Enfermedad mínima residual en leucemia mieloide aguda no promielocítica: Resultados preliminares de un estudio colaborativo internacional / Minimal residual disease in non-myelocytic acute myeloid leukemia: preliminary results of an international collaborative study

A pesar de los avances en los protocolos de tratamiento y en las medidas de soporte en pacientes con Leucemia Mieloide Aguda (LMA), 27% presentan recaídas de la enfermedad. Esto se debe, entre otras causas, a la persistencia de pequeñas cantidades de células malignas (blastos) resistentes a la terapia. Estas pequeñas cantidades de blastos remanentes se denominan Enfermedad Mínima Residual (EMR). La determinación de EMR requiere de técnicas no solo muy sensibles, sino también específicas, y permite evaluar la respuesta individual a la terapia. La introducción de la EMR como parámetro de respuesta y estratificación está bien definida en Leucemia Linfoblástica Aguda (LLA). Por el contrario, aunque existen publicaciones sobre el impacto pronóstico de la EMR en LMA, aún no se encuentra incluida en forma sistemática en los protocolos nacionales actuales, entre otros motivos, por lo laborioso de la determinación y por la necesidad de validación de la misma. Debe tenerse en cuenta que el inmunofenotipo de los blastos mieloides suele ser más heterogéneo que el de los blastos en LLA, presentando, en muchos casos, subpoblaciones diferentes entre sí, lo cual dificulta su detección certera y no hay consenso definido en cuanto a la metodología más eficaz. En este trabajo describimos una nueva estrategia de marcación y análisis estandarizada en un estudio multicéntrico internacional para LMA y la utilidad de la EMR como parámetro de respuesta y de estratificación. Asimismo, detallamos los resultados preliminares de nuestra cohorte de pacientes (AU)

Despite the improvement in treatment and supportive care of patients with Acute Myeloid Leukemia (AML), 27% of them relapse. This is due to the persistence of small amounts of malignant cells (blasts) resistant to therapy, among other causes. These small amounts of blasts are called Minimal Residual Disease (MRD). The determination of MRD requires not only techniques with high sensitivity but also with high specificity, and allows to evaluate the individual response to treatment. The introduction of MRD as a response parameter is well established in Acute Lymphoblastic Leukemia (ALL), and it is used in current stratification protocols. On the other hand, even though there are some reports regarding the prognostic impact of MRD in AML, it is still not included in the current national protocols due to the lack of validation of the determination, among other causes. This is due to the fact that the immunophenotype of myeloid blasts is more heterogeneous than in ALL, presenting different subpopulations, which difficults their accurate detection. Thus, there is still no consensus regarding the most effective approach. In this article, we describe a new staining and analysis strategy standardized by an international multicentric study, and the utility of EMR as a response and stratification parameter. Additionally, we show the preliminary results of our patient cohort. (AU)

Imaging Flow Cytometry for High-Throughput Phenotyping of Synthetic Cells.

The reconstitution of basic cellular functions in micrometer-sized liposomes has led to a surge of interest in the construction of synthetic cells. Microscopy and flow cytometry are powerful tools for characterizing biological processes in liposomes with fluorescence readouts. However, applying each method separately leads to a compromise between information-rich imaging by microscopy and statistical population analysis by flow cytometry. To address this shortcoming, we here introduce imaging flow cytometry (IFC) for high-throughput, microscopy-based screening of gene-expressing liposomes in laminar flow. We developed a comprehensive pipeline and analysis toolset based on a commercial IFC instrument and software. About 60 thousands of liposome events were collected per run starting from one microliter of the stock liposome solution. Robust population statistics from individual liposome images was performed based on fluorescence and morphological parameters. This allowed us to quantify complex phenotypes covering a wide range of liposomal states that are relevant for building a synthetic cell. The general applicability, current workflow limitations, and future prospects of IFC in synthetic cell research are finally discussed.

Performance-enhanced clogging-free viscous sheath constriction impedance flow cytometry.

As a label-free and high-throughput single cell analysis platform, impedance flow cytometry (IFC) suffers from clogging caused by a narrow microchannel as mechanical constriction (MC). Current sheath constriction (SC) solutions lack systematic evaluation of the performance and proper guidelines for the sheath fluid. Herein, we hypothesize that the viscosity of the non-conductive liquid is the key to the performance of SC, and propose to employ non-conductive viscous sheath flow in SC to unlock the tradeoff between sensitivity and throughput, while ensuring measurement accuracy. By placing MC and SC in series in the same microfluidic chip, we established an evaluation platform to prove the hypothesis. Through modeling analysis and experiments, we confirmed the accuracy (error < 1.60% ± 4.71%) of SC w.r.t. MC, and demonstrated that viscous non-conductive PEG solution achieved an improved sensitivity (7.92×) and signal-to-noise ratio (1.42×) in impedance measurement, with the accuracy maintained and free of clogging. Viscous SC IFC also shows satisfactory ability to distinguish different types of cancer cells and different subtypes of human breast cancer cells. It is envisioned that viscous SC IFC paves the way for IFC to be really usable in practice with clogging-free, accurate, and sensitive performance.

