Natural Killer Cell Markers Research Articles

Glycosaminoglycan from Apostichopus japonicus induces immunomodulatory activity in cyclophosphamide-treated mice and in macrophages.

This study was designed to systematically elucidate the immunomodulation effect of glycosaminoglycan from Apostichopus japonicus (AHG) in cyclophosphamide (CY)-induced immunosuppression model and potential mechanism responsible for the activation of macrophages. The results showed that the treatment with AHG could increase natural killer (NK) cell cytotoxicity, carbon clearance and marker enzymes activities in CY-induced immunosuppression mice, indicating that the innate immunity experienced recovery to some extent. Moreover, CY-induced reductions in thymus and spleen indices, serum levels of cytokines, immunoglobulins and hemolysin, as well as the ratio of spleen lymphocyte subsets were recovered by AHG, suggesting that AHG could improve the adaptive immunity through cellular immunity and humoral immunity. Delightedly, it was found that AHG at 10 mg/kg body weight could restore the CY-induced immunosuppression in mice to normal level on both innate and adaptive immunity. Furthermore, AHG also promoted both the expression of NO, TNF-α, IL-6, IL-1β, IL-18 and MCP-1 protein and related mRNA in macrophages. It was revealed that AHG activated macrophages through the phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear factor-B (NF-κB). In conclusion, AHG exerts remarkable immunomodulatory activities in both innate and adaptive immune system. These findings should have great value for further study on the immunopotentiating mechanisms of this biomacromolecule.

Symposium review: Immunological detection of the bovine conceptus during early pregnancy

Infertility and subfertility reduce the economic viability of dairy production. Inflammation reduces conception rates in dairy cattle, but surprisingly little information exists about the populations and the functions of immune cells at the conceptus-maternal interface during the periattachment period in dairy cattle. Early pregnancy is accompanied by immune stimulation at insemination and conceptus secretion of IFN-τ, pregnancy-associated glycoproteins, prostaglandins, and other molecules whose effects on immune function during early pregnancy have not been determined. Our working hypothesis is that pregnancy induces changes in immune cell populations and functions that are biased toward immunological tolerance, tissue remodeling, and angiogenesis. This review summarizes current knowledge, starting with insemination and proceeding through early pregnancy, as this is the period of maximal embryo loss. Results indicated that early pregnancy is accompanied by a marked increase in the proportion of endometrial immune cells expressing markers for natural killer (CD335) cells and cytotoxic T cells (CD8) along with an increase in cells expressing major histocompatibility class II antigens (macrophages and dendritic cells). This is accompanied by increased abundance of mRNA for IL-15, a natural killer growth factor, and IL-10 in the endometrium during early pregnancy. Furthermore, expression of indoleamine 2,3 dioxygenase was 15-fold greater in pregnant compared with cyclic heifers at d 17, but then declined by d 20. This enzyme converts tryptophan to kynurenine, which alters immune function by creating a localized tryptophan deficiency and by activation of the aryl hydrocarbon receptor and induction of downstream tolerogenic mediators. Expression of the aryl hydrocarbon receptor is abundant in the bovine uterus, but its temporal and spatial regulation during early pregnancy have not been characterized. Pregnancy is also associated with increased expression of proteins known to inhibit immune activation, including programed cell death ligand-1 (CD274), lymphocyte activation gene-3 (CD223), and cytotoxic T-lymphocyte associated protein-4 (CD152). These molecules interact with receptors on antigen-presenting cells and induce lymphocyte tolerance. Current results support the hypothesis that early pregnancy signaling in dairy heifers involves changes in the proportions of immune cells in the endometrium as well as induction of molecules known to mediate tolerance. These changes are likely essential for uterine wall remodeling, placentation, and successful pregnancy.

Natural killer T Cells: A Powerful Via in the Regulation of Non Communicable Chronic Diseases

The Natural Killer T cells (NKT) constitute a population of T lymphocytes that co-express an antigen receptor (TCR) and a marker of natural killer cells (NK1.1). We have found that after stimulation through TCR, the NKT cells secrete various cytokines that play an important role in the innate immune response and have a fundamental participation in the initial stages of the immune response to many pathogens and tumours. NKT cells belong to a group of autoreactive T cells that are generated in the thymus, which is why they have been found to play an important role in the regulation of different autoimmune diseases, such as type 1 diabetes, systemic lupus erythematosus, multiple sclerosis, and others. Also, in adulthood there is an aging of the immune system known as immunosenescence, where a decrease and alteration of the function of NKT cells has been observed, which leads to a greater oncological, viral and autoimmune diseases. It has also recently been found that these cells participate in bronchial inflammation in patients with allergic asthma as well as in rhinitis and atopic dermatitis; having these cells a clear role in the regulation of various diseases and that has not been studied as a therapeutic target.

