Carboxyfluorescein Succinimidyl Ester Research Articles

Storage-Induced Micro-Erythrocytes Can Be Quantified and Sorted by Flow Cytometry.

Refrigerated storage of red cell concentrates before transfusion is associated with progressive alterations of red blood cells (RBC). Small RBC (type III echinocytes, sphero-echinocytes, and spherocytes) defined as storage-induced micro-erythrocytes (SME) appear during pretransfusion storage. SME accumulate with variable intensity from donor to donor, are cleared rapidly after transfusion, and their proportion correlates with transfusion recovery. They can be rapidly and objectively quantified using imaging flow cytometry (IFC). Quantifying SME using flow cytometry would further facilitate a physiologically relevant quality control of red cell concentrates. RBC stored in blood bank conditions were stained with a carboxyfluorescein succinimidyl ester (CFSE) dye and incubated at 37°C. CFSE intensity was assessed by flow cytometry and RBC morphology evaluated by IFC. We observed the accumulation of a CFSEhigh RBC subpopulation by flow cytometry that accounted for 3.3 and 47.2% at day 3 and 42 of storage, respectively. IFC brightfield images showed that this CFSEhigh subpopulation mostly contains SME while the CFSElow subpopulation mostly contains type I and II echinocytes and discocytes. Similar numbers of SME were quantified by IFC (based on projected surface area) and by flow cytometry (based on CFSE intensity). IFC and scanning electron microscopy showed that ≥95% pure subpopulations of CFSEhigh and CFSElow RBC were obtained by flow cytometry-based sorting. SME can now be quantified using a common fluorescent dye and a standard flow cytometer. The staining protocol enables specific sorting of SME, a useful tool to further characterize this RBC subpopulation targeted for premature clearance after transfusion.

Sperm acquire epididymis-derived proteins through epididymosomes.

Are epididymosomes implicated in protein transfer from the epididymis to spermatozoa? We characterized the contribution of epididymal secretions to the sperm proteome and demonstrated that sperm acquire epididymal proteins through epididymosomes. Testicular sperm are immature cells unable to fertilize an oocyte. After leaving the testis, sperm transit along the epididymis to acquire motility and fertilizing abilities. It is well known that marked changes in the sperm proteome profile occur during epididymal maturation. Since the sperm is a transcriptional and translational inert cell, previous studies have shown that sperm incorporate proteins, RNA and lipids from extracellular vesicles (EVs), released by epithelial cells lining the male reproductive tract. We examined the contribution of the epididymis to the post-testicular maturation of spermatozoa, via the production of EVs named epididymosomes, released by epididymal epithelial cells. An integrative analysis using both human and mouse data was performed to identify sperm proteins with a potential epididymis-derived origin. Testes and epididymides from adult humans (n = 9) and adult mice (n = 3) were used to experimentally validate the tissue localization of four selected proteins using high-resolution confocal microscopy. Mouse epididymal sperm were co-incubated with carboxyfluorescein succinimidyl ester (CFSE)-labeled epididymosomes (n = 4 mice), and visualized using high-resolution confocal microscopy. Adult (12-week-old) C57BL/CBAF1 wild-type male mice and adult humans were used for validation purposes. Testes and epididymides from both mice and humans were obtained and processed for immunofluorescence. Mouse epididymal sperm and mouse epididymosomes were obtained from the epididymal cauda segment. Fluorescent epididymosomes were obtained after labeling the epididymal vesicles with CFSE dye followed by epididymosome isolation using a density cushion. Immunofluorescence was performed following co-incubation of sperm with epididymosomes in vitro. High-resolution confocal microscopy and 3D image reconstruction were used to visualize protein localization and sperm-epididymosomes interactions. Through in silico analysis, we first identified 25 sperm proteins with a putative epididymal origin that were conserved in both human and mouse spermatozoa. From those, the epididymal origin of four sperm proteins (SLC27A2, EDDM3B, KRT19 and WFDC8) was validated by high-resolution confocal microscopy. SLC27A2, EDDM3B, KRT19 and WFDC8 were all detected in epithelial cells lining the human and mouse epididymis, and absent from human and mouse seminiferous tubules. We found region-specific expression patterns of these proteins throughout the mouse epididymides. In addition, while EDDM3B, KRT19 and WFDC8 were detected in both epididymal principal and clear cells (CCs), SLC27A2 was exclusively expressed in CCs. Finally, we showed that CFSE-fluorescently labeled epididymosomes interact with sperm in vitro and about 12-36% of the epididymosomes contain the targeted sperm proteins with an epididymal origin. N/A. The human and mouse sample size was limited and our results were descriptive. The analyses of epididymal sperm and epididymosomes were solely performed in the mouse model due to the difficulties in obtaining epididymal luminal fluid human samples. Alternatively, human ejaculated sperm and seminal EVs could not be used because ejaculated sperm have already contacted with the fluids secreted by the male accessory sex glands, and seminal EVs contain other EVs in addition to epididymosomes, such as the abundant prostate-derived EVs. Our findings indicate that epididymosomes are capable of providing spermatozoa with a new set of epididymis-derived proteins that could modulate the sperm proteome and, subsequently, participate in the post-testicular maturation of sperm cells. Additionally, our data provide further evidence of the novel role of epididymal CCs in epididymosome production. Identifying mechanisms by which sperm mature to acquire their fertilization potential would, ultimately, lead to a better understanding of male reproductive health and may help to identify potential therapeutic strategies to improve male infertility. This work was supported by the Spanish Ministry of Economy and Competitiveness (Ministerio de Economía y Competividad; fondos FEDER 'una manera de hacer Europa' PI13/00699 and PI16/00346 to R.O.; and Sara Borrell Postdoctoral Fellowship, Acción Estratégica en Salud, CD17/00109 to J.C.), by National Institutes of Health (grants HD040793 and HD069623 to S.B., grant HD104672-01 to M.A.B.), by the Spanish Ministry of Education, Culture and Sports (Ministerio de Educación, Cultura y Deporte para la Formación de Profesorado Universitario, FPU15/02306 to F.B.), by a Lalor Foundation Fellowship (to F.B. and M.A.B.), by the Government of Catalonia (Generalitat de Catalunya, pla estratègic de recerca i innovació en salut, PERIS 2016-2020, SLT002/16/00337 to M.J.), by Fundació Universitària Agustí Pedro i Pons (to F.B.), and by the American Society for Biochemistry and Molecular Biology (PROLAB Award from ASBMB/IUBMB/PABMB to F.B.). Confocal microscopy and transmission electron microscopy was performed in the Microscopy Core facility of the Massachusetts General Hospital (MGH) Center for Systems Biology/Program in Membrane Biology which receives support from Boston Area Diabetes and Endocrinology Research Center (BADERC) award DK57521 and Center for the Study of Inflammatory Bowel Disease grant DK43351. The Zeiss LSM800 microscope was acquired using an NIH Shared Instrumentation Grant S10-OD-021577-01. The authors have no conflicts of interest to declare.

