Search results for "Flow cytometry"

Tips and tricks for flow cytometry-based analysis and counting of microparticles

2015

Submicron-sized extra-cellular vesicles generated by budding from the external cell membranes, microparticles (MPs) are important actors in transfusion as well as in other medical specialties. After briefly positioning their role in the characterization of labile blood products, this technically oriented chapter aims to review practical points that need to be considered when trying to use flow cytometry for the analysis, characterization and absolute counting of MP subsets. Subjects of active discussions relative to instrumentation will include the choice of the trigger parameter, possible standardization approaches requiring instrument quality-control, origin and control of non-specific ba…

Dependence of T-lymphocyte activation on the extent of cellular damage

2010

Mechanically damaged cells release intracellular substances, resulting in the activation of CD4- and CD8-positive T-lymphocytes. The goal of this investigation was to quantify and compare fractions of activated CD4- and CD8-positive T-lymphocytes, based on the quantity of damaged cells in a given blood sample. Blood samples were mechanically stressed by vortexing intensely. Subsequently, different quantities of distressed blood samples were mixed with samples of fresh, whole blood. Afterwards, the extent of CD4- and CD8-positive T-cell activation was examined in the mixture by flow cytometry. Sine-like curves of T-cell activation were observed for both CD4- (T-helper mediated) and CD8- (cyt…

Performance Comparison of a Flow Cytometry-based and Two Commercial Chemiluminescent Immunoassays for Detection and Quantification of Antibodies Bind…

2021

ABSTRACTThe performance of a laboratory-developed quantitative IgG/IgA flow cytometry-based immunoassay (FCI) using Jurkat T cells stably expressing full-length native S protein was compared against Elecsys® electrochemiluminiscent (ECLIA) Anti-SARS-CoV-2 S (Roche Diagnostics, Pleasanton, CA, USA), and LIAISON® SARS-CoV-2 TrimericS IgG chemiluminiscent assay (CLIA) (Diasorin S.p.a, Saluggia, IT) for detection and quantitation of SARS-CoV-2-specific antibodies. A total of 225 serum/plasma specimens from 120 acute or convalescent COVID-19 individuals were included. Overall, IgG/IgA-FCI yielded the highest number of positives (n=179), followed by IgA-FCI (n=177), Roche ECLIA (n=175), IgG-FCI (…

B and T cell immune responses elicited by the BNT162b2 (Pfizer–BioNTech) COVID-19 vaccine in nursing home residents

2021

ABSTRACTObjectivesThe immunogenicity of the BNT162b2 COVID-19 vaccine is understudied in elderly people with comorbidities. We assessed SARS-CoV-2-S-targeted antibody and T cell responses following full vaccination in nursing home residents (NHR).MethodsWe recruited 60 NHR (44 female; median age, 87.5 years), of whom 10 had previously had COVID-19, and 18 healthy controls (15 female; median age, 48.5 years). Pre- and post-vaccination blood specimens were available for quantitation of total antibodies binding RBD and enumeration of SARS-CoV-2-S-reactive IFN-γ CD4+ and CD8+ T cells by flow cytometry.ResultsThe seroconversion rate in presumably SARS-CoV-2 naïve NHR (95.3%), either with or with…

Exosomes in NSCLC as a source of biomarkers

2019

Abstract Background Exosomes are small membranous vesicles (around 40-130 nm), that have been detected in different biological samples, that play a key role in NSCLC and being relevant in stem cell differentiation as well. The main objective of this study was to analyze the exosomes cargo from NSCLC cell cultures growth in monolayer (2D) and suspension conditions (3D, lung tumorespheres). Methods Cultures were established from NSCLC resected patients and cell lines. Exosomes isolation was performed by ultracentrifugation. Characterization was carried out by NTA, electron microscopy, immunoblot and flow cytometry. Mutational status of EGFR and RAS genes was analyzed by BEAMing dPCR. Transcri…

SAT0025 MIR 106A, MIR 19A-B, MIR 20A and MIR21A regulate vγ9vδ2 functions participating in the inflammatory responses occurring in rheumatoid arthrit…

2017

Background miRNAs are non-coding RNAs which have significant roles in regulating gene expression. The miR17-92 cluster appears to be a key factor in the inflammatory pathways activated during RA. Objectives In this study we aimed to evaluate miR17–92 expression and functions in γδ T cell subsets in RA patients, γδ T cells, in fact produce proinflammatory cytokines such as IFN-g, IL-6 and IL-8 that may contribute to the inflammatory responses in RA. Methods Heparinized peripheral blood from 10 early RA untreated patients and 10 healthy donors was obtained for this study. Polyclonal Vγ9Vδ2 T cell lines were generated first by magnetic isolation followed by sorting (FACSAria) and further analy…

P087 Increased wnt ligands expression in M2c macrophages is associated with fibrosis in Stat6 knockout mice

2017

Aldara-Induced Psoriasis-Like Skin Inflammation: Isolation and Characterization of Cutaneous Dendritic Cells and Innate Lymphocytes

2014

Psoriasis is a chronic auto-inflammatory skin disease of unknown etiology affecting millions of people worldwide. Dissecting the cellular networks and molecular signals promoting the development of psoriasis critically depends on appropriate animal models. Topical application of Aldara cream containing the Toll-like receptor (TLR)7-ligand Imiquimod induces skin inflammation and pathology in mice closely resembling plaque-type psoriasis in humans. The particular power of the Aldara model lies in examining the early events during psoriatic plaque formation, which is difficult to achieve in patients. Hence, recent reports using this model have challenged currently prevailing concepts concernin…

Flow Cytometry in Cancer Immunotherapy: Applications, Quality Assurance, and Future

2014

Cancer immunotherapy seeks to elicit or augment the antitumor immune response in a patient in order to enlist the help of the patient’s own immune system for tumor control. In this context, immune monitoring provides evidence of immunogenicity, guides the choice and dosage of antigens, assesses the effects of immune modulators and therapy combinations, and has the potential to reveal early biomarkers of clinical efficacy. In view of their role in the anticancer immune response, the quantity and quality of tumor antigen-specific effector CD4+ and CD8+ T cells are of particular interest, and characterization of regulatory T cells and myeloid-derived suppressor cells is increasingly relevant. …

Synthesis, biological evaluation, and structure-activity relationship study of novel cytotoxic aza-caffeic acid derivatives.

2010

Abstract Three series of aza-caffeic acid derivatives with different linkers were designed and synthesized. Each of the synthesized derivatives was then used in cytotoxicity screening on either 8 or 12 human cancer cell lines. The structure–activity relationships on three structural regions A, B, and C are analyzed in detail, indicating that a nine bond linker B, containing a piperazine unit, is the most favorable linker leading to the generation of molecules with potent cytotoxicities. Compound ( E )-1-(4-(3,4-dichlorobenzyl)piperazin-1-yl)-3-(4-(4-ethoxybenzyloxy)-3,5-dimethoxyphenyl)prop-2-en-1-one ( 80 ) exhibited the most significant and selective cytotoxicity to KB, BEL7404, K562, and…