Human natural killer (NK) cells can be subdivided in several subpopulations on the basis of the relative expression of the adhesion molecule CD56 and the activating receptor CD16. Whereas blood ...CD56brightCD16dim/- NK cells are classically viewed as immature precursors and cytokine producers, the larger CD56dimCD16bright subset is considered as the most cytotoxic one. In peripheral blood of healthy donors, we noticed the existence of a population of CD56dimCD16dim NK cells that was frequently higher in number than the CD56bright subsets and even expanded in occasional control donors but also in transporter associated with antigen processing-deficient patients, two familial hemophagocytic lymphohistiocytosis type II patients, and several common variable immunodeficiency patients. This population was detected but globally reduced in a longitudinal cohort of 18 HIV-1-infected individuals. Phenotypically, the new subset contained a high percentage of relatively immature cells, as reflected by a significantly stronger representation of NKG2A+ and CD57- cells compared to their CD56dimCD16bright counterparts. The phenotype of the CD56dimCD16dim population was differentially affected by HIV-1 infection as compared to the other NK cell subsets and only partly restored to normal by antiretroviral therapy. From the functional point of view, sorted CD56dimCD16dim cells degranulated more than CD56dimCD16bright cells but less than CD56dimCD16- NK cells. The population was also identified in various organs of immunodeficient mice with a human immune system ("humanized" mice) reconstituted from human cord blood stem cells. In conclusion, the CD56dimCD16dim NK cell subpopulation displays distinct phenotypic and functional features. It remains to be clarified if these cells are the immediate precursors of the CD56dimCD16bright subset or placed somewhere else in the NK cell differentiation and maturation pathway.
Neurotrophins such as nerve growth factor and brain-derived neurotrophic factor have been described to be involved in the pathogenesis of asthma. Neurturin (NTN), another neurotrophin from the glial ...cell line-derived neurotrophic factor family, was shown to be produced by human immune cells: monocytes, B cells, and T cells. Furthermore, it was previously described that the secretion of inflammatory cytokines was dramatically stimulated in NTN knockout (NTN(-/-)) mice. NTN is structurally similar to TGF-β, a protective cytokine in airway inflammation. This study investigates the implication of NTN in a model of allergic airway inflammation using NTN(-/-) mice. The bronchial inflammatory response of OVA-sensitized NTN(-/-) mice was compared with wild-type mice. Airway inflammation, Th2 cytokines, and airway hyperresponsiveness (AHR) were examined. NTN(-/-) mice showed an increase of OVA-specific serum IgE and a pronounced worsening of inflammatory features. Eosinophil number and IL-4 and IL-5 concentration in the bronchoalveolar lavage fluid and lung tissue were increased. In parallel, Th2 cytokine secretion of lung draining lymph node cells was also augmented when stimulated by OVA in vitro. Furthermore, AHR was markedly enhanced in NTN(-/-) mice after sensitization and challenge when compared with wild-type mice. Administration of NTN before challenge with OVA partially rescues the phenotype of NTN(-/-) mice. These findings provide evidence for a dampening role of NTN on allergic inflammation and AHR in a murine model of asthma.
The correct statement is: "Co-author Jacques Zimmer is a PLOS ONE Editorial Board member. (2013) Correction: Mouse Lung and Spleen Natural Killer Cells Have Phenotypic and Functional Differences, in ...Part Influenced by Macrophages.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Natural killer (NK) cells are important effectors of both innate and adaptive immune responses. Although human and mouse NK cells are extensively characterized, much less is known about the rat ...cells, partly because of the current lack of reliable isolation techniques. We aimed to develop a method for isolating highly pure 'untouched' rat NK cells by negative selection from splenocytes. Thereafter, we characterized them phenotypically and functionally in comparison with those isolated by positive selection targeting the NKR-P1 receptor. Our novel method isolated highly pure untouched NK cells reproducibly with 97 ± 0·7% (n = 7), 96·6 ± 0·8% (n = 3) and 88·3 ± 1·5% (n = 9) in LEWIS, Fischer and athymic nude rats, respectively. The positively selected NK cells were less homogeneous and exhibited undesired method-related activation profiles. Resting negatively selected NK cells were less proliferative and less robust compared with positively selected NK cells. Although resting positively selected NK cells were more cytotoxic, interleukin-2 (IL-2) activation increased the cytotoxicity of negatively selected cells three-fold. The negatively selected NK cells responded to cross-linking of the NKR-P1 receptor by calcium mobilization from intracellular stores. However, combined IL-2 and IL-12 activation resulted in significantly more interferon-γ release from positively selected NK cells. This new NK-cell isolation method will allow a deeper insight into rat NK-cell phenotypes and the roles of their receptors in the biology of these cells.