In-vitro and in-vivo anti-allergic effects of magnolol on allergic rhinitis via inhibition of ORAI1 and ANO1 channels

Ethnopharmacological relevanceFlos Magnoliae (the dried flower buds of Magnolia biondii Pamp, FM) is a known herbal traditional medicine used for the symptomatic relief of nasal congestion and rhinorrhea caused by rhinitis and sinusitis. Magnolol, a neolignan from the magnolia family, is a secondary metabolite known to have anti-allergic and anti-inflammatory effects. However, the underlying mechanisms and therapeutic effect of magnolol in the treatment of allergic rhinitis (AR) remain elusive. Aims of the studyAnoctamin 1 (ANO1), a calcium-activated anion channel, mediates mucus and electrolyte secretion in nasal airway epithelial cells, whereas calcium release-activated calcium channel protein 1 (ORAI1) participates in the activation of T-lymphocytes and mast cells. The aim of our study is to understand the mechanisms of action of magnolol against AR, i.e., whether it acts through the modulation of ANO1 and ORAI1 channels that are expressed in nasal epithelial cells and T-lymphocytes, respectively. Materials and methodsWhole-cell patch clamp was used to record the activity of ORAI1 and ANO1 ion channels in ORAI1 or ANO1 overexpressed HEK293T cells, while the Ussing chamber apparatus was used to measure electrolyte transport via the epithelium, in Calu-3 cells cultured in an air-liquid interface. Additionally, calcium imaging of Jurkat T-lymphocytes was used to assess changes in the intracellular calcium concentration. Magnolol toxicity was assessed using the CCK-8 assay, and its effect on T-lymphocyte proliferation was measured by labeling human primary T-lymphocytes with carboxyfluorescein succinimidyl ester. Finally, OVA-induced Balb/c mice were employed to evaluate the effect of magnolol on nasal symptoms, as well as cytokine and eosinophil infiltration in AR. ResultsMagnolol inhibits ORAI1 and ANO1 channels in a concentration-dependent manner. Magnolol (30 μM) inhibits anti-CD3 induced cellular proliferation and production of IL-2 via ORAI1 channels in T-lymphocytes. Further, ATP-induced electrolyte transport mediated by ANO1 channels is significantly inhibited by magnolol in IL-4 sensitized Calu-3 cells. Notably, 300 μM magnolol significantly attenuates cytokine and eosinophil infiltration, thus alleviating AR symptoms in mice OVA-induced AR. ConclusionMagnolol may be a promising therapeutic agent for the treatment and prevention of AR.

Superior stemness of a rapidly growing subgroup of isolated human auricular chondrocytes and the potential for use in cartilage regenerative therapy.

IntroductionIn cartilage regenerative medicine, transplanted chondrocytes contain a mixture of populations, that complicates the regeneration of uniform cartilage tissue. Our group previously reported that chondrocytes with higher chondrogenic ability could be enriched by selection of rapidly growing cells. In this study, the detailed properties of rapidly growing chondrocytes were examined and compared to slowly growing cells.MethodsHuman auricular chondrocytes were fluorescently labeled with carboxyfluorescein succinimidyl ester (CFSE) and analyzed using flow cytometry, focusing on division rates as indicated by fluorescence intensity and cell morphology according to the forward scatter and side scatter. Rapid and slow growing cell groups were harvested on days 2 and 4 after CFSE labeling, and their ability to produce cartilage matrix in vitro was examined. To compare the chondrogenic ability in vivo, the cells were seeded on poly-l-lactic acid scaffolds and transplanted into nude mice. Gene expression differences between the rapid and slow cell groups were investigated by microarray analysis.ResultsOn day 2 after CFSE labeling, the rapidly growing cell group showed the highest proliferation rate. The results of pellet culture showed that the rapid cell group produced more glycosaminoglycans per cell than the slow cell group. The amount of glycosaminoglycan production was highest in the rapid cell group on day 2 after CFSE labeling, indicating high chondrogenic ability. Furthermore, microarray, gene ontology, and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed upregulation of genes that promote cell division such as origin recognition complex subunit 1 and downregulation of genes that inhibit cell division such as cyclin dependent kinase inhibitor 1A. Besides cell cycle-related genes, chondrocyte-related genes such as serpin family B member 2, clusterin, bone morphogenetic protein 2, and matrix metalloproteinase 3 were downregulated, while fibroblast growth factor 5 which is involved in stem cell maintenance, and coiled-coil and C2 domain containing 2A, which is required for cilia formation, were upregulated.ConclusionThe results showed that the rapid cell group proliferated well and had more undifferentiated properties, suggesting a higher stemness. The present findings provide a basis for the use of the rapid cell group in cartilage regeneration.

