scholarly journals Platelet-derived growth factor mediates survival of leukemic large granular lymphocytes via an autocrine regulatory pathway

Blood ◽  
2010 ◽  
Vol 115 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Jun Yang ◽  
Xin Liu ◽  
Susan B. Nyland ◽  
Ranran Zhang ◽  
Lindsay K. Ryland ◽  
...  
Keyword(s):  
T Cells ◽  
Growth Factor ◽  
Nk Cells ◽  
Nk Cell ◽  
Cytotoxic T Cells ◽  
Platelet Derived Growth Factor ◽  
Leukemic Cells ◽  
Immunocytochemical Staining ◽  
Term Survival ◽  
Lgl Leukemia

Abstract Large granular lymphocyte (LGL) leukemia results from chronic expansion of cytotoxic T cells or natural killer (NK) cells. Apoptotic resistance resulting from constitutive activation of survival signaling pathways is a fundamental pathogenic mechanism. Recent network modeling analyses identified platelet-derived growth factor (PDGF) as a key master switch in controlling these survival pathways in T-cell LGL leukemia. Here we show that an autocrine PDGF regulatory loop mediates survival of leukemic LGLs of both T- and NK-cell origin. We found high levels of circulating PDGF-BB in platelet-poor plasma samples from LGL leukemia patients. Production of PDGF-BB by leukemic LGLs was demonstrated by immunocytochemical staining. Leukemic cells expressed much higher levels of PDGFR-β transcripts than purified normal CD8+ T cells or NK cells. We observed that phosphatidylinositol-3-kinase (PI3 kinase), Src family kinase (SFK), and downstream protein kinase B (PKB)/AKT pathways were constitutively activated in both T- and NK-LGL leukemia. Pharmacologic blockade of these pathways led to apoptosis of leukemic LGLs. Neutralizing antibody to PDGF-BB inhibited PKB/AKT phosphorylation induced by LGL leukemia sera. These results suggest that targeting of PDGF-BB, a pivotal regulator for the long-term survival of leukemic LGLs, may be an important therapeutic strategy.

KIR Positive Subsets of Human CD56+CD3+ NKT Cells Are Different in Frequency from Equivalant KIR Positive CD56+CD3- NK Cell Subsets.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3878-3878
Author(s):  
Ilka Bondzio ◽  
Andreas Arendt ◽  
Jurgen Schmitz ◽  
Volker Huppert
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Nk Cell ◽  
Cytotoxic T Cells ◽  
Killer Cell ◽  
Nkt Cells ◽  
Nkt Cell ◽  
Cell Clones ◽  
Number Of Publications

Abstract Killer cell immunoglobulin-like receptors (KIRs) are known to modulate the cytotoxic ability of human Natural Killer (NK) cells, as well as a subset of T cells. To date, only a very small number of publications have discussed the role of KIRs on T cells, e.g. CMV-specific CD4+CD28-KIR+ cytotoxic T cells (van Bergen, J., J Immunol. 2004), so we investigated whether CD56+CD3+ NKT cells might also have KIR-positive subsets. Whole human blood as well as magnetically sorted human CD56+CD3+ NKT cells were analyzed for their expression of various KIR molecules using a novel panel of fluorochrome-conjugated, anti-KIR monoclonal antibodies (CD158a/h (KIR2DL1/DS1), CD158b (KIR2DL2), CD158e (KIR3DL1), CD158i (KIR2DS4), KIR2D; Miltenyi Biotec). KIR-positive CD56+CD3+ NKT cells were identified in every donor tested. Donors possessing NK cells of a specific KIR phenotype also possessed CD56+CD3+ NKT cells with the same KIR phenotype. KIRs were also expressed in a clonal fashion on CD56+CD3+ NKT cells, similarly to NK cells. The investigated KIRs were also shown to be expressed on unseparated NK and CD56+CD3+ NKT cells from whole blood. In addition, the ratio between KIR expression on NK and CD56+CD3+ NKT cells was calculated for each donor analyzed. The results show that there is no correlation between the frequencies of KIR expression on NK cells with that of CD56+CD3+ NKT cells. For example, the expression of CD158a/h in one donor was found to be the highest of all CD56+CD3+ NKT cells analyzed, but the lowest of all NK cells by comparison to the other donors tested. For all KIR phenotypes analyzed, the frequency of KIR+ NK cells was higher than the frequency of KIR+ CD56+CD3+ NKT cells in all samples (range: 1.1 to 25.3-fold higher). Interestingly, the frequency of KIR+ NK cells versus KIR+ CD56+CD3+ NKT cells differs significantly between donors: in one donor the frequency of KIR expression is between 7.3 to 25.3-fold higher in NK cells for multiple KIR phenotypes, while this range is more narrow in other donors (2.0–5.4-fold higher). The frequencies of CD56+CD3+ NKT cell subsets staining positive for particular KIRs differ significantly between donors, e.g. for CD158b, the number of positive CD56+CD3+ NKT cells fall within a range of 4.8% to 43.3%. For CD56+CD3+ NKT cells sorted with MACS® Technology, a similarly wide-ranging distribution of CD158b (KIR2DL2) expression was found (0.85%–5.82%), though at a lower level. Further research will be required to explore these differences as they may point to different mechanisms of KIR regulation. The identification of KIR-positive CD56+CD3+ NKT cells may also provide an opportunity for their use for functional KIR studies instead of NK cell clones, as the cloning of CD56+CD3+ NKT cells may prove easier (i.e. using standard T cell cloning methods) than that of NK cells.

