T ratio of 20:1. NK cells were not cytotoxic towards autologous phytohemagglutinin (PHA) or allogeneic PHA-induced T-cell blasts. Increasing the IL2 concentration during overnight NK cell incubation from 300 to 1000 IU/ml did not significantly enhance the cytotoxicity against U266 myeloma cells or control K562 cells. IL15 was more potent than IL2 in inducing NK cell proliferation. The optimal IL15 concentration was 300 IU/ml (range tested: 0–3000 IU/ml). The use of both cytokines in concert was less effective than the use of IL15 alone, probably due to homology of the IL2 and IL15 b and g receptors. We conclude that T cell and monocyte depletion of PBMC results in a preparation significantly enriched for NK cells (±50%) that effectively kills KIR-ligand mismatched primary myeloma cells and myeloma cell lines. IL15 is the superior cytokine for enhancing NK cell proliferation. The exciting anti-leukemic effects mediated by KIR-ligand mismatched NK cells have thus far only been reported in the haplo-identical transplant setting. In view of our positive in vitro data in MM, we will evaluate in a phase II trial wheter the repeated transfusion of KIR-ligand-mismatched, T-cell depleted NK cells from haplo-identical donors after immunosuppressive treatment with fludarabine and dexamethasone (to avoid rejection of donor NK cells) and tumor reduction with melphalan followed by a delayed auto-transplant can improve outcome in patients who have high risk MM or who have relapsed after a previous auto-transplant. This will be the first clinical application of KIR-ligand-mismatched NK cells in autologous transplantation and the first such trial in myeloma. Figure Figure

scholarly journals Highly Enhanced Expression of CD70 on Human T-Lymphotropic Virus Type 1-Carrying T-Cell Lines and Adult T-Cell Leukemia Cells

2008 ◽  
Vol 82 (8) ◽  
pp. 3843-3852 ◽  
Author(s):  
Masanori Baba ◽  
Mika Okamoto ◽  
Takayuki Hamasaki ◽  
Sawako Horai ◽  
Xin Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Cell Leukemia ◽  
Expression Levels ◽  
T Lymphotropic Virus ◽  
Adult T Cell Leukemia ◽  
Enhanced Expression ◽  
T Cell Lines

ABSTRACT Human T-lymphotropic virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia (ATL). In Japan, the number of HTLV-1 carriers is estimated to be 1.2 million and more than 700 cases of ATL have been diagnosed every year. Considering the poor prognosis and lack of curative therapy of ATL, it seems mandatory to establish an effective strategy for the treatment of ATL. In this study, we attempted to identify the cell surface molecules that will become suitable targets of antibodies for anti-ATL therapy. The expression levels of approximately 40,000 host genes of three human T-cell lines carrying HTLV-1 genomes were analyzed by oligonucleotide microarray and compared with the expression levels of the genes in an HTLV-1-negative T-cell line. The HTLV-1-carrying T-cell lines used for experiments had totally different expression patterns of viral genome. Among the genes evaluated, the expression levels of 108 genes were found to be enhanced more than 10-fold in all of the T-cell lines examined and 11 of the 108 genes were considered to generate the proteins expressed on the cell surface. In particular, the CD70 gene was upregulated more than 1,000-fold and the enhanced expression of the CD70 molecule was confirmed by laser flow cytometry for various HTLV-1-carrying T-cell lines and primary CD4+ T cells isolated from acute-type ATL patients. Such expression was not observed for primary CD4+ T cells isolated from healthy donors. Since CD70 expression is strictly restricted in normal tissues, such as highly activated T and B cells, CD70 appears to be a potential target for effective antibody therapy against ATL.

