Carboxyfluorescein Diacetate Succinimidyl Ester Research Articles

The effect of microvesicles derived from K562 cells on proliferation and apoptosis of human bone marrow mesenchymal stem cells.

Microvesicles (MVs) are small membrane-bound particles that act as a vehicle to transfer their contents, such as proteins, RNAs, and miRNAs, to the target cells, making them undergo several changes. Depending on the origin and the target cell, MVs may cause cell survival or apoptosis. This study investigated the effects of MVs released from the leukemic K562 cell line on the human bone marrow mesenchymal stem cells (hBM-MSCs) to evaluate changes in the survival or apoptosis of the cells in an in vitro system. In this experimental study, we added the isolated MVs from the K562 cell line to hBM-MSCs, and after three and then seven days, subsequently cell count, cell viability, transmission electron microscopy, tracing MVs by carboxyfluorescein diacetate, succinimidyl ester (CFSE) solution, flow cytometry analysis for Annexin-V/PI staining and qPCR for the evaluation of BCL-2, KI67, and BAX expression were carried out. On the 10th day of the culture, hBM-MSCs were examined by Oil red O and Alizarin Red staining to evaluate their differentiation into adipocytes and osteoblasts. There was a significant decrease in cell viability and KI67 and BCL-2 expression; however, BAX was significantly upregulated in the hBM-MSCs compared to control groups. Annexin-V/PI staining results also showed the apoptotic effects of K562-MVs on hBM-MSCs. Moreover, the differentiation of hBM-MSCs into adipocytes and osteoblasts was not observed. MVs from the leukemic cell line could affect the viability of normal hBM-MSCs and induce cell apoptosis.

Extensively Hydrolyzed Hypoallergenic Infant Formula with Retained T Cell Reactivity.

Immunoglobulin E (IgE)-mediated cow's milk allergy (CMA) can be life-threatening and affects up to 3% of children. Hypoallergenic infant formulas based on hydrolyzed cow's milk protein are increasingly considered for therapy and prevention of cow's milk allergy. The aim of this study was to investigate the allergenic activity and ability to induce T cell and cytokine responses of an infant formula based on extensively hydrolyzed cow's milk protein (whey) (eHF, extensively hydrolyzed formula) supplemented with Galactooligosaccharides (GOS) and Limosilactobacillus fermentum CECT5716 (LF) to determine its suitability for treatment and prevention of CMA. eHF and standard protein formula based on intact cow's milk proteins (iPF) with or without Galactooligosaccharide (GOS) and Limosilactobacillus fermentum CECT5716 (LF) were investigated with allergen-specific antibodies and tested for IgE reactivity and allergenic activity in basophil degranulation assays with sera from cow's milk (CM)-allergic infants/children. Their ability to stimulate T cell proliferation and cytokine secretion in cultured peripheral blood mononuclear cells (PBMC) from CM-allergic infants and children was studied with a FACS-based carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution assay and xMAP Luminex fluorescent bead-based technology, respectively. An eHF supplemented with GOS and LF exhibiting almost no IgE reactivity and allergenic activity was identified. This eHF induced significantly lower inflammatory cytokine secretion as compared to an intact protein-based infant formula but retained T cell reactivity. Due to strongly reduced allergenic activity and induction of inflammatory cytokine secretion but retained T cell reactivity, the identified eHF may be used for treatment and prevention of CMA by induction of specific T cell tolerance.

FASCIA Method in the Assessment of Lymphocyte Mitogen Responses in the Laboratory Diagnostics of Primary Immunodeficiencies

Lymphocyte responses to mitogens constitute a key part of the diagnostics of combined immunodeficiency (CID). Currently, mostly radioactive thymidine incorporation and carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution methods are used. Flow-cytometric assay for specific cell-mediated immune-response in activated whole blood (FASCIA) has been put forth as an easy-to-perform option for the measurement of lymphocyte responses with the advantage of recognizing different lymphocyte subtypes and avoiding the use of radioactive reagents. Our aim was to analyze retrospectively the usefulness of FASCIA in the diagnostics of CID. We included all lymphocyte stimulation tests done with FASCIA in HUSLAB (Helsinki, Finland) between February 2015 and September 2018 in our analysis. The cohort was divided into two groups according to the patients’ final diagnoses: CID (n = 30) or non-CID (n = 159). We evaluated the stimulation responses with a combined FASCIA score (the average of all mitogen responses). The FASCIA score was significantly lower among the CID group compared to the other patients (p = 0.002), and in the ROC analysis, the AUC was 0.75 (p < 0.001) for the FASCIA score. When the three mitogens were analyzed separately, phytohemagglutinin (PHA) was best in separating patients with CID from non-CID (in the ROC analysis AUC 0.71, p = 0.001). Immunosuppressive medication affected the FASCIA result significantly and needs to be considered when evaluating the results. In conclusion, FASCIA can reliably detect the CID patients in the absence of immunosuppressive medication. It emerges as a method with many benefits compared to tests requiring radioactive reagents or the complicated CFSE staining.