A high-throughput technique to map cell images to cell positions using a 3D imaging flow cytometer.

We develop a high-throughput technique to relate positions of individual cells to their three-dimensional (3D) imaging features with single-cell resolution. The technique is particularly suitable for nonadherent cells where existing spatial biology methodologies relating cell properties to their positions in a solid tissue do not apply. Our design consists of two parts, as follows: recording 3D cell images at high throughput (500 to 1,000 cells/s) using a custom 3D imaging flow cytometer (3D-IFC) and dispensing cells in a first-in-first-out (FIFO) manner using a robotic cell placement platform (CPP). To prevent errors due to violations of the FIFO principle, we invented a method that uses marker beads and DNA sequencing software to detect errors. Experiments with human cancer cell lines demonstrate the feasibility of mapping 3D side scattering and fluorescent images, as well as two-dimensional (2D) transmission images of cells to their locations on the membrane filter for around 100,000 cells in less than 10 min. While the current work uses our specially designed 3D imaging flow cytometer to produce 3D cell images, our methodology can support other imaging modalities. The technology and method form a bridge between single-cell image analysis and single-cell molecular analysis.

Potential of cell tracking velocimetry as an economical and portable hematology analyzer.

Anemia and iron deficiency continue to be the most prevalent nutritional disorders in the world, affecting billions of people in both developed and developing countries. The initial diagnosis of anemia is typically based on several markers, including red blood cell (RBC) count, hematocrit and total hemoglobin. Using modern hematology analyzers, erythrocyte parameters such as mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), etc. are also being used. However, most of these commercially available analyzers pose several disadvantages: they are expensive instruments that require significant bench space and are heavy enough to limit their use to a specific lab and lead to a delay in results, making them less practical as a point-of-care instrument that can be used for swift clinical evaluation. Thus, there is a need for a portable and economical hematology analyzer that can be used at the point of need. In this work, we evaluated the performance of a system referred to as the cell tracking velocimetry (CTV) to measure several hematological parameters from fresh human blood obtained from healthy donors and from sickle cell disease subjects. Our system, based on the paramagnetic behavior that deoxyhemoglobin or methemoglobin containing RBCs experience when suspended in water after applying a magnetic field, uses a combination of magnets and microfluidics and has the ability to track the movement of thousands of red cells in a short period of time. This allows us to measure not only traditional RBC indices but also novel parameters that are only available for analyzers that assess erythrocytes on a cell by cell basis. As such, we report, for the first time, the use of our CTV as a hematology analyzer that is able to measure MCV, MCH, mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), the percentage of hypochromic cells (which is an indicator of insufficient marrow iron supply that reflects recent iron reduction), and the correlation coefficients between these metrics. Our initial results indicate that most of the parameters measured with CTV are within the normal range for healthy adults. Only the parameters related to the red cell volume (primarily MCV and RDW) were outside the normal range. We observed significant discrepancies between the MCV measured by our technology (and also by an automated cell counter) and the manual method that calculates MCV through the hematocrit obtained by packed cell volume, which are attributed to the artifacts of plasma trapping and cell shrinkage. While there may be limitations for measuring MCV, this device offers a novel point of care instrument to provide rapid RBC parameters such as iron stores that are otherwise not rapidly available to the clinician. Thus, our CTV is a promising technology with the potential to be employed as an accurate, economical, portable and fast hematology analyzer after applying instrument-specific reference ranges or correction factors.

Picturing of the Lung Tumor Cellular Composition by Multispectral Flow Cytometry.

The lung tumor microenvironment plays a critical role in the tumorigenesis and metastasis of lung cancer, resulting from the crosstalk between cancer cells and microenvironmental cells. Therefore, comprehensive identification and characterization of cell populations in the complex lung structure is crucial for development of novel targeted anti-cancer therapies. Here, a hierarchical clustering approach with multispectral flow cytometry was established to delineate the cellular landscape of murine lungs under steady-state and cancer conditions. Fluorochromes were used multiple times to be able to measure 24 cell surface markers with only 13 detectors, yielding a broad picture for whole-lung phenotyping. Primary and metastatic murine lung tumor models were included to detect major cell populations in the lung, and to identify alterations to the distribution patterns in these models. In the primary tumor models, major altered populations included CD324+ epithelial cells, alveolar macrophages, dendritic cells, and blood and lymph endothelial cells. The number of fibroblasts, vascular smooth muscle cells, monocytes (Ly6C+ and Ly6C-) and neutrophils were elevated in metastatic models of lung cancer. Thus, the proposed clustering approach is a promising method to resolve cell populations from complex organs in detail even with basic flow cytometers.

