Herein, an advanced bioconjugation technique to synthesize hybrid polymer-antibody nanoprobes tailored for fluorescent cell barcoding in flow cytometry-based immunophenotyping of leukocytes is applied. A novel approach of attachment combining two fluorescent dyes on the copolymer precursor and its conjugation to antibody is employed to synthesize barcoded nanoprobes of antibody polymer dyes allowing up to six nanoprobes to be resolved in two-dimensional cytometry analysis. The major advantage of these nanoprobes is the construct design in which the selected antibody is labeled with an advanced copolymer bearing two types of fluorophores in different molar ratios. The cells after antibody recognition and binding to the target antigen have a characteristic double fluorescence signal for each nanoprobe providing a unique position on the dot plot, thus allowing antibody-based barcoding of cellular samples in flow cytometry assays. This technique is valuable for cellular assays that require low intersample variability and is demonstrated by the live cell barcoding of clinical samples with B cell abnormalities. In total, the samples from six various donors were successfully barcoded using only two detection channels. This barcoding of clinical samples enables sample preparation and measurement in a single tube.
- MeSH
- Fluorescent Dyes * chemistry MeSH
- Immunophenotyping MeSH
- Polymers MeSH
- Antibodies * MeSH
- Flow Cytometry methods MeSH
- Publication type
- Journal Article MeSH
Schimke immuno-osseous dysplasia is a rare multisystemic disorder caused by biallelic loss of function of the SMARCAL1 gene that plays a pivotal role in replication fork stabilization and thus DNA repair. Individuals affected from this disease suffer from disproportionate growth failure, steroid resistant nephrotic syndrome leading to renal failure and primary immunodeficiency mediated by T cell lymphopenia. With infectious complications being the leading cause of death in this disease, researching the nature of the immunodeficiency is crucial, particularly as the state is exacerbated by loss of antibodies due to nephrotic syndrome or immunosuppressive treatment. Building on previous findings that identified the loss of IL-7 receptor expression as a possible cause of the immunodeficiency and increased sensitivity to radiation-induced damage, we have employed spectral cytometry and multiplex RNA-sequencing to assess the phenotype and function of T cells ex-vivo and to study changes induced by in-vitro UV irradiation and reaction of cells to the presence of IL-7. Our findings highlight the mature phenotype of T cells with proinflammatory Th1 skew and signs of exhaustion and lack of response to IL-7. UV light irradiation caused a severe increase in the apoptosis of T cells, however the expression of the genes related to immune response and regulation remained surprisingly similar to healthy cells. Due to the disease's rarity, more studies will be necessary for complete understanding of this unique immunodeficiency.
- MeSH
- Apoptosis genetics MeSH
- Arteriosclerosis genetics etiology immunology MeSH
- Child MeSH
- DNA Helicases genetics MeSH
- Humans MeSH
- Bone Diseases, Metabolic etiology genetics MeSH
- Nephrotic Syndrome etiology genetics MeSH
- DNA Repair * genetics MeSH
- Osteochondrodysplasias * genetics immunology MeSH
- Pulmonary Embolism genetics etiology MeSH
- Growth Disorders genetics etiology MeSH
- Primary Immunodeficiency Diseases * genetics diagnosis immunology MeSH
- Immunologic Deficiency Syndromes genetics immunology MeSH
- T-Lymphocytes immunology MeSH
- Ultraviolet Rays adverse effects MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Glycosylated sphingolipids (GSLs) are a diverse group of cellular lipids typically reported as being rare in normal mammary tissue. In breast cancer (BCa), GSLs have emerged as noteworthy markers associated with breast cancer stem cells, mediators of phenotypic plasticity, and contributors to cancer cell chemoresistance. GSLs are potential surface markers that can uniquely characterize the heterogeneity of the tumor microenvironment, including cancer cell subpopulations and epithelial-mesenchymal plasticity (EMP). In this study, mass spectrometry analyses of the total sphingolipidome in breast epithelial cells and their mesenchymal counterparts revealed increased levels of Gb3 in epithelial cells and significantly elevated GD2 levels in the mesenchymal phenotype. To elucidate if GSL-related epitopes on BCa cell surfaces reflect EMP and cancer status, we developed and rigorously validated a 12-color spectral flow cytometry panel. This panel enables the simultaneous detection of native GSL epitopes (Gb3, SSEA1, SSEA3, SSEA4, and GD2), epithelial-mesenchymal transition markers (EpCAM, TROP2, and CD9), and lineage markers (CD45, CD31, and CD90) at the single-cell level. Next, the established panel was used for the analysis of BCa primary tumors and revealed surface heterogeneity in SSEA1, SSEA3, SSEA4, GD2, and Gb3, indicative of native epitope presence also on non-tumor cells. These findings further highlighted the phenotype-dependent alterations in GSL surface profiles, with differences between epithelial and stromal cells in the tumor. This study provides novel insights into BCa heterogeneity, shedding light on the potential of native GSL-related epitopes as markers for EMP and cancer status in fresh clinical samples. The developed single-cell approach offers promising avenues for further exploration.