NK Cell KIR Reconstitution after Allogeneic Hematopoietic Cell Transplant (HCT) Is Affected by T Cell Number and Function.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1406-1406
Author(s):  
Sarah Cooley ◽  
Valarie McCullar ◽  
Rosanna Wangen ◽  
Tracy L. Bergemann ◽  
John E. Wagner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Growth Factor ◽  
Nk Cells ◽  
Clinical Outcomes ◽  
Nk Cell ◽  
Cell Number ◽  
Hematopoietic Cell ◽  
Naive T Cells ◽  
Naïve T Cells

Abstract NK cell KIR interactions are among the variables known to affect clinical outcomes including relapse, graft versus host disease (GVHD) and survival after HCT. We hypothesized that T cells in graft sources available for HCT may affect KIR recovery and the therapeutic potential of KIR alloreactivity. We studied KIR reconstitution (the percentage of KIR+ NK cells measured by flow cytometry) in blood collected from recipients at day +100 after T cell deplete (TCD-BMT) and unmanipulated (U-BMT) unrelated BM transplants. We found that KIR reconstitution was suppressed compared to the healthy donors, significantly more so after U-BMT transplants (donor: 48.42 ± 2.35% KIR+ NK cells versus recipient: 26.74 ± 1.94, n = 36; P < .001) than after TCD-BMT transplants (donor: 53.34 ± 3.25% versus recipient: 42.68 ± 3.32%, n = 38; P = .017), with P = .001 between the recipient groups. Additionally, multivariate Cox proportional hazards models showed that improved KIR recovery independently correlated with improved survival and that higher NK cell IFN-γ production independently correlated with more frequent acute GVHD in that patient cohort. These data suggested that T cell number in the graft affects KIR reconstitution and transplant outcome. We next examined other sources of hematopoietic cells in which T cell function may be suppressed either by growth factor mobilization (sibling donor unmanipulated peripheral blood: SibU-PB) or the innate naivety of the T cells (umbilical cord blood: UCB). KIR+ NK reconstitution on recovering cells at day +100 after all HCT graft types was significantly less than that on normal donor cells (normals 55.33 ± 1.73%, n = 124; all P < .0006). U-BMT recipients had significantly lower KIR+ NK recovery (27.31 ± 2.06%, n = 36 vs. SibU-PB: 37.58 ± 3.29%, n = 29; TCD-BMT: 42.68 ± 3.32%, n = 38; or UCB, 37.99 ± 2.54%, n = 49) when compared to all other transplant types. The highest absolute T cell inoculum, found in SibU-PB, showed KIR reconstitution similar to that of TCD-BMT, which had the lowest T cell content (p=0.29), perhaps due to the lower alloreactivity of the Sib grafts and to the G-CSF-priming which preferentially mobilizes T cells with a suppressive phenotype. Similarly, KIR reconstitution was better after UCB compared to U-BMT (P = .0027), possibly due to the more permissive interactions with naive T cells. These results suggest that reduced T cell number after T cell depletion, suppressed T cells found after growth factor mobilization, or naive T cells present in UCB grafts enhance in vivo KIR reconstitution after allogeneic HCT when compared to unmanipulated marrow grafts. Such enhanced KIR reconstitution may have clinical consequences. Graft T cells may directly compete for cytokines and growth factors, or may be a surrogate marker for other transplant factors such as the development of GVHD and the requirement for intensive post-transplant immunosuppression. Understanding these interactions will allow judicious selection of hematopoietic cell source to select for enhanced KIR recovery. For example, among unrelated unmanipulated donor grafts, KIR+ NK recovery was significantly better using UCB than adult donors and further investigation may show that this is advantageous to improve clinical outcomes.