Discrepant Expression Between mRNA and Protein of HTLV-I Basic Leucine Zipper Factor (HBZ) Makes HTLV-I Infected CD4 Lymphocytes and Adult T Cell Leukemia Cells Less Susceptible to HBZ-Specific Cytotoxic T Lymphocytes

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4995-4995
Author(s):  
Koichiro Suemori ◽  
Hiroshi Fujiwara ◽  
Toshiki Ochi ◽  
Masao Matsuoka ◽  
Jean Michel Mesnard ◽  
...  
Keyword(s):  
T Cell ◽  
T Lymphocytes ◽  
Infected Cell ◽  
Protein Expression ◽  
Cell Lines ◽  
Target Cells ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Expression Levels ◽  
Specific Ctls

Abstract [Background]Adult T cell leukemia (ATL) is caused by human T-cell leukemia virus type 1 (HTLV-1) and still remains one of the chemotherapy-resistant leukemias. Accumulating the successful evidence of allogeneic hematopoietic stem cell transplantation (allo-HSCT), the immunotherapeutic strategy for ATL has become to look promising. The fact that more than half of primary ATL cells lack the immunogenic oncoprotien HTLV-1 Tax has been promoting researchers to find an alternative target antigen to develop the cellular immunotherapy for ATL. Recently, HTLV-1 basic leucine zipper factor (HBZ), which is encoded by the minus strand of HTLV-1 proviral genome and is transcribed from 3’-LTR, has been highlighted as the important molecule in ATL leukemogenesis. Since almost all ATL cells express HBZ mRNA, we attempted to verify whether HBZ can be a target of cellular immunotherapy for ATL. [Methods] At first, we synthesized a variety of HBZ-derived 9 amino acid peptides (9 mer) that are predicted to have high binding affinity to HLA-A*0201 molecule. CD8+ T lymphocytes from an HLA-A*0201+ healthy donor were stimulated with peptide-loaded autologous monocyte-derived mature dendritic cells repetitively. Thereafter, epitope specificity, HLA-restriction, and cytotoxic activity of induced cytotoxic T lymphocytes (CTLs) were determined by standard 51Cr-release assays. HBZ and Tax mRNA expression levels of target cells, including primary ATL cells, HTLV-1-infected cell lines, peripheral blood lymphocytes isolated from HTLV-1 carriers and HTLV-1-uninfected individuals, and K562-A*0201 and C1R-A*0201 cells transfected with HBZ gene, were simultaneously measured by real-time quantitative PCR (RQ-PCR). The relative expression levels of HBZ and Tax mRNA were determined by comparative Ct method, and the results were shown as the relative values to those of HTLV-1-infected cell line MT4. HBZ protein expression was determined by Western blotting using anti-HBZ serum which was produced by immunizing rabbits with purified six-His-tagged HBZ polypeptide corresponding to the bZIP domain of HBZ. The detection of HBZ-specific and Tax-specific CTLs was performed by tetramer assays. [Results] We identified an HBZ-derived 9-mer epitope, HBZ26–34 (GLLSLEEEL), with high binding affinity to HLA-A*0201 measured by using HLA-A*0201 gene-transfected T2 cell. We successfully established an HBZ26–34 peptide-specific CTL clone designated as HBZ-1. HBZ-1 exerted cytotoxicity against HBZ gene-transfected K562-A*0201 and C1R-A*0201 cells, but not against HLA-A*0201-positive HTLV-1-infected cells or ATL cells. HTLV-1 infection and HBZ gene transfection did not alter the HLA class I expression of target cells. Expression levels of HBZ mRNA appeared to be higher in ATL cells, HTLV-1-infected cell lines, and HBZ gene-transfected cells than those in HTLV-1 carrier cells. Abundant HBZ protein expression was detected in only HBZ gene-transfected K562-A*0201 and C1R-A*0201 cells, but HBZ protein expression levels in HTLV-1-infected cell lines and ATL cells appeared to be very low. We further examined Tax-specific and HBZ-specific CTLs in an HLA-A*0201-positive ATL patient who received allo-HSCT from the HLA-identical sibling donor. In this patient, Tax mRNA and HBZ mRNA were similarly expressed in ATL cells; however, only Tax-specific CTLs but not HBZ-specific CTLs were detected in both before and after allo-HSCT at full donor chimerism. [Conclusions] Although HBZ mRNA was apparently detected in all HTLV-1-infected cell lines and ATL cells, HBZ protein in these cells was insufficiently expressed to be recognized by HBZ-specific CTLs. Our observations in a transplanted patient with ATL also suggest that HBZ protein may be less immunogenic due to discrepant expression level between mRNA and protein.

