Influence of in vitro IL-2 or IL-15 alone or in combination with Hsp-70-derived 14-mer peptide (TKD) on the expression of NK cell activatory and inhibitory receptors

Exploring Natural Killer Cell Testing in Embryo Implantation and Reproductive Failure: An Overview of Techniques and Controversies

The blastocyst nidation is the most crucial stage to a successful pregnancy, as the white cells work to promote a favorable endometrial microenvironment for this process. Intriguingly, this implantation window lasts, on average, 6 days in most regular women, and its quality is affected by many pathological conditions. Since the grounds of reproductive failure in healthy couples are still uncharted, studies have widely suggested a potential hostile role of the immune system in the equilibrium of the maternal-fetal interface. In recent years, natural killer cells have been the highlight as they represent the greatest lymphocyte in the uterus and have immune surveillance through cytotoxicity during the implantation window. This review explored the main techniques used for natural killer (NK) cell testing in the implantation window over the last 13 years on the PubMed® database. Of 2167 published articles potentially relevant for the review, only thirty-three were about cell evaluation in healthy women, met the inclusion criteria, and had their methodology critically analyzed. Here, we bring a summary from the study group and sample collection to evidence comments about their findings and correlations. Meanwhile, we also summarize the current relationship between NK cells and endometrial receptivity with reproductive failure to help enhance the possibilities for future research. In conclusion, our overview points out that restricted and unstandardized methods support the controversy between the NK population and unsuccessful embryo implantation, which is an obstacle to studying why healthy eggs do not thrive and finding a solution for one of the most controversial topics in human reproduction.

Natural killer cells for pancreatic cancer immunotherapy: Role of nanoparticles

Advanced pancreatic cancer patients have a dismal prognosis despite advances in integrative therapy. The field of tumor immunology has witnessed significant advancements for cancer treatment. However, immunotherapy for pancreatic cancer is not very effective due to its highly complex tumor microenvironment (TME). Natural killer (NK) cells are lymphocytes that play an important role in the innate immune system. NK cells do not require antigen pre-sensitization, nor are they confined by the major histocompatibility complex (MHC). NK cells have the potential to eliminate cancer cells through CAR-dependent and CAR-independent pathways, demonstrating reduced levels of systemic toxicity in the process. The availability of several potential sources of NK cells is an additional benefit that contributes to meeting the therapeutic criteria. Adding nanotechnology to enhance the functions of effector NK cells is also an appealing strategy. This article primarily discusses various approaches recently been utilized to enhance the NK functions for the treatment of pancreatic cancer. In addition, new advances in boosting NK cell therapeutic efficacy by nanoparticle mediation are presented, with a focus on pancreatic cancer.

Monalizumab efficacy correlates with HLA-E surface expression and NK cell activity in head and neck squamous carcinoma cell lines

PURPOSE

NKG2A, an inhibitory receptor expressed on NK cells and T cells, leads to immune evasion by binding to HLA-E expressed on cancer cells. Here, we investigated the relationship between HLA-E surface expression on head and neck squamous cell carcinoma (HNSCC) cell lines and the efficacy of monalizumab, an NKG2A inhibitor, in promoting NK cell activity.

METHODS

Six HNSCC cell lines were used as target cells. After exposure to IFN- γ, HLA-E surface expression on HNSCC cell lines was measured by flow cytometry. Peripheral blood mononuclear cells (PBMCs) from healthy donors and isolated NK cells were used as effector cells. NK cells were stimulated by treatment with IL-2 and IL-15 for 5 days, and NK cell-induced cytotoxicity was analyzed by CD107a degranulation and 51Cr release assays.

RESULTS

We confirmed that HLA-E expression was increased by IFN-γ secreted by NK cells and that HLA-E expression was different for each cell line upon exposure to IFN-γ. Cell lines with high HLA-E expression showed stronger inhibition of NK cell cytotoxicity, and efficacy of monalizumab was high. Combination with cetuximab increased the efficacy of monalizumab. In addition, stimulation of isolated NK cells with IL-2 and IL-15 increased the efficacy of monalizumab, even in the HLA-E low groups.