scholarly journals Natural killer-like T-cell lymphomas: aggressive lymphomas of T-large granular lymphocytes [see comments]

Blood ◽  
1996 ◽  
Vol 87 (4) ◽  
pp. 1474-1483 ◽  
Author(s):  
WR Macon ◽  
ME Williams ◽  
JP Greer ◽  
RD Hammer ◽  
AD Glick ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Natural Killer ◽  
Nk Cell ◽  
Cytotoxic T Cells ◽  
Cell Receptor ◽  
Lymphoproliferative Disease ◽  
Cell Subpopulation ◽  
T Cell Lymphomas ◽  
Lgl Leukemia

Natural killer (NK)-like T cells are major histocompatibility complex- unrestricted cytotoxic T cells that are surface CD3-positive, express NK-cell antigens, and rearrange their T-cell receptor. Most neoplasms arising from this T-cell subpopulation have been a chronic lymphoproliferative disease referred to as T-large granular lymphocyte (LGL) leukemia. Only 10 NK-like T-cell lymphomas have been described in detail previously; this study presents the clinicopathologic features of six others and distinguishes these lymphomas from T-LGL leukemia. All patients presented with B-symptoms and often had marked hepatosplenomegaly without significant peripheral lymphadenopathy. Four of the six patients were immunosuppressed. All had CD3, CD8, CD56- positive tumors, presumably of hepatosplenic (n = 3), intestinal (n = 1), pulmonary (n = 1), or nodal (n = 1) origin. Three patients had lymphomatous bone marrow infiltrates, and four had peripheral blood involvement by neoplastic large lymphocytes, some of which had a blastic appearance or resembled virocytes. Azurophilic granules, ultrastructurally corresponding to cytoplasmic dense core and/or double density granules, were seen in all cases. T-cell clonality was shown in five tumors by Southern blot analysis, and three had abnormal karyotypes. Two untreated patients died 20 days after presentation, and three patients who received combination chemotherapy died within 5 months of presentation. One patient remains in complete remission 22 months after treatment. These findings suggest NK-like T-cell lymphomas are aggressive, are clinicopathologically distinct from T-LGL leukemia, and should be in the differential diagnosis of extranodal T-cell lymphoproliferations, including those in immunosuppressed patients. Furthermore, the LGL morphology, phenotype, and tissue distribution of some NK-like T-cell lymphomas suggest they arise from thymic- independent T cells of the hepatic sinusoids and intestinal mucosa.

scholarly journals NK cells integrate signals over large areas when building immune synapses but require local stimuli for degranulation

2021 ◽  
Vol 14 (684) ◽  
pp. eabe2740
Author(s):  
Quentin Verron ◽  
Elin Forslund ◽  
Ludwig Brandt ◽  
Mattias Leino ◽  
Thomas W. Frisk ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Intracellular Signaling ◽  
Large Scale ◽  
Spatial Organization ◽  
Nk Cell ◽  
Microcontact Printing ◽  
Cytotoxic T Cells ◽  
Target Cells ◽  
Immune Synapses