T Cell Exhaustion and Downregulation of Cytotoxic NK Cells – an Immune Escape Mechanism in Adult Acute Lymphoblastic Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3781-3781
Author(s):  
Eolia Brissot ◽  
Sawa Ito ◽  
Kit Lu ◽  
Carly Cantilena ◽  
B. Douglas Smith ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Research Funding ◽  
Immune Escape ◽  
Nk Cell ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Healthy Donors

Abstract Adult acute lymphoblastic leukemia (ALL) remains a therapeutic challenge with less than 40% long term survival. There is growing evidence that malignant diseases exert an “immune editing” effect which blocks antitumor immunity and permits tumor growth through immune evasion. Such tumor escape represents an obstacle for anticancer immunotherapy. In ALL such immune escape mechanisms are not well characterized. We therefore profiled cellular immunity in ALL, by characterizing the subsets of T cells, regulatory T cells (Treg), natural killers (NK) cells and γd T cells, using various functional markers including T cell exhaustion and NK cell activating or inhibitory molecules. Forty ALL patients were included in the study. The median age was 39 y (range, 18-75). Thirty-six presented with B-lineage ALL and 4 with T-lineage ALL. Mononuclear cells were isolated from blood (n=19) or bone marrow (n=21) at the onset of leukemia or at relapse. The median infiltration of blasts was 85% (range 24-96%). Healthy donor peripheral blood (n=12) and bone marrow (n=9), from age and gender matched population, were simultaneously analyzed as controls. Extra-and intra cellular staining were performed using using antibodies directed against CD3, CD4, CD8, CD45, CD45, CD45RA, CD45RO, CCR7, CD95, CD27, CD19, CD14, CD127, CD25, Foxp3, Helios, αβTCR, HLA-DR, CD117, CD20, CD10, CD22, CD34, LAG3, PD1, PDL1, CD56, NKG2A, NKG2C, NKG2D, KIR2DL1, KIR2DL3, CD57, CD33, CD11b, CD15, CD38 and CD24. Data were acquired on a BD LSRFORTESSA flow cytometer. The expression of programmed cell death 1 (PD-1, CD279) receptor on CD8+T cells was significantly increased in blood and bone marrow of ALL patients compared to healthy donors (p<0.0001 and p=0.004, respectively) (Fig. 1). Focusing on the different subsets, CD8+ effector memory T cells significantly over-expressed PD-1 in blood and bone marrow of ALL patients compared to healthy donors (p=0.008 and p=0.04, respectively). Moreover, there was a significant positive correlation between PD-1 expression on CD8+ effector memory T cells and blast infiltration (R2=0.23, 95%CI 0.026-0.76, p=0.04). Expression of the co-inhibitory receptor lymphocyte-activation gene 3 (LAG-3, CD223) was similar in ALL patients compared to healthy donors. A significantly higher frequency of T regulators (CD25+, CD127 low, Foxp3+) was found in bone marrow microenvironment in ALL patients (4.3% versus 1.6%, p=0.02). Concerning γd T cells, frequency was similar in blood and bone marrow of ALL patients compared with healthy donors. There was a significantly lower frequency of CD56dimNKG2A+KIR-CD57- (p=0.02) in the bone marrow of ALL patients indicating a maturation arrest. Interestingly, expression of the activating receptor NKG2D which plays an important role in triggering the NK cell–mediated tumor cell lysis was significantly reduced in NK cells of ALL patients while no difference in NK cell expression of NKG2C was found(Fig. 2). Adult patients with ALL show evidence of immune-editing of T cells and NK cells. This global immunosuppressive mechanism may contribute to the eventual escape of ALL from immune control. PD-1, overexpression, described in acute myeloid leukemia and chronic myeloid leukemia has been implicated in T-cell exhaustion and subsequent tumor immune evasion. Our data suggests similar immune escape mechanisms pertain in ALL. Effective antileukemia immunotherapy will require targeting one or more of these immunosuppressive pathways to achieve optimum results. Disclosures Fathi: Seattle Genetics, Inc.: Consultancy, Research Funding; Takeda pharmaceuticals International Co.: Research Funding; Exelixis: Research Funding; Ariad: Consultancy.

