scholarly journals Optimization of a Density Gradient Centrifugation Protocol for Isolation of Peripheral Blood Mononuclear Cells

2018 ◽  
Vol 64 (2) ◽  
pp. 83-90 ◽  
Author(s):  
Georgiana Mihaela Şerban ◽  
Ion Bogdan Mănescu ◽  
Doina Ramona Manu ◽  
Minodora Dobreanu
Keyword(s):  
Mononuclear Cells ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Phase 1 ◽  
Sample Volume ◽  
Mean Value ◽  
Phase 2 ◽  
Cell Recovery ◽  
Peripheral Blood Mononuclear ◽  
Mean Values

Abstract Objective: Peripheral blood mononuclear cells (PBMC) are extremely important in the body’s immune response. Their isolation represents a major step in many immunological experiments. In this two phase study, we aimed to establish an optimum protocol for PBMC isolation by density-gradient centrifugation. Methods: During Phase-1, we compared two commercially available PBMC isolation protocols, Stemcell Technologies (ST) and Miltenyi Biotec (MB), in terms of PBMC recovery and purity. Twelve blood samples were assigned to each protocol. Each sample was divided in three subsamples of 1ml, 2ml and 3ml in order to assess the influence of blood sample volume on isolation performance. During Phase-2, a hybrid protocol was similarly tested, processing six blood samples. Additionally, we performed a flow cytometric analysis using an Annexin-V/Propidium-Iodide viability staining protocol. Results: Phase-1 results showed that, for all subsample volumes, ST had superior PBMC recovery (mean values: 56%, 80% and 87%, respectively) compared to MB (mean values: 39%, 54% and 43%, respectively). However, platelet removal was significantly higher for MB (mean value of 96.8%) than for ST (mean value of 75.2%). Regarding granulocyte/erythrocyte contamination, both protocols performed similarly, yielding high purity PBMC (mean values: 97.3% for ST and 95.8% for MB). During Phase-2, our hybrid protocol yielded comparable results to MB, with an average viability of 89.4% for lymphocytes and 16.9% for monocytes. Conclusions: ST yields higher cell recovery rates and MB excels at platelet removal, while the hybrid protocol is highly similar to MB. Both cell recovery and viability increase with blood sample volume.

scholarly journals Low-Density Granulocyte Contamination From Peripheral Blood Mononuclear Cells of Patients With Sepsis and How to Remove It – A Technical Report

2021 ◽  
Vol 12 ◽  
Author(s):  
Judith Schenz ◽  
Manuel Obermaier ◽  
Sandra Uhle ◽  
Markus Alexander Weigand ◽  
Florian Uhle
Keyword(s):  
Healthy Volunteers ◽  
Density Gradient ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Low Density ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

Elucidating the mechanisms contributing to the dysregulated host response to infection as part of the syndrome is a current challenge in sepsis research. Peripheral blood mononuclear cells are widely used in immunological studies. Density gradient centrifugation, a common method, is of limited use for blood drawn from patients with sepsis. A significant number of low-density granulocytes co-purify contributing to low purity of isolated peripheral blood mononuclear cells. Whole blood anticoagulated with lithium heparin was drawn from patients with sepsis (n=14) and healthy volunteers (n=11). Immediately after drawing, the plasma fraction was removed and PBMC were isolated from the cellular fraction by density gradient centrifugation. Samples derived from patients with sepsis were subsequently incubated with cluster of differentiation 15 MicroBeads and granulocytes were depleted using magnetic-activated cell sorting. Core cellular functions as antigen presentation and cytokine secretion were analyzed in cells isolated from healthy volunteers (n=3) before and after depletion to confirm consistent functionality. We report here that depleting CD15+ cells after density gradient centrifugation is a feasible way to get rid of the low-density granulocyte contamination. Afterwards, the purity of isolated, functionally intact peripheral blood mononuclear cells is comparable to healthy volunteers. Information on the isolation purity and identification of the containing cell types are necessary for good comparability between different studies. Depletion of CD15+ cells after density gradient centrifugation is an easy but highly efficient way to gain a higher quality and more reliability in studies using peripheral blood mononuclear cells from septic patients without affecting the functionality of the cells.

scholarly journals Separation and Optimisation of a Sucrose Density Gradient Centrifugation Protocol for Isolation of Peripheral Blood Mononuclear Cells (PBMC)

2018 ◽  
pp. 1-4
Author(s):  
Sudeep Nagaraj ◽  
Shubha Nivargi ◽  
Leelavathy Nanjappa ◽  
Jagadish Tavarekere Venkataravanappa
Keyword(s):  
Density Gradient ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Mononuclear Cells ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells ◽  
One Step

One step centrifugation procedure used commonly for separation of blood cells is the ficoll gradient centrifugation. In this method, after centrifugation, the peripheral blood mononuclear cells (PBMCs) are located on the top of the separation fluid, whereas other blood cells erythrocytes and granulocytes sediment to the bottom. In the present study 75% of lymphocyte suspension could be separated by using a one-step density gradient centrifugation of sodium heparin blood with Sucrose. Sucrose was diluted into different concentrations using miliQ water (10%, 20%, 30%, 40%, 50%, 60%,70%, 80%, 90%, 100%,). 4 mL of diluted blood was layered on 4 mL of each sucrose solution and centrifuged for 45 minutes at 1000 rpm. Clear separation of PBMCs could be observed in solution with 40% sucrose. The separated PBMCs were analysed in haeme analyser which showed 75% lymphocytes, 23% monocytes and 2% of other cells.

scholarly journals Delays during PBMC isolation have a moderate effect on yield, but severly compromise cell viability

2022 ◽  
Author(s):  
Tanja Golke ◽  
Patrick Mucher ◽  
Patricia Schmidt ◽  
Astrid Radakovics ◽  
Manuela Repl ◽  
...  
Keyword(s):  
Cell Viability ◽  
Density Gradient ◽  
Standard Method ◽  
Mononuclear Cells ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Initial Density ◽  
Minor Effect ◽  
Peripheral Blood Mononuclear ◽  
The Impact

Background: Peripheral blood mononuclear cells (PMBCs) are a versatile material for clinical routine as well as for research projects. However, their isolation via density gradient centrifugation is still time-consuming. When samples are taken beyond usual laboratory handling times, it may sometimes be necessary to pause the isolation process. Our aim was to evaluate the impact of delays up to 48 hours after the density gradient centrifugation on PBMC yield, purity and viability. Methods: PBMCs were isolated from samples of 20 donors, either with BD Vacutainer CPT tubes (CPT) or with the standard Ficoll method. Isolation was paused after initial density gradient centrifugation for 0, 24, or 48 hours. PBMC yield, purity and viability were compared. Results: The yield did not change significantly over time when CPT were used (55%/52%/47%), but did after isolation with the standard method (62%/40%[p<0.0001]/53%[p<0.01]). Purity was only affected if CPT were used (95%/93%[p=n.s./92%[p<0.05] vs. 97% for all time points with standard method). Whereas viable PBMCs decreased steadily for CPT isolates (62%/51%