CONCLUSION

Monalizumab efficacy was correlated with HLA-E surface expression and was enhanced when NK cell activity was increased by cetuximab or cytokines. These results suggest that monalizumab may be potent against HLA-E-positive tumors and that monalizumab efficacy could be improved by promoting NK cell activity.

Natural peptides for immunological regulation in cancer therapy: Mechanism, facts and perspectives

Cancer incidence and mortality rates are increasing annually. Treatment with surgery, chemotherapy and radiation therapy (RT) is unsatisfactory because many patients have advanced disease at the initial diagnosis. However, the emergence of immunotherapy promises to be an effective strategy to improve the outcome of advanced tumors. Immune checkpoint antibodies, which are at the forefront of immunotherapy, have had significant success but still leave some cancer patients without benefit. For more cancer patients to benefit from immunotherapy, it is necessary to find new drugs and combination therapeutic strategies to improve the outcome of advanced cancer patients and achieve long-term tumor control or even eradication. Peptides are promising choices for tumor immunotherapy drugs because they have the advantages of low production cost, high sequence selectivity, high tissue permeability, low toxicity and low immunogenicity etc., and the adjuvant matching and technologies like nanotechnology can further optimize the effects of peptides. In this review, we present the current status and mechanisms of research on peptides targeting multiple immune cells (T cells, natural killer (NK) cells, dendritic cells (DCs), tumor-associated macrophages (TAMs), regulatory T cells (Tregs)) and immune checkpoints in tumor immunotherapy; and we summarize the current status of research on peptide-based tumor immunotherapy in combination with other therapies including RT, chemotherapy, surgery, targeted therapy, cytokine therapy, adoptive cell therapy (ACT) and cancer vaccines. Finally, we discuss the current status of peptide applications in mRNA vaccine delivery.

The Natural Cytotoxicity Receptor NKp44 (NCR2, CD336) Is Expressed on the Majority of Porcine NK Cells Ex Vivo Without Stimulation

Natural killer (NK) cells have been studied extensively in humans and mice for their vital role in the vertebrate innate immune system. They are known to rapidly eliminate tumors or virus infected cells in an immune response utilizing their lytic properties. The natural cytotoxicity receptors (NCRs) NKp30 (NCR3), NKp44 (NCR2), and NKp46 (NCR1) are important mediators of NK-cell cytotoxicity. NKp44 expression was reported for NK cells in humans as well as in some non-human primates and found exclusively on activated NK cells. Previously, no information was available on NKp44 protein expression and its role in porcine lymphocytes due to the lack of species-specific monoclonal antibodies (mAbs). For this study, porcine-specific anti-NKp44 mAbs were generated and their reactivity was tested on blood and tissue derived NK cells in pigs of different age classes. Interestingly, NKp44 expression was detected ex vivo already on resting NK cells; moreover, the frequency of NKp44⁺ NK cells was higher than that of NKp46⁺ NK cells in most animals analyzed. Upon in vitro stimulation with IL-2 or IL-15, the frequency of NKp44⁺ NK cells, as well as the intensity of NKp44 expression at the single cell level, were increased. Since little is known about swine NK cells, the generation of a mAb (clone 54-1) against NKp44 will greatly aid in elucidating the mechanisms underlying the differentiation, functionality, and activation of porcine NK cells.

Natural Killer Cells in the Malignant Niche of Multiple Myeloma

Natural killer (NK) cells represent a subset of CD3- CD7+ CD56+/dim lymphocytes with cytotoxic and suppressor activity against virus-infected cells and cancer cells. The overall potential of NK cells has brought them to the spotlight of targeted immunotherapy in solid and hematological malignancies, including multiple myeloma (MM). Nonetheless, NK cells are subjected to a variety of cancer defense mechanisms, leading to impaired maturation, chemotaxis, target recognition, and killing. This review aims to summarize the available and most current knowledge about cancer-related impairment of NK cell function occurring in MM.

