Natural killers

BACKGROUND: Melioidosis is a neglected tropical disease endemic across South East Asia and Northern Australia. The etiological agent, Burkholderia pseudomallei (B.pseudomallei), is a Gram-negative, rod-shaped, motile bacterium residing in the soil and muddy water across endemic regions of the tropical world. The bacterium is known to cause persistent infections by remaining latent within host cells for prolonged duration. Reactivation of the recrudescent disease often occurs in elders whose immunity wanes...

Objective The main aim of this study was to investigate the ovarian reserve, menstruation, and lymphocyte subpopulation in systemic lupus erythematosus (SLE) patients of childbearing age. Methods We enrolled 40 SLE patients of childbearing age and 40 age-matched healthy controls. Anti-Müllerian hormone (AMH) was tested by electrochemiluminescence, and lymphocyte subsets were tested by flow cytometry. Menstruation situation was obtained by interview. Results The AMH level of the SLE group was significantly lower than that of the control group ( p < 0...

Objective: Exosomes are nanovesicles that are released from normal and tumor cells and are detectable in cell culture supernatant and human biological fluids. Although previous studies have explored exosomes released from cancer cells, little is understood regarding the functions of exosomes released by normal cells. Natural killer (NK) cells display rapid immunity to metastatic or hematological malignancies, and efforts have been undertaken to clinically exploit the antitumor properties of NK cells. However, the characteristics and functions of exosomes derived from NK cells remain unknown...

Human cytomegalovirus (HCMV) is a major human pathogen, causing serious diseases in immunocompromised populations and congenially infected neonates. One of the main immune cells acting against the virus are Natural Killer (NK) cells. Killing by NK cells is mediated by a small family of activating receptors such as NKp30 that interact with the cellular ligand B7-H6. The outcome of B7-H6-NKp30 interaction was, so far, mainly studied with regard to NK recognition and killing of tumors. Here, we demonstrated that the expression of B7-H6 is upregulated following HCMV infection and that HCMV uses two of its genes: US18 and US20, to interfere with B7-H6 surface expression, in a mechanism involving endosomal degradation, in order to evade NK cell recognition...

BACKGROUND: We systematically assessed the prognostic and predictive value of infiltrating adaptive and innate immune cells in a large cohort of patients with advanced mesothelioma. METHODS: A tissue microarray from 302 samples was constructed. Markers of adaptive immune response in T-cells (CD8(+), FOXP3(+), CD4(+), CD45RO(+), CD3(+)) and B-cells (CD20(+)), and of innate immune response; neutrophils (NP57(+)), natural killer cells (CD56(+)) and macrophages (CD68(+)) were evaluated...

PURPOSE OF REVIEW: In recent years, the rules of engagement between natural killer (NK) cells and their targets have become better defined with the identification of an array of NK surface molecules, notably the killer immunoglobulin-like (KIR) receptors and their ligands on target cells through which signals of activation or suppression of NK function are mediated. After allogeneic stem cell transplantation (SCT), the opportunity for NK cell activation can occur both in human leucocyte antigen (HLA) matched and HLA mismatched pairs...

The physiological changes that occur immediately following cancer surgeries initiate a chain of events that ultimately result in a short pro-, followed by a prolonged anti-, inflammatory period. Natural Killer (NK) cells are severely affected during this period in the recovering cancer patient. NK cells play a crucial role in anti-tumour immunity because of their innate ability to differentiate between malignant versus normal cells. Therefore, an opportunity arises in the aftermath of cancer surgery for residual cancer cells, including distant metastases, to gain a foothold in the absence of NK cell surveillance...

AIM: Natural cytotoxicity receptors (NCR) are unique markers that regulate natural killer (NK) cell cytotoxicity and cytokine production. In this study, we investigated the expression of NCR (NKp46, NKp44, and NKp30) and cytokine production in NK cells derived from the uterine endometrium of women with recurrent pregnancy loss (RPL). We also investigated the expression of NCR in peripheral blood NK cells in pregnant women with and without a history of RPL. METHODS: The expression of NCR (NKp46, NKp44, and NKp30) in NK cells (CD56(dim) and CD56(bright) ) in the uterine endometrium was analyzed using 3-color flow cytometry...

Mouse liver contains both Eomes-dependent conventional natural killer (cNK) cells and Tbet-dependent liver-resident type I innate lymphoid cells (ILC1). In order to better understand the role of ILC1, we attempted to generate mice that would lack liver ILC1, while retaining cNK, by conditional deletion of Tbet in NKp46+ cells. Here we report that the Ncr1 (iCre)Tbx21 (fl/fl) mouse has a roughly equivalent reduction in both the cNK and ILC1 compartments of the liver, limiting its utility for investigating the relative contributions of these two cell types in disease models...

Human leukocyte antigen (HLA) class I ligands and Killer immunoglobulin-like receptors (KIRs) regulate the cytolytic activity of natural killer (NK) cells and certain T cells. We examined their genetic predisposition to disease susceptibility and clinical phenotypes in Taiwanese ankylosing spondylitis (AS) patients. KIR genotyping and Human Leucocyte Antigen C (HLA-C) sequencing were performed in 653 Taiwanese AS patients and 952 healthy controls. KIR genotype distributions and HLA-C allele frequencies were compared in patients and controls and among patients with and without HLA-B27 positivity, early age onset and spinal syndesmophytes...