Immune synapses are large-scale, transient molecular assemblies that serve as platforms for antigen presentation to B and T cells and for target recognition by cytotoxic T cells and natural killer (NK) cells. The formation of an immune synapse is a tightly regulated, stepwise process in which the cytoskeleton, cell surface receptors, and intracellular signaling proteins rearrange into supramolecular activation clusters (SMACs). We generated artificial immune synapses (AIS) consisting of synthetic and natural ligands for the NK cell–activating receptors LFA-1 and CD16 by microcontact printing the ligands into circular-shaped SMAC structures. Live-cell imaging and analysis of fixed human NK cells in this reductionist system showed that the spatial distribution of activating ligands influenced the formation, stability, and outcome of NK cell synapses. Whereas engagement of LFA-1 alone promoted synapse initiation, combined engagement of LFA-1 and CD16 was required for the formation of mature synapses and degranulation. Organizing LFA-1 and CD16 ligands into donut-shaped AIS resulted in fewer long-lasting, symmetrical synapses compared to dot-shaped AIS. NK cells spreading evenly over either AIS shape exhibited similar arrangements of the lytic machinery. However, degranulation only occurred in regions containing ligands that therefore induced local signaling, suggesting the existence of a late checkpoint for degranulation. Our results demonstrate that the spatial organization of ligands in the synapse can affect its outcome, which could be exploited by target cells as an escape mechanism.

scholarly journals Natural Killer Cells: The Linchpin for Successful Cancer Immunotherapy

2021 ◽  
Vol 12 ◽  
Author(s):  
Kari A. Shaver ◽  
Tayler J. Croom-Perez ◽  
Alicja J. Copik
Keyword(s):  
T Cells ◽  
Immune System ◽  
Nk Cells ◽  
Cancer Immunotherapy ◽  
Natural Killer ◽  
Nk Cell ◽  
Checkpoint Inhibitors ◽  
Cytotoxic T Cells ◽  
Current Evidence ◽  
Cell Therapies

Cancer immunotherapy is a highly successful and rapidly evolving treatment modality that works by augmenting the body’s own immune system. While various immune stimulation strategies such as PD-1/PD-L1 or CTLA-4 checkpoint blockade result in robust responses, even in patients with advanced cancers, the overall response rate is low. While immune checkpoint inhibitors are known to enhance cytotoxic T cells’ antitumor response, current evidence suggests that immune responses independent of cytotoxic T cells, such as Natural Killer (NK) cells, play crucial role in the efficacy of immunotherapeutic interventions. NK cells hold a distinct role in potentiating the innate immune response and activating the adaptive immune system. This review highlights the importance of the early actions of the NK cell response and the pivotal role NK cells hold in priming the immune system and setting the stage for successful response to cancer immunotherapy. Yet, in many patients the NK cell compartment is compromised thus lowering the chances of successful outcomes of many immunotherapies. An overview of mechanisms that can drive NK cell dysfunction and hinder immunotherapy success is provided. Rather than relying on the likely dysfunctional endogenous NK cells to work with immunotherapies, adoptive allogeneic NK cell therapies provide a viable solution to increase response to immunotherapies. This review highlights the advances made in development of NK cell therapeutics for clinical application with evidence supporting their combinatorial application with other immune-oncology approaches to improve outcomes of immunotherapies.

scholarly journals NK cells integrate signals over large areas when building immune synapses but require local stimuli for degranulation

2020 ◽  
Author(s):  
Quentin Verron ◽  
Elin Forslund ◽  
Ludwig Brandt ◽  
Mattias Leino ◽  
Thomas W. Frisk ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Large Scale ◽  
Nk Cell ◽  
Cytotoxic T Cells ◽  
Target Cells ◽  
Signaling Proteins ◽  
Immune Synapse ◽  
Surface Receptors ◽  
Immune Synapses