Comparison of modulation interference microscopy, DNA spectrometry, DNA cytometry, and flow cytofluorimetry in the assessment of phytohemagglutinin-induced activity of human blood lymphocytes

Rationale: The study of the structural particulars and functional state of immune cells and primarily lymphocytes is of great importance for both fundamental and clinical medicine. It requires the development of simple and reliable analytic methods that would allow for fast and effective real-time assessment of cell activity.Aim: To evaluate the effectiveness of the interference microscopy compared to DNA spectrometry, DNA cytometry, and flow cytometry with an internalized fluorescent label CFSE (carboxyfluorescein succinimidyl ester) in the assessment of PHA-induced proliferation of human blood lymphocytes.Materials and methods: Phytohemagglutinin (PHA)-induced proliferative activity of blood lymphocytes from 10 healthy volunteers was studied with various methodological strategies. Blast transformation of lymphocytes was induced by their incubation for 5 days with PHA 5 μg/mL. The cell proliferative activity was assessed as follows: 1) by DNA spectrometry at 260/280 nm using Tecan Infinite 200 Pro with a specialized NanoQuant Plate™; 2) by cytophotometry followed by cell distribution analysis assessing deoxyribonucleic acid (DNA) content after staining with Felgen's dye with an imaging system based on an Olympus BX41 light microscope with a ProgRes CF camera; 3) by flow cytometry using an internalized fluorescent label CFSE; the analysis was performed with a BD FACS Calibur flow cytometer; 4) by measurement of the lymphocyte interference profile with a modulation interference microscope MIM-340 (Schwabe, Russia). The functional activity of the nucleus (FAN) was determined and used as a criterion for assessment of the lymphocyte functional state.Results: Incubation of lymphocytes with PHA led to an increase in the linear size by 22.2±2.8%, a decrease in phase height by 46.3±4.7% (p=0.019), and an increase in FAN by 75.9±9.4%, vs control (p=0.046). As measured by isolated DNA spectroscopy, PHA stimulation of lymphocytes was associated with an increase in the amount of DNA by 55% vs baseline (409.8±22.3 ng/μL and 264.3±25.0 ng/μL, respectively, p=0.049). Felgen's reaction revealed that the proportion of nuclei containing more than 2n DNA was 2% in the control cells and 14.8% in the PHA-activated lymphocytes, with a difference between the groups of 12.8%. CFSE staining with subsequent incubation and assessment by flow cytofluorimetry demonstrated an increase in the percentage of proliferating cells from 1.68±0.9% in the control to 55.56±5.6% (p=0.00068) in the mitogen-stimulated sample.Conclusion: Modulation interference microscopy does not require the sample preparation and demonstrated comparable and even higher effectiveness compared to conventional methods for assessment of lymphocyte activity. At the same time, it allows for evaluation of the lymphocyte functional state in real time in the process of cultivation. This opens ample opportunities for evaluation immune cells for research and diagnostic purposes.

Steps Toward Standardized In Vitro Assessment of Immunomodulatory Equine Mesenchymal Stromal Cells Before Clinical Application.

Inflammation-associated disorders are significant causes of morbidity in horses. Equine single-donor mesenchymal stromal cells (sdMSCs) hold promise as cell-therapy candidates due to their secretory nonprogenitor functions. This has been demonstrated by mononuclear cell suppression assays (MSAs) showing that sdMSCs are blood mononuclear cell (BMC) suppressive in vitro. sdMSCs derived from umbilical cord blood are of clinical interest due to their ease of procurement, multipotency, and immunomodulatory ability. Due to the inherent donor-to-donor heterogeneity of MSCs, the development of robust and easily deployable methods of potency assessment is critical for improving MSCs' predictability in treating inflammatory diseases. This study focuses on the development of robust in vitro potency assays and the assessment of potential sdMSC therapeutic end products generated from pooled sdMSCs (pMSCs). We hypothesized that, compared to MSA using only one donor, MSA using pooled BMCs (pBMCs) is a more robust sdMSC potency assay due to reduced donor BMC heterogeneity. pBMCs were generated by pooling equine BMCs isolated from peripheral blood of five donors in equal ratios. pBMCs were labeled with carboxyfluorescein succinimidyl ester (CFSE) and stored in liquid nitrogen until use. Similarly, pooling sdMSCs from multiple equine donors in equal ratios generated pMSCs. sdMSC cultures were assessed with pBMCs in MSA using Bromodeoxyuridine ELISA and CFSE. Proliferation assessment of BMCs from individual donors revealed varied responses to concanavalin A (ConA) stimulation. MSA using BMCs from single donors further demonstrated BMC donor variability. Utilizing this assay, we have also found that the immunosuppressive potencies of pMSCs are at least equal, if not more, than the calculated mean of individual cultures. MSA based on pBMCs provides a consistent and reproducible equine sdMSC potency assay. This knowledge could be used in production monitoring of cellular potency and as release criteria before clinical use.