A prospective analysis of natural killer (NK) cell phenotype and function was performed on fresh peripheral blood samples from untreated patients with B-cell chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). Compared to healthy controls, CD56(dim) NK cells in CLL patients displayed reduced expression of the NKG2D activating receptor and increased CD27 expression, which indicates declines in mature cells. In addition, NK cells from CLL patients showed reduced degranulation responses toward transformed B cells alone or with rituximab and were more sensitive to activation-induced cell death...

Simultaneous reestablishment of p53/p19(Arf) and interferon-β pathways in melanoma cells culminates in a cell death process that displays features of necroptosis along with the release of immunogenic cell death molecules and unleashes an antitumor immune response mediated by natural killer cells, neutrophils as well as CD4(+) and CD8(+) T lymphocytes.

Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis are characterized by an increase in hepatic triglyceride content with infiltration of immune cells, which can cause steatohepatitis and hepatic insulin resistance. C-C chemokine receptor 7 (CCR7) is primarily expressed in immune cells, and CCR7 deficiency leads to the development of multi-organ autoimmunity, chronic renal disease, and autoimmune diabetes. Here, we investigated the effect of CCR7 on hepatic steatosis in a mouse model and its underlying mechanism...

BACKGROUND: HIV-1 viremia has been shown to induce several phenotypic and functional abnormalities in natural killer (NK) cells. To assess immune defects associated with HIV viremia, we examined NK cell function, differentiation status and phenotypic alterations based on expression of inhibitory and activating receptors on NK cells in HIV-1 subtype C chronically infected participants from Durban, South Africa. METHODS: NK cell phenotypic profiles were characterized by assessing Siglec-7, NKG2A and NKG2C markers on frozen peripheral blood mononuclear cells (PBMCs) from viremic, antiretroviral therapy (ART)-naïve HIV-1 chronically infected participants (n=23), HIV-1 chronically infected participants who have been on combination antiretroviral therapy (cART) for at least 12 months (n=23) compared to healthy donors (n=23)...

BACKGROUND AND AIMS: The administration of ex-vivo expanded Natural killer (NK) cells as potential antitumor effector cells appears to be suitable for effector cell-based immunotherapies in high-risk cancer patients. However, the GMP-conform manufacturing of clinical-grade NK cells at sufficiently high numbers represent a great challenge. Therefore, we improved and optimized previous expansion protocols for those effector cells through the use of newly developed culture medium, IL-21 and autologous feeder cells...

The metastatic spread of malignant cells to distant anatomical locations is a prominent cause of cancer-related death. Metastasis is governed by cancer-cell-intrinsic mechanisms that enable neoplastic cells to invade the local microenvironment, reach the circulation, and colonize distant sites, including the so-called epithelial-to-mesenchymal transition. Moreover, metastasis is regulated by microenvironmental and systemic processes, such as immunosurveillance. Here, we outline the cancer-cell-intrinsic and -extrinsic factors that regulate metastasis, discuss the key role of natural killer (NK) cells in the control of metastatic dissemination, and present potential therapeutic approaches to prevent or target metastatic disease by harnessing NK cells...

Large granular lymphocytic (LGL) leukemia is a rare form of low grade leukemia characterized by large cytotoxic T cells or natural killer cells on morphological examination. Immunosuppressive therapy is employed as first-line therapy. Treatment options in refractory cases include the anti-CD52 antibody alemtuzumab and purine analogues. We report a rare case that responded to the anti-CD20 monoclonal antibody rituximab. A 77-year-old female presented with complaints of fatigue, fever, and chills of 3 months' duration...

OBJECTIVES: To identify the possible role of natural killer (NK) cells in the pathogenesis of type 1 diabetes mellitus (T1DM) through studying the expression of the KLRC3 gene, which encodes the NK cell activating receptor (NKG2E). METHODS: This study was conducted at Alexandria University Children's Hospital from April to October 2015. The study was conducted with 30 newly diagnosed T1DM patients (15 males and 15 females), aged 7-13 years (10.6±1.8 years) and 20 non-diabetic subjects served as age- and sex-matched controls...

BACKGROUND AND AIMS: Natural killer (NK) cells play an important role in the pathogenesis of HCV infection. We have previously shown that culture-derived HCV (HCVcc) enhance tumor necrosis-factor-related apoptosis-inducing ligand (TRAIL) expression on healthy but not on HCV-infected patient-derived NK cells, which was likely dependent on accessory cells. Here we sought mechanistic insights involved in altered TRAIL upregulation in this setting. METHODS: Peripheral blood mononuclear cells (PBMC) from controls and HCV-infected patients were exposed to HCVcc...

Acute myelogenous leukemia (AML) is primarily a disease of the elderly, and as such, our approach to treatment needs to be tailored to address an aging population. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only potentially curative treatment for intermediate and high risk AML, and until recently, its use had been limited to a younger population and dependent on availability of a donor. Advances in conditioning regimens, supportive care, and the use of alternative donor sources have greatly expanded access to this therapy...