A Novel HIV Envelope Bi-Specific Killer Engager Enhances Natural Killer Cell Mediated ADCC Responses Against HIV-Infected Cells

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2517-2517 ◽  
Author(s):  
Zachary B. Davis ◽  
Todd Lenvik ◽  
Louis Hansen ◽  
Martin Felices ◽  
Sarah Cooley ◽  
...  
Keyword(s):  
T Cell ◽  
Nk Cells ◽  
Cell Lines ◽  
Research Funding ◽  
Nk Cell ◽  
Mhc I ◽  
Variable Heavy ◽  
Infected Cells ◽  
T Cell Lines ◽  
Hiv Envelope

Abstract Natural Killer (NK) cells, a critical component of the immune response to viral infection, recognize and destroy cells with diminished expression of major histocompatibility class-I (MHC-I) molecules and expression of ligands for activating NK receptors such as NKG2D. Down-modulation of MHC-I is a hallmark of viral infection, as it allows infected cells to evade a CD8 T-cell response. Stalling of the cell cycle to enhance viral replication induces NK activation ligands such as the NKG2D ligands unique long binding proteins (ULBP)-1 and -2 which could trigger NK destruction of infected cells. Unfortunately, incomplete down-modulation of MHC-I by HIV leaves HLA-C on the cell surface, which inhibits the majority of NK cells from killing infected targets. CD16, the low affinity Fc receptor, is the most potent NK cell activating receptor. It mediates antibody dependent cell-mediated cytotoxicity (ADCC), and can override inhibition by MHC-I. We designed a series of bi-specific killer-engager (BiKE) constructs to direct NK cell ADCC against an HIV-infected target. We linked the Fab portions of broadly neutralizing (bn)Abs to a novel llama-derived nanobody EF91 that binds CD16 at high affinity and signals strong activation. We chose to use EF91 as its structure is unique compared to the use of a single chain variable fragment (scFv). Rather than being composed of a variable heavy (VH) and variable light (VL) chain, the nanobody is composed of a single variable heavy (VHH) domain. A distinct advantage to using a CD16 nanobody over a scFv is in the purity of the generated product. During protein folding it is not uncommon for the wrong VH to associate with the wrong VL; the result of which is a nonfunctional product. Since the nanobody is single VHH, and does not require association with another domain, there is less risk of a misfolded product. Nanobodies are also known to have similar, if not increased, affinity for their target molecules. In the case of EF91, this may result in more robust activation of NK cells than with a traditional scFv. We tested a BiKE constructed with the bnAb, VRC01, which recognizes the CD4 binding domain of HIV-Env. The specificity of our novel anti-CD16 nanobody was demonstrated by binding of our BiKE construct to CD16+ NK cells (Figure 1A). Function of our BiKE construct was tested by incubating it with chronically infected T-cell lines (HIV-IIIB and ACH-2) or with their respective uninfected counterparts (H9 and CEM). We only observed binding to infected cells (Figure 1B), demonstrating HIV-Env binding specificity to the HIV strains ACH-2 (LAI strain) and HIV-IIIB. The ability of the anti-Env BiKE construct to mediate ADCC and IFNγ production was tested against two uninfected CD4 T-cell lines or their infected counterparts. While NK cells degranulated when incubated with the infected cell lines (50% against HIV-IIIB and 20% against LAI), this response was markedly enhanced when co-incubated with the HIV-Env specific BiKE (80% against HIV-IIIB and 60% against LAI) (Figure 1C). Furthermore, the HIV-Env BiKE enhanced IFNγ production against HIV-infected T-cell lines compared to responses in the absence of BiKE (28% against HIV-IIIB compared to 36% with BiKE; 15% against ACH-2 compared to 37% with BiKE) (Figure 1D). Our data demonstrate that a BiKE construct containing the Fab of an HIV bnAb and an anti-CD16 component can eliminate HIV-infected targets that express the HIV-envelope on their surface. The reservoir of latently infected CD4 T cells lack expression of any recognizable virus protein on the cell surface, we plan to combine our BiKE strategy with cellular activation using IL-15. Alternatively, we can construct a tri-specific engager (TriKE) with an IL-15 segment that may activate CD4 T cells while enhancing NK cell killing. Disclosures Cooley: Fate Therapeutics: Research Funding. Vallera:Oxis Biotech: Consultancy, Membership on an entity's Board of Directors or advisory committees. Miller:Fate Therapeutics: Consultancy, Research Funding; Oxis Biotech: Consultancy, Other: SAB.