Assays based on Förster resonance energy transfer (FRET) can be used to study many processes in cell biology. Although this is most often done with microscopy for fluorescence detection, we report two ways to measure FRET in living cells by flow cytometry. Using a conventional flow cytometer and the "3-cube method" for intensity-based calculation of FRET efficiency, we measured the enzymatic activity of specific kinases in cells expressing a genetically-encoded reporter. For both AKT and protein kinase A, the method measured kinase activity in time-course, dose-response, and kinetic assays. Using the Cytek Aurora spectral flow cytometer, which applies linear unmixing to emission measured in multiple wavelength ranges, FRET from the same reporters was measured with greater single-cell precision, in real time and in the presence of other fluorophores. Results from gene-knockout studies suggested that spectral flow cytometry might enable the sorting of cells on the basis of FRET. The methods we present provide convenient and flexible options for using FRET with flow cytometry in studies of cell biology.
The genus Acaryochloris is unique among phototrophic organisms due to the dominance of chlorophyll d in its photosynthetic reaction centres and light-harvesting proteins. This allows Acaryochloris to capture light energy for photosynthesis over an extended spectrum of up to ~760 nm in the near infra-red (NIR) spectrum. Acaryochloris sp. has been reported in a variety of ecological niches, ranging from polar to tropical shallow aquatic sites. Here, we report a new Acarychloris strain isolated from an NIR-enriched stratified microbial layer 4-6 mm under the surface of stromatolite mats located in the Hamelin Pool of Shark Bay, Western Australia. Pigment analysis by spectrometry/fluorometry, flow cytometry and spectral confocal microscopy identifies unique patterns in pigment content that likely reflect niche adaption. For example, unlike the original A. marina species (type strain MBIC11017), this new strain, Acarychloris LARK001, shows little change in the chlorophyll d/a ratio in response to changes in light wavelength, displays a different Fv/Fm response and lacks detectable levels of phycocyanin. Indeed, 16S rRNA analysis supports the identity of the A. marina LARK001 strain as close to but distinct from from the A. marina HICR111A strain first isolated from Heron Island and previously found on the Great Barrier Reef under coral rubble on the reef flat. Taken together, A. marina LARK001 is a new cyanobacterial strain adapted to the stromatolite mats in Shark Bay.
- Publication type
- Journal Article MeSH
A critical component of the EuroFlow standardization of leukemia/lymphoma immunophenotyping is instrument setup. Initially, the EuroFlow consortium developed a step-by-step standard operating protocol for instrument setup of ≥8-color flow cytometers that were available in 2006, when the EuroFlow activities started. Currently, there are 14 instruments from 9 manufacturers capable of 3-laser excitation and ≥8 color measurements. The specific adaptations required in the instrument set-up to enable them to acquire the standardized 8-color EuroFlow protocols are described here. Overall, all 14 instruments can be fitted with similar violet, blue and red lasers for simultaneous measurements of ≥8 fluorescent dyes. Since individual instruments differ both on their dynamic range (scale) and emission filters, it is not accurate to simply recalculate the target values to different scale, but adjustment of PMT voltages to a given emission filter and fluorochrome, is essential. For this purpose, EuroFlow has developed an approach using Type IIB (spectrally matching) particles to set-up standardized and fully comparable fluorescence measurements, in instruments from different manufacturers, as demonstrated here for the FACSCanto II, and Navios and MACSQuant flow cytometers. Data acquired after such adjustment on any of the tested cytometry platforms could be fully superimposed and therefore analyzed together. The proposed approach can be used to derive target values for any combination of spectrally distinct fluorochromes and any distinct emission filter of any new flow cytometry platform, which enables the measurement of the 8-color EuroFlow panels in a standardized way, by creating superimposable datafiles.