Low-Dose Interleukin-2 Therapy Enhances Cytotoxicity of CD56bright NK Cells in Patients with Chronic Gvhd

Introduction: Natural killer (NK) cells play an important role in defense against infections and cancer. Two major subsets of mature NK cells have been described. CD56bright CD16- NK cells, which normally represent only 5-10% of circulating NK cells, are thought to exhibit less cytolytic activity and greater immune regulatory functions than CD56dim CD16+ NK cells. However, recent studies have reported that cytolytic activity of CD56bright NK cells increases when these cells are stimulated with IL-15or the combination of IL-12, IL-15 and IL-18. Previous studies from our center have shown that daily administration of low-dose IL-2 in patients with chronic graft-versus-host disease (cGVHD) induces selective expansion of CD4+FoxP3+Helios+ regulatory T cells and CD56bright NK cells and improves clinical manifestations of cGVHD. The function of CD56bright NK cells expanded by low-dose IL-2 has not previously been studied.Methods: Single cell mass cytometry (CyTOF) with a panel of 35 metal tagged antibodies was performed on cryopreserved peripheral blood mononuclear cells (PBMC) from 10 adult patients with active cGVHD receiving daily low-dose IL-2 therapy. Patients in this clinical trial received extracorporeal photopheresis (ECP) for 8 weeks prior to starting daily low dose IL-2. ECP therapy (twice weekly) was continued when patients began low-dose IL-2 (1x106 IU/M2/day x 8 weeks). The analytic panel included 26 cell surface markers to identify distinct lymphocyte subsets and 9 intracellular markers to measure functional status and activation of specific signaling pathways. viSNE was used to visualize of high-dimensional data on a two-dimensional map and quantify single cell mass cytometry data. NK cytolytic activity was measured in flow cytometry-based cytotoxicity assays. CD56bright and CD56dim NK cells from 8 adult patients were purified from cryopreserved PBMC by cell sorting and incubated with labeled K562 cells for 4 hours followed by staining with 7-AAD and Annexin-V. E:T ratio of 1:1 was used for incubation with K562 targets.Results: No changes in extracellular or intracellular NK cell markers or quantitative changes in NK cells were observed during the initial 8 week ECP treatment period. Selective expansion of CD56bright NK cells was noted after 1 week of IL-2 therapy (9W) and continued during 8 weeks of daily IL-2 therapy. Increased expression of NKp30, Nkp46, NKG2D, HLA-DR and Ki67 occurred in expanded CD56bright NK cells with peak expression at 1 week after starting IL-2 (9W). At later time points during IL-2 therapy, expression of NKG2D, HLA-DR and Ki67 returned to baseline (Figure 1A). Expression of CD56, CD122 and NKG2A continued to increase during IL-2 treatment. In contrast, expression of CD25 by expanded CD56bright NK cells decreased during IL-2 treatment. Expression of phosphorylated signaling proteins did not change in any NK cell subset during IL-2 treatment. Cytolytic activity was measured in CD56bright and CD56dim NK cell subsets at different times during ECP and IL-2 therapy. After thawing, flow-sorted NK cell subsets were cultured for 16-20 hours with IL-2 (100 IU/ml). Cells were then washed and incubated with tumor targets (K562) for 4 hours and % killing was assessed by flow cytometry. Compared to pre IL-2 treatment, cytolytic activity of CD56bright NK cells increased during IL-2 treatment while cytotoxicity of CD56dim NK cells did not change. Notably, cytotoxicity of CD56bright NK cells became significantly higher than CD56dim NK cells during IL-2 therapy (Figure 1B).Conclusion: Single cell mass cytometry revealed that daily low dose IL-2 therapy induces selective expansion, activation and increased expression of activating NK receptors in CD56bright NK cells. CD56dim NK cells were not affected by IL-2 therapy. In vitro assays revealed that cytolytic activity of CD56bright NK cells increased during IL-2 treatment and exceeded the cytotoxicity of CD56dim NK cells. CD56bright NK cells, traditionally considered to be minimally tumor-responsive, are effectively stimulated by daily low dose IL-2 exposure to enable potent cytotoxicity in response to tumor targets. In patients receiving low-dose IL-2 after allogeneic HSCT, expanded CD56bright NK cells may contribute to graft versus leukemia (GVL) and help prevent relapse after transplant. DisclosuresNikiforow:Kite Pharma: Consultancy. Ho:Jazz Pharmaceuticals: Consultancy. Antin:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Soiffer:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

Notch Activation Rescues Exhaustion in CISH-Deleted Human iPSC-Derived Natural Killer Cells to Promote In Vivo Persistence and Enhance Anti-Tumor Activity