scholarly journals Tumor-Experienced Human NK Cells Express High Levels of PD-L1 and Inhibit CD8+ T Cell Proliferation

2021 ◽  
Vol 12 ◽  
Author(s):  
Jessica M. Sierra ◽  
Florencia Secchiari ◽  
Sol Y. Nuñez ◽  
Ximena L. Raffo Iraolagoitia ◽  
Andrea Ziblat ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
Nk Cells ◽  
Cancer Patients ◽  
Nk Cell ◽  
The Cancer Genome Atlas ◽  
T Cell Proliferation ◽  
Dependent Manner ◽  
Effector Functions

Natural Killer (NK) cells play a key role in cancer immunosurveillance. However, NK cells from cancer patients display an altered phenotype and impaired effector functions. In addition, evidence of a regulatory role for NK cells is emerging in diverse models of viral infection, transplantation, and autoimmunity. Here, we analyzed clear cell renal cell carcinoma (ccRCC) datasets from The Cancer Genome Atlas (TCGA) and observed that a higher expression of NK cell signature genes is associated with reduced survival. Analysis of fresh tumor samples from ccRCC patients unraveled the presence of a high frequency of tumor-infiltrating PD-L1+ NK cells, suggesting that these NK cells might exhibit immunoregulatory functions. In vitro, PD-L1 expression was induced on NK cells from healthy donors (HD) upon direct tumor cell recognition through NKG2D and was further up-regulated by monocyte-derived IL-18. Moreover, in vitro generated PD-L1hi NK cells displayed an activated phenotype and enhanced effector functions compared to PD-L1- NK cells, but simultaneously, they directly inhibited CD8+ T cell proliferation in a PD-L1-dependent manner. Our results suggest that tumors might drive the development of PD-L1-expressing NK cells that acquire immunoregulatory functions in humans. Hence, rational manipulation of these regulatory cells emerges as a possibility that may lead to improved anti-tumor immunity in cancer patients.

scholarly journals Cyclosporin A inhibition of interleukin 2 gene expression, but not natural killer cell proliferation, after interferon induction in vivo.