Natural killer cell‑based immunotherapy for lung cancer: Challenges and perspectives (Review)

Despite the marked success of molecular targeted therapy in lung cancer in this era of personalized medicine, its efficacy has been limited by the presence of resistance mechanisms. The prognosis of patients with lung cancer remains poor, and there is an unmet need to develop more effective therapies to improve clinical outcomes. The increasing insight into the human immune system has led to breakthroughs in immunotherapy and has prompted research interest in employing immunotherapy to treat lung cancer. Natural killer (NK) cells, which serve as the first line of defense against tumors, can induce the innate and adaptive immune responses. Therefore, the use of NK cells for the development of novel lung-cancer immunotherapy strategies is promising. A growing number of novel approaches that boost NK cell antitumor immunity and expand NK cell populations ex vivo now provide a platform for the development of antitumor immunotherapy. The present review outlined the biology of NK cells, summarized the role of NK cells in lung cancer and the effect of the tumor microenvironment on NK cells, highlighted the potential of NK cell-based immunotherapy as an effective therapeutic strategy for lung cancer and discussed future directions.

Exosomal miRNAs in urine associated with children's cardiorenal parameters: a cross-sectional study

Aims:

The authors sought to examine associations between urinary exosomal miRNAs (exo-miRs), emerging biomarkers of renal health, and cardiorenal outcomes in early childhood.

Materials & methods:

The authors extracted exo-miRs in urine from 88 healthy Mexican children aged 4–6 years. The authors measured associations between 193 exo-miRs and cardiorenal outcomes: systolic/diastolic blood pressure, estimated glomerular filtration rate and urinary sodium and potassium levels. The authors adjusted for age, sex, BMI, socioeconomic status, indoor tobacco smoke exposure and urine specific gravity.

Results:

Multiple exo-miRs were identified meeting a false discovery rate threshold of q < 0.1. Specifically, three exo-miRs had increased expression with urinary sodium, 17 with urinary sodium-to-potassium ratio and one with decreased estimated glomerular filtration rate.

Conclusions:

These results highlight urinary exo-miRs as early-life biomarkers of children's cardiorenal health.

Sialylation of Human Natural Killer (NK) Cells is Regulated by IL-2

Sialic acids are terminal sugars on the cell surface that are found on all cell types including immune cells like natural killer (NK) cells. The attachment of sialic acids to different glycan structures is catalyzed by sialyltransferases in the Golgi. However, the expression pattern of sialyltransferases in NK cells and their expression after activation has not yet been analyzed. Therefore, the present study determines which sialyltransferases are expressed in human NK cells and if activation with IL-2 changes the sialylation of NK cells. The expression of sialyltransferases was analyzed in the three human NK cell lines NK-92, NKL, KHYG-1 and primary NK cells. NK-92 cells were cultured in the absence or presence of IL-2, and changes in the sialyltransferase expression were measured by qPCR. Furthermore, specific sialylation was investigated by flow cytometry. In addition, polySia and NCAM were measured by Western blot analyses. IL-2 leads to a reduced expression of ST8SIA1, ST6GAL1 and ST3GAL1. α-2,3-Sialylation remained unchanged, while α-2,6-sialylation was increased after IL-2 stimulation. Moreover, an increase in the amount of NCAM and polySia was observed in IL-2-activated NK cells, whereas GD3 ganglioside was decreased. In this study, all sialyltransferases that were expressed in NK cells could be identified. IL-2 regulates the expression of some sialyltransferases and leads to changes in the sialylation of NK cells.

