A deep profiler's guide to cytometry Bendall, Sean C; Nolan, Garry P; Roederer, Mario ...
Trends in immunology,
07/2012, Letnik:
33, Številka:
7
Journal Article
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In recent years, advances in technology have provided us with tools to quantify the expression of multiple genes in individual cells. The ability to measure simultaneously multiple genes in the same ...cell is necessary to resolve the great diversity of cell subsets, as well as to define their function in the host. Fluorescence-based flow cytometry is the benchmark for this; with it, we can quantify 18 proteins per cell, at >10 000 cells/s. Mass cytometry is a new technology that promises to extend these capabilities significantly. Immunophenotyping by mass spectrometry provides the ability to measure >36 proteins at a rate of 1000 cells/s. We review these cytometric technologies, capable of high-content, high-throughput single-cell assays.
Structured-illumination microscopy can double the resolution of the widefield fluorescence microscope but has previously been too slow for dynamic live imaging. Here we demonstrate a high-speed ...structured-illumination microscope that is capable of 100-nm resolution at frame rates up to 11 Hz for several hundred time points. We demonstrate the microscope by video imaging of tubulin and kinesin dynamics in living Drosophila melanogaster S2 cells in the total internal reflection mode.
Fluorescence correlation spectroscopy (FCS) is an ideal analytical tool for studying concentrations, propagation, interactions and internal dynamics of molecules at nanomolar concentrations in living ...cells. FCS analyzes minute fluorescence-intensity fluctuations about the equilibrium of a small ensemble (<10(3)) of molecules. These fluctuations act like a 'fingerprint' of a molecular species detected when entering and leaving a femtoliter-sized optically defined observation volume created by a focused laser beam. In FCS the fluorescence fluctuations are recorded as a function of time and then statistically analyzed by autocorrelation analysis. The resulting autocorrelation curve yields a measure of self-similarity of the system after a certain time delay, and its amplitude describes the normalized variance of the fluorescence fluctuations. By fitting the curves to an appropriate physical model, this method provides precise information about a multitude of measurement parameters, including diffusion coefficients, local concentration, states of aggregation and molecular interactions. FCS operates in real time with diffraction-limited spatial and sub-microsecond temporal resolution. Assessing diverse molecular dynamics within the living cell is a challenge well met by FCS because of its single-molecule sensitivity and high dynamic resolution. For these same reasons, however, intracellular FCS measurements also harbor the large risk of collecting artifacts and thus producing erroneous data. Here we provide a step-by-step guide to the application of FCS to cellular systems, including methods for minimizing artifacts, optimizing measurement conditions and obtaining parameter values in the face of diverse and complex conditions of the living cell. A discussion of advantages and disadvantages of one-photon versus two-photon excitation for FCS is available in Supplementary Methods online.
Elucidating the spectrum of epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) states in clinical samples promises insights on cancer progression and drug resistance. ...Using mass cytometry time-course analysis, we resolve lung cancer EMT states through TGFβ-treatment and identify, through TGFβ-withdrawal, a distinct MET state. We demonstrate significant differences between EMT and MET trajectories using a computational tool (TRACER) for reconstructing trajectories between cell states. In addition, we construct a lung cancer reference map of EMT and MET states referred to as the EMT-MET PHENOtypic STAte MaP (PHENOSTAMP). Using a neural net algorithm, we project clinical samples onto the EMT-MET PHENOSTAMP to characterize their phenotypic profile with single-cell resolution in terms of our in vitro EMT-MET analysis. In summary, we provide a framework to phenotypically characterize clinical samples in the context of in vitro EMT-MET findings which could help assess clinical relevance of EMT in cancer in future studies.
