Search results for "Killer Cell"

A murine intestinal intraepithelial NKp46-negative innate lymphoid cell population characterized by group 1 properties

2017

The Ly49E receptor is preferentially expressed on murine innate-like lymphocytes, such as epidermal Vγ3 T cells, intestinal intraepithelial CD8αα(+) T lymphocytes, and CD49a(+) liver natural killer (NK) cells. As the latter have recently been shown to be distinct from conventional NK cells and have innate lymphoid cell type 1 (ILC1) properties, we investigated Ly49E expression on intestinal ILC populations. Here, we show that Ly49E expression is very low on known ILC populations, but it can be used to define a previously unrecognized intraepithelial innate lymphoid population. This Ly49E-positive population is negative for NKp46 and CD8αα, expresses CD49a and CD103, and requires T-bet expre…

IFNL3/4 genotype is associated with altered immune cell populations in peripheral blood in chronic hepatitis C infection

2016

Single-nucleotide polymorphisms near the interferon lambda 3 (IFNL3) gene predict outcomes to infection and anti-viral treatment in hepatitis C virus (HCV) infection. To identify IFNL3 genotype effects on peripheral blood, we collected phenotype data on 400 patients with genotype 1 chronic hepatitis C (CHC). The IFNL3 responder genotype predicted significantly lower white blood cells (WBCs), as well as lower absolute numbers of monocytes, neutrophils and lymphocytes for both rs8099917 and rs12979860. We sought to define the WBC subsets driving this association using flow cytometry of 67 untreated CHC individuals. Genotype-associated differences were seen in the ratio of CD4CD45RO+ to CD4CD4…

Association between γ marker, human leucocyte antigens and killer immunoglobulin‐like receptors and the natural course of human cytomegalovirus infec…

2017

Natural killer (NK) cells provide a major defence against cytomegalovirus (HCMV) infection through the interaction of their surface receptors, including the activating and inhibitory killer immunoglobulin-like receptors (KIRs), and human leukocyte antigens (HLA) class I molecules. Also GM allotypes, able to influence the NK antibody-dependent cell-mediated cytotoxicity (ADCC), appear to be involved in the immunological control of virus infections, including HCMV. In some cases, their contribution requires epistatic interaction with other genes of the immune system, such as HLA. In the present report, with the aim to gain insight into the immune mechanisms controlling HCMV, we have studied t…

Immunomodulatory activity of Humulus lupulus bitter acids fraction: Enhancement of natural killer cells function by NKp44 activating receptor stimula…

2019

Abstract Humulus lupulus (Hop) contains numerous metabolites with anticancer potential. Despite this, their immunomodulatory activity, and in particular of bitter acids, is unknown. In this study, we demonstrated that a Hop pellet extract fraction containing bitter acids possesses immunomodulatory activity by enhancing Natural Killer (NK) cells function. After fractionation by semi-preparative Liquid Chromatography, three different fractions were obtained. The phytocomplex and the fractions were tested to verify the ability to modulate the NK compartment. Cytofluorimetric analysis revealed that a fraction containing bitter acids was able to up-regulate of NKG2D and NKp44 activating receptor…

2017

ABSTRACTTissue immunosurveillance is an important mechanism to prevent cancer. Skin treatment with the carcinogen 7,12-dimethylbenz(a)anthracene (DMBA), followed by the tumor promoter 12-O-tetra-decanoyl-phorbol-13-acetate (TPA), is an established murine model for squamous cell carcinoma (SCC). However, the innate immunological events occurring during the initiation of chemical carcinogenesis with DMBA remain elusive. Here, we discovered that natural killer (NK) cells and Langerhans cells (LC) cooperate to impair this oncogenic process in murine skin. The depletion of NK cells or LC caused an accumulation of DNA-damaged, natural killer group 2D-ligand (NKG2D-L) expressing keratinocytes and …

Cutaneous manifestations associated with anosmia, ageusia and enteritis in SARS-CoV-2 infection - a possible pattern? Observational study and review …

2021

BACKGROUND: The cutaneous manifestations of coronavirus disease 2019 (COVID-19) have been covered insufficiently in the literature. METHODS: Thirty-nine patients admitted to the study hospital with confirmed COVID-19 who experienced various skin manifestations during hospitalization or in the convalescence period, were analysed retrospectively. RESULTS: Thirty-nine patients with COVID-19, admitted to the study hospital between 23 March and 12 September 2020, had intra-infectious rash or lesions of cutaneous vasculitis during convalescence. The most common cutaneous manifestations of COVID-19 were erythematous and erythematous papular rash. Twenty-seven of the 39 patients had anosmia (69.2%)…

Lipid Antigen Presentation by CD1b and CD1d in Lysosomal Storage Disease Patients

2019

The lysosome has a key role in the presentation of lipid antigens by CD1 molecules. While defects in lipid antigen presentation and in invariant Natural Killer T (iNKT) cell response were detected in several mouse models of lysosomal storage diseases (LSD), the impact of lysosomal engorgement in human lipid antigen presentation is poorly characterized. Here, we analyzed the capacity of monocyte-derived dendritic cells (Mo-DCs) from Fabry, Gaucher, Niemann Pick type C and Mucopolysaccharidosis type VI disease patients to present exogenous antigens to lipid-specific T cells. The CD1b- and CD1d-restricted presentation of lipid antigens by Mo-DCs revealed an ability of LSD patients to induce CD…

MICA-129 Dimorphism and Soluble MICA Are Associated With the Progression of Multiple Myeloma

2018

Natural killer (NK) cells are immune innate effectors playing a pivotal role in the immunosurveillance of multiple myeloma (MM) since they are able to directly recognize and kill MM cells. In this regard, among activating receptors expressed by NK cells, NKG2D represents an important receptor for the recognition of MM cells, being its ligands expressed by tumor cells, and being able to trigger NK cell cytotoxicity. The MHC class I-related molecule A (MICA) is one of the NKG2D ligands; it is encoded by highly polymorphic genes and exists as membrane-bound and soluble isoforms. Soluble MICA (sMICA) is overexpressed in the serum of MM patients, and its levels correlate with tumor progression. …

Myeloid Cells Restrict MCMV and Drive Stress- Induced Extramedullary Hematopoiesis through STAT1

2019

Cytomegalovirus (CMV) has a high prevalence worldwide, is often fatal for immunocompromised patients, and causes bone marrow suppression. Deficiency of signal transducer and activator of transcription 1 (STAT1) results in severely impaired antiviral immunity. We have used cell- type restricted deletion of Stat1 to determine the importance of myeloid cell activity for the defense against murine CMV (MCMV). We show that myeloid STAT1 limits MCMV burden and infection- associated pathology in the spleen but does not affect ultimate clearance of infection. Unexpectedly, we found an essential role of myeloid STAT1 in the induction of extramedullary hematopoiesis (EMH). The EMH- promoting function…

An Inflammatory Profile Correlates With Decreased Frequency of Cytotoxic Cells in Coronavirus Disease 2019

2020

Abstract Increased production of inflammatory cytokines and myeloid-derived suppressor cells occurs in patients with coronavirus disease 2019. These inversely correlated with perforin-expressing natural killer (NK) and CD3+ T cells. We observed a lower number of perforin-expressing NK cells in intensive care unit (ICU) patients compared with non-ICU patients, suggesting an impairment of the immune cytotoxic arm as a pathogenic mechanism.