Cytokine-inducible SH2-containing protein (CIS) is a critical negative regulator of IL-15 signaling in natural killer (NK) cells and is encoded by CISH gene in human. Recent studies in a murine model demonstrate that CIS is a potent inhibitory checkpoint in NK cell-mediated tumor immunity. However, it is unclear if CIS similarly regulates human NK cell-mediated anti-tumor activity. Unlike CTLA-4 and PD1 that are expressed at the cell surface and can be blocked by antibody-mediated therapy, CIS is expressed intracellularly. Therefore, we deleted CISH gene in human induced pluripotent stem cells (iPSCS) using CRISPR/Cas9 technology and characterized the CISH-knockout iPSC lines. Our study demonstrates that CISH does not regulate maintenance of undifferentiated human pluripotent stem cells. We then derived NK cells from these gene-modified iPSCs using a two-stage in vitro hematopoietic-lymphoid differentiation protocol developed by our group. Initial hematopoietic differentiation of the iPSCs was unaffected by CISH deletion. However, deletion of CISH in iPSCs markedly delayed the second stage of in vitro NK cell differentiation. Specifically, whereas NK cell differentiation was typically fully complete with >90% NK cells after 4 weeks using WT iPSCs, the CISH-/- iPSC- cells only produced ~10% CD45+CD56+ NK cells at 4 weeks, though by 5 weeks these cultures were >80% NK cells. The CISH-/- iPSC-derived NK cells demonstrated typical NK surface maker expression, including CD94, CD16, NKG2D, NKp44, NKp46, FasL, and KIRs. Initial studies demonstrated that CISH-/- human iPSC-derived NK cells had significantly reduced ability to expand in vitro with evidence of NK cell exhaustion, including increased TIM-3 expression, decreased IFN-γ production and decreased cytotoxicity. RNA-seq analysis also confirmed that expression of exhaustion-related genes, including TIM3, CTLA4, and 2B4, were all significantly increased in CISH-/- NK cells. Interestingly, mass cytometric (CyTOF) analysis of CISH-/- NK cells with a panel of 36 phenotypic and functional NK cell markers identified an exhausted sub-population (increased expression of exhaustion marker TIM3 and inhibitory receptors such as ILT2 and Siglec7, as well as decreased proliferation marker Ki67). Importantly, this exhaustion could be rescued by co-culturing CISH-/- NK cells with Notch ligand-expressing OP9-DL4 stromal cells, leading to production of fully functionally mature NK cells. The CISH-/- NK cells stimulated by Notch maintained better expansion and improved cytotoxic function with low concentrations of either IL15 or IL2 compared to WT-iPSC-derived NK cells. CISH-/- NK cells demonstrate increased cytotoxic activity against leukemia cell lines K562 and MOLM-13 cells in vitro. Moreover, single-cell cytokine response analysis of CISH-/- NK cells after Notch stimulation showed >10 fold enrichment of polyfunctional cell subsets with effector cytokine production (Granzyme B, IFN-γ, MIP-1α, Perforin, TNF-α) compared with WT NK cells or NK cells from peripheral blood. In a MOLM-13 xenograft model, CISH-/- NK cells displayed significantly increased persistence in peripheral blood in comparison with WT NK cells (CISH-/- NK cells 6.81 ± 0.85 % vs WT NK cells 2.05 ± 0.25 N=5). More importantly, CISH-/- NK cells show significantly better control of tumor progression in the MOLM-13 xenograft model compared with WT NK cells. Together, these studies demonstrate CISH plays a key role to regulate NK cell activation-induced exhaustion and that Notch activation prevents this exhaustion to enable production of functionally hyperactive NK cells. DisclosuresGuan:Vivace: Equity Ownership. Malmberg:Fate Therapeutics Inc.: Consultancy, Research Funding. Kaufman:Fate Therapeutics: Consultancy, Research Funding.

NK Cells from Human Pluripotent Stem Cells for Immunotherapy

Natural Killer (NK) cells are a one of innate lymphocytes and show cytotoxicity against tumour cells without prior antigen specific stimulation. . NK cells can demonstrate stronger cytotoxicity than T cells in the absence of MHC Class I, and survive short lifespan from several weeks to one month. It suggested that NK cells show low risk of cytokine long-term secretion inside patient's body. Previous studies have developed peripheral blood mononuclear cells (PBMC) derived NK cells expansions or NK cells differentiation from cord blood (CB) cells for immunotherapy. Expansion trial using K562 tumor cell line, or with IL-15, or an anti-tumor antibody dasatinib is not sufficient to obtain NK cells with high cytotoxicity.More recently, NK cells induction from human pluripotent stem cells (hPSCs), taking the advantage of their unlimited growth potential, has been reported. Although previous studies regarding hPSC-derived NK cells seems impressive and successful, most systems used a bovine and human serum, which might result in the unstable yield and efficiency in the production of Hematopoietic progenitor cells (HPCs) and NK cells for immunotherapy. To resolve those problems, we tried to induce functional NK cells from hPSCs in xeno and serum free condition.This study used three hPSC cell lines; human ES cell (cell line: KhES1) and iPS cells (cell line: 409B2 and CB-A11) to check reproducibility. To differentiate hPSCs into hematopoietic cells, changed cytokine combinations and chemically defined medium in step-wise manner. We first induced HPC from hPSCs over 90% purity by 12 days culture. At this point, we selected two media to induce NK cells. We compared serum-containing medium that previous report used (Medium A) and chemically-defined medium (Medium B) by evaluating the differentiation efficiency and function of NK cells. NK cell marker CD56 (NCAM) was gradually expressed after additional 16 days culture (28 days of differentiation). Until hPSC-derived NK cells were maturated, we traced the expression of NK specific markers and transcriptional factors. On day48, the frequency of CD56 positive cells showed no significant differences between medium A (79.15 ± 5.30%) and medium B (80.90 ± 1.27%). In both conditions, NK cells expressed specific receptors such as CD161, NKG2D, killer immunoglobulin-like receptors (KIRs), NKG2a (CD94/CD159a heterodimeric inhibitory receptor), NKp44 and NKp46. hPSC-derived NK cells showed the compatible size and morphology to NK cells isolated from peripheral blood NK (PB-NK) cells: their nucleus was kidney-like shape and cytoplasm contained azurophilic granules. For functional assay, leukemia cell line K562 was incubated with 51 chromium (51Cr) for 1 hour at 37 degrees. After that, K562 was co-cultured with purified CD56 positive hPSC-derived NK cells for 4 hours at 37 degrees. The cytotoxic activity of NK cells was confirmed by 51Cr release from K562. PBMC-NK cells showed 49.65 ± 3.46% of killing activity against K562 target cells, while the killing potential of PSC-derived NK cell showed killing potential against K562 cells (Medium A: 25.4 ± 5.52%, Medium B: 23.25 ± 9.26%) which was slightly lower than that of PB-NK cells. Next trial, we are going to transplant hPSC-derived NK cells into immune deficiency mice. In detail, this mice was infected luciferase expressed K562. Using IVIS imaging system to detect intensity of luciferase, we characterized hPSC-derived NK cells potential in vivo.Here we have developed a novel and robust method to facilitate efficient NK cells differentiation in serum and xeno-free condition in all clones. They showed similar phenotypes compare to PBMC derived NK cells in terms of morphology, surface markers, translational factors and cytotoxicity against leukemia cell line K562 in vitro. This technology expected to be applicable not only to immunotherapy but also to model studies of the NK cells associating diseases. DisclosuresNo relevant conflicts of interest to declare.