Development of a mouse model of ascending infection and preterm birth.

Microbial invasion of the intraamniotic cavity and intraamniotic inflammation are factors associated with spontaneous preterm birth. Understanding the route and kinetics of infection, sites of colonization, and mechanisms of host inflammatory response is critical to reducing preterm birth risk. This study developed an animal model of ascending infection and preterm birth with live bacteria (E. coli) in pregnant CD-1 mice with the goal of better understanding the process of microbial invasion of the intraamniotic cavity and intraamniotic inflammation. Multiple experiments were conducted in this study. To determine the dose of E. coli required to induce preterm birth, CD-1 mice were injected vaginally with four different doses of E. coli (103, 106, 1010, or 1011 colony forming units [CFU]) in 40 μL of nutrient broth or broth alone (control) on an embryonic day (E)15. Preterm birth (defined as delivery before E18.5) was monitored using live video. E. coli ascent kinetics were measured by staining the E. coli with lipophilic tracer DiD for visualization through intact tissue with an in vivo imaging system (IVIS) after inoculation. The E. coli were also directly visualized in reproductive tissues by staining the bacteria with carboxyfluorescein succinimidyl ester (CFSE) prior to administration and via immunohistochemistry (IHC) by staining tissues with anti-E. coli antibody. Each pup's amniotic fluid was cultured separately to determine the extent of microbial invasion of the intraamniotic cavity at different time points. Intraamniotic inflammation resulting from E. coli invasion was assessed with IHC for inflammatory markers (TLR-4, P-NF-κB) and neutrophil marker (Ly-6G) for chorioamnionitis at 6- and 24-h post-inoculation. Vaginally administered E. coli resulted in preterm birth in a dose-dependent manner with higher doses causing earlier births. In ex vivo imaging and IHC detected uterine horns proximal to the cervix had increased E. coli compared to the distal uterine horns. E. coli were detected in the uterus, fetal membranes (FM), and placenta in a time-dependent manner with 6 hr having increased intensity of E. coli positive signals in pups near the cervix and in all pups at 24 hr. Similarly, E. coli grew from the cultures of amniotic fluid collected nearest to the cervix, but not from the more distal samples at 6 hr post-inoculation. At 24 hr, all amniotic fluid cultures regardless of distance from the cervix, were positive for E. coli. TLR-4 and P-NF-κB signals were more intense in the tissues where E. coli was present (placenta, FM and uterus), displaying a similar trend toward increased signal in proximal gestational sacs compared to distal at 6 hr. Ly-6G+ cells, used to confirm chorioamnionitis, were increased at 24 hr compared to 6 hr post-inoculation and control. We report the development of mouse model of ascending infection and the associated inflammation of preterm birth. Clinically, these models can help to understand mechanisms of infection associated preterm birth, determine targets for intervention, or identify potential biomarkers that can predict a high-risk pregnancy status early in pregnancy.

Study of the effects of Lemna minor extracts on human immune cell populations.

Lemna minor is a plant with a huge repertoire of secondary metabolites. The literature indicates that extracts of Lemna minor have antioxidant, antiradical, immunomodulatory and anti-inflammatory properties. The objective of the present study was to find a suitable technique to extract active compounds from this plant and verify whether these extracts have immunomodulatory activity. We grew L. minor on a standard medium with Gamborg B5 and vitamins. We extracted compounds from the plant by maceration and decoction. The phytochemical profile of the extracts was characterized by chromatography, spectrophotometry, and spectroscopy. The extracts were tested on cultures of mononuclear cells from four human subjects. These cells were pulsed with carboxyfluorescein succinimidyl ester, grown in triplicate in standard culture medium without (control) and with increasing concentrations of Lemna extracts. Flow cytometry was used to evaluate cell death and proliferation of the total mononuclear cell population and of CD4+, CD8+, B cell and monocyte populations. The Lemna extracts were not cytotoxic and did not cause cell necrosis or apoptosis in immune cells. At low concentrations, they induced very limited proliferation of CD4+ cells within 48 hours. At high concentrations, they induced proliferation of CD8+ cells and B lymphocytes within 48 hours. Unfortunately, we failed to confirm any immunomodulatory activity of Lemna extracts. Growth and death rates of human immune cells were not significantly affected by adding Lemna extracts to the culture medium.

P.161: Small Molecule Inhibitor of Toll-like Receptor-4, TAK-242, Attenuates Allogenic Immune Responses In Vitro