1990 ◽  
Vol 171 (3) ◽  
pp. 745-762 ◽  
Author(s):  
M T Kasaian ◽  
C A Biron
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
T Cell ◽  
Nk Cells ◽  
Cell Expansion ◽  
Nk Cell ◽  
Poly I:C ◽  
Low Density ◽  
Athymic Mice

The IFN inducer, poly(I:C), elicits acute NK cell blastogenesis and proliferation in vivo. The role of IL-2 in mediating this proliferation was investigated in the studies presented here. Blast NK cells were isolated from poly(I:C)-treated, T cell-deficient athymic mice. Dividing cells, incorporating [3H]thymidine, were enriched in the J11d- low density populations isolated from poly(I:C)-treated mice, and were characterized as NK by the following criteria: (a) they were eliminated by treatment with anti-AGM1 in vivo; and (b) they directly mediated lysis of NK-sensitive target cells in a single cell cytotoxicity assay with autoradiography. These poly(I:C)-induced blast NK cells were responsive to IL-2, but, when compared with in vivo activated T cells, responsiveness required 1,000-fold higher concentrations of the factor. The technique of in situ hybridization was used to evaluate induction of IL-2 gene expression after poly(I:C) treatment in vivo. Treatment of euthymic, athymic, and severe combined immunodeficient mice with poly(I:C) activated IL-2 gene expression in a small percentage of spleen leukocytes. The transcription-positive cells were enriched in low density cell populations. These findings demonstrate that IL-2 transcription occurs after IFN induction in vivo, and suggest that an endogenous source of IL-2 exists other than the mature T cell. To assess the IL-2 dependence of in vivo NK cell expansion, poly(I:C)-treated athymic mice were given cyclosporin A (CsA), an agent that regulates IL-2 production at the level of gene transcription. The drug resulted in an 85-100% reduction in the percentages of cells transcribing IL-2. In contrast, CsA administration did not block IFN-enhanced NK cell cytolytic activity, expansion of large granular lymphocyte numbers, or NK cell proliferation. These findings demonstrate that although the proliferation of blast NK cells can be supported by IL-2, IL-2 is not an important mediator of IFN-induced NK cell expansion. Moreover, they establish that the acute proliferation of NK cells in response to IFNs is CsA insensitive.

scholarly journals NK Cell Induced T Cell Anergy Depends on GRAIL Expression

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 790
Author(s):  
Grazyna Galazka ◽  
Malgorzata Domowicz ◽  
Alicja Ewiak-Paszynska ◽  
Anna Jurewicz
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd4 T Cells ◽  
Nk Cell ◽  
Regulatory Function ◽  
T Cell Proliferation ◽  
Thymidine Uptake ◽  
Cell Expression

NK cells (natural killer cells) being a part of the innate immune system have been shown to be involved in immunoregulation of autoimmune diseases. Previously we have shown that HINT1/Hsp70 treatment induced regulatory NK cells ameliorating experimental autoimmune encephalomyelitis (EAE) course and CD4+ T cells proliferation. NK cells were isolated from mice treated with HINT1/Hsp70 and co-cultured with proteolipid protein (PLP)-stimulated CD4+ T cells isolated from EAE mice. Cell proliferation was assessed by thymidine uptake, cytotoxicity by lactate dehydrogenase (LDH) release assay and fluorescence activated cell sorting (FACS) analysis, protein expression by Western blot, mRNA by quantitative RT-PCR. Gene related to anergy in lymphocytes (GRAIL) expression was downregulated by specific siRNA and GRAIL overexpression was induced by pcDNA-GRAIL transfection. HINT1/Hsp70 pretreatment of EAE SJL/J mice ameliorated EAE course, suppressed PLP-induced T cell proliferation by enhancing T cell expression of GRAIL as GRAIL downregulation restored T cell proliferation. HINT1/Hsp70 treatment induced immunoregulatory NK cells which inhibited PLP-stimulated T cell proliferation not depending on T cell necrosis and apoptosis. This immunoregulatory NK cell function depended on NK cell expression of GRAIL as GRAIL downregulation diminished inhibition of NK cell suppression of T cell proliferation. Similarly GRAIL overexpression in NK cells induced their regulatory function. HINT1/Hsp70 treatment generated regulatory NK cells characterized by expression of GRAIL.