In Vitro Drug Studies of Inhibiting MDSC to Improve Efficacy of ICI (immune check point inhibitor) Therapy in Ph(-) myeloproliferative Neoplasm

Although there has been much progress in the use of immune check-point inhibitor (ICI) therapy to treat cancers, very few studies have been published regarding the ICI therapy in Ph(-) myeloproliferative neoplasm (MPN). One clinical trial by Mascarenhas and his associates (ASH annual meeting 2020) in treating nine myelofibrosis patients with pembrolizumab was a anegative trial with no patients responded. Recent studies suggest a leading role for MDSCs in the immunosuppressive tumor micro-environments (TME) which could be the main cause of therapeutic resistance to ICI therapy. Therefore, we perform in vitro experiments to test some of potential drug to inhibit MDSC which may be added to the ICI therapy for future clinical ICI therapy in MPN. Material & Methods: 1) in vitro culture for MDSC formation. Peripheral blood mononuclear cells (PBMC) were isolated from patients with ph(-) MPN by Ficoll Hypaque (GE Healthcare) density gradient centrifugation. Monocytes were isolated using CD14 MicroBeads (Miltenyi Biotec) and cultured in RPMI1640 media supplemented with 10% heat- inactivated FBS and 10 ng/mL IL-6 and GM-CSF (R&D Systems Inc) for 5 days. 2) Drug treatment. Where indicated, monocytes were treated with 0.01% DMSO or 1 umol/L each of Ibrutinib (in 0.01% DMSO), Ruxolitinib (in 0.01% DMSO). Lenalidomide (in 0.01% DMSO) for 1 hour every day during the MDSC cultures. 3) Flow cytometry: Cultured MDSC cells were subject for flow cytometric assessment on BD Accuri C6 flow cytometer. Monocytic MDCS was determined as HLA-DRdim/- and CD14+; guanulocytic MDCS as HLA-DRdim/-, CD14-, and CD33+, (BD Biosciences Inc). The flow data were processed using FlowJo vX. 4) T cell proliferation assay. T cells were isolated from a T4 or T8 isolation kits then T cells were labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE; Life Technologies). T cells were nonspecifically activated with anti-CD3/CD28 beads (Life Technologies) and cocultured at 1:1 ratios of T cells to the MDSC obtained from in vitro culture, in the presence of 10 ng/mL IL2 (Invitrogen). After 3 days, T-cell proliferation levels (CFSE) in gated CD4+ and CD8+ cells was assessed respectively by flow cytometry. The flow data were processed using FlowJo vX. Results: After 5 days cultures, Fig 1a ,b, c, shows Ruxolitinib, Ibrutinib, Lenalidomide significantly inhibits M-MDSC formation presented as (mean + SE ( % of DMSO )) of 79.72 + 4.66 ( n=27) , 73.19 + 4.71 (n=31), and 72.48 + 5.89 (n=20)respectively; Inhibits G-MDSC as of 77.82 + 5.66 (n=27) ,66.34 + 5.79 (n=31), (73.59 + 7.03) (n=20) respectively. Fig 2 showed CFSE levels in proliferated CD4+ (Fig. 2 A-D) and CD8+ (Fig.2 E-H) cells in a representative MF patient. Conclusion: Ibrutinib, Ruxolitinib, Lenalidomide significantly inhibits MDSC formation in vitro in patients with MPN and improves T cell function. A further clinical trial to evaluate the combination of ICI therapy with MDSC inhibitor such as Ibrutinib , Ruxolitinib or Lenalidomide may be worthwhile in treating patients with Myelofibrosis. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Identification and characterization of slow‑cycling cells in Ewing sarcoma.

Ewing sarcoma (ES) is an aggressive primary malignant bone tumor that predominantly affects children and young adults. Multimodal treatment approaches have markedly improved the survival of patients with localized ES. However, local recurrence and distant metastasis following curative therapies remain a main concern for patients with ES. Recent studies have suggested that slow-cycling cells (SCCs) are associated with tumor progression, local recurrence and distant metastasis in various types of cancers. According to the results of these studies, it was hypothesized that SCCs may play a critical role in tumor progression, chemoresistance and local/distal recurrence in patients with ES. The present study applied a label-retaining system using carboxyfluorescein diacetate succinimidyl ester (CFSE) to identify and isolate SCCs in ES cell lines. In addition, the properties of SCCs, including sphere formation ability, cell cycle distribution and chemoresistance, in comparison with non-SCCs were investigated. RNA sequencing also revealed several upregulated genes in SCCs as compared with non-SCCs; the identified genes not only inhibited cell cycle progression, but also promoted the malignant properties of SCCs. On the whole, the present study successfully identified SCCs in ES cells through a label-retaining system using CFSE. Moreover, to the best of our knowledge, the present study is the first to describe the characteristic properties of SCCs in ES. The findings of this study, if confirmed, may prove to be useful in elucidating the underlying molecular mechanisms and identifying effective therapeutic targets for ES.