Roles of Extracellular HSPs as Biomarkers in Immune Surveillance and Immune Evasion

Extracellular heat shock proteins (ex-HSPs) have been found in exosomes, oncosomes, membrane surfaces, as well as free HSP in cancer and various pathological conditions, also known as alarmins. Such ex-HSPs include HSP90 (α, β, Gp96, Trap1), HSP70, and large and small HSPs. Production of HSPs is coordinately induced by heat shock factor 1 (HSF1) and hypoxia-inducible factor 1 (HIF-1), while matrix metalloproteinase 3 (MMP-3) and heterochromatin protein 1 are novel inducers of HSPs. Oncosomes released by tumor cells are a major aspect of the resistance-associated secretory phenotype (RASP) by which immune evasion can be established. The concepts of RASP are: (i) releases of ex-HSP and HSP-rich oncosomes are essential in RASP, by which molecular co-transfer of HSPs with oncogenic factors to recipient cells can promote cancer progression and resistance against stresses such as hypoxia, radiation, drugs, and immune systems; (ii) RASP of tumor cells can eject anticancer drugs, targeted therapeutics, and immune checkpoint inhibitors with oncosomes; (iii) cytotoxic lipids can be also released from tumor cells as RASP. ex-HSP and membrane-surface HSP (mHSP) play immunostimulatory roles recognized by CD91+ scavenger receptor expressed by endothelial cells-1 (SREC-1)+ Toll-like receptors (TLRs)+ antigen-presenting cells, leading to antigen cross-presentation and T cell cross-priming, as well as by CD94+ natural killer cells, leading to tumor cytolysis. On the other hand, ex-HSP/CD91 signaling in cancer cells promotes cancer progression. HSPs in body fluids are potential biomarkers detectable by liquid biopsies in cancers and tissue-damaged diseases. HSP-based vaccines, inhibitors, and RNAi therapeutics are also reviewed.

Interleukin-15-Stimulated Natural Killer Cells Clear HIV-1-Infected Cells following Latency Reversal Ex Vivo

Current efforts toward human immunodeficiency virus (HIV) eradication include approaches to augment immune recognition and elimination of persistently infected cells following latency reversal. Natural killer (NK) cells, the main effectors of the innate immune system, recognize and clear targets using different mechanisms than CD8⁺ T cells, offering an alternative or complementary approach for HIV clearance strategies. We assessed the impact of interleukin 15 (IL-15) treatment on NK cell function and the potential for stimulated NK cells to clear the HIV reservoir. We measured NK cell receptor expression, antibody-dependent cell-mediated cytotoxicity (ADCC), cytotoxicity, interferon gamma (IFN-γ) production, and antiviral activity in autologous HIV replication systems. All NK cell functions were uniformly improved by IL-15, and, more importantly, IL-15-treated NK cells were able to clear latently HIV-infected cells after exposure to vorinostat, a clinically relevant latency-reversing agent. We also demonstrate that NK cells from HIV-infected individuals aviremic on antiretroviral therapy can be efficiently stimulated with IL-15. Our work opens a promising line of investigation leading to future immunotherapies to clear persistent HIV infection using NK cells.IMPORTANCE In the search for an HIV cure, strategies to enhance immune function to allow recognition and clearance of HIV-infected cells following latency reversal are being evaluated. Natural killer (NK) cells possess characteristics that can be exploited for immunotherapy against persistent HIV infection. We demonstrate that NK cells from HIV-positive donors can be strongly stimulated with IL-15, improving their antiviral and cytotoxic potential and, more importantly, clearing HIV-infected cells after latency reversal with a clinically relevant drug. Our results encourage further investigation to design NK cell-based immunotherapies to achieve HIV eradication.

Diversification of human NK cells: Lessons from deep profiling

NK cells are innate lymphocytes with important roles in immunoregulation, immunosurveillance, and cytokine production. Originally defined on the functional basis of their "natural" ability to lyse tumor targets and thought to be a relatively homogeneous group of lymphocytes, NK cells possess a remarkable degree of phenotypic and functional diversity due to the combinatorial expression of an array of activating and inhibitory receptors. Diversification of NK cells is multifaceted: mechanisms of NK cell education that promote self-tolerance result in a heterogeneous repertoire that further diversifies upon encounters with viral pathogens. Here, we review the genetic, developmental, and environmental sources of NK cell diversity with a particular focus on deep profiling and single-cell technologies that will enable a more thorough and accurate dissection of this intricate and poorly understood lymphocyte lineage.