Adoptively-Infused NK Cells Maintain Their Antitumor Effects in Vivo in the Presence of CyclosporineA (CSA)

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2563-2563
Author(s):  
Hisayuki Yokoyama ◽  
Andreas Lundqvist ◽  
Maria Berg ◽  
Muthalagu Ramanathan ◽  
Rebecca Lopez ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Median Survival ◽  
Nk Cell ◽  
Stimulation Index ◽  
Surface Expression ◽  
Inhibition Of Proliferation

Abstract Animal models show infusions of donor NK cells given after allogeneic HCT can prevent GVHD while simultaneously mediating a graft-vs-tumor effect. However, it is unclear whether adoptively infused NK cells can mediate these beneficial effects in the presence of CSA, which is commonly given after HCT to prevent GVHD. In this study, we analyzed the in vitro effects of pharmacological concentrations of CSA on NK cell phenotype, cell proliferation, and tumor cytotoxicity. We also evaluated in vivo whether CSA administration would reduce the anti-tumor effects of adoptively infused NK cells in tumor bearing mice. PBMCs collected from healthy donors were labeled with CFSE then were stimulated in vitro with IL-2 for 7 days in the presence or absence of CSA (1000ng/ml). CFSE proliferation assays on fresh PBMC showed CSA inhibited IL-2 stimulated CD3+ T-cell proliferation more than CD3−/CD56+ NK cell proliferation (mean percentage inhibition of proliferation 49.4% vs. 22.2% for T cells and NK cells respectively; p&lt;0.05). CD3−/CD56+ NK cells were then isolated from PBMCs of healthy donors and expanded in vitro with irradiated EBV-LCL and IL-2 for 10 days. In contrast to T-cells, CSA only minimally inhibited IL-2 induced proliferation of expanded NK cells (mean 9.5% inhibition of proliferation by CFSE staining). T cells and NK cells were next isolated from PBMCs and stimulated with either OKT3, PMA-Ionomycin (PI), or IL-2. A [3H] TdR uptake assay showed T cell proliferation was inhibited at a substantially higher level by CSA (mean stimulation index for OKT3: 0.03, for PI: 0.35, for IL-2: 0.55) compared to that of expanded NK cells (mean stimulation index for IL-2: 0.82, p&lt;0.05). Furthermore, an ELISA assay showed CSA treatment reduced IL-2 induced secretion of INF-g by T cells more than expanded NK cells (mean reduction in INF-g secretion in T cells of 94.7 % vs. 36.5 % in NK cells, p&lt;0.05). Compared to controls, culturing in vitro expanded NK cells in CSA did not alter surface expression of the activating receptors NKp30, NKp42, and NKG2D but did reduce surface expression of NKp44 and TRAIL (mean reduction in surface expression 36% and 36.3% respectively). Cytotoxic granule release assessed by CD107a staining was inhibited by CSA in CD8+ melanoma specific T cells co-cultured with melanoma cells (mean 12.2 % inhibition) in contrast to NK cells co-cultured with K562 cells where CSA increased CD107a expression a mean 29.7% (p&lt;0.05). Furthermore, at a 20:1 E:T ratio, 51Cr cytotoxity assays showed CSA did not reduce the cytotoxicity of in vitro expanded NK cells against renal cell carcinoma (RCC) cells (58% mean lysis) compared to NK cells cultured in control media (55% mean; p=n.s.). In contrast, melanoma specific T-cell killing of tumor targets was significantly lower in CTL cultures containing CSA compared to control media (38.0% vs. 50.2% respectively P&lt;0.05). Next, we assessed the impact of CSA administration on the anti-tumor effects of adoptive NK cell infusions in tumor bearing animals where syngeneic NK cell infusions following bortezomib treatment have been shown to delay tumor progression and prolong survival. BALB/c mice injected with 100,000 luciferase transfected RENCA tumor cells i.v. received 3 weekly treatments with the combination of bortezomib (5ug/mouse i.v.) and 2×106 syngeneic NK cells i.v. with or without daily administration of CSA (15mg/kg sc). Bioluminescence imaging in controls that did not receive CSA showed tumor growth was slower and survival was prolonged in mice receiving adoptive NK cell infusions (median survival 53 days) compared to mice that did not receive NK cells (median survival 30.2 days; p&lt;0.05). CSA administration did not impair the anti-tumor effects of adoptive NK cell infusions; mice receiving CSA and adoptive NK cell infusions had similar tumor growth and survival as recipients of NK cells without CSA (median survival 47 vs. 53 days; p=n.s.). These results show that CSA is significantly more immunosuppressive to T cells compared to NK cells and provide evidence that the anti-tumor effects of adoptively infused in vitro expanded NK cells are maintained even in the presence CSA.