Introduction: Development of innate and adaptive immune response against transplanted islets has a major impact on the poor long term survival of allogenic islet transplants. Our previous studies have shown that TAK-242, a small molecule inhibitor of toll-like receptor-4 either in a soluble form or covalently linked to the islet surface can effectively protect islets from damage inflicted by sterile inflammation in vitro and also prolongs survival of syngeneic islet transplants. Based on recent reports indicating crosstalk between TLR-4 and major histocompatibility complex molecules, we hypothesized that TAK-242 can inhibit proliferation of lymphocytes in response to allogenic stimulation. Methods: Human peripheral blood mononuclear cells labeled with carboxyfluorescein succinimidyl ester were tested for proliferation in a one-way mixed lymphocyte reaction against mitomycin treated, CellTrace Violet-labeled allogenic splenocytes as stimulators. Proliferation of CD4+ and CD8+ T cells was analyzed by flow cytometry. Concentrations of pro-inflammatory cykokines in the culture supernatant was measured by Luminex Multiplex Bead Assay. Varying concentrations (0–30 µM) of TAK242 or MAP84, an inactive structure analog of TAK242, were added to the culture medium. Results: Addition of TAK-242 to the mixed lymphocyte reaction dose dependently inhibited proliferation of both CD4+ and CD8+ T cells (Fig. 1A). The inhibition of proliferation was optimal on day 5. Proliferation of CD4+ and CD8+ T cells was not affected by the addition of MAP84 at similar concentrations. Cytokine measurements showed that IL-2 concentrations were not inhibited by TAK-242. However, proinflammatory cytokines IL-1beta, IL-6, IP-10 and TNF-alpha were significantly inhibited specifically by TAK-242 (Fig. 1B). These results mirrored our previous data showing TAK-242 inhibition of pro-inflammatory cytokines by islets stimulated with TLR-4 ligands. Conclusion: The present data has shown for the first time that blockade of toll-like receptor-4 by TAK-242 is an effective method to attenuate development of T cell response against allogenic targets in addition to the inhibition of inflammation. Crosstalk between TLR pathway with other critical receptors involved the development of immune response is likely to play a role in this inhibition. Further experiments to decipher the mechanism underlying this unique immunosuppressive property of TAK-242 are in progress.

Exogenous HMGB1 Promotes the Proliferation and Metastasis of Pancreatic Cancer Cells.

Background: Exogenous HMGB1 plays a vital role in tumor recurrence, and HMGB1 is ubiquitous in the tumor microenvironment. However, the mechanism of action is still unclear. We investigated the role of exogenous HMGB1 in tumor proliferation and metastasis using human SW1990 and PANC-1 cells after radiotherapy and explored the possible molecular mechanism.Materials and Methods: Residual PANC-1 cells and SW1990 cells were isolated after radiotherapy. The supernatant after radiotherapy was collected. The relative expression of HMGB1 was evaluated by Enzyme Linked Immunosorbent Assay (ELISA). Electron microscope (EMS) was used to collect the images of pancreatic cancer cells pre and post radiotherapy treatment. The proliferation of pancreatic cancer cells which were treated with different radiation doses was measured by Carboxy Fluorescein Succinimidyl Ester (CFSE). The migration rates of pancreatic cancer cells were measured by wound healing assays. Subsequently, the expression of related proteins was detected by Western Blot. In vivo, the subcutaneous pancreatic tumor models of nude mice were established, and therapeutic capabilities were tested.Results: HMGB1 was detected in the supernatant of pancreatic cancer cells after radiotherapy. The results of CFSE showed that exogenous HMGB1 promotes the proliferation and metastasis of pancreatic cancer cells. The western blot results showed activation of p-GSK 3β and up-regulation of N-CA, Bcl-2, and Ki67 in response to HMGB1 stimulation, while E-CA expression was down-regulated in pancreatic cancer cells in response to HMGB1 stimulation. In vivo, ethyl pyruvate (EP, HMGB1 inhibitor) inhibits the growth of tumors and HMGB1 promotes the proliferation of tumors after radiation.Conclusion: Radiotherapy induces HMGB1 release into the extracellular space. Exogenous HMGB1 promotes the proliferation and metastasis of PANC-1 cells and SW1990 cells by activation of p-GSK 3β which is mediated by Wnt pathway.

Empirical identification and validation of tumor-targeting T cell receptors from circulation using autologous pancreatic tumor organoids

BackgroundTumor-specific cytotoxic T cells and T cell receptors are effective tools for cancer immunotherapy. Most efforts to identify them rely on known antigens or lymphocytes that have infiltrated into the...

A Radioactive-Free Method for the Thorough Analysis of the Kinetics of Cell Cytotoxicity

The cytotoxic activity of T cells and Natural Killer cells is usually measured with the chromium release assay (CRA), which involves the use of 51Chromium (51Cr), a radioactive substance dangerous to the operator and expensive to handle and dismiss. The accuracy of the measurements depends on how well the target cells incorporate 51Cr during labelling which, in turn, depends on cellular division. Due to bystander metabolism, the target cells spontaneously release 51Cr, producing a high background noise. Alternative radioactive-free methods have been developed. Here, we compare a bioluminescence (BLI)-based and a carboxyfluorescein succinimidyl ester (CFSE)-based cytotoxicity assay to the standard radioactive CRA. In the first assay, the target cells stably express the enzyme luciferase, and vitality is measured by photon emission upon the addition of the substrate d-luciferin. In the second one, the target cells are labelled with CFSE, and the signal is detected by Flow Cytometry. We used these two protocols to measure cytotoxicity induced by treatment with NK cells. The cytotoxicity of NK cells was determined by adding increasing doses of human NK cells. The results obtained with the BLI method were consistent with those obtained with the CRA- or CFSE-based assays 4 hours after adding the NK cells. Most importantly, with the BLI assay, the kinetic of NK cells’ killing was thoroughly traced with multiple time point measurements, in contrast with the single time point measurement the other two methods allow, which unveiled additional information on NK cell killing pathways.