Evaluation of T Cell Proliferation Using CFSE Dilution Assay: A Comparison between Stimulation with PHA and Anti-CD3/Anti-CD28 Coated Beads.

A decrease in T cell count or reduced T cell function can be indicative of T cell immunodeficiency. In the present study, T-cell function was assessed using Carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution test after stimulation with commonly used Phytohaemagglutinin (PHA) or anti-CD3/anti-CD28 coated beads in pediatric patients with recurrent infections. Seven infants with recurrent infections and seven sex/age-matched healthy infants were included in this study. A blood cell count, immunophenotyping, and serum immunoglobulin level were performed. The proliferation of T cells was also assessed with CFSE dilution after stimulation with PHA or anti-CD3/anti-CD28 coated beads. This study showed increased IgA, IgG, and IgM levels in patients compared to the controls. In contrast to the controls, the immunophenotyping results showed a significant decline in the number of CD4+ T cells in patients. Although there was no difference in CD3+ T cell proliferation between patients and controls, the CD4+ and CD8+ T cell proliferation rates were significantly decreased in patients when stimulated with PHA. As a mitogen with the potential for maximum proliferation of T cells, PHA is better able to distinguish between patients with recurrent infections and controls than anti-CD3/anti-CD28, which mimics only the TCR pathway for stimulation of T cells.

Predicting response of micrometastases with MIRDcell V3: proof of principle with 225Ac-DOTA encapsulating liposomes that produce different activity distributions in tumor spheroids.

The spatial distribution of radiopharmaceuticals within multicellular clusters is known to have a significant effect on their biological response. Most therapeutic radiopharmaceuticals distribute nonuniformly in tissues which makes predicting responses of micrometastases challenging. The work presented here analyzes published temporally dependent nonuniform activity distributions within tumor spheroids treated with actinium-225-DOTA encapsulating liposomes (225Ac-liposomes) and uses these data in MIRDcellV3.11 to calculate absorbed dose distributions and predict biological response. The predicted responses are compared with experimental responses. Four types of liposomes were prepared having membranes with different combinations of release (R) and adhesion (A) properties. The combinations were R-A-, R-A+, R+A-, and R+A+. These afford different penetrating properties into tissue. The liposomes were loaded with either carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) or 225Ac. MDA-MB-231 spheroids were treated with the CFDA-SE-liposomes, harvested at different times, and the time-integrated CFDA-SE concentration at each radial position within the spheroid was determined. This was translated into mean 225Ac decays/cell versus radial position, uploaded to MIRDcell, and the surviving fraction of cells in spherical multicellular clusters was simulated. The MIRDcell-predicted surviving fractions were compared with experimental fractional-outgrowths of the spheroids following treatment with 225Ac-liposomes. The biological responses of the multicellular clusters treated with 225Ac-liposomes with physicochemical properties R+A+, R-A+, and R-A- were predicted by MIRDcell with statistically significant accuracy. The prediction for R+A- was not predicted accurately. In most instances, MIRDcell predicts responses of spheroids treated with 225Ac-liposomes that result in different tissue-penetrating profiles of the delivered radionuclides.

Periodontitis may induce gut microbiota dysbiosis via salivary microbiota

The aim of this study was to identify whether periodontitis induces gut microbiota dysbiosis via invasion by salivary microbes. First, faecal and salivary samples were collected from periodontally healthy participants (PH group, n = 16) and patients with severe periodontitis (SP group, n = 21) and analysed by 16S ribosomal RNA sequencing. Significant differences were observed in both the faecal and salivary microbiota between the PH and SP groups. Notably, more saliva-sourced microbes were observed in the faecal samples of the SP group. Then, the remaining salivary microbes were transplanted into C57BL6/J mice (the C-PH group and the C-SP group), and it was found that the composition of the gut microbiota of the C-SP group was significantly different from that of the C-PH group, with Porphyromonadaceae and Fusobacterium being significantly enriched in the C-SP group. In the colon, the C-SP group showed significantly reduced crypt depth and zonula occludens-1 expression. The mRNA expression levels of pro-inflammatory cytokines, chemokines and tight junction proteins were significantly higher in the C-SP group. To further investigate whether salivary bacteria could persist in the intestine, the salivary microbiota was stained with carboxyfluorescein diacetate succinimidyl ester and transplanted into mice. We found that salivary microbes from both the PH group and the SP group could persist in the gut for at least 24 h. Thus, our data demonstrate that periodontitis may induce gut microbiota dysbiosis through the influx of salivary microbes.