Human natural killer (NK) cells can be subdivided into different populations based on the relative expression of the surface markers CD16 and CD56. The two major subsets are CD56bright CD16dim/⁻ and ...CD56dim CD16⁺, respectively. In this review, we will focus on the CD56bright NK cell subset. These cells are numerically in the minority in peripheral blood but constitute the majority of NK cells in secondary lymphoid tissues. They are abundant cytokine producers but are only weakly cytotoxic before activation. Recent data suggest that under certain conditions, they have immunoregulatory properties, and that they are probably immediate precursors of CD56dim NK cells. CD56bright NK cell percentages are expanded or reduced in a certain number of diseases, but the significance of these variations is not yet clear.
The microbiota can play important roles in the development of human immunity and the establishment of immune homeostasis. Lifestyle factors including diet, hygiene, and exposure to viruses or ...bacteria, and medical interventions with antibiotics or anti‐ulcer medications, regulate phylogenetic variability and the quality of cross talk between innate and adaptive immune cells via mucosal and skin epithelia. More recently, microbiota and their composition have been linked to protective effects for health. Imbalance, however, has been linked to immune‐related diseases such as allergy and cancer, characterized by impaired, or exaggerated immune tolerance, respectively. In this AllergoOncology position paper, we focus on the increasing evidence defining the microbiota composition as a key determinant of immunity and immune tolerance, linked to the risk for the development of allergic and malignant diseases. We discuss novel insights into the role of microbiota in disease and patient responses to treatments in cancer and in allergy. These may highlight opportunities to improve patient outcomes with medical interventions supported through a restored microbiome.
Increasing scientific evidence indicates the influence of microbiota on the immune response contributing to the prevention or progression of immune‐related diseases such as allergy and cancer. A variety of factors have been identified influencing microbiota composition. This opens new avenues to beneficially modulate patients’ responses to cancer or allergy treatments.
There are currently no established radiological parameters that predict response to immunotherapy. We hypothesised that multiparametric, longitudinal magnetic resonance imaging (MRI) of physiological ...parameters and pharmacokinetic models might detect early biological responses to immunotherapy for glioblastoma targeting NG2/CSPG4 with mAb9.2.27 combined with natural killer (NK) cells. Contrast enhanced conventional T1-weighted MRI at 7±1 and 17±2 days post-treatment failed to detect differences in tumour size between the treatment groups, whereas, follow-up scans at 3 months demonstrated diminished signal intensity and tumour volume in the surviving NK+mAb9.2.27 treated animals. Notably, interstitial volume fraction (ve), was significantly increased in the NK+mAb9.2.27 combination therapy group compared mAb9.2.27 and NK cell monotherapy groups (p = 0.002 and p = 0.017 respectively) in cohort 1 animals treated with 1 million NK cells. ve was reproducibly increased in the combination NK+mAb9.2.27 compared to NK cell monotherapy in cohort 2 treated with increased dose of 2 million NK cells (p<0.0001), indicating greater cell death induced by NK+mAb9.2.27 treatment. The interstitial volume fraction in the NK monotherapy group was significantly reduced compared to mAb9.2.27 monotherapy (p<0.0001) and untreated controls (p = 0.014) in the cohort 2 animals. NK cells in monotherapy were unable to kill the U87MG cells that highly expressed class I human leucocyte antigens, and diminished stress ligands for activating receptors. A significant association between apparent diffusion coefficient (ADC) of water and ve in combination NK+mAb9.2.27 and NK monotherapy treated tumours was evident, where increased ADC corresponded to reduced ve in both cases. Collectively, these data support histological measures at end-stage demonstrating diminished tumour cell proliferation and pronounced apoptosis in the NK+mAb9.2.27 treated tumours compared to the other groups. In conclusion, ve was the most reliable radiological parameter for detecting response to intralesional NK cellular therapy.