- MeSH
- Hematologic Neoplasms diagnosis MeSH
- Immunophenotyping instrumentation standards MeSH
- Humans MeSH
- Flow Cytometry instrumentation standards MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND INFORMATION: Macarpine (MA) is a quaternary benzophenanthridine plant alkaloid isolated from Macleaya microcarpa or Stylophorum lasiocarpum. Benzophenanthridine alkaloids are interesting natural products that display antiproliferative, antimicrobial, antifungal and anti-inflammatory activities, and also fluorescence properties. In a previous study, we demonstrated that thanks to its ability to interact with DNA and its spectral properties MA could be used as a supravital DNA probe for fluorescence microscopy and flow cytometry including analyses of the cell cycle. In this study, we evaluated the suitability of MA as a DNA dye for time-lapse microscopy and flow-cytometric cell sorting. RESULTS: Living A-375 and MEF cells stained with MA were monitored by time-lapse microscopy for 24 h. Mitoses were observed at MA concentrations up to 0.5 μg/ml during the first 2-3 h. After this period of time, cells treated with MA at concentrations of 0.75 and 0.5 μg/ml underwent apoptosis. Cells cultivated with MA at concentration of 0.25 μg/ml or lower survived throughout the 24 h period. Toxicity of MA was dependent on light wavelength and frequency of image capturing. The intensity of MA fluorescence decreased during the incubation. MA concentration of 0.1 μg/ml was identified as the most suitable for live cell imaging with respect to fluorescence intensity and toxicity. MA at the concentration 10 μg/ml was used for sorting of enhanced green fluorescent protein (EGFP)-labelled neurons and fibroblasts yielding profiles similar to those obtained with DRAQ5. Contrary to DRAQ5, MA-stained cells survived in culture, and the sorted cells lost the MA signal suggesting reversible binding of the dye to the DNA. CONCLUSION: The results proved that MA may readily be used for chromosomes depicting and mitosis monitoring by time-lapse microscopy. In addition, MA has shown to be a suitable probe for sorting of EGFP-labelled cells, including neurons, that survived the labelling process. SIGNIFICANCE: In consideration of the results, we highly anticipate an onward use of MA in a broad range of applications based on live cell sorting and imaging, for example, cell synchronisation and monitoring of proliferation as an important experimental and/or diagnostic utility.
- MeSH
- Benzophenanthridines analysis MeSH
- Cell Culture Techniques MeSH
- Cell Cycle physiology MeSH
- DNA analysis MeSH
- Fluorescent Dyes analysis MeSH
- Microscopy, Fluorescence methods MeSH
- Humans MeSH
- Flow Cytometry * methods MeSH
- Cell Separation methods MeSH
- Cell Survival MeSH
- Green Fluorescent Proteins metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Úvod: Biklonální gamapatie nejistého významu (BGUS) je méně obvyklé onemocnění charakterizované přítomností dvou monoklonálních gradientů a relativně příznivým biologickým chováním. Cíl: Cílem práce bylo posouzení možného přínosu či naopak limitací obvyklých parametrů používaných u monoklonální gamapatie nejistého významu (MGUS) ve skupině jedinců s BGUS. Metody: Analyzovaná sestava čítala 18 vzorků sér od jedinců s BGUS (9x IgG–IgA, 7x IgG–IgM a 2x IgG–IgG typ). Pro analýzu byl použit turbidimetr SPA Plus a stanovované parametry zahrnovaly sérové hladiny volných lehkých řetězců imunoglobulinu (FreeLite™), hladiny polyklonálních imunoglobulinů a hladiny párů těžkých/lehkých řetězců imunoglobulinu (HevyLite ™). Výsledky a závěr: Pilotní analýza a zjištěné výsledky potvrzují skutečnost, že u velké části BGUS dochází k ovlivnění některých parametrů užívaných ve stratifikaci a sledování jedinců s MGUS, zejména v případě odlišnosti lehkých řetězců v obou molekulách monoklonálních imunoglobulinů. Jako velmi perspektivní se jeví analýza párů těžkých/lehkých řetězců imunoglobulinu (HLC), zohledňující možnost izotypové suprese alternativního páru s ovlivněním HLC indexu. Avšak v podmínkách běžné klinické praxe je zřejmé, že zásadní pro určení prognózy BGUS bude nutná izolace a analýza klonálních populací buněk na molekulárně-cytogenetické úrovni.