KIR Expression on inVitro-Derived Natural Killer Cells Does Not Regulate Killing of Allogeneic Targets

Natural killer (NK) cells play an essential role in early innate killing of virally-infected and tumor targets. NK cell-mediated activity is regulated by a repertoire of activating and inhibitory receptors that recognize ligands on diseased, stressed, or tumor targets. Killer cell immunoglobulin-like receptors (KIRs) are a family of polymorphic receptors that can be inhibitory or activating based on their intracellular signaling motifs. Expression of certain KIR haplotypes plays a key role in survival and relapse prevention for patients with acute myelogenous leukemia (AML) who receive allogeneic hematopoietic cell transplantation. Therefore, KIR haplotypes are an important consideration in selecting allogeneic donors for patients with AML. However, it is unclear if KIRs play a role in adoptive transfer of NK cells that are becoming more routinely utilized to treat refractory AML and other malignancies. To better address this question we used umbilical cord blood to isolate both CD34+ hematopoietic stem cells and CD45+CD56+ NK cells (UCB-56-NK) from the same umbilical cord blood unit. The CD34+ hematopoietic stem cells were then differentiated in vitro into CD56+ NK cells (UCB-34-NK). Despite originating from the same donor and sharing the same genetic background, as well as comparable expression of Fas ligand, TRAIL, NKp46, NKp44, NKG2A, and NKG2D, the UCB-34-NK cells have characteristically low KIR expression, whereas the UCB-56-NK cells have high KIR expression. This phenotype was further confirmed by mass cytometric (CyTOF) analysis of UCB-56-NK cells and UCB-34-NKcells with a panel of 36 phenotypic and functional NK cell markers. This unique system allows us to study the role of KIR expression independent of any other variations in donor or cell characteristics. The cytotoxicity and NK cell activation of UCB-34-NK cells and UCB-56-NK cells are compared to control NK cells isolated from peripheral blood (PB-NK cells) with standard in vitro cytotoxicity assays against neuroblastoma lines with varying HLA genotypes and a control K562 leukemic targets. Our data demonstrates that there is no statistical difference in NK cytotoxicity and activation of UCB-34-NK cells and UCB-56-NK cells across a spectrum of target cell HLA types, despite the differences in KIR expression. For example, at effector to target (E:T) ratios of 1:5 and 1:20 against neuroblastoma line IMR32, UCB-34-NK cells (KIR-low) demonstrated 68.5% and 84.1% maximal Caspase 3/7 activation, compared to 81.3% and 89.6% by UCB-56-NK cells (KIR-high). Additionally, we have used human induced pluripotent stem cells to derive NK cells (iPSC-NK cells) that vary in KIR expression levels. These CD45+CD56+ iPSC-NKs are differentiated from the same well-established iPSC line in the laboratory and therefore again share the same genetic background, and they have similar NK cell surface receptor expression of Fas ligand, TRAIL, NKp46, NKp44, and NKG2D, but differ in levels of KIR expression. Again in vitro cytotoxicity against hematopoietic tumor targets such as K562 and MOLM13 do not demonstrate a significant difference in killing, despite these KIR differences. For example, in targeting erythroleukemia K562 cells, iPSC-NK cells with high levels of KIR expression at E:T ratios of 1:2.5, 1:5, and 1: 10 have Caspase 3/7 activation of 21.1%, 28.2%, and 41.0%, compared to 20.1%, 22.0%, and 31.2% by iPSC-NK cells with low KIR expression. Together, these studies demonstrate that in vitro-derived NK cells do not require KIR expression to become licensed for anti-tumor activity and these cells are able to kill tumor targets whether or not they express KIRs. These studies better enable use of these allogeneic NK cell populations for off-the-shelf NK cell-based therapies without the need to optimize for KIR profiles for patients of differing HLA haplotypes. DisclosuresMalmberg:Fate Therapeutics Inc.: Consultancy, Research Funding. Kaufman:Fate Therapeutics: Consultancy, Research Funding.