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Human deficiency in transporter associated with antigen processing (TAP) is characterized by a very low surface expression of human leukocyte antigen (HLA) class I molecules in hematopoietic and non ...hematopoietic cells. Among the latter, TAP-deficient skin fibroblasts have previously been shown by us to be very sensitive to lysis by activated autologous NK cells, even in the presence of cytokines that up-regulate HLA class I expression, a mechanism sufficient to protect normal fibroblasts from NK cell-mediated killing. Our complementary investigations on two TAP-deficient skin fibroblast cell lines surprisingly revealed that in response to proinflammatory cytokines, up-regulation of HLA-DR molecules at the cell surface is much less marked than in the case of normal skin fibroblasts. In contrast, the surface molecules CD40 and CD54 increase as much as observed on normal cells, suggesting that TAP-deficient fibroblasts are able to efficiently transduce cytokine-mediated stimulating signals. Transfection of an intact TAP gene into one of the TAP-deficient fibroblast cell lines restored a normal HLA class I expression that strongly increased upon IFN-γ-mediated stimulation, whereas HLA-DR still remained lower than in control cells. These results suggest that, in addition to the defect in the HLA class I antigen presentation pathway, HLA-DR up-regulation is affected in TAP-deficient skin fibroblasts through an unknown mechanism probably independent from TAP.
Abstract
Glioblastoma multiforme (GBM) is the most malignant brain cancer and despite advances in present treatment regimen, the patients’ survival remains low, emphasizing importance of continued ...research to develop novel therapies. One of the promising treatment strategies is immunotherapy. However, detailed studies of the immune status of GBM patients are required to design appropriate immunotherapy tailored to these patients. Our preliminary characterization of 63 GBM patients’ biopsies using IHC staining for CD3, CD4 and CD8 markers revealed a great heterogeneity in the amounts of T-cell infiltrates between and within the patients’ tumors. The amounts of CD3+, CD4+ and CD8+ T-cells were quantified and correlated with patients’ survival outcomes. Reduced CD3+ T-cell infiltration into the tumor (<5%) was associated with shorter median survival of 7 months compared to 12 months in the patients with >5% T-cells (p=0.0029). Similarly, significant (p=0.0062) positive correlation of the level of CD8+ cells infiltration with longer patients’ survival was observed. In further studies we focused on detailed characterization of tumor infiltrating and peripheral blood lymphocytes and based on these results we propose several mechanisms impairing the patients’ immune system. Within the tumor microenvironment immunosuppression is driven by increased expression of CD39 and CD73 molecules that leads to high levels of extracellular adenosine resulting in T-cell suppression. Additionally, we observed modulation of Fas expression on tumor cells and FasL concentration in patients’ plasma dependent on the immune cells’ status. This may result in either tumor's escape from Fas-mediated cytotoxicity or apoptosis of the immune cells. A subpopulation of the patients had elevated CD8+ regulatory T-cells that are known to suppress APCs - a major immune cell population infiltrating the tumor. However, in contrast to other published reports, we didn't detect CD4+ Tregs among TILs. In addition, we demonstrated a systemic immunosuppression due to decreased numbers of T-helper cells in the peripheral blood compared to healthy donors (p=0.0391) and their up-regulated expression of the inhibitory receptor CD152 (p=0.0039). Moreover, increased concentration of IL-10 (p=0.0039) and decreased concentration of IL-2 and IL-12 in patients’ plasma comparing to healthy donors’ indicates that the immune response balance is shifted towards Th2 anti-inflammatory response.In conclusion, our preliminary results showing that the increased T-cells infiltration to the tumor correlates with patients’ longer survival, suggest that there is a potential for developing immunotherapies against GBM. However, further studies revealed a large repertoire of immunosuppressive mechanisms developed by the tumor that need to be taken into consideration when designing an immunotherapy tailored to GBM patients.
Citation Format: {Authors}. {Abstract title} abstract. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3542. doi:1538-7445.AM2012-3542
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