The Overexpression of Enhancer of Zeste Homologue 2 Is Associated with Tumor Proliferation and Aggressive Behavior in Adult T-Cell Leukemia/Lymphoma.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3959-3959
Author(s):  
Daisuke Sasaki ◽  
Yoshitaka Imaizumi ◽  
Hiroo Hasegawa ◽  
Akemi Osaka ◽  
Kazuto Tsuruda ◽  
...  
Keyword(s):  
T Cell ◽  
Lymph Nodes ◽  
Cell Lines ◽  
Western Blotting ◽  
Acute Type ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Adult T Cell Leukemia ◽  
Atll Cell ◽  
Enhancer Of Zeste

Abstract Abstract 3959 Poster Board III-895 Background Enhancer of zeste homologue 2 (EZH2) is a critical component of the Polycomb Repressive Complexes PRC2, which mediates epigenetic gene silencing by the trimethylation of Lys27 of histone 3 (H3K27). This regulation is not only involved in embryonic development and stem cell renewal, but also in tumor progression. Adult T-cell leukemia/lymphoma (ATLL) is a single disease entity etiologically associated with human T-cell leukemia virus type-1 (HTLV-1). Its clinical behavior, however, is quite diverse among patients and is thus subclassified into several subtypes. The prognosis of the aggressive subtypes is very poor based on standard chemotherapy, and so the development of a new therapeutic approach is urgent. Results In a comparative microarray analysis of primary ATLL samples, the acute type showed significantly higher EZH2, YY1, and RYBP (RING1 and YY1 binding protein) expressions compared with the chronic type. Further analysis employing real-time quantitative RT-PCR of various Polycomb group (PcG)-related proteins, including the ones mentioned above, revealed that the mRNAs of two other PRC2 components, EED and RBBP4, were also significantly elevated in ATLL, irrespective of the subtypes, compared with lymphocytes from HTLV-1 carriers. These results suggest that the dysregulation of PRC2 is a key event in the development and progression of ATLL. In the immunohistochemical analysis of ATLL lymph nodes, the nuclei of over 90% of ATLL cells were positive for EZH2, which in clear contrast to reactive or indolent B-lymphoma lymph nodes in which a few cells were positive. It has been shown that activated Akt phosphorylates EZH2 at serine 21 and suppresses its methyltransferase activity. Western blotting of EZH2 showed that EZH2 of primary ATLL cells was not phospholyrated and remained in its active form. Indeed, the trimethylation of H3K27 in ATLL cells was confirmed by Western blotting and immunohistochemistry, whereas it was completely absent in lymphocytes from HTLV-1 carriers. Finally, in studies using ATLL cell lines, the knockdown of EZH2 by siRNA caused decrease in cell proliferation. Moreover, ATLL cell lines showed high sensitivities to histone deacetylase (HDAC) inhibitors as LBH589, and LBH589 decreased EZH2 expression. EZH2 inhibitor 3-deazaneplancin A (DZNeP) also reduced cell growth, not only in primary ATLL cells, but also in ATLL cells lines. These results strongly support the rationale for developing molecular targeting therapies against EZH2 in ATLL. Disclosures: No relevant conflicts of interest to declare.

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