Differential Effects of a Glucagon-Like Peptide 1 Receptor Agonist in Non-Alcoholic Fatty Liver Disease and in Response to Hepatectomy

Non-alcoholic fatty liver disease (NAFLD) is associated with post-operative liver failure (PLF) and impaired liver regeneration. We investigated the effects of a glucagon-like peptide-1 (GLP-1) receptor agonist on NAFLD, PLF and liver regeneration in mice fed chow diet or methionine/choline-deficient diet (MCD) or high fat diet (HFD). Fc-GLP-1 decreased transaminases, reduced intrahepatic triglycerides (TG) and improved MCD-induced liver dysfuction. Macrophage/Kupffer cell-related markers were also reduced although Fc-GLP-1 increased expression of genes related to natural killer (NK), cytotoxic T lymphocytes and hepatic stellate cell (HSC) activation. After partial hepatectomy (PH), survival rates increased in mice receiving Fc-GLP-1 on chow or MCD diet. However, the benefit of Fc-GLP-1 on NASH-like features was attenuated 2 weeks post-PH and liver mass restoration was not improved. At this time-period, markers of NK cells and cytotoxic T lymphocytes were further elevated in Fc-GLP-1 treated mice. Increased HSC related gene expression in livers was observed together with decreased retinyl ester content and increased retinal and retinoic acid, reflecting HSC activation. Similar effects were found in mice fed HFD receiving Fc-GLP-1. Our results shed light on the differential effects of a long-acting GLP-1R agonist in improving NAFLD and PLF, but not enhancing liver regeneration in mice.

Immune-associated traits measured in milk of Holstein-Friesian cows as proxies for blood serum measurements

Previous work has highlighted that immune-associated (IA) traits measurable in blood are associated with health, productivity, and reproduction in dairy cows. The aim of the present study was to determine relationships between IA traits measured in blood serum and those simultaneously measured in milk as well as their association with disease phenotypes. All animals were Holstein-Friesian cows from the Langhill research herd (n = 546) housed at the SRUC Dairy Research Centre in Scotland. Milk and serum samples were collected on 20 separate occasions between July 2010 and March 2015 and analyzed by ELISA for haptoglobin (Hp), tumor necrosis factor-α (TNF-α), and natural antibodies binding keyhole limpet hemocyanin (NAbKLH) and lipopolysaccharide (NAbLPS). Data were analyzed using mixed linear models that included pedigree information. Analyses revealed positive phenotypic correlations between milk and serum NAb (0.59 ≤ r ≤ 0.77), Hp (r = 0.37), and TNF-α (r = 0.12). Milk and serum NAb were also found to have a strong genetic correlation (0.81 ≤ r ≤ 0.94) and were genetically correlated with cow lameness (0.66 and 0.79 for milk NAbKLH and serum NAbLPS, respectively). Clinical mastitis was found to be phenotypically correlated with both milk and serum Hp (0.09 ≤ r ≤ 0.23). Serum Hp was also strongly genetically correlated with other cellular IA traits such as percent NKp46+ (a natural killer cell marker; 0.35) and percent peripheral blood mononuclear cells (PBMC; -0.90). Similarly, genetic correlations were found to exist between serum TNF-α and percent NKp46+ (0.22), percent PBMC (0.41), and percent lymphocytes (0.47). Excluding serum Hp, all milk and serum IA traits were repeatable, ranging from 0.11 (milk Hp) to 0.43 (serum NAbLPS). Between-animal variation was highest in milk and serum NAb (0.34-0.43) and significant estimates of heritability were also observed in milk and serum NAb (0.17-0.37). Our findings show that certain IA traits, such as NAbKLH and NAbLPS, found in milk and serum are strongly correlated and highlight the potential of using routinely collected milk samples as a less invasive and cost-effective source of informative data for predictive modeling of animal IA traits.

A Library-Based Screening Strategy for the Identification of DARPins as Ligands for Receptor-Targeted AAV and Lentiviral Vectors

Delivering genes selectively to the therapeutically relevant cell type is among the prime goals of vector development. Here, we present a high-throughput selection and screening process that identifies designed ankyrin repeat proteins (DARPins) optimally suited for receptor-targeted gene delivery using adeno-associated viral (AAV) and lentiviral (LV) vectors. In particular, the process includes expression, purification, and in situ biotinylation of the extracellular domains of target receptors as Fc fusion proteins in mammalian cells and the selection of high-affinity binders by ribosome display from DARPin libraries each covering more than 1012 variants. This way, DARPins specific for the glutamate receptor subunit GluA4, the endothelial surface marker CD105, and the natural killer cell marker NKp46 were generated. The identification of DARPins best suited for gene delivery was achieved by screening small-scale vector productions. Both LV and AAV particles displaying the selected DARPins transduced only cells expressing the corresponding target receptor. The data confirm that a straightforward process for the generation of receptor-targeted viral vectors has been established. Moreover, biochemical analysis of a panel of DARPins revealed that their functional cell-surface expression as fusion proteins is more relevant for efficient gene delivery by LV particles than functional binding affinity.

The Role of Invariant NKT in Autoimmune Liver Disease: Can Vitamin D Act as an Immunomodulator?