Inhibitory Effects of Cold Atmospheric Plasma on Inflammation and Tumor-Like Feature of Fibroblast-Like Synoviocytes from Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic, debilitating systemic disease characterized by chronic inflammation and progressive joint destruction. Fibroblast-like synoviocytes (FLSs) are one of the most important players in the pathophysiology of RA, acting like tumor cells and secreting inflammatory cytokines. Previous research has shown that cold atmospheric plasma (CAP) inhibits cancer cells and may have anti-inflammatory properties. This study examined the effects of argon plasma jet-produced CAP on the suppression of invasion and inflammation caused by cultured RA-FLS. The findings revealed that CAP reduced cell viability and elevated the percentage of apoptotic RA-FLS by producing reactive oxygen species. Carboxyfluorescein diacetate succinimidyl ester (CFSE) staining confirmed that CAP could decrease the proliferation of RA-FLS. Furthermore, CAP effectively reduced the production of inflammatory factors (e.g., NF-κB and IL-6) as well as destructive factors like receptor activator of nuclear factor kappa-B ligand (RANKL) and matrix metalloproteinases-3 (MMP-3). These data suggest that CAP could be a promising treatment for slowing the progression of RA by reducing tumor-like features and inflammation in RA-FLS.

In Vitro Generation of BK polyomavirus-specific T cells for adoptive cell therapy in refractory cystitis hemorrhagic patients after hematopoietic stem cell transplantation

IntroductionBKPyV associated hemorrhagic cystitis (BKPyV-HC) is a major and prevalent outcome of hematopoietic stem cell transplantation (HSCT) with no standard treatment option. Adoptive T cell therapy (ACT) against transplant-associated viruses has shown promising potential. We sought to produce virus-specific T cells (VSTs) against BKPyV with the aim of treating refractory HSCT-associated HC.MethodsPeripheral blood mononuclear cells (PBMC) from healthy donors were isolated by Ficoll-Hypaque density gradient centrifugation. BKPyV-pulsed, monocyte-derived dendritic cells (mo-DCs) and T cells were co-cultured and expanded over 2–3 weeks with the addition of IL-2. The T cells were examined for various functional assays.ResultsComparison analysis of Carboxyfluorescein diacetate succinimidyl ester (CFSE) indicated that the percentage of proliferated cells were significantly higher in donors (49.62 ± 7.09%) than controls (7.96 ± 4.55%). Furthermore, expanded T cells exhibited specificity to BKPyV antigens by IFN-γ ELISPOT assay. The expanded cells showed cytotoxic function versus human lymphoblastoid cell line (LCL). Final VST products mainly comprised of CD8/CD69 double-positive T cells, which were significantly higher in donors (46.8 ± 7.1%) than controls (16.91 ± 3.40%).ConclusionIn this study we demonstrated the feasibility of producing functional BKPyV-specific T cells in healthy donors using BKPyV PepMixes. These functional cells were able to proliferate and produce IFN-γ cytokine in response to BKPyV PepMixes. In addition, these T cells had cytotoxic ability against BKPyV antigen-expressing target cells.

Gpr174 Knockout Alleviates DSS-Induced Colitis via Regulating the Immune Function of Dendritic Cells.

BackgroundDysfunction of the immune system would disturb the intestinal homeostasis and lead to inflammatory bowel disease (IBD). Dendritic cells (DCs) help maintain intestinal homeostasis and immediately respond to pathogens or injuries once the mucosa barriers are destroyed during IBD. G protein-coupled receptors(GPR)174 is an essential regulator of immunity that is widely expressed in most immune cells, including DCs. However, the role of GPR174 in regulating the immune function of DC in colitis has not been investigated.MethodsDextran sodium sulfate (DSS) was administered to establish the mice colitis model. Data of weight, length of colon, disease activity index (DAI), and macroscopic scores were collected. The flow cytometry was used to detect the infiltrations of T cells and DCs, the mean fluorescence intensity (MFI) of CD80, CD86, CD40, and major histocompatibility complex-II (MHC-II). And T cells proliferataion was measured by carboxyfluorescein diacetate succinimidyl ester (CFSE). The expression of cytokines (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), interferon-γ (IFN-γ), interleukin -4 (IL-4)) and GPR174 mRNA were measured by Elisa, quantitative polymerase chain reaction (qPCR), and immunofluorescence. RNA of bone-marrow-derived dendritic cells (BMDCs) was extracted for sequencing. Adoptive transfer of BMDCs was administrated intravenously.ResultsGpr174-/- mice exposed to 3% DSS showed significant alleviation characterized by reduced loss of weight, more minor colon damage, and better DAI and macroscopic scores. The expression of pro-inflammatory cytokines (TNF-α, IL-6) decreased, while anti-inflammatory cytokine (IL-10) increased compared with WT mice. In vitro, Gpr174-/- BMDCs showed less maturity, with a declined expression of MHC-II, CD80, CD86 and reduced TNF-α, higher IL-10 after LPS stimulation. Gpr174-/- BMDCs were less capable of activating OT-II naïve CD4+ T cells than WT BMDCs and induced more Th0 cells to differentiate into Treg while less into Th1. Furthermore, the transcriptome sequencing analysis exhibited that Gpr174 participated in TNF-α (NF-κB) signaling, leukocyte transendothelial migration, and Th1/Th2 cell differentiation pathways. Adoptive transfer of Gpr174-/- BMDCs to WT mice ameliorated DSS-induced colitis.ConclusionOur study indicated that GPR174 was involved in the pathogenesis of IBD by regulating the maturation of the dendritic cells to maintain immune homeostasis. TNF-α (NF-κB) signaling pathway, leukocyte transendothelial migration, and Th1/Th2 cell differentiation pathways may be the target pathway.