AbstractImmune synapses are large-scale, transient molecular assemblies that serve as platforms for antigen presentation to B and T cells, and target recognition by cytotoxic T cells and natural killer (NK) cells. The formation of an immune synapse is a tightly regulated, stepwise process where the cytoskeleton, cell-surface receptors and signaling proteins rearrange into supramolecular activation clusters (SMACs). Here we use a reductionist system of microcontact-printed artificial immune synapses (AIS) shaped as hallmark SMAC structures to show that the spatial distribution of activating ligands influences the formation, stability and outcome of NK cell synapses. Organizing ligands into donut-shaped AIS resulted in fewer long-lasting, symmetrical synapses compared to dot-shaped AIS. NK cells spreading evenly over either AIS exhibited similar arrangement of the lytic machinery, however degranulation was only possible in regions allowing local signaling. Our results demonstrate that the macroscopic organization of ligands in the synapse can affect its outcome, which could be exploited by target cells as an escape mechanism.

scholarly journals Quantitative Multiplex Immunohistochemistry Identifies Immunosuppression in the AML Bone Marrow and NK-Cells As Prognostic Biomarker in Intermediate-Risk Patients

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2774-2774
Author(s):  
Oscar Brück ◽  
Olli Dufva ◽  
Sami Blom ◽  
Riku Turkki ◽  
Mette Ilander ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Research Funding ◽  
Nk Cell ◽  
Cytotoxic T Cells ◽  
Helper T Cells ◽  
Intermediate Risk ◽  
Risk Patients ◽  
Immune Contexture ◽  
Cell Proportion

Abstract BACKGROUND A complex interaction between blasts and surrounding cells in the acute myeloid leukemia (AML) bone marrow (BM) microenvironment sustains blast proliferation and confers chemoresistance. T- and NK-cells have been shown to be dysfunctional in AML, which might be associated with immune evasion and poor prognosis. Here, we present a comprehensive analysis of the immune contexture of the AML BM at diagnosis and study its interaction with clinicopathological variables. METHODS Diagnostic BM biopsies (n=69) were collected from AML patients treated in the Helsinki University Hospital during 2005-2017 and age and gender-matched controls (n=12) to construct tissue microarrays (TMA). Using 8-plex immunohistochemistry (mIHC) and computerized image analysis, we determined cell abundance and immunophenotypic states of millions of immune cells. Immunoprofiles were integrated with a total of 120 clinicopathological variables including cytogenetics and molecular genetics, ELN (European Leukemia Net) risk classification, disease burden parameters, and patient demographics. RESULTS Unsupervised hierarchical clustering of the immunologic contexture defined by mIHC analysis grouped AML patients distinctly from control subjects (Fig 1a). By extracting significant differences (Mann-Whitney U test, q<0.05) and annotating immunologic markers as either anti-cancer or immunosuppression drivers based on literature, we observed an interesting polarization of increased immunosuppression in AML compared to control BM (Fig 1b). In AML patients, lower fraction of granzyme B expressing (GrB+) cells was noted both in CD3+CD4+ helper T-cells (10.9% vs 24.3%, q=0.002, in AML vs control BM) and CD3+CD8+ cytotoxic T-cells (23.5% vs 33.5%, q=0.02). Moreover, we observed pronounced T-cell inhibition features, such as higher proportion of regulatory T-cells (1.5% vs 0.0% FOXP3+ of helper T-cells, q<0.001), and lower expression of class I HLA in BM cells (89.1% vs 100.0%, q<0.001). Putative exhausted PD1+ T-cells were also markedly enriched in the AML BM (15.7% vs 1.7% PD1+ of helper T-cells and 13.2% vs 2.0% PD1+ of cytotoxic T-cells, q<0.001). Among the high interpatient heterogeneity, we discovered two main immune profiles. Cluster 1 was characterized with higher proportion (Log2 fold change >0.5, q<0.05) of cytotoxic T-cells and expression of CD57, CD27, and CD25 in T-cells, as well as higher expression of PD-L1 in the BM. Moreover, lower expression (Log2 fold change <0.5, q<0.05) of OX40 and CD45RO in T-cells and proportion of CD11c+BDCA1+ (type 1 myeloid dendritic cells) were observed. Patients of Cluster 1 were associated with longer event-free survival (EFS; HR 1.9, p=0.049) as well as lower age (median 53.6 vs 64.4 years, p=0.001). No connection between immunologic clusters and FLT3 or NPM1 genotype, complex karyotype, ELN risk class, blast proportion or leukocyte count was found. To support clinical decision-making in ELN 2017 intermediate-risk patients, we developed a risk stratification model focusing on this particular subgroup (n=28) using L1-penalized Cox regression. Patient age over 60 years (HR 8.1, CI95% 2.5-26.6 p<0.001) and low proportion of CD45+CD2+CD3- NK-cells (HR 0.92, CI95% 0.85-0.99 p=0.03) predicted worse EFS. In intermediate-risk patients (n=68) of a separate validation cohort (n=145) analyzed with flow cytometry, low NK cell proportion and high age predicted worse EFS (HR 2.7 CI95% 1.6-4.6 p<0.001) and OS (HR 3.9 CI95% 2.1-7.3 p<0.001) after adjusting with induction therapy protocol. Lower NK-cell proportion was associated with FLT3-ITD genotype (0.45% vs 1.1% NK-cells/all cells in FLT3-ITD+ vs FLT3-ITD- AML patients, p=0.01), and higher than median PB leukocyte (WBC) count (0.50% vs 1.9% NK-cells/all cells in patients with PB WBC ≥7.8x10E9/L vs <7.8x10E9/L, p<0.001). CONCLUSIONS Using TMA cytometrics with mIHC and automated image analysis for detailed characterization of the immune contexture, we discovered pronounced immune exhaustion and suppression in AML BM. An aging-related immune profile was identified and was associated with poor prognosis. Furthermore, survival prediction of intermediate-risk patients might be enhanced by considering patient age and NK-cell proportion. Taken together, immunophenotyping of AML patients might improve risk stratification and identify a subgroup benefiting from immunomodulatory treatments. Disclosures Pallaud: Novartis: Employment. Marques Ramos:Novartis: Employment. Porkka:Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Mustjoki:Ariad: Research Funding; Novartis: Honoraria, Research Funding; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding.