IL15 Infusion of Cancer Patients Expands the Subpopulation of Cytotoxic CD56bright NK Cells and Increases NK-Cell Cytokine Release Capabilities

The cytokine IL15 is required for survival and activation of natural killer (NK) cells as well as expansion of NK-cell populations. Here, we compare the effects of continuous IL15 infusions on NK-cell subpopulations in cancer patients. Infusions affected the CD56^bright NK-cell subpopulation in that the expansion rates exceeded those of CD56^dim NK-cell populations with a 350-fold increase in their total cell numbers compared with 20-fold expansion for the CD56^dim subset. CD56^bright NK cells responded with increased cytokine release to various stimuli, as expected given their immunoregulatory functions. Moreover, CD56^bright NK cells gained the ability to kill various target cells at levels that are typical for CD56^dim NK cells. Some increased cytotoxic activities were also observed for CD56^dim NK cells. IL15 infusions induced expression changes on the surface of both NK-cell subsets, resulting in a previously undescribed and similar phenotype. These data suggest that IL15 infusions expand and arm CD56^bright NK cells that alone or in combination with tumor-targeting antibodies may be useful in the treatment of cancer. Cancer Immunol Res; 5(10); 929-38. ©2017 AACR.

Cytokine-induced killer cell therapy for modulating regulatory T cells in patients with non-small cell lung cancer

Previous studies have reported that regulatory T cells (Tregs), which are physiologically engaged in the maintenance of immunological self-tolerance, have a critical role in the regulation of the antitumor immune response. Targeting Tregs has the potential to augment cancer vaccine approaches. The current study therefore aimed to evaluate the role of cytokine-induced killer (CIK) cell infusion in modulating Tregs in patients with non-small cell lung cancer (NSCLC). A total of 15 patients with advanced NSCLC were treated by an infusion of CIK cells derived from autologous peripheral blood mononuclear cells (PBMCs). By using flow cytometry and liquid chip analysis, subsets of T cells and natural killer (NK) cells in peripheral blood, and plasma cytokine profiles in the treated patients, were analyzed at 2 and 4 weeks after CIK cell infusion. Cytotoxicity of PBMCs (n=15) and NK cells (n=6) isolated from NSCLC patients was evaluated before and after CIK cell therapy. Progression-free survival (PFS) and overall survival (OS) were also assessed. Analysis of the immune cell populations before and after treatment showed a significant increase in NK cells (P<0.05) concomitant with a significant decrease in Tregs (P<0.01) at 2 weeks post-infusion of CIK cells compared with the baseline. NK group 2D receptor (NKG2D) expression on NK cells was also significantly increased at 2 weeks post-infusion compared with the baseline (P<0.05). There was a positive correlation between NKG2D expression and the infusion number of CIK cells (P<0.05). When evaluated at 2 weeks after CIK cell therapy, the cytotoxicity of PBMCs and isolated NK cells was significantly increased compared with the baseline (P<0.01 and P<0.05). Correspondingly, plasma cytokine profiles showed significant enhancement of the following antitumor cytokines: Interferon (IFN)-γ (P<0.05), IFN-γ-inducible protein 10 (P<0.01), tumor necrosis factor-α (P<0.001), granulocyte-macrophage colony-stimulating factor (P<0.01), monocyte chemotactic protein-3 (P<0.01) and interleukin-21 (P<0.05) at 2 weeks post-infusion, compared with the baseline. At the same time, the expression of transforming growth factor-β1, which is primarily produced by Tregs, was significantly decreased compared with the baseline (P<0.05). Median PFS and OS in the CIK cell treatment group were significantly increased compared with the control group (PFS, 9.98 vs. 5.44 months, P=0.038; OS, 24.17 vs. 20.19 months, P=0.048). No severe side-effects were observed during the treatment period. In conclusion, CIK cell therapy was able to suppress Tregs and enhance the antitumor immunity of NK cells in advanced NSCLC patients. Therefore, CIK cell treatment may improve PFS and OS in patients with advanced NSCLC. CIK cell infusion may have therapeutic value for patients with advanced NSCLC, as a treatment that can be combined with chemotherapy and radiotherapy.