Heterologous Expression, Purification, and Immunomodulatory Effects of Recombinant Lipoprotein GUDIV-103 Isolated from Ureaplasma diversum.

Ureaplasma diversum is a bacterial pathogen that infects cattle and can cause severe inflammation of the genital and reproductive systems. Lipid-associated membrane proteins (LAMPs), including GUDIV-103, are the main virulence factors in this bacterium. In this study, we heterologously expressed recombinant GUDIV-103 (rGUDIV-103) in Escherichia coli, purified it, and evaluated its immunological reactivity and immunomodulatory effects in bovine peripheral blood mononuclear cells (PBMCs). Samples from rabbits inoculated with purified rGUDIV-103 were analysed using indirect enzyme-linked immunosorbent assay and dot blotting to confirm polyclonal antibody production and assess kinetics, respectively. The expression of this lipoprotein in field isolates was confirmed via Western blotting with anti-rGUDIV-103 serum and hydrophobic or hydrophilic proteins from 42 U. diversum strains. Moreover, the antibodies produced against the U. diversum ATCC 49783 strain recognised rGUDIV-103. The mitogenic potential of rGUDIV-103 was evaluated using a lymphoproliferation assay in 5(6)-carboxyfluorescein diacetate succinimidyl ester–labelled bovine PBMCs, where it induced lymphocyte proliferation. Quantitative polymerase chain reaction analysis revealed that the expression of interleukin-1β, toll-like receptor (TLR)-α, TLR2, TLR4, inducible nitric oxide synthase, and caspase-3–encoding genes increased more in rGUDIV-103–treated PBMCs than in untreated cells (p < 0.05). Treating PBMCs with rGUDIV-103 increased nitric oxide and hydrogen peroxide levels. The antigenic and immunogenic properties of rGUDIV-103 suggested its suitability for immunobiological application.

Effect of miltirone on proliferation and apoptosis of leukemia THP-1 cells

To investigate the toxicity and related mechanism of miltirone to human acute myeloid leukemia THP-1 cells. To be specific, the active components and targets of miltirone were retrieved from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and the target proteins were converted into standard gene names with UniProt. Acute leukemia-rela-ted target genes were screened from GeneCards and DisGeNET. Venn diagram was constructed with Venny 2.1 to yield the common targets of the disease and the drug. The protein-protein interaction(PPI) network was constructed by STRING and Cytoscape 3.8.2. THP-1 cells in the logarithmic growth phase were treated with dimethyl sulfoxide(DMSO), and 2.5, 5, 10, 15, and 20 μmol·L~(-1) miltirone for 24 h, respectively. The proliferation rate of cells was analyzed by carboxyfluorescein diacetate succinimidyl ester(CFSE), apoptosis rate by flow cytometry with Annexin V-PE/7 AAD staining, and cell morphology by acridine orange staining. Real-time quantitative PCR(qPCR) was employed to detect the mRNA levels of nuclear receptor coactivator 2(NCOA2), poly(ADP-ribose) polymerase-1(PARP1), B-cell lymphoma-2(Bcl-2)-associated X protein(Bax), Bcl-2, and cysteine aspartyl protease-3(caspase-3). The effect of miltirone on apoptosis was detected in presence of caspase inhibitor Z-VAD-FMK. A total of 26 targets of miltirone, 1 046 genes related to acute leukemia, and 6 common targets of the two were screened out. Flow cytometry result showed miltirone at 10 μmol·L~(-1) can inhibit proliferation and promote apoptosis of THP-1 cells. The typical manifestations of apoptosis, such as cell shrinkage, nuclear rupture, and chromatin agglomerate were displayed by acridine orange staining. The decreased mRNA levels of NCOA2 and PARP1 and increased Bax/Bcl-2 ratio and the activity of pro-apoptotic protein caspase-3 were observed. Z-VAD-FMK can attenuate the apoptosis-inducing effect of miltirone. This study indicates that miltirone can inhibit the proliferation and promote the apoptosis of THP-1 cells, by down-regulating NCOA2 and PARP1, raising Bax/Bcl-2 ratio, and activating caspase-3.

Comparison of [3H]-Thymidine, Carboxyfluorescein Diacetate Succinimidyl Ester and Ki-67 in Lymphocyte Proliferation.