Natural killer T (NKT) cells are a distinct lineage of T cells which express both the T cell receptor (TCR) and natural killer (NK) cell markers. Invariant NKT (iNKT) cells bear an invariant TCR and recognize a small variety of glycolipid antigens presented by CD1d (nonclassical MHC-I). CD1d-restricted iNKT cells are regulators of immune responses and produce cytokines that may be proinflammatory (such as interferon-gamma (IFN-γ)) or anti-inflammatory (such as IL-4). iNKT cells also appear to play a role in B cell regulation and antibody production. Alpha-galactosylceramide (α-GalCer), a derivative of the marine sponge, is a potent stimulator of iNKT cells and has been proposed as a therapeutic iNKT cell activator. Invariant NKT cells have been implicated in the development and perpetuation of several autoimmune diseases such as multiple sclerosis and systemic lupus erythematosus (SLE). Animal models of SLE have shown abnormalities in iNKT cells numbers and function, and an inverse correlation between the frequency of NKT cells and IgG levels has also been observed. The role of iNKT cells in autoimmune liver disease (AiLD) has not been extensively studied. This review discusses the current data with regard to iNKT cells function in AiLD, in addition to providing an overview of iNKT cells function in other autoimmune conditions and animal models. We also discuss data regarding the immunomodulatory effects of vitamin D on iNKT cells, which may serve as a potential therapeutic target, given that deficiencies in vitamin D have been reported in various autoimmune disorders.

Stereotactic Ablative Radiation Therapy Induces Systemic Differences in Peripheral Blood Immunophenotype Dependent on Irradiated Site

Despite the strong interest in combining stereotactic ablative radiation therapy (SAR) with immunotherapy, limited data characterizing the systemic immune response after SAR are available. We hypothesized that the systemic immune responseto SAR would differ by irradiated site owing to inherent differences in the microenvironment of various organs. Patients receiving SAR to any organ underwent prospective blood banking before and 1 to 2weeks after SAR. Peripheral blood mononuclear cells (PBMCs) and serum were isolated. PBMCs were stained with fluorophore-conjugated antibodies against T and natural killer (NK) cell markers. Cells were interrogated by flow cytometry, and the results were analyzed using FlowJo software. Serum cytokine and chemokine levels were measured using Luminex. We analyzed the changes from before to after therapy using paired t tests or 1-way analysis of variance (ANOVA) with Bonferroni's post-test. A total of 31 patients had evaluable PBMCs for flow cytometry and 37 had evaluable serum samples for Luminex analysis. The total number of NK cells andcytotoxic (CD56dimCD16+) NK cells decreased (P=.02) and T-cell immunoglobulin- and mucin domain-containing molecule-3-positive (TIM3+) NK cells increased (P=.04) after SAR to parenchymal sites (lung and liver) but not tobone or brain. The total memory CD4+ T cells, activated inducible co-stimulator-positive and CD25+CD4+ memory T cells, and activated CD25+CD8+ memory Tcells increased after SAR to parenchymal sites but not bone or brain. The circulating levels of tumor necrosis factor-α (P=.04) and multiple chemokines, including RANTES (P=.04), decreased after SAR to parenchymal sites but not bone or brain. Our data suggest SAR to parenchymal sites induces systemic immune changes, including a decrease in total and cytotoxic NK cells, an increase in TIM3+ NK cells, and an increase in activated memory CD4+ and CD8+ T cells. SAR to nonparenchymal sites did not induce these changes. By comparing the immune response after radiation to different organs, our data suggest SAR induces systemic immunologic changes that are dependent on the irradiated site.

Educated natural killer cells show dynamic movement of the activating receptor NKp46 and confinement of the inhibitory receptor Ly49A.

Educated natural killer (NK) cells have inhibitory receptors specific for self major histocompatibility complex (MHC) class I molecules and kill cancer cells more efficiently than do NK cells that do not have such receptors (hyporesponsive NK cells). The mechanism behind this functional empowerment through education has so far not been fully described. In addition, distinctive phenotypic markers of educated NK cells at the single-cell level are lacking. We developed a refined version of the image mean square displacement (iMSD) method (called iMSD carpet analysis) and used it in combination with single-particle tracking to characterize the dynamics of the activating receptor NKp46 and the inhibitory receptor Ly49A on resting educated versus hyporesponsive murine NK cells. Most of the NKp46 and Ly49A molecules were restricted to microdomains; however, individual NKp46 molecules resided in these domains for shorter periods and diffused faster on the surface of educated, compared to hyporesponsive, NK cells. In contrast, the movement of Ly49A was more constrained in educated NK cells compared to hyporesponsive NK cells. Either disrupting the actin cytoskeleton or adding cholesterol to the cells prohibited activating signaling, suggesting that the dynamics of receptor movements within the cell membrane are critical for the proper activation of NK cells. The faster and more dynamic movement of NKp46 in educated NK cells may facilitate a swifter response to interactions with target cells.

Uterine natural killer cell progenitor populations predict successful implantation in women with endometriosis-associated infertility.