Interleukin-15 stimulates natural killer cell-mediated killing of both human pancreatic cancer and stellate cells

Pancreatic ductal adenocarcinoma (PDAC) is the 4^th leading cause of cancer-related death in Western countries with a 5-year survival rate below 5%. One of the hallmarks of this cancer is the strong desmoplastic reaction within the tumor microenvironment (TME), orchestrated by activated pancreatic stellate cells (PSC). This results in a functional and mechanical shield which causes resistance to conventional therapies. Aiming to overcome this resistance by tackling the stromal shield, we assessed for the first time the capacity of IL-15 stimulated natural killer (NK) cells to kill PSC and pancreatic cancer cells (PCC). The potency of IL-15 to promote NK cell-mediated killing was evaluated phenotypically and functionally. In addition, NK cell and immune checkpoint ligands on PSC were charted. We demonstrate that IL-15 activated NK cells kill both PCC and PSC lines (range 9-35% and 20-50%, respectively) in a contact-dependent manner and significantly higher as compared to resting NK cells. Improved killing of these pancreatic cell lines is, at least partly, dependent on IL-15 induced upregulation of TIM-3 and NKG2D. Furthermore, we confirm significant killing of primary PSC by IL-15 activated NK cells in an ex vivo autologous system. Screening for potential targets for immunotherapeutic strategies, we demonstrate surface expression of both inhibitory (PD-L1, PD-L2) and activating (MICA/B, ULBPs and Galectin-9) ligands on primary PSC. These data underscore the therapeutic potential of IL-15 to promote NK cell-mediated cytotoxicity as a treatment of pancreatic cancer and provide promising future targets to tackle remaining PSC.

Study of Natural Cytotoxicity Receptors in Patients with HIV/AIDS and Cancer: A Cross-Sectional Study

The NCR receptors play a fundamental role in the cytotoxicity mediated by NK cells against tumor cells. In the current study, we investigated possible HIV/AIDS-related changes in the expression of the NCR receptors comparing healthy donors, HIV/AIDS patients, and HIV/AIDS patients with cancer (HIV/AIDSWC). The NCRs were quantified in NK cells (NK^dim and NK^bright) and T lymphocytes from peripheral blood samples by flow cytometry. We found a significant decrease in the frequency of NK cells expressing NKp46 in HIV/AIDS group (p = 0.0012). There was a decrease in the frequency of NK cells expressing NKp46 in the HIV/AIDSWC group; however, this was not statistically significant. We found a significant decrease in the frequency of NK cells expressing NKp30 in the HIV/AIDS group (p = 0.0144). There was a decrease in the frequency of NK cells expressing NKp30 and in the HIV/AIDSWC group, but this was not statistically significant. There were no changes in the distribution of NK cells and their subtypes in both groups.

Influence of In Vitro IL-2 or IL-15 Alone or in Combination with Hsp 70 Derived 14-Mer Peptide (TKD) on the Expression of NK Cell Activatory and Inhibitory Receptors on Peripheral Blood T Cells, B Cells and NKT Cells