Evaluation of Flow Cytometry for Cell Count and Detection of Bacteria in Biological Fluids.

The analysis of biological fluids is crucial for the diagnosis and monitoring of diseases causing effusions and helps in the diagnosis of infectious diseases. The gold standard method for cell count in biological fluids is the manual method using counting chambers. The microbiological routine procedures consist of Direct Gram staining and culture on solid or liquid media. We evaluate the analytical performance of SYSMEX UF4000 (Sysmex, Kobe, Japan) and Sysmex XN10 (Sysmex, Kobe, Japan) in comparison with cytological and microbiological routine procedures. A total of 526 biological fluid samples were included in this study (42 ascitic, 31 pleural, 31 peritoneal, 125 cerebrospinal, 281 synovial, and 16 peritoneal dialysis fluids). All samples were analyzed by flow cytometry and subsequently processed following cytological and/or microbiological routine procedures. With regard to cell counts, UF4000 (Sysmex, Kobe, Japan) showed a performance that was at least equivalent to those of the reference methods and superior to those of XN10 (Sysmex, Kobe, Japan). Moreover, the bacterial count obtained with UF4000 (Sysmex, Kobe, Japan) was significantly higher among culture or Direct Gram stain positive samples. We established three optimal cutoff points to predict Direct Gram stain positive samples for peritoneal (465.0 bacteria/µL), synovial (1200.0 bacteria/µL), and cerebrospinal fluids (17.2 bacteria/µL) with maximum sensitivity and negative predictive values. Cell count and detection of bacteria by flow cytometry could be used upstream cytological and microbiological routine procedures to improve and accelerate the diagnosis of infection of biological fluid samples. IMPORTANCE The analysis of biological fluids is crucial for the diagnosis and monitoring of diseases causing effusions and helps in the diagnosis of infectious diseases. The possibility of carrying out cytological and microbiological analyses of biological fluid samples on the same automated machine would simplify the sample circuit (addressing the sample in a single laboratory, 24/7). It would also minimize the quantity of sample required. The performance of cytological and microbiological analysis by the flow cytometer UF 4000 (Sysmex, Kobe, Japan) has never been evaluated yet. This study has shown that bacterial count by flow cytometry using UF4000 (Sysmex, Kobe, Japan) could be used upstream of microbiological routine procedures to improve and to accelerate the diagnosis of infection of biological fluid samples.

Field-Portable Leukocyte Classification Device Based on Lens-Free Shadow Imaging Technique.

The complete blood count (CBC) is one of the most important clinical steps in clinical diagnosis. The instruments used for CBC are usually expensive and bulky and require well-trained operators. Therefore, it is difficult for medical institutions below the tertiary level to provide these instruments, especially in underprivileged countries. Several reported on-chip blood cell tests are still in their infancy and do not deviate from conventional microscopic or impedance measurement methods. In this study, we (i) combined magnetically activated cell sorting and the differential density method to develop a method to selectively isolate three types of leukocytes from blood and obtain samples with high purity and concentration for portable leukocyte classification using the lens-free shadow imaging technique (LSIT), and (ii) established several shadow parameters to identify the type of leukocytes in a complete leukocyte shadow image by shadow image analysis. The purity of the separated leukocytes was confirmed by flow cytometry. Several shadow parameters such as the "order ratio" and "minimum ratio" were developed to classify the three types of leukocytes. A shadow image library corresponding to each type of leukocyte was created from the tested samples. Compared with clinical reference data, a correlation index of 0.98 was obtained with an average error of 6% and a confidence level of 95%. This technique offers great potential for biological, pharmaceutical, environmental, and clinical applications, especially where point-of-care detection of rare cells is required.

Integrating Thermal Sensors in a Microplate Format: Simultaneous Real-Time Quantification of Cell Number and Metabolic Activity.