Cytotoxic cells induced during lymphocytic choriomeningitis virus infection of mice: natural killer cell activity in cultured spleen leukocytes concomitant with T-cell-dependent immune interferon production

1980 ◽  
Vol 30 (2) ◽  
pp. 473-483
Author(s):  
R M Welsh ◽  
W F Doe
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Nk Cell ◽  
Cytotoxic T Cells ◽  
Cell Activity ◽  
Lymphocytic Choriomeningitis ◽  
Type I ◽  
Spleen Cells

The characteristics and specificities of spleen and peritoneal cytotoxic cells generated during lymphocytic choriomeningitis virus (LCMV) infection of C3H/St mice were examined. Activated natural killer (NK) cell activity was identified in fresh leukocyte populations from the 2nd to 8th days postinfection, whereas virus-specific cytotoxic T-cell activity was detected from the 6th to 14th days. When leukocytes were cultured overnight at 37 degrees C before assay, T-cell activity was still observed, but nonspecific activated NK cell-like cytotoxicity was only detected on the 6th and to a lesser degree the 8th day postinfection. Overnight culture of leukocytes taken earlier in the infection eliminated their NK cell activity. Similar activities were seen with spleen cell, plastic-adherent peritoneal cell, and nonadherent peritoneal cell populations. The virus-specific cytotoxicity observed with adherent peritoneal cells was due to contamination with cytotoxic T cells, as shown by H-2-restricted cytotoxicity and sensitivity to anti-theta antibody and complement. The nonspecific cultured day 6 effector cell from either the spleen or peritoneum displayed killing specificities and other physical properties identical to those of activated NK cells, but had sensitivities to anti-theta antibody and complement intermediate between activated day 3 NK cells and cytotoxic T cells. Culture stable NK-like cells were not found in athymic nude mice, suggesting a T-cell-dependent mechanism. Whereas LCMV spleen homogenates contained 10-fold-higher levels of interferon at day 2 than at day 6 postinfection, substantially more (nearly 20-fold) interferon was made in cultures of day 6 cells than day 2 cells. Spleen interferon was predominantly type I, whereas the culture interferon was predominantly type II, as shown by acid lability studies. Significant levels of interferon were produced by nylon-wool-passed day 6 spleen cells, and virtually all interferon production was eliminated by treatment of either day 2 or day 6 cells with antibody to theta antigen and complement, suggesting that T cells produced the interferon in vitro. Furthermore, athymic nude mice had no culture-stable NK cells 6 days postinfection, and spleen cells from them failed to produce significant levels of interferon in vitro. Addition of interferon (type I, fibroblast) to cultured C3H spleen cells affect the already elevated levels of cytotoxicity in day 6 cultures, suggesting that the NK cells in the day 6 culture were already activated. Our results suggest that T cells responding to LCMV infection secrete interferon type II which causes the continued activation of NK cells in culture. The resulting population of activated NK cells therefore appears to be relatively stable in culture and to express more theta antigen because of this T-cell dependence. Although one could mistakenly or allospecific cytotoxic T cells or cytotoxic macrophages, more careful examination shows that they are most likely activated NK cells...