Induction of Triple-negative Breast Cancer Cells to Immunogenic Cell Death and Increase Cross-Presentation by Streptomyces sanyensis

Pharmacognosy Research,2021,13,3,165-172.DOI:10.5530/pres.13.3.9Published:June 2021Type:Original ArticleAuthors:Xingguo Quan, Ji-Young Lee, Jin Hee Park, Md. Masudul Haque, Hee Yeon Kim, Ilhwan Kim, Anbok Lee, Il-Whan Choi, and SaeGwang Park Author(s) affiliations:Xingguo Quan1, Ji-Young Lee2, Jin Hee Park1, Md. Masudul Haque1, Hee Yeon Kim3, Ilhwan Kim4, Anbok Lee3, Il-Whan Choi1, SaeGwang Park1,* 1Department of Microbiology and Immunology, College of Medicine, Inje University, Busan, SOUTH KOREA. 2Department of Internal Medicine, College of Medicine, Inje University, Busan, SOUTH KOREA. 3Department of Surgery, College of Medicine, Inje University, Busan, SOUTH KOREA. 4Department of Internal Medicine, Division of Oncology Inje University College of Medicine, Haeundae Paik Hospital, Cancer Center, Busan, SOUTH KOREA. Abstract:Background: Biomass extract of Streptomyces sanyensis (BE-SS), which is a marine microorganism, has antitumor activity and has white-to-gray aerial mycelium and long chains of long spores in aerial mycelium. Objectives: The anti-cancer effect of BE-SS on triple-negative breast cancer (TNBC) was confirmed and cell death by BE-SS was confirmed to have immunogenicity and whether it could be used for immuno-cancer therapy. Materials and Methods: Human and mouse TNBC cells (MDA-MB-231, HS578T, 4T1-hemagglutinin (HA) and TUBO-P2J-HA cells) were treated with BE-SS at different concentrations for 72 hr and their cytotoxicity was detected using the sulforhodamine B-based (SRB) method. Flow cytometry was used to determine the type of cell death by Annexin V/7-AAD staining and to measure surface exposure to damage-related molecular pattern (DAMP) molecules including calreticulin (CRT), heat shock protein (HSP) 70/90. Carboxyfluorescein succinimidyl ester (CFSE) dilution assay was used to evaluate the immunogenicity of dead cells induced by BE-SS. Results: BE-SS reduced the viability of human (MDA-MB-231 and HS578T-cells) and mouse (4T1-HA and TUBO-P2J-HA cells) breast cancer cells. At 72 h, the IC50 of human and mouse breast cancer cells was 0.02-0.6 μg/ml and 0.005-0.37 μg/ml, respectively. BE-SStreated breast cancer cells were positively stained with Annexin V. Surface exposure to DAMP molecules increased in a dose-and time-dependent manner. CFSE dilution analysis showed that dendritic cells (DCs) fed with BE-SS treated breast cancer cells successfully stimulated tumor-specific T-cell proliferation without inhibiting DC function and T-cell proliferation. Conclusion: BE-SS can induce immunogenicity and apoptosis in breast cancer cells and may be a good adjuvant for TNBC immunotherapy. Keywords:Apoptosis, Cross-presentation, DAMPs, Immunogenic cell death, Streptomyces sanyensis, TNBCView:PDF (751.62 KB)

Evaluation of B cell and T cell Phenotypes in CVID Patients and its Correlation with the Clinical Phenotypes: Study Protocol

Background: Common variable immunodeficiency (CVID) is the most frequent symptomatic primary immunodeficiency, which manifests a wide range of clinical phenotypes from recurrent infections of the respiratory system to autoimmunity, enteropathy and lymphoproliferative disorders. Some abnormalities in T and B lymphocyte subpopulations may associate with the development of such clinical complications. Aim of study: The main objective of this case-control study is to investigate the frequency and absolute count of different lymphocyte subsets in CVID patients as well as the cellular proliferation response. Correlation between lymphocyte abnormalities and different clinical phenotypes of the disease such as infection only (IO), autoimmunity (AI), chronic enteropathy (CE) and lymphoproliferative disorders (LP) are determined. We also aim to evaluate the prognosis of CVID for each clinical manifestation based on lymphocyte phenotype. Methods: A population of genetically unsolved CVID patients after whole exome sequencing (WES) will be subdivided into 4 clinical phenotypes i.e. IO, AI, CE and LP and an equal number of age and sex-matched healthy controls (HC) will be examined for the frequency of distinct subgroups of CD19+ B cells, CD4+ T cells and CD8+ T cells by flow cytometry. The proliferation response of their CD4+ T cells is then evaluated by Carboxyfluorescein succinimidyl ester (CFSE) test, using stimulation of isolated peripheral blood mononuclear cells with anti-CD3 and anti-CD28 antibodies. Data analysis will be assessed by parametric or nonparametric tests based on normality of data distribution using IBM SPSS Statistics, V.24 and Stata software V.14. Ethics and dissemination: Ethical approval of this study is received from the Ethics Committee of Tehran University of Medical Sciences (ID number: IR.TUMS.VCR.REC.1396.3380) and all participants will be asked to sign the informed consent statement. Due to the wide range of variables, objectives and questions, the findings of this study are intended to release as multiple publications in peer-reviewed journals and presented at national and international conferences.

Plasma EVs Display Antigen-Presenting Characteristics in Patients With Allergic Rhinitis and Promote Differentiation of Th2 Cells.