Microplates have become a standard tool in the pharmaceutical industry and academia for a broad range of screening assays. One of the most commonly performed assays is the cell proliferation assay, which is often used for the purpose of drug discovery. Microplate readers play a crucial role in this field, as they enable high-throughput testing of large sample numbers. Common drawbacks of the most popular plate reader technologies are that they are end-point-based and most often require the use of detection reagents. As a solution, with this work, we aim to expand the possibilities of real-time and label-free monitoring of cell proliferation inside a microplate format by introducing a novel thermal-based sensing approach. For this purpose, we have developed thin-film sensors that can easily be integrated into the bottom of standard 96-well plates. First, the accuracy and precision of the sensors for measuring temperature and thermal effusivity are assessed via characterization experiments. These experiments highlight the fast response of the sensors to changes in temperature and thermal effusivity, as well as the excellent reproducibility between different sensors. Later, proof-of-principle measurements were performed on the proliferation of Saccharomyces cerevisiae. The proliferation measurements show that the thermal sensors were able to simultaneously detect relative changes in cell number as well as changes in metabolic activity. This dual functionality makes the presented sensor technology a promising candidate for monitoring microplate assays.

Label-free imaging flow cytometry for analysis and sorting of enzymatically dissociated tissues.

Biomedical research relies on identification and isolation of specific cell types using molecular biomarkers and sorting methods such as fluorescence or magnetic activated cell sorting. Labelling processes potentially alter the cells' properties and should be avoided, especially when purifying cells for clinical applications. A promising alternative is the label-free identification of cells based on physical properties. Sorting real-time deformability cytometry (soRT-DC) is a microfluidic technique for label-free analysis and sorting of single cells. In soRT-FDC, bright-field images of cells are analyzed by a deep neural net (DNN) to obtain a sorting decision, but sorting was so far only demonstrated for blood cells which show clear morphological differences and are naturally in suspension. Most cells, however, grow in tissues, requiring dissociation before cell sorting which is associated with challenges including changes in morphology, or presence of aggregates. Here, we introduce methods to improve robustness of analysis and sorting of single cells from nervous tissue and provide DNNs which can distinguish visually similar cells. We employ the DNN for image-based sorting to enrich photoreceptor cells from dissociated retina for transplantation into the mouse eye.

Measurement of hematopoietic progenitor cells using XN2000 hematology analyzer.

INTRODUCTION: Stem cell enumeration by the hematopoietic progenitor cells (HPC) mode is a novel method available from Sysmex XN2000 hematology analyzer. A small amount of blood (190 µL) is required, and the results are available in a few minutes without manual gating or presample treatment. The present study compares stem cell measurements using XN2000 analyzer HPC mode and FC500 flow cytometry analyzer using peripheral blood (PB) specimens and apheresis products. METHODS: In this prospective study, CD34-positive cell counts were enumerated using an FC500 flow cytometry analyzer and compared with XN2000 Sysmex analyzer (XN-HPC mode) in the same samples. Results were compared using Bland-Altman plots. RESULTS: A total of 103 samples were used. In the PB samples, the median HPC count and CD34-positive cells were 83.5 × 106 /L and 78.0 × 106 /L, respectively. The mean Bland-Altman difference was 4.5 × 106 /L (Limits: -51.7 to 60.7 × 106 /L), with a Pearson's correlation of 0.79. In the apheresis products, the median HPC count and CD34-positive cells were 1468 × 106 /L (IQR: 1049 - 1960 × 106 /L) and 1327 × 106 /L (IQR: 910 - 2001 × 106 /L), respectively. The mean Bland-Altman difference was 179.0 × 106 /L (Limits: -2022.2 - 2380.2 × 106 /L), with a Pearson's correlation of 0.58. CONCLUSION: The XN-HPC mode has an excellent correlation and minimal disagreement for stem cell enumeration in PB compared with flow cytometry and could replace it. There is high disagreement in apheresis products, and therefore, the XN-HPC mode cannot be recommended.

Estudo do composto STX140, um análogo do estradiol, em linhagens de melanoma humano / STX140 compound study in human melanoma