Previous studies from Multhoff and colleagues reported that plasma membrane Hsp70 acts as a tumour-specific recognition structure for activated NK cells, and that the incubation of NK cells with Hsp70 and/or a 14-mer peptide derived from the N-terminal sequence of Hsp70 (TKDNNLLGRFELSG, TKD, aa 450–463) plus a low dose of IL-2 triggers NK cell proliferation and migration, and their capacity to kill cancer cells expressing membrane Hsp70. Herein, we have used flow cytometry to determine the influence of in vitro stimulation of peripheral blood mononuclear cells from healthy individuals with IL-2 or IL-15, either alone or in combination with TKD peptide on the cell surface expression of CD94, NK cell activatory receptors (CD16, NK2D, NKG2C, NKp30, NKp44, NKp46, NKp80, KIR2DL4, DNAM-1 and LAMP1) and NK cell inhibitory receptors (NKG2A, KIR2DL2/L3, LIR1/ILT-2 and NKR-P1A) by CD3+CD56+ (NKT), CD3+CD4+, CD3+CD8+ and CD19+ populations. NKG2D, DNAM-1, LAMP1 and NKR-P1A expression was upregulated after the stimulation with IL-2 or IL-15 alone or in combination with TKD in NKT, CD8+ T cells and B cells. CD94 was upregulated in NKT and CD8+ T cells. Concurrently, an increase in a number of CD8+ T cells expressing LIR1/ILT-2 and CD4+ T cells positive for NKR-P1A was observed. The proportion of CD8+ T cells that expressed NKG2D was higher after IL-2/TKD treatment, when compared with IL-2 treatment alone. In comparison with IL-15 alone, IL-15/TKD treatment increased the proportion of NKT cells that were positive for CD94, LAMP1 and NKRP-1A. The more potent effect of IL-15/TKD on cell surface expression of NKG2D, LIR1/ILT-2 and NKRP-1A was observed in B cells compared with IL-15 alone. However, this increase was not of statistical significance. IL-2/TKD induced significant upregulation of LAMP1 in CD8+ T cells compared with IL-2 alone. Besides NK cells, other immunocompetent cells present within the fraction of peripheral blood mononuclear cells were influenced by the treatment with low-dose interleukins themselves or in combination with hsp70 derived (TKD) peptide.

Human NK Cell Diversity in Viral Infection: Ramifications of Ramification

Natural killer (NK) cells are a unique lymphocyte lineage with remarkable agility in the rapid destruction of virus-infected cells. They are also the most poorly understood class of lymphocyte. A spectrum of activating and inhibitory receptors at the NK cell surface leads to an unusual and difficult-to-study mechanism of cellular recognition, as well as a very high capacity for diversity at the single-cell level. Here, we review the evidence for the role of NK cells in the earliest stage of human viral infection, and in its prevention. We argue that single-cell diversity is a logical evolutionary adaptation for their position in the immune response and contributes to their ability to kill virus-infected cells. Finally, we look to the future, where emerging single-cell technologies will enable a new generation of rigorous and clinically relevant studies on NK cells accounting for all of their unique and diverse characteristics.

KIR2DL4 expression rather than its single nucleotide polymorphisms correlates with pre-eclampsia

OBJECTIVE

To evaluate the single nucleotide polymorphisms and expression of KIR2DL4 (killer cell immunoglobulin-like receptors) gene in pre-eclampsia patients.

METHODS

KIR2DL4 gene polymorphisms were detected in 100 patients with pre-eclampsia and 100 healthy pregnant women, respectively, by using PCR-SS. Then, the expression of KIR2DL4 was measured in 5 cases of placentas tissues with pre-eclampsia and normal pregnancies by using qRT-PCR.

RESULTS

Compared with healthy controls, 16 loci of single nucleotide polymorphisms (SNP) were identified in pre-eclampsia patients, including 7 new polymorphisms loci. But, no significant difference was found in genotype distributions and allele frequencies in pre-eclampsia and controls (P>0.05). However, qRT-PCR results showed that KIR2DL4 mRNA in placenta tissues with pre-eclampsia was significantly lower than those with normal pregnancy, and the difference was statistically significant.

CONCLUSION

Decreased level of KIR2DL4 rather than its SNP is correlated with the susceptibility of pre-eclampsia.

Critical roles of co-activation receptor DNAX accessory molecule-1 in natural killer cell immunity

Natural killer (NK) cells, which can exert early and powerful anti-tumour and anti-viral responses, are important components of the innate immune system. DNAX accessory molecule-1 (DNAM-1) is an activating receptor molecule expressed on the surface of NK cells. Recent findings suggest that DNAM-1 is a critical regulator of NK cell biology. DNAM-1 is involved in NK cell education and differentiation, and also plays a pivotal role in the development of cancer, viral infections and immune-related diseases. However, tumours and viruses have developed multiple mechanisms to evade the immune system. They are able to impair DNAM-1 activity by targeting the DNAM-1 receptor-ligand system. We have reviewed the roles of DNAM-1, and its biological functions, with respect to NK cell biology and DNAM-1 chimeric antigen receptor-based immunotherapy.