Current Approaches to Engineering of NK Cells for Cancer Immunotherapy

2018 ◽  
Vol 24 (24) ◽  
pp. 2810-2824 ◽  
Author(s):  
M.A. Streltsova ◽  
E.V. Barsov ◽  
S.A. Erokhina ◽  
A.M. Sapozhnikov ◽  
E.I. Kovalenko
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Cancer Immunotherapy ◽  
Nk Cell ◽  
Tumor Regression ◽  
Cytotoxic T Cells ◽  
Biologically Active ◽  
Graft Versus Host Reaction ◽  
Surface Receptors ◽  
Cancer Types

Natural Killer (NK) cells belong to a unique subtype of lymphocytes with a great potential for cancer immunotherapy due to their ability to rapidly recognize and efficiently kill tumor cells. Their anti-cancer potential can be further increased by genetic and non-genetic modifications. However, the attempts of genetic improvements of NK cells over the past 20 years have been hampered by the difficulties of gene delivery into this cell type, thus preventing researchers from producing clinically relevant numbers of viable and biologically active NK cells. Currently, several successful approaches to genetic modification of NK cells have been described, and clinically applicable cell therapy products have been characterized. Now that we understand much better the ways of NK cell optimization to enhance their tumor regression-inducing capabilities, novel approaches to engineering NK surface receptors are being developed. In this review, we focus on the advantages and perspectives of various approaches to modification of NK cells. Positive results of several preclinical studies are described, demonstrating that genetically modified NK cells can be comparable to therapeutic T cells in their efficiency of recognizing and destroying tumor targets. Moreover, using allogenic NK cells to treat a number of cancer types might have even wider and eager clinical adoption than cytotoxic T cells due to a much decreased risk of graft versus host reaction inherent in NK cell-based immunotherapeutic products.

scholarly journals Maintenance with Histamine and IL-2 Induces a Marked Expansion of Activated CD56bright NK Cells in Acute Myeloid Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1422-1422
Author(s):  
Angelica Cuapio ◽  
Mirte Post ◽  
Sabine Cerny-Reiterer ◽  
Markus Osl ◽  
Volker Huppert ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Nk Cell ◽  
Leukemic Cells ◽  
Cell Numbers ◽  
Before And After ◽  
Cell Subpopulations ◽  
Maintenance Of Remission