O câncer de pele pode ser classificado como não melanoma e melanoma. O melanoma apresenta baixa incidência entre os cânceres de pele, porém é a forma mais letal e é considerado um dos tipos mais resistentes ao tratamento. Devido à infiltração de células malignas nos tecidos, vasos linfáticos e vasos sanguíneos, o melanoma invade e se espalha rapidamente. Suas metástases são frequentemente localizadas em linfonodos, cérebro, fígado e outros órgãos. Melanomas metastáticos abrigam múltiplas mutações gênicas e muitos tumores apresentam resistência aos tratamentos, como por exemplo com inibidores BRAF, devido à mutações e ativação de vias paralelas. Ou seja, existe uma necessidade clara da busca de novas opções de tratamento. Em trabalho realizado por nosso grupo, Massaro et al mostraram que o derivado de estradiol 2- Metoxiestradiol induz apoptose em células de melanoma e senescência. Neste sentido, o composto STX140, (um análogo do estradiol com biodisponibilidade superior), que já se mostrou eficaz no combate ao câncer de mama em diversos estudos in vitro e in vivo, será então avaliado para sua ação no melanoma de forma inédita. Este trabalho teve como principal objetivo explorar a ação antitumoral em células de melanoma do composto STX140, especialmente a indução de senescência. Utilizando a cultura de células de melanoma foram realizados os ensaios de: viabilidade celular - IC50, formação de colônias, análise do ciclo celular e caracterização de morte celular por citometria de fluxo, ensaio In vitro scratch, coloração para ß-galactosidase, PCR quantitativo e ELISA. Os resultados mostraram que o composto STX140: diminui a viabilidade celular, inibe a proliferação, formação de colônias e migração em linhagens de melanoma (não resistentes e resistentes ao vemurafenibe, inibidor de BRAF). Além do mais, o composto atuou diminuindo a secreção da interleucina pró-tumoral IL-8 em células resistentes. O STX140 induziu senescência nas células de melanoma que foram positivas para ß-galactosidase, também havendo aumento da expressão de genes chave de vias de senescência (CDKN1A e GADD45A) nas células de melanoma resistentes tratadas com o composto. Em conclusão, o STX140 mostrou ter um potencial antitumoral contra o melanoma, diminuindo sua viabilidade celular, inibindo sua proliferação e migração, induzindo senescência, diminuindo a secreção de interleucina pró- tumoral, com efeito mais acentuado nas linhagens de melanoma resistente

Skin cancer can be classified as non-melanoma and melanoma. Melanoma has a low incidence among skin cancers, but it is the most lethal form and is considered one of the most resistant to treatment. Due to the infiltration of malignant cells into tissues, lymphatic vessels and blood vessels, melanoma invades and spreads rapidly. Its metastases are often located in lymph nodes, brain, liver and other organs. Metastatic melanomas presents multiple gene mutations and many tumors are resistant to treatments, such as with BRAF inhibitors, due to mutations and activation of parallel pathways. In other words, there is a clear need to search for new treatment options. In work carried out by our group, Massaro et al showed that the estradiol derivative 2- Methoxyestradiol induces apoptosis in melanoma cells and senescence. In this sense, the compound STX140, (an estradiol analogue with superior bioavailability), which has already been shown to be effective against breast cancer in vitro and in vivo studies will be then evaluated for its action on melanoma. The main objective of this work is to explore the antitumor action of the compound STX140 in melanoma cells, especially the induction of senescence. Using the melanoma cell culture the following assays were performed: cell viability - IC50, clonogenic, cell cycle analysis and cell death characterization by flow cytometry, wound assay, staining for ß-galactosidase, quantitative PCR and ELISA. Preliminary data from this work showed that the compound STX140: decreases cell viability, inhibits proliferation, colony formation and migration in melanoma cell lines (non-resistant and resistant to vemurafenib, BRAF inhibitor). It also decreased the secretion of pro-tumor interleukin IL-8 in resistant cells. STX140 induced senescence in melanoma cells, that were positive for ß-galactosidase, and there was also increased expression of key genes of senescence pathways (CDKN1A and GADD45A) in resistant melanoma cells treated with the compound. In conclusion, STX140 has been shown to have antitumor potential against melanoma, decreasing its cell viability, inhibiting its proliferation and migration, inducing senescence, decreasing pro-tumor interleukin secretion, with a more pronounced effect on resistant melanoma cell lines

Identification of new human mesenchymal stem cell biomarker by aptamers / Identificação de novos biomarcadores de células tronco mesenquimais de origem humana por meio de aptâmeros