BackgroundPatients with T cell deficiency <10% of normal proliferation are indicated to receive immune reconstruction by hematopoietic stem cell transplantation (HSCT). This study aimed to investigate whether non-radioactive assays can be used to quantitatively detect the lymphocyte proliferation <10% of normal as radioactive [3H]-thymidine.”MethodsRadioactive [3H]-thymidine, non-radioactive carboxyfluorescein diacetate succinimidyl ester (CFSE), and Ki-67 protein expressions were used to measure the lymphocyte proliferation as calculated using the stimulation index (SI), subtraction percentage, and proliferation index (FlowJo software). Normal references were established for comparison in the absence of parallel healthy controls.ResultsNormal ranges of mitogen-stimulated lymphocyte proliferation were established as a SI of 15–267 (CSFE 47–92%, Ki-67 42–79%) with phytohemagglutinin (PHA) 5 μg/ml stimulation; 19–139 (CFSE 62–83%, 45–74% Ki-67) with concanavalin-A (ConA) 5 μg/ml stimulation; 7–53 (CFSE 6–23%, Ki-67 10–24%) with pokeweed mitogen (PWM) 0.1 ug/ml stimulation; 3–28 (CFSE 4–10%, Ki-67 5–14%) with candida 10 ug/ml stimulation; and 2–27 (CFSE 6–41%, Ki-67 6–30%) with bacille Calmette-Guerin (BCG) 0.02 ng/ml stimulation. The normalized CFSE-proliferation index was between 2.1 and 3.0. Although there was no significant correlation between these three assays in the healthy controls, the SI value for <10% [3H]-thymidine proliferation in those with T cell deficiency was compatible with CFSE- and Ki-67-stained lymphocyte percentages, and validated in patients with IL2RG, RAG1, and ZAP70 mutations. When calculating [3H]-thymidine <10% of normal lymphocyte proliferation, the threshold of parallel controls was more reliable than previously established normal references.ConclusionThe large quantitative value of radioactive [3H]-thymidine was more easily recognizable than that for non-radioactive CFSE and Ki-67. Even though the correlation was not significant, those identified to have <10% of normal proliferation by [3H]-thymidine could be consistently detected by CFSE and Ki-67, and consequently indicated for HSCT.

Imaging flow cytometry challenges the usefulness of classically used extracellular vesicle labeling dyes and qualifies the novel dye Exoria for the labeling of mesenchymal stromal cell–extracellular vesicle preparations

Background aimsExtracellular vesicles (EVs) are involved in mediating intercellular communication processes. An important goal within the EV field is the study of the biodistribution of EVs and the identification of their target cells. Considering that EV uptake is assumed to be important for EVs in mediating intercellular communication processes, labeling with fluorescent dyes has emerged as a broadly distributed strategy for the identification of EV target cells and tissues. However, the accuracy and specificity of commonly utilized labeling dyes have not been sufficiently analyzed. MethodsBy combining recent advances in imaging flow cytometry for the phenotypic analysis of single EVs and aiming to identify target cells for EVs within therapeutically relevant mesenchymal stromal cell (MSC)-EV preparations, the authors explored the EV labeling efficacy of various fluorescent dyes, specifically carboxyfluorescein diacetate succinimidyl ester, calcein AM, PKH67, BODIPY TR ceramide (Thermo Fisher Scientific, Darmstadt, Germany) and a novel lipid dye called Exoria (Exopharm Limited, Melbourne, Australia). ResultsThe authors’ analyses qualified Exoria as the only dye that specifically labeled EVs within the MSC-EV preparations. Furthermore, the authors demonstrated that Exoria labeling did not interfere with the immunomodulatory properties of the MSC-EV preparations as tested in a multi-donor mixed lymphocyte reaction assay. Within this assay, labeled EVs were differentially taken up by different immune cell types. ConclusionsOverall, the results qualify Exoria as an appropriate dye for the labeling of EVs derived from the authors’ MSC-EV preparations. This study also demonstrates the need for the development of next-generation EV characterization tools that are able to localize and confirm the specificity of EV labeling.

JAK1 signaling in dendritic cells promotes peripheral tolerance in autoimmunity through PD-L1-mediated regulatory Tcell induction.

Dendritic cells (DCs) induce peripheral Tcell tolerance, but cell-intrinsic signaling cascades governing their stable tolerogenesis remain poorly defined. Janus Kinase 1 (JAK1) transduces cytokine-receptor signaling, and JAK inhibitors (Jakinibs), including JAK1-specific filgotinib, break inflammatory cycles in autoimmunity. Here, we report in heterogeneous DC populations of multiple secondary lymphoid organs that JAK1 promotes peripheral Tcell tolerance during experimental autoimmune encephalomyelitis (EAE). Mice harboring DC-specific JAK1 deletion exhibit elevated peripheral CD4+ Tcell expansion, less regulatory Tcells (Tregs), and worse EAE outcomes, whereas adoptive DC transfer ameliorates EAE pathogenesis by inducing peripheral Tregs, programmed cell death ligand 1 (PD-L1) dependently. This tolerogenic program is substantially reduced upon the transfer of JAK1-deficient DCs. DC-intrinsic IFN-γ-JAK1-STAT1 signaling induces PD-L1, which is required for DCs to convert CD4+ Tcells into Tregs invitro and attenuated upon JAK1 deficiency and filgotinib treatment. Thus, DC-intrinsic JAK1 promotes peripheral tolerance, suggesting potential unwarranted DC-mediated effects of Jakinibs in autoimmune diseases.