Uterine natural killer (uNK) cells play a critical role early in gestation. As we previously identified altered uNK cell development in endometriosis-associated infertility, we herein sought to characterize natural killer (NK) cell profiles in endometriosis that may predict embryo implantation. Study participants had a surgical diagnosis of endometriosis-associated infertility. Endometrial tissue and peripheral blood were obtained from 58 women. Thirty-three patients underwent artificial reproductive technology (IVF, ICSI, or IUI) within a mean of 9.5months of surgery. NK and hematopoietic progenitor cells from endometrium and blood were analyzed by flow cytometry. Successful implantation was defined as a positive pregnancy test. In successful implantation, populations of endometrial CD34+ hematopoietic stem cells were higher (3.97% vs 0.69%; P<.0004), and coexpression of NK cell marker CD56 was increased (81.1% vs 60.9%; P<.034) compared with patients who had failed implantation. In contrast, levels of blood NK progenitors were similar in both groups. Our study revealed that uterine NK progenitor cell populations are markedly different in patients with endometriosis who proceed to successful or failed embryo implantation and may define a novel predictor of implantation success. Our findings also highlight the fundamental differences inherent in NK cell repertoires between blood and uterine compartments.

Rapid loss of group 1 innate lymphoid cells during blood stage Plasmodium infection.

ObjectivesInnate lymphoid cells (ILCs) share many characteristics with CD4+ T cells, and group 1 ILCs share a requirement for T‐bet and the ability to produce IFNγ with T helper 1 (Th1) cells. Given this similarity, and the importance of Th1 cells for protection against intracellular protozoan parasites, we aimed to characterise the role of group 1 ILCs during Plasmodium infection.MethodsWe quantified group 1 ILCs in peripheral blood collected from subjects infected with with Plasmodium falciparum 3D7 as part of a controlled human malaria infection study, and in the liver and spleens of Pc AS‐infected mice. We used genetically‐modified mouse models, as well as cell‐depletion methods in mice to characterise the role of group 1 ILCs during Pc AS infection.ResultsIn a controlled human malaria infection study, we found that the frequencies of circulating ILC1s and NK cells decreased as infection progressed but recovered after volunteers were treated with antiparasitic drug. A similar observation was made for liver and splenic ILC1s in P. chabaudi chabaudi AS (Pc AS)‐infected mice. The decrease in mouse liver ILC1 frequencies was associated with increased apoptosis. We also identified a population of cells within the liver and spleen that expressed both ILC1 and NK cell markers, indicative of plasticity between these two cell lineages. Studies using genetic and cell‐depletion approaches indicated that group 1 ILCs have a limited role in antiparasitic immunity during Pc AS infection in mice.DiscussionOur results are consistent with a previous study indicating a limited role for natural killer (NK) cells during Plasmodium chabaudi infection in mice. Additionally, a recent study reported the redundancy of ILCs in humans with competent B and T cells. Nonetheless, our results do not rule out a role for group 1 ILCs in human malaria in endemic settings given that blood stage infection was initiated intravenously in our experimental models, and thus bypassed the liver stage of infection, which may influence the immune response during the blood stage.ConclusionOur results show that ILC1s are lost early during mouse and human malaria, and this observation may help to explain the limited role for these cells in controlling blood stage infection.

Complexity and function of natural killer T cells with potential application to hepatic transplant survival.

One of the major innate-like lymphocyte populations enriched in the liver consists of natural killer T (NKT) cells, which recognize self and foreign lipid antigens presented by the nonpolymorphic class I major histocompatibility complex-like molecule CD1d. NKT cells express natural killer cell markers as well as T cell receptors (TCRs) and can be classified into 2 categories: type I NKT cells use a semi-invariant TCR, whereas type II NKT cells express diverse but still limited TCRs. An emerging body of evidence points to their opposing roles in inflammation, including ischemia/reperfusion injury. Improved understanding of their roles in experimental models as well as in humans and the means by which their function can be manipulated may provide therapeutic benefit in liver diseases and in organ transplantation. Liver Transplantation 23 1589-1592 2017 AASLD.

CD56+ immune cell infiltration and MICA are decreased in breast lobules with fibrocystic changes

PurposeWhile the role of natural killer (NK) cells in breast cancer therapy has been investigated, little information is known about NK cell function and presence in nonmalignant and premalignant breast tissue. Here, we investigate and quantify NK cell marker CD56 and activating ligand MICA in breast tissue with benign breast disease.MethodsSerial tissue sections from 88 subjects, 44 with benign breast disease (BBD) who remained cancer-free, and 44 with BBD who later developed cancer, were stained with H&E, anti-MICA, and anti-CD56. Up to ten representative lobules were identified on each section. Using digital image analysis, MICA and CD56 densities were determined for each lobule, reported as percent of pixels in the lobule that registered as stained by each antibody. Analyses were performed on a per-subject and per-lobule basis.ResultsPer-subject multivariate analyses showed associations of CD56 and MICA with age: CD56 was increased in older subjects (p = 0.03), while MICA was increased in younger subjects (p = 0.005). Per-lobule analyses showed that CD56 and MICA levels were both decreased in lobules with fibrocystic change, with median levels of CD56 and MICA staining, respectively, at 0.31 and 7.0% in fibrocystic lobules compared to 0.76 and 12.2% in lobules without fibrocystic change (p < 0.001 for each). Among fibrocystic lobules, proliferative/atypical lobules showed significantly lower expression compared to nonproliferative lobules for MICA (p = 0.02) but not for CD56 (p = 0.80).ConclusionLevels of CD56+ NK cells and activating ligand MICA were decreased in breast lobules with fibrocystic change, and MICA levels showed a significant stepwise decrease with increasing histopathologic abnormality. MICA levels were also significantly decreased in older subjects, who generally have higher risk of developing cancer. These findings advance a model in which MICA promotes cytotoxic activity in CD56+ NK cells to protect against tumorigenesis in breast lobules, and suggest further research is warranted.