Stem cells are undifferentiated cells that can be distinguished from others by their ability to self-renew and to differentiate into new specific cell types. Mesenchymal stem cells (MSC) are adult stem cells that can be obtained from different sources, such as adipose tissue, bone marrow, dental pulp, and umbilical cord. They can either replicate, originating new identical cells, or differentiate into cells of mesodermal origin and from other germ layers. MSC have been studied as new tools for regenerative therapy. Although encouraging results have been demonstrated, MSC-based therapies still face a great barrier: the difficulty of isolating these cells from heterogeneous environments. MSC are currently characterized by immunolabelling through a set of multiple surface membrane markers, including CD29, CD73, CD90 and CD105, which are also expressed by other cell types. Hence, the present work aimed to identify new specific biomarkers for the characterization of human MSC using DNA aptamers produced by the SELEX (Systematic Evolution of Ligands by EXponential Enrichment) technique. Our results showed that MSC from different origins bound to DNA candidate aptamers, that is, DNA or RNA oligonucleotides selected from random libraries that bind specifically to biological targets. Aptamer-bound MSC could be isolated by fluorescenceactivated cell sorting (FACS) procedures, enhancing the induction of differentiation into specific phenotypes (chondrocytes, osteocytes and adipocytes) when compared to the whole MSC population. Flow cytometry analyses revealed that candidate aptamers bound to 50% of the MSC population from dental pulp and did not present significant binding rates to human fibroblasts or lymphocytes, both used as negative control. Moreover, immunofluorescence images and confocal analyses revealed staining of MSC by aptamers localized in the surfacemembrane of these cells. The results also showed internal staining of human monocytes by our investigated aptamers. A non-specific control aptamer (CNTR APT) obtained from the random pool was then utilized to compare the specificity of the aptamers bound to the analyzed non-apoptotic cells, showing no staining for MSC. However, 40% of the monocytes bound to the CNTR APT. Normalized data based on the cells bound to candidate aptamers compared to those bound to the CNTR APT, revealed a 10 to 16-fold higher binding rate for MSC against 2-fold for monocytes. Despite its low specificity, monocyte-aptamer binding occurs probably due to the expression of shared markers with MSC, since monocytes are derived from hematopoietic stem cells and are important for the immune system ability to internalize/phagocyte external molecules. Given that, we performed a pull-down assay followed by mass spectrometry analysis to detect which MSC-specific protein or other target epitope not coexpressed by monocytes or the CNTR APT would bind to the candidate aptamer. Distinguishing between MSC and monocyte epitopes is important, as both cells are involved in immunomodulatory effects after MSC transplantations. ADAM17 was found to be a target of the APT10, emerging as a possible biomarker of MSC, since its involvement in the inhibition of the TGF signaling cascade, which is responsible for the differentiation of MSC. Thus, MSC with a higher stemness profile should overexpress the protein ADAM17, which presents a catalytic site with affinity to APT10. Another target of Apt 10 is VAMP3, belonging to a transmembrane protein complex that is involved in endocytosis and exocytosis processes during immune and inflammatory responses. Overall, proteins identified as targets of APT10 may be cell surface MSC biomarkers, with importance for MSC-based cell and immune therapies

Células tronco são células indiferenciadas que podem ser distinguidas de outros tipos celulares por meio da habilidade de se auto renovarem e de se diferenciarem em novos tipos celulares. Células tronco mesenquimais (MSC) são células tronco adultas encontradas em diferentes tecidos como tecido adiposo, polpa de dente e cordão umbilical. Estas células podem se autodividir em células idênticas ou se diferenciarem em células de origem mesodermal. Estas células têm sido estudadas em novas aplicações que envolvem terapia regenerativas. Embora resultados encorajadores tenham sido demonstrados, terapias que utilizam MSC ainda encontram uma grande barreira: a dificuldade no isolamento destas células a partir de um ambiente heterogêneo. MSC são caracterizadas por populações positivas em ensaios de imunomarcação para os epítopos membranares CD29, CD73, CD90 e CD105, presentes também em outros tipos celulares. Assim, o presente trabalho tem o objetivo de identificar novos biomarcadores de MSC de origem humana, utilizando aptâmeros de DNA produzidos pela técnica SELEX (Systematic Evolution of Ligands by EXponential Enrichment) como ferramenta. Nossos resultados mostraram que MSC de diferentes origens ligam-se a aptâmeros (oligonucleotídeos de DNA ou RNA que atuam como ligantes específicos de alvos moleculares) de DNA candidatos que atuam no isolamento de MSC por meio da técnica FACS de separação celular, promovendo uma maior indução de diferenciação em células específicas (condrócitos, osteócitos e adipócitos) comparada com a população total de MSC. Análises de citometria de fluxo mostraram que os aptâmeros candidatos se ligam a 50% das MSC de polpa de dente e não apresentam taxa de ligação significante para fibroblastos e linfócitos de origem humana - utilizados como controles negativo. Além domais, imagens de imunofluorescência e confocal mostraram ligação na superfície da membrana de MSC e a marcação interna de monócitos a estes aptâmeros. Portanto, um aptâmero controle (CNTR APT) foi utilizado para comparar a especificidade dos aptâmeros ligados a células viáveis, mostrando a não ligação deste aptâmero a MSC. Porém, 40% da população de monócitos ligou-se ao CNTR APT. Uma normalização baseada na comparação entre as taxas de ligação entre células ligadas com aptâmeros candidatos e o aptâmero controle gerou uma taxa de especificidade entre 10-16 vezes maior para MSC contra 2,5 vezes para os monócitos. Deste modo, embora os resultados tenham mostrado uma taxa de ligação entre monócitos e aptâmeros, as MSC ligadas aos aptâmeros candidatos possuem uma maior taxa de especificidade devido a uma maior presença de antígenos que são expressos em ambas as células. Um ensaio de Pull Down seguido de espectrometria de massas foi utilizado para a identificação de biomarcadores que se ligariam aos aptâmeros candidatos, e que não seriam co-expressos por monócitos e por antígenos ligados ao aptâmero controle. Deste modo, a proteína ADAM17 foi identificada nas amostras de APT10 ligadas às MSC. Tal proteína está relacionada à inibição de uma cascata de sinalização da família de proteínas TGF, responsável pela diferenciação de MSC. Assim, MSC com maior potencial tronco deveriam expressar ADAM17 em maior quantidade. Tal proteína apresenta um sítio catalítico que demonstra interagir com o APT10, de acordo com predição Docking entre proteína e DNA. Foi identificada também, a proteína VAMP3, que pertence a um complexo proteico transmembranar responsável pelos processos de endocitose e exocitose, e que podem ter um papel importante na liberação de citocinas e outras moléculas relacionadas às respostas imune e inflamatórias. Deste modo, o APT10 identificou proteínas importantes que devem estar relacionas com a melhora de imunoterapias que utilizam MSC