Introduction: Biclonal gammopathy of undetermined significance (BGUS) is a less frequent disease characterized by the presence of two monoclonal gradients and a relatively favourable biological development. Objective: The objective was to assess potential benefits and/or limitations of laboratory parameters typically used with monoclonal gammopathy of undetermined significance (MGUS) when applied to a group of BGUS patients. Methods: The analysed batch comprised 18 serum samples from BGUS patients (9x IgG–IgA, 7x IgG–IgM a 2x IgG–IgG type). The assays were performed with a SPA Plus turbidimeter. Serum levels of polyclonal immunoglobulins, free light immunoglobulin chains (FreeLite™), and pairs of heavy/light immunoglobulin chains (HevyLite™) were assayed. Results and conclusion: The results of the pilot analyses confirm that a significant portion of BGUS patients exhibits changes of certain parameters typically applied to the stratification and monitoring of MGUS patients, particularly when the light chains in both molecules of monoclonal immunoglobulins differ. The analysis of heavy/light immunoglobulin chain pairs (HLC) appears very promising, indicating the possibility of an isotype suppression of the alternative pair affecting the HLC index. It is apparent, however, that the isolation and analysis of cell clones on a molecular and cytogenetic level will be essential for BGUS prognosis in clinical practice.
- MeSH
- Electrophoresis, Gel, Two-Dimensional MeSH
- Cytogenetic Analysis MeSH
- Immunoglobulin kappa-Chains analysis diagnostic use blood MeSH
- Immunoglobulin lambda-Chains analysis diagnostic use blood MeSH
- Immunoglobulin Light Chains analysis diagnostic use blood MeSH
- Humans MeSH
- Cell Transformation, Neoplastic MeSH
- Paraproteinemias diagnosis MeSH
- Prognosis MeSH
- Flow Cytometry MeSH
- Spectral Karyotyping MeSH
- Immunoglobulin Heavy Chains analysis diagnostic use blood MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
There is a wide range of techniques utilizing fluorescence of doxorubicin (Dox) commonly used for analysis of intracellular accumulation and destiny of various drug delivery systems containing this anthracycline antibiotic. Unfortunately, results of these studies can be significantly influenced by doxorubicin degradation product, 7,8-dehydro-9,10-desacetyldoxorubicinone (D*) forming spontaneously in aqueous environment, whose fluorescence strongly interfere with that of doxorubicin. Here, we define two microscopy techniques enabling to distinguish and separate Dox and D* emission based either on its spectral properties or on fluorescence lifetime analysis. To analyze influx and nuclear accumulation of Dox (free or polymer-bound) by flow cytometry, we propose using an indirect method based on its DNA intercalation competition with Hoechst 33342 rather than a direct measurement of doxorubicin fluorescence inside the cells.
- MeSH
- Cell Nucleus metabolism MeSH
- 3T3 Cells MeSH
- DNA metabolism MeSH
- Doxorubicin analogs & derivatives metabolism pharmacology MeSH
- Spectrometry, Fluorescence MeSH
- Hydrophobic and Hydrophilic Interactions MeSH
- Drug Delivery Systems MeSH
- Humans MeSH
- Lymphoma, T-Cell drug therapy metabolism MeSH
- Mice MeSH
- Tumor Cells, Cultured MeSH
- Polymers metabolism MeSH
- Antibiotics, Antineoplastic metabolism pharmacology MeSH
- Flow Cytometry MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Quaternary benzo[c]phenanthridine alkaloids (QBAs) are natural products isolated from plants of Fumariaceae, Papaveraceae, Ranunculaceae and Rutaceae families. They are intensively studied for their biological activities, but they have also attractive fluorescence properties. Chromophores responsible for fluorescence are fused aromatic ring systems with electron-donor groups containing oxygen (OH, OCH3, OCH2O). Recently we have described fluorescent characteristics of QBAs - macarpine (MA), sanguirubine (SR), chelirubine (CHR), sanguilutine (SL), chelilutine (CHL), sanguinarine (SA) and chelerythrine (CHE) - on interaction with living cells. All these alkaloids immediately enter the living cells and MA-, CHRand SA-bound DNA; they showed a nucleus architecture similar to common DNA dyes. Moreover, MA binds to DNA stoichiometrically and can rapidly report the cellular DNA content in living cells at a resolution adequate for cell cycle analysis. QBAs could be excited by common argon lasers (488 nm) emitting light in the 575-755 nm range. Spectral characteristics of MA allow simultaneous surface immunophenotyping. These characteristics allow multiple applications of the above-mentioned QBAs with significant diagnostic utility. They can be used as supravital fluorescent DNA probes both in fluorescence microscopy and flow cytometry including multiparameter analysis.