Excessive Accumulation of Intracellular Ca2+ After Acute Exercise Potentiated Impairment of T-cell Function.

Ca2+ is an important intracellular second messenger known to regulate several cellular functions. This research aimed to investigate the mechanisms of exercise-induced immunosuppression by measuring intracellular calcium levels, Ca2+-regulating gene expression, and agonist-evoked proliferation of murine splenic T lymphocytes. Mice were randomly assigned to the control, sedentary group (C), and three experimental groups, which performed a single bout of intensive and exhaustive treadmill exercise. Murine splenic lymphocytes were separated by density-gradient centrifugation immediately (E0), 3h (E3), and 24h after exercise (E24). Fura-2/AM was used to monitor cytoplasmic free Ca2+ concentration in living cells. The combined method of carboxyfluorescein diacetate succinimidyl ester (CFSE) labeling and flow cytometry was used for the detection of T cell proliferation. The transcriptional level of Ca2+-regulating genes was quantified by using qPCR. Both basal intracellular Ca2+ levels and agonist (ConA, OKT3, or thapsigargin)-induced Ca2+ transients were significantly elevated at E3 group (p<0.05 vs. control). However, mitogen-induced cell proliferation was significantly decreased at E3 group (p<0.05 vs. control). In parallel, the transcriptional level of plasma membrane Ca2+-ATPases (PMCA), sarco/endoplasmic reticulum Ca2+-ATPases (SERCA), TRPC1, and P2X7 was significantly downregulated, and the transcriptional level of IP3R2 and RyR2 was significantly upregulated in E3 (p<0.01 vs. control). In summary, this study demonstrated that acute exercise affected intracellular calcium homeostasis, most likely by enhancing transmembrane Ca2+ influx into cells and by reducing expression of Ca2+-ATPases such as PMCA and SERCA. However, altered Ca2+ signals were not transduced into an enhanced T cell proliferation suggesting other pathways to be responsible for the transient exercise-associated immunosuppression.

Single-Cell Analysis of Human B Lymphoid and Neutrophil/Monocyte Lineage Restriction

Lifelong production of most types of mature blood cells is sustained by a small population of cells with extensive regenerative potential. However, the detailed steps that restrict multipotent or even bipotent human hematopoietic cells to any single lineage remain poorly understood. Those that segregate the human B-lymphoid and neutrophil/monocyte (NM) lineages are of particular interest as these appear to identify a stage that might control the different properties of human leukemias that display perturbed NM and/or B-cell programs. To undertake a refined analysis of this normal lineage restriction process in human cells, we first devised a culture system that permits it to be tracked clonally and efficiently (50%). Initial experiments showed this could be achieved using a combination of multiple stromal cell types and human growth factor-supplemented medium. To elucidate the intervening transitional steps we then used multiplexed flow cytometry to compare the progeny generated in this culture system over a 2-week time course from previously defined lymphoid progenitor-enriched (P-L), NM progenitor-enriched (P-NM) and less restricted P-mix cord blood (CB) subsets. The results suggested that gain of CD45RA (RA) expression and loss of CLEC12A (C) expression appeared to accompany the sequential restriction of early CD34+ progenitors first to cells with dual NM+B-lineage potential and then just to B-lineage potential.Subsequent tracking of the lineage outputs of CD34+ RA-C- cells initially produced in larger numbers from unfractionated CD34+ CB cells either in vitro or in xenografted immunodeficient mice, confirmed the CD34+ RA-C- subset to be highly enriched in cells with dual NM+B potential. In contrast, co-generated CD45RA+ (RA+C-) and RA+CLEC12A+ (RA+C+) phenotypes displayed separate B- and NM lineage-restricted activity, respectively, as indicated by their largely exclusive clonal outputs of CD19+ pre-B and CD14+/CD15+ NM precursors. In agreement with these phenotypically established separate NM and B-lineage outputs, RA+C- cells were found to contain higher levels of B-lineage-associated gene transcripts (e.g., DNTT, CD79A, and EBF1), whereas RA+C+ cells contained higher levels of the NM transcription factor mRNAs encoded by SPI1 and CEBPA. In a further optimized stroma-free liquid culture system, the RA-C- cells could be shown to produce continuously RA+C- and RA+C+ progeny after another 3-4 days, and also RA-C- progeny which are not produced from more restricted RA+C- and RA+C+ cells, suggesting that the acquired expression of RA precedes the separation of NM and B-lineage potential that is then marked by the differential activation of C expression in RA+ cells.To examine more precisely how the process of B+NM restriction to a single lineage might be related to successive cell cycles, we labeled RA-C- cells with carboxyfluorescein diacetate succinimidyl ester (CFSE) to enable the phenotypes and growth potential of the the progeny obtained after 6 days to be directly related to their prior division histories. This revealed extensive heterogeneity in the overall distribution of the initial progeny cell cycle times but with a clear segregation in the outputs of the faster and slower dividing cells. Notably, the faster dividers produced ultimately small M+B or uni-lineage clones whereas the initially slow dividers subsequently produced larger clones, 25% of which still contained CD34+ cells or N+M+B progeny.Taken together, these findings identify new hallmark phenotypic changes that identify a critical step in the lineage restriction of primitive human hematopoietic cells with dual NM+B-lineage potential and a previously unknown association of this process with a shortening of their cell cycle transit time. DisclosuresNo relevant conflicts of interest to declare.