Influência da Delfinidina como potencial modulador da capacidade imunorregulatória das Células-Tronco Mesenquimais / Influence of Delphinidin as a potential modulator of the immunoregulatory capacity of Mesenchymal Stem Cells

As Células-Tronco Mesenquimais (CTMs), são células multipotentes, presentes em diversos tecidos, sendo bastante estudada devido sua capacidade imunorregulatória por meio da liberação de fatores solúveis. Fatores estes que atuam sobre as funções de células do sistema imunitário. Simultaneamente, estudos indicam que os compostos flavonoides, em destaque a Delfinidina, presente em alguns frutos e flores, possuem atuação anti-inflamatória e inibitória sobre células do sistema imunitário. Todavia, são escassos os estudos em relação entre a capacidade imunorregulatória da CTM e a influência da Delfinidina, sendo este o objetivo deste estudo. Inicialmente, a Delfinidina 3-O-ß-D-glicosídeo foi escolhido, devido a sua maior estabilidade e a dose de 50 µM foi selecionada após análise por citometria de fluxo que mostrou aumento da fase proliferativa do ciclo celular. Posteriormente ao realizar análise da produção de fatores solúveis pelas CTM, os resultados mostraram aumento da produção de IL-10, TGF-ß e Oxido nítrico pelas CTM tratadas com Delfinidina. Bem como, diminuição da expressão de p-NF-κB/NF-κB pelas CTMs tratadas com Delfinidina, quando avaliadas por Wersten Blot. Adicionalmente, para analisar a Delfinidina sobre os efeitos imunorregulatórios da CTM sob macrófagos (RAW 264.7), célula esta, importante no sistema imune inato. Foram realizadas culturas condicionadas, com posterior análise da produção de fatores solúveis, os resultados mostraram aumento da produção de IL-10, e diminuição da produção de TNF-α, IL-1α e IL-12 pelos macrófagos, nas culturas condicionadas. Assim como, diminuição da expressão do fator p-NF-κB/NF-κB pelos macrófagos nas culturas condicionadas, quando avaliadas por Wersten Blot. Ademais, ao analisar a atividade metabólica dos macrófagos por ensaio de MTT, os resultados mostraram que as culturas condicionadas e a Delfinidina per si foi capaz de diminuir a atividade metabólica, sem alterar os efeitos anti-inflamatórios sobre a célula. Em síntese, a Delfinidina mostrou acentuar a atuação imunorregulatória da CTM sobre a linhagem macrofágica, célula esta, de grande importância para o sistema imune inato