Abstract In acute myeloid leukemia (AML), residual leukemic (stem) cells that escape initial chemotherapy are considered a major source of relapse. Clinical trials have used IL-2 for AML patients with the aim to reduce relapse rates by eliminating residual leukemic cells through activation of NK and T cells. However, monotherapy with IL-2 has led to disappointing results. Nevertheless, recent clinical trials have shown that the co-administration of IL-2 and histamine dihydrochloride (HDC) provides maintenance of remission in AML. Histamine suppresses the formation of reactive oxygen species (ROS) thereby protecting NK and T cells from ROS-induced dysfunction and apoptosis. In addition, IL-2 is considered to maintain the anti-leukemic activity of NK cells. However, the direct effect of this treatment on NK cell numbers and anti-AML activity has not been studied in detail so far. In this study, we analyzed the immunophenotype and function of NK cells in a cohort of 7 AML patients (FAB M2, n=1; M4, n=2; M4-eo with inv 16, n=2; M5, n=2) treated with HDC plus IL-2. All patients had received induction chemotherapy with daunorubicin (45 mg/m² i.v. days 1-3), cytosine arabinoside, ARA-C (2 x 100 mg/m² i.v., days 1-7) and etoposide (100 mg/m² i.v., days 1-5) as well as at least 3 cycles of consolidation chemotherapy with high dose or intermediate dose ARA-C (Sperr et al, Clin Cancer Res 2004;10:3965-3971 and Krauth et al, J Immunol 2006;176:1759-1768). After having achieved a complete hematologic remission, patients were treated with HDC (0.5 mg) plus recombinant IL-2 (0.9 x 106 IU) twice daily s.c. for 21 days per cycle. Blood was drawn before and during treatment with HDC plus IL-2. We found that after one week of treatment with HDC plus IL-2, NK cell numbers increased in peripheral blood (from 101.8 ± 28.25 cells/µl before therapy to 208.2 ± 38.27 cells/µl after therapy, p<0.05). In the NK cell fraction, we observed an astonishing increment of CD56bright NK cells in all treated patients (from 7.2±0.97% or 17.6±5.8 cells/µl before therapy to 38.8±4.4% or 104±19.4 cells/µl after therapy, p<0.05; see Fig.1A/B). The cytotoxic activity of the CD56bright cells, as determined by NK cell degranulation and target cell lysis using the cell line K562, showed a significant increase in comparison to cells obtained before treatment (p<0.05). This was associated with an increased expression of KIR as well as the activation markers NKp44 (see Fig.1C), NKp46, and CD25 on NK cells. Furthermore, we observed a significant increase in expression of CD56 on NK cells after treatment with HDC plus IL-2 in our AML patients (2.5 ± 0.55 fold increase in the mean fluorescence intensity of CD56, p=0.02), whereas CD16 expression did not change significantly. In addition, treatment with HDC+IL-2 also induced an increased proportion of circulating CD4+CD25highCD127low/neg regulatory T cells (Treg). Finally, in vitro stimulation of NK cells with histamine plus IL-2 mimicked the effects observed in vivo. Interestingly, the in vitro treatment was also associated with an increased expression of CD56 without altered expression of CD16, suggesting that this effect could be a specific and reliable indicator of in vivo responses of NK cells to HDC plus IL-2 therapy. In conclusion, treatment with HDC plus IL-2 causes a striking increase in CD56bright NK cells. These specifically expanded NK cells exhibit an activated phenotype with enhanced potential to kill leukemic cells. We propose that the maintenance of remission in AML patients treated with HDC plus IL-2 might, at least in part, be the result of an improved anti-leukemic NK cell function. Fig 1. Effect of HDC plus IL2 on NK cells of AML patients. A) Representative dot plots of the CD56bright and CD56dim NK cell subpopulations from an AML patient treated with histamine+IL2 before and after treatment. B) Absolute cell numbers of CD56bright NK cells of 7 AML patients before and after treatment, *** p<0.01. C) Follow-up of NKp44 and KIR expression after HDC plus IL-2 therapy. Shown are histograms for NKp44 and KIR expression on total CD56+ CD3- NK cells of one patient representative for the majority of patients tested. Fig 1. Effect of HDC plus IL2 on NK cells of AML patients. A) Representative dot plots of the CD56bright and CD56dim NK cell subpopulations from an AML patient treated with histamine+IL2 before and after treatment. B) Absolute cell numbers of CD56bright NK cells of 7 AML patients before and after treatment, *** p<0.01. C) Follow-up of NKp44 and KIR expression after HDC plus IL-2 therapy. Shown are histograms for NKp44 and KIR expression on total CD56+ CD3- NK cells of one patient representative for the majority of patients tested. Disclosures Sperr: MEDA Pharma GmbH & Co. KG: Speakers Bureau. Valent:MEDA Pharma GmbH & Co. KG: Speakers Bureau.

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