Increased NK cell immunity in a transgenic mouse model of NKp46 overexpression

Natural Killer (NK) cells employ activating receptors like the Natural Cytotoxicity Receptors (NCRs: NKp30, NKp44 and NKp46), of which only NKp46 has a mouse orthologue (Ncr1), to eliminate abnormal cells. NKp46/Ncr1 is considered a selective marker for NK cells, although it is also found on a subset of ILCs, where it appears to be without function. The influenza virus hemagglutinin (HA) was the first ligand identified for Ncr1/NKp46 followed by other viral, bacterial and even fungal ligands. NKp46/Ncr1 also recognizes unknown self and tumor ligands. Here we describe the generation of a transgenic mouse where the Ncr1 gene is expressed in the Rosa locus, preceded by a floxed stop sequence allowing Ncr1/NKp46 expression in various tissues upon crossing with Cre transgenic mouse lines. Surprisingly, while several crossings were attempted, Ncr1 overexpression was successful only where cre recombinase expression was dependent on the Ncr1 promoter. Ncr1 overexpression in NK cells increased NK cell immunity in two hallmark Ncr1 related pathologies, influenza virus infection and B16 melanoma. These data suggest that increasing NK cell cytotoxicity by enforced NKp46/Ncr1 expression serves as a potential therapeutic opportunity for the treatment of various pathologies, and in immunotherapy.

Emerging targets in cancer immunotherapy.

The first generation of immune checkpoint inhibitors (anti-CTLA-4 and anti-PD-1/PD-L1) targeted natural immune homeostasis pathways, co-opted by cancers, to drive anti-tumor immune responses. These agents led to unprecedented results in patients with previously incurable metastatic disease and may become first-line therapies for some advanced cancers. However, these agents are efficacious in only a minority of patients. Newer strategies are becoming available that target additional immunomodulatory mechanisms to activate patients' own anti-tumor immune responses. Herein, we present a succinct summary of emerging immune targets with reported pre-clinical efficacy that have progressed to active investigation in clinical trials. These emerging targets include co-inhibitory and co-stimulatory markers of the innate and adaptive immune system. In this review, we discuss: 1) T lymphocyte markers: Lymphocyte Activation Gene 3 [LAG-3], T-cell Immunoglobulin- and Mucin-domain-containing molecule 3 [TIM-3], V-domain containing Ig Suppressor of T cell Activation [VISTA], T cell ImmunoGlobulin and ITIM domain [TIGIT], B7-H3, Inducible T-cell Co-stimulator [ICOS/ICOS-L], CD27/CD70, and Glucocorticoid-Induced TNF Receptor [GITR]; 2) macrophage markers: CD47/Signal-Regulatory Protein alpha [SIRPα] and Indoleamine-2,3-Dioxygenase [IDO]; and 3) natural killer cell markers: CD94/NKG2A and the Killer Immunoglobulin-like receptor [KIR] family. Finally, we briefly highlight combination strategies and potential biomarkers of response and resistance to these cancer immunotherapies.

Decidual Natural Killer Cells (Cd56+) Population in the Placental Bed in Accidental Hemorrhage

Background: Accidental hemorrhage is defined as abnormal complete or partial separation of normally implanted placenta after 20 weeks of gestation and prior to birth. Risk factors which have been found associated with accidental hemorrhage include maternal age, parity, smoking, hypertension, past history of accidental hemorrhage, thrombophilic disorders, abdominal trauma and polyhydramnios. Aim of the Work: The aim of our study was to find if there is any role for decidual natural killer cells in cases with placental abruption. Patients and Methods: This is a case control study in which 60 pregnant women recruited from Obstetric Department of Ain Shams University Maternity Hospital. Patients were subjected to emergency cesarean section. Multiple tissue biopsies (5 mm thick) were taken from the decidua basalis of the placental bed and immunostained for decidual CD 56+ve bright natural killer cell marker. Results: Our results show that there was a highly statistically significant difference between the study and control group as regard immunohistochemical scores (according to CD 56+ %), In control group: score 0 = 0.0%, score 1+ = 0.0%, score 2+ = 18.5%, score 3+ = 29.6%, score 4+ = 51.9% while in the study group: score 0 = 25.9%, score 1+ = 40.7%, score 2+ = 29.6%, score 3+ = 3.7%, score 4+ = 0.0%; (Chi square 42.133 FE) and (P. value = 0.000). Also there was a highly statistically significant difference between the study and control group as regard dNK cells density (uNK cells as a percentage of total stromal cells), in control group: low density = 18.5% and high density = 81.5% while in the study group: low density = 96.3% and high density = 3.7%; (Chi square 33.400 FE) and (P. value = 0.000). Conclusion: These findings suggest that low dNK score and density was associated with cases of placental abruption.