Mesenchymal Stem Cells (MSCs) are multipotent cells present in various tissues, being widely studied due to their immunoregulatory capacity through the release of soluble factors. These factors act on the functions of cells of the immune system. Simultaneously, studies indicate that flavonoid compounds, especially Delphinidin, present in some fruits and flowers, have anti inflammatory and inhibitory effects on immune system cells. However, there are few studies on the relationship between the immunoregulatory capacity of MSC and the influence of Delphinidin, which is the objective of this study. Initially, Delphinidin 3-O-ß-D-glycoside was chosen due to its greater stability and the 50 µM dose was selected after analysis by flow cytometry which showed an increase in the proliferative phase of the cell cycle. Subsequently, when analyzing the production of soluble factors by MSCs, the results showed an increase in the production of IL-10, TGF-ß and nitric oxide by MSCs treated with Delphinidin. As well as decreased expression of p-NF-κB/NF-κB by MSCs treated with Delphinidin, when evaluated by Wersten Blot. Additionally, to analyze Delphinidin on the immunoregulatory effects of MSC on macrophages (RAW 264.7), this cell is important in the innate immune system. Conditioned cultures were performed, with subsequent analysis of the production of soluble factors, the results showed an increase in the production of IL-10, and a decrease in the production of TNF-α, IL-1α and IL-12 by macrophages, in the conditioned cultures. As well as decreased expression of p-NF-κB/NF-κB factor by macrophages in conditioned cultures, when evaluated by Wersten Blot. Furthermore, when analyzing the metabolic activity of macrophages by MTT assay, the results showed that conditioned cultures and Delphinidin itself was able to decrease the metabolic activity, without altering the anti-inflammatory effects on the cell. In summary, Delphinidin has shown to enhance the immunoregulatory action of MSC on the macrophage lineage, a cell that is of great importance for the innate immune system

FaDA: A web application for regular laboratory data analyses.

Web-based data analysis and visualization tools are mostly designed for specific purposes, such as the analysis of data from whole transcriptome RNA sequencing or single-cell RNA sequencing. However, generic tools designed for the analysis of common laboratory data for noncomputational scientists are also needed. The importance of such web-based tools is emphasized by the continuing increases in the sample capacity of conventional laboratory tools such as quantitative PCR, flow cytometry or ELISA instruments. We present a web-based application FaDA, developed with the R Shiny package that provides users with the ability to perform statistical group comparisons, including parametric and nonparametric tests, with multiple testing corrections suitable for most standard wet-laboratory analyses. FaDA provides data visualizations such as heatmaps, principal component analysis (PCA) plots, correlograms and receiver operating curves (ROCs). Calculations are performed through the R language. The FaDA application provides a free and intuitive interface that allows biologists without bioinformatic skill to easily and quickly perform common laboratory data analyses. The application is freely accessible at https://shiny-bird.univ-nantes.fr/app/Fada.

In silico-labeled ghost cytometry.

Characterization and isolation of a large population of cells are indispensable procedures in biological sciences. Flow cytometry is one of the standards that offers a method to characterize and isolate cells at high throughput. When performing flow cytometry, cells are molecularly stained with fluorescent labels to adopt biomolecular specificity which is essential for characterizing cells. However, molecular staining is costly and its chemical toxicity can cause side effects to the cells which becomes a critical issue when the cells are used downstream as medical products or for further analysis. Here, we introduce a high-throughput stain-free flow cytometry called in silico-labeled ghost cytometry which characterizes and sorts cells using machine-predicted labels. Instead of detecting molecular stains, we use machine learning to derive the molecular labels from compressive data obtained with diffractive and scattering imaging methods. By directly using the compressive 'imaging' data, our system can accurately assign the designated label to each cell in real time and perform sorting based on this judgment. With this method, we were able to distinguish different cell states, cell types derived from human induced pluripotent stem (iPS) cells, and subtypes of peripheral white blood cells using only stain-free modalities. Our method will find applications in cell manufacturing for regenerative medicine as well as in cell-based medical diagnostic assays in which fluorescence labeling of the cells is undesirable.

Rapid detection of bacterial infection using a novel single-tube, four-colour flow cytometric method: Comparison with PCT and CRP.

BACKGROUND: A key factor behind the unnecessary use of antibiotics is the lack of rapid and accurate diagnostic tests. In this study, we developed a novel and fast flow cytometric single-tube method to detect bacterial infections within 30 minutes. METHODS: Quantitative flow cytometric four-colour analysis of host biomarkers CD35, CD64, CD329, and MHC class I expression on neutrophils and lymphocytes was performed on samples taken from 841 febrile patients with suspected infection. Obtained data was incorporated into the four-colour bacterial infection (FCBI)-index, using the developed bacterial infection algorithm. FINDINGS: In distinguishing between microbiologically confirmed bacterial (n = 193) and viral (n = 291) infections, the FCBI-index method was superior to serum C-reactive protein (CRP) and procalcitonin (PCT). In 269 confirmed viral respiratory tract infections, 43% (95% CI: 37-49%) of the patients had an increased FCBI-index, suggesting probable bacterial coinfection. INTERPRETATION: The proposed FCBI-index test might be a potent additional tool when assessing appropriateness of empiric antibiotic treatment. FUNDING: This study has been financially supported by Turku University Hospital (Turku, Finland) and The Finnish Medical Foundation.