Phenotype of Memory HCV CD8+ T Cells in Chronic HCV

Abstract Background Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, with approximately 71 million chronically infected individuals worldwide. After acute infection, a majority of healthy adults will develop persistent viremia. An infection with HCV activates the immune system to defend the host with a broad range of innate and adaptive immune responses. Cellular immune response shows antiviral immunity by means of virus specific CD8+ T cytotoxic lymphocytes and CD4+ T helper cells. After resolution of infection, a population of the virus-specific memory CD8+ T cells protects the host against reinfection. These subsets of memory cells differ with respect to their anatomical localization, their phenotype and their protective potential. Objectives The aim of the present study is to find out the phenotype pattern of HCV specific memory CD8+ T cells in chronic HCV patients in comparison to HCV exposed seronegative high-risk individuals. Patients and Methods This case control study included 60 individuals categorized into two main groups, (group I) included 20 chronic HCV patients and (group II= control group) included 40 HCV seronegative healthcare workers. Both groups were subjected to carboxyfluorescein diacetate succinimidyl ester (CFSE) proliferation assay in response to HCV specific peptides. Group II was divided into 2 subgroups according to proliferation index (cut-off&amp;lt;2) into, proliferation index +ve high-risk group (+PIHRG) (20 healthcare workers) and proliferation index -ve high-risk group (-PIHRG) (20 healthcare workers). Then flow cytometric analysis of HCV specific CD8+ T cells was done for the all subjects to determine the expression of CD127, CCR7, CD45RO and CD45RA on both proliferating and non-proliferating fractions of cells. Results We found that expression of CD45RA was significantly increased and CCR7 was significantly decreased on HCV CD8+ T cells in the chronic HCV group than in the high risk groups in response to different HCV peptides. Conclusion During persistent viremia in chronic HCV infection subthreshold signal levels established by HCV different proteins provide anergy of virus specific memory CD8+ T cells that are unable to differentiate into full effector cells upon a possible reencounter with the antigen. So, chronic HCV patients in our study showed predominance of less differentiated effector memory phenotype (CD45RA+, CCR7-) in peripheral blood in comparison to HCV exposed seronegative high-risk individuals who don’t show overt infection.

Effects of glucocorticoids on the proliferation of CD19 CAR-T cells targeting B-cell tumor cell lines

目的评估糖皮质激素对CD19嵌合抗原受体T细胞（CAR-T细胞）靶向杀瘤过程中增殖的影响。方法健康志愿者的外周血单个核细胞（PBMC）作为T细胞来源，经CD3磁珠分选及CD19 CAR慢病毒转染制备CD19 CAR-T细胞；采用流式细胞术（FCM）测定CD19 CAR-T细胞转染率及其在培养体系中所占比例；采用CFDA SE细胞增殖示踪荧光探针试剂标记CD19 CAR-T细胞后测定其荧光强度；LDH细胞毒性检测方法检测不同浓度的糖皮质激素对B细胞肿瘤细胞株杀伤活性的影响。结果①CD19 CAR-T细胞CD19 CAR转染率为（51.34±5.28）％。②24 h后不同剂量甲泼尼龙对Nalm6、Pfeiffer及U2932细胞的杀伤活性高于地塞米松，48 h后低浓度（4 mg/ml）甲泼尼龙对Nalm6、Pfeiffer、U2932细胞杀伤活性高于低浓度（0.75 mg/ml）地塞米松，而高浓度（12 mg/ml）甲泼尼龙杀伤活性低于高浓度（2.25 mg/ml）地塞米松。但各个时间不同剂量甲泼尼龙组对EHEB细胞的杀伤活性均低于对应时间、剂量的地塞米松。③CD19 CAR-T细胞在不同浓度糖皮质激素作用下的比例及平均荧光强度比较，地塞米松对CD-19 CAR-T细胞的增殖抑制作用强于甲泼尼龙，两种糖皮质激素的高浓度组较低浓度组对CD19 CAR-T细胞的增殖抑制作用更明显。④CD19 CAR-T细胞与不同肿瘤细胞共培养体系中，其比例及平均荧光强度比较，地塞米松对CD19 CAR-T细胞的增殖抑制作用强于甲泼尼龙，两种糖皮质激素的高浓度组较低浓度组对CD19 CAR-T细胞的增殖抑制更明显。结论CD19 CAR-T细胞靶向不同肿瘤细胞株过程中地塞米松对CD19 CAR-T细胞的扩增和增殖抑制作用大于甲泼尼龙，高剂量组该抑制作用更加明显。