In classical Hodgkin lymphoma (cHL), the host antitumor immune response is ineffective. Hodgkin Reed-Sternberg (HRS) cells have multifaceted mechanisms to evade the immune system, including ...9p24.1/CD274(PD-L1)/PDCD1LG2(PD-L2) genetic alterations, overexpression of PD-1 ligands, and associated T-cell exhaustion and additional structural bases of aberrant antigen presentation. The clinical success of PD-1 blockade in cHL suggests that the tumor microenvironment (TME) contains reversibly exhausted T effector cells (Teffs). However, durable responses are observed in patients with β2-microglobulin/major histocompatibility complex (MHC) class I loss on HRS cells, raising the possibility of non-CD8+ T cell–mediated mechanisms of efficacy of PD-1 blockade. These observations highlight the need for a detailed analysis of the cHL TME. Using a customized time-of-flight mass cytometry panel, we simultaneously assessed cell suspensions from diagnostic cHL biopsies and control reactive lymph node/tonsil (RLNT) samples. Precise phenotyping of immune cell subsets revealed salient differences between cHLs and RLNTs. The TME in cHL is CD4+ T-cell rich, with frequent loss of MHC class I expression on HRS cells. In cHLs, we found concomitant expansion of T helper 1 (Th1)-polarized Teffs and regulatory T cells (Tregs). The cHL Th1 Tregs expressed little or no PD-1, whereas the Th1 Teffs were PD-1+. The differential PD-1 expression and likely functional Th1-polarized CD4+ Tregs and exhausted Teffs may represent complementary mechanisms of immunosuppression in cHL.
•Newly diagnosed primary cHLs have a concomitant increase in CD4+ Th1-polarized Tregs and differentiated Teffs.•Primary cHLs exhibit 2 major complementary bases of immunosuppression: likely exhausted PD-1+ Th1 Teffs and active PD-1− Th1 Tregs.
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Sources of variability in experimentally derived data include measurement error in addition to the physical phenomena of interest. This measurement error is a combination of systematic components, ...originating from the measuring instrument and random measurement errors. Several novel biological technologies, such as mass cytometry and single-cell RNA-seq (scRNA-seq), are plagued with systematic errors that may severely affect statistical analysis if the data are not properly calibrated.
We propose a novel deep learning approach for removing systematic batch effects. Our method is based on a residual neural network, trained to minimize the Maximum Mean Discrepancy between the multivariate distributions of two replicates, measured in different batches. We apply our method to mass cytometry and scRNA-seq datasets, and demonstrate that it effectively attenuates batch effects.
our codes and data are publicly available at https://github.com/ushaham/BatchEffectRemoval.git.
yuval.kluger@yale.edu.
Supplementary data are available at Bioinformatics online.
The throughput of cell mechanical characterization has recently approached that of conventional flow cytometers. However, this very sensitive, label-free approach still lacks the specificity of ...molecular markers. Here we developed an approach that combines real-time 1D-imaging fluorescence and deformability cytometry in one instrument (RT-FDC), thus opening many new research avenues. We demonstrated its utility by using subcellular fluorescence localization to identify mitotic cells and test for mechanical changes in those cells in an RNA interference screen.
Given the limited efficacy of clinical approaches that rely on ex vivo generated dendritic cells (DCs), it is imperative to design strategies that harness specialized DC subsets in situ. This ...requires delineating the expression of surface markers by DC subsets among individuals and tissues. Here, we performed a multiparametric phenotypic characterization and unbiased analysis of human DC subsets in blood, tonsil, spleen, and skin. We uncovered previously unreported phenotypic heterogeneity of human cDC2s among individuals, including variable expression of functional receptors such as CD172a. We found marked differences in DC subsets localized in blood and lymphoid tissues versus skin, and a striking absence of the newly discovered Axl+ DCs in the skin. Finally, we evaluated the capacity of anti-receptor monoclonal antibodies to deliver vaccine components to skin DC subsets. These results offer a promising path for developing DC subset-specific immunotherapies that cannot be provided by transcriptomic analysis alone.
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•CyTOF reveals interindividual heterogeneity among DC subsets, especially cDC2s•Human skin harbors cDCs with a unique phenotype and lacks Axl+ DCs•Axl+ DCs display phenotypic and functional diversity, and pDCs exhibit plasticity•Receptor profiling identifies targets for antigen delivery to skin DC subsets
Dendritic cells (DCs) are potent initiators of immune responses; however, human DC subsets have yet to be successfully harnessed for immunotherapies. By combining CyTOF and unbiased analysis, Alcántara-Hernández et al. profile the heterogeneity of human DC subsets among individuals and tissues, providing comprehensive insights for the development of DC-based therapeutics.
We introduce an optical method to stimulate individual neurons in brain slices in any arbitrary spatiotemporal pattern, using two-photon uncaging of MNI-glutamate with beam multiplexing. This method ...has single-cell and three-dimensional precision. By sequentially stimulating up to a thousand potential presynaptic neurons, we generated detailed functional maps of inputs to a cell. We combined this approach with two-photon calcium imaging in an all-optical method to image and manipulate circuit activity.