Heat-Shock Proteins 70 Induce Pro-Inflammatory Maturation Program in Decidual CD1a(+) Dendritic Cells

PROBLEM

The aim of the study was to assess possible binding of a mixture of constitutive Hsc70 and inducible Hsp70 forms (HSP70) to Toll-like receptor (TLR) 4 and CD91 receptors on decidual CD1a(+) dendritic cells (DCs) and their influence on DCs maturation status.

METHOD OF STUDY

Immunohistology and immunofluorescence of paraffin-embedded first trimetester and term pregnancy decidua were performed together with flow cytometry detection of antigens in DCs after stimulation of decidual mononuclear cells with HSP70.

RESULTS

Hsc70 and Hsp70 labeling revealed intracellular and nuclear staining in trophoblast cells. The numbers of Hsc70(+) and Hsp70(+) cells of decidual tissue were higher in early pregnancy decidua than in decidua at term. HSP70 binds CD91 and TLR4 receptors on CD1a(+) DCs and increased the expression of CD83, HLA-DR, CD80, and CD86, but decreased CC receptor (CCR) 5. HSP70 increased CC ligand (CCL) 3 and CCL22. HSP70 in the concentration of 1 μg/mL increased the percentage of interferon-γ and interleukin (IL)-15-expressing cells over the cells expressing IL-4.

CONCLUSION

HSP70 binds CD91 and TLR4 on decidual CD1a(+) DCs, causes their maturation, and increases IL-15 in the context of Th1 cytokine/chemokine domination, which could support immune response harmful for ongoing pregnancy.

NK cell-based immunotherapies in Pediatric Oncology

The past decade has seen several anticancer immunotherapeutic strategies transition from "promising preclinical models" to treatments with proven clinical activity or benefit. In 2013, the journal Science selected the field of Cancer Immunotherapy as the overall number-1 breakthrough for the year in all of scientific research. In the setting of cancer immunotherapy for adult malignancies, many of these immunotherapy strategies have relied on the cancer patient's endogenous antitumor T-cell response. Although much promising research in pediatric oncology is similarly focused on T-cell reactivity, several pediatric malignancies themselves, or the chemo-radiotherapy used to achieve initial responses, can be associated with profound immune suppression, particularly of the T-cell system. A separate component of the immune system, also able to mediate antitumor effects and less suppressed by conventional cancer treatment, is the NK-cell system. In recent years, several distinct immunotherapeutic approaches that rely on the activity of NK cells have moved from preclinical development into clinical testing, and some have shown clear antitumor benefit. This review provides an overview of NK cell-based immunotherapy efforts that are directed toward childhood malignancies, with an emphasis on protocols that are already in clinical testing.

Two new cases of KIR3DP1, KIR2DL4-negative genotypes, one of which is also lacking KIR3DL2

The killer immunoglobulin-like receptor (KIR) genes KIR2DL4, KIR3DL2, and KIR3DP1 are present in virtually all humans. KIR2DL4 encodes a receptor present on uterine and decidual natural killer (NK) cells and some peripheral blood NK cells. Its only known ligand is the human leukocyte antigen-G molecule expressed on extravillous trophoblasts, and on tissues in some diseases. KIR3DL2 binds HLA-A*03 and HLA-A*11 as well as HLA-B*27 dimers, and microbial CpG DNA. KIR3DP1 is a pseudogene. During our immunogenetic studies we found two individuals, one from Lower Silesia district in Poland, and another from Western Ukraine, who were reproducibly negative for KIR2DL4 and KIR3DP1 genes, using three different PCR systems. Both individuals displayed very similar genotypes, possessing only KIR3DL3, KIR2DL3, KIR2DP1, KIR2DS1, and probably a rare variant of KIR2DL1. The Pole had also KIR3DL2, which the Ukrainian was apparently lacking. The Lower Silesia has been populated after the Second World War by a remarkable percentage with displaced people from Western Ukraine, which might contribute to genetic similarity of the two individuals described here.