BackgroundAllergic rhinitis (AR) is characterized by IgE-mediated mucosa response after exposure to allergens. Extracellular vesicles (EVs) are nano-size vesicles containing biological cargos for intercellular communications. However, the role of plasma EVs in pathogenesis of AR remains largely unknown.MethodsPlasma EVs from patients with AR were isolated, quantified, and characterized. The expression of Der p 1 and antigen-presenting molecules on EVs was determined by Western blot, flow cytometry, or ELISA. PKH26- and CFSE (carboxyfluorescein succinimidyl ester)-stained AR-EVs were used to determine the uptake of EVs by CD4+T cells and their effects on CD4+T cell proliferation, respectively.ResultsPlasma EVs in healthy control (HC) and AR patients were similar in the concentration of particles, expression for specific EV markers, and both had structural lipid bilayer. However, the levels of Der p 1 on plasma EVs from both mild and moderate-severe AR patients were significantly higher than that on HC. The levels of antigen-presenting molecules on plasma EVs were similar from three subjects. Moreover, levels of Der p 1 on EVs in plasma, but not nasal secretion, were significantly associated with the symptom score of AR patients and level of plasma IL-13. Additionally, plasma EVs from patients with AR promoted the development of Th2 cells, while no effect was found on CD4+ T-cell proliferation.ConclusionsPlasma EVs derived from patients with AR exhibited antigen-presenting characteristics and promoted differentiation of Th2 cells, thus providing novel understanding of the pathogenesis of AR.

Bio-O1-04 - PD1 regulates T cell exhaustion phenotypes and disease aggressiveness in CTCL

<h3>Introduction:</h3> Cutaneous T cell lymphomas (CTCLs) are a heterogenous group of lymphomas of the skin-homing CD4+ T cell. Although the median survival for patients with stage IV disease is generally poor, there is significant heterogeneity with some stage-matched patients surviving <6 months while others survive >10 years. Currently, it is unclear why this is the case, and whether there are any biomarkers for patients with the most aggressive forms of disease. To address this knowledge gap, we sought to combine multi-omics and functional assays to a clinically annotated cohort of CTCLs to identify drivers of disease heterogeneity. <h3>Materials and methods:</h3> To explore the molecular underpinnings of disease heterogeneity in CTCL, we combined whole-genome sequencing, RNA-sequencing, immunophenotyping, and ex vivo proliferation assays on sorted malignant cells from 14 patients with leukemic CTCL. Whole genome sequencing was analyzed for single nucleotide and copy number variants. To determine ex vivo proliferation, sorted malignant cells were stained with carboxyfluorescein succinimidyl ester (CFSE), cultured with T cell receptor stimulation or cytokines and assessed via flow cytometry. <h3>Results:</h3> Unexpectedly, we observed significant heterogeneity in the ability of malignant CTCL cells to proliferate to T cell receptor and cytokine signals ex vivo. A subset of samples proliferated to more stimuli than healthy controls, another group of samples similarly to controls, and yet another group significantly less. Strikingly, unbiased DNA and RNA-seq analyses revealed a critical role for the co-inhibitory receptor and tumor suppressor PD1. PDCD1 (the gene which encodes PD1) was the most highly expressed gene in samples that failed to proliferate ex vivo compared to those that proliferate highly. The single gene significantly more frequently mutated in highly proliferating samples was PD1. Integrating genomic, transcriptomic, and functional data, we observed that most samples harbored features of T cell exhaustion, including diminished proliferation and effector cytokine production, and expression of markers of T cell exhaustion. However, samples with deletions of PD1 reversed this phenotype. These samples had higher ex vivo proliferation and effector cytokine production, and lower expression of T cell exhaustion markers. Accordingly, samples with deletions of PD1 had significantly worse prognoses in both stage IV disease and in stage II-III MF. <h3>Conclusions:</h3> By integrating genotype, transcriptome, and functional status, we have identified that a majority of CTCLs harbor features of T cell exhaustion. A subset of CTCLs which harbor PD1 deletions reverse the T cell exhaustion phenotype. Consistent with this, PD1-deleted CTCLs have significantly worse overall survival in stage-matched patients. Our data establishes T cell exhaustion status and PD1 deletions as novel drivers of heterogeneity in cutaneous T cell lymphoma.

Immunomodulatory effects of astragalus polysaccharide on human peripheral blood mononuclear cells co-cultured with cervical cancer cell line.

To investigate immunomodulatory effects of Astragalus polysaccharides (APS) on the co-culture of peripheral blood mononuclear cells (PBMCs) with HeLa cervical cancer cell line. To assess the proliferation of PBMCs, carboxyfluorescein succinimidyl ester (CFSE)-labeled PBMCs were co-cultured with HeLa cells and treated with different concentrations of APS. Supernatants of cell culture were collected for cytokines assay via enzyme-linked immunosorbent assay (ELISA). The impact of APS on the proliferation of PBMCs, induction of regulatory T cells (Tregs), and myeloid-derived suppressor cells (MDSCs) was carried out by flow cytometry. It was observed that APS could increase the proliferation of PBMCs co-cultured with HeLa cells (P < 0.05). However, APS had no significant effects on the induction of Tregs and MDSCs in the co-culture assay (P > 0.05). Furthermore, ELISA results demonstrated that APS could decrease IL-10 and TGF-β concentration (P < 0.05). The above-mentioned characteristics showed that APS might be able to modulate immune responses and improve anti-tumor effects through increasing the proliferation of PBMCs and decreasing inhibitory cytokines secretion as critical mediators of immune suppression in the tumor microenvironment.

Lymphocytes subsets in correlation with clinical profile in CVID patients without monogenic defects

Objectives Common variable immunodeficiency (CVID) patients experience clinical manifestations rather than recurrent respiratory infections including autoimmunity, enteropathy and lymphoproliferation. We evaluated correlation of lymphocyte subpopulations with such manifestations. Methods: Twenty-six genetically unsolved CVID patients subdivided into 4 phenotypes: infection only (IO), autoimmunity (AI), chronic enteropathy (CE) and lymphoproliferative disorders (LP) were examined for B and T lymphocyte by flow cytometry and TCD4+ proliferation by Carboxyfluorescein succinimidyl ester (CFSE) test. Results We detected reduced memory B and increased total, Effector Memory (EM), cytotoxic and activated TCD8+ in IO, AI and CE, decreased plasmablasts, total and naive TCD4+, Regulatory TCD4+ (Treg) and naive TCD8+ in IO and CE, elevated CD21low B and Terminally Differentiated Effector Memory (TEMRA) TCD8+ in IO and AI, increased helper T (Th2) and Th17 in IO, decreased Th1 in AI and defective total and naive B and Central Memory (CM) TCD4+ in CE. IO showed reduced TCD4+ proliferation response. Conclusions In genetically unsolved CVID patients, increased Th2 and Th17 and reduced Treg is associated with IO, increased CD21low B and TEMRA TCD8+ and reduced Th1 is contributed to AI and reduced total and naive B, CM TCD4+ and naive TCD8+ and expanded total TCD8+ is correlated with CE.

A safe and effective mucosal RSV vaccine in mice consisting of RSV phosphoprotein and flagellin variant.

Respiratory syncytial virus (RSV) is a major cause of serious acute lower respiratory tract infection in infants and the elderly. The lack of a licensed RSV vaccine calls for the development of vaccines with other targets and vaccination strategies. Here, we construct a recombinant protein, designated P-KFD1, comprising RSV phosphoprotein (P) and the E.-coli-K12-strain-derived flagellin variant KFD1. Intranasal immunization with P-KFD1 inhibits RSV replication in the upper and lower respiratory tract and protects mice against lung disease without vaccine-enhanced disease (VED). The P-specific CD4+ Tcells provoked by P-KFD1 intranasal (i.n.) immunization either reside in or migrate to the respiratory tract and mediate protection against RSV infection. Single-cell RNA sequencing (scRNA-seq) and carboxyfluorescein succinimidyl ester (CFSE)-labeled cell transfer further characterize the Th1 and Th17 responses induced by P-KFD1. Finally, we find that anti-viral protection depends on either interferon-γ (IFN-γ) or interleukin-17A (IL-17A). Collectively, P-KFD1 is a promising safe and effective mucosal vaccine candidate for the prevention of RSV infection.

Immunomodulatory Properties of Wharton’s Jelly-Derived Mesenchymal Stem Cells from Three Anatomical Segments of Umbilical Cord

Mesenchymal stem cells (MSCs) are multipotent progenitor cells that are reported to be immune-privileged and immune-evasive. MSCs are capable of differentiating into specific cell types for subsequent use in cell-based therapy. They express low levels of human leucocyte antigen (HLA)-ABC and no HLA-DR. Wharton’s jelly-derived MSCs (WJ-MSCs) were also found to express human leukocyte antigen G (HLA-G), which renders them immunosuppressive. This study aimed to determine whether cultured WJ-MSCs retain their immune-privileged and immune-evasive properties after cell differentiation, and whether these properties differ among MSCs derived from different anatomical segments of the umbilical cord. Umbilical cords of healthy pregnant mothers undergoing caesarean section were obtained and grouped by three anatomical segments: fetal, middle, and maternal segments. WJ-MSCs were isolated, culture-expanded, and differentiated into osteogenic cells. Expression of HLA-DR, HLA-ABC, and HLA-G were quantified using flow cytometry. Both undifferentiated and osteodifferentiated WJ-MSCs were subsequently co-cultured with allogeneic peripheral blood mononuclear cells with/without lipopolysaccharide (LPS) stimulation for five days. Lymphocyte proliferation assay was performed using carboxyfluorescein succinimidyl ester (CFSE) as a tracker. Our results showed no significant difference existed in the HLA profiles among WJ-MSCs from different segments and between WJ-MSCs with and without osteogenic differentiation. Mean levels for HLA-G, HLABC, and HLA-DR were 24.82±17.64, 52.50±18.41, and 1.00±1.68%, respectively. Stimulation with LPS and WJ-MSCs increased peripheral blooc mononuclear cells (PBMC) proliferation. However, PBMC proliferation was significantly lower when PBMCs were co-cultured with osteodifferentiated WJ-MSCs (p &lt; .05; with LPS stimulation and p &lt; .001 without LPS stimulation) than when they were co-cultured with undifferentiated WJ-MSCs. These findings suggest that cultured WJ-MSCs stimulate lymphocyte proliferation and are not immune-privileged. Osteodifferentiated WJ-MSCs reduced the immunogenicity of WJ-MSCs, and this reduction in PBMC proliferation was even more pronounced in the presence of LPS (p &lt; .05). In conclusion, cultured WJ-MSCs are not immune-privileged. Osteodifferentiated WJ-MSCs are less immunogenic than undifferentiated WJ-MSCs, in which case hypoimmunogenicity is more profound under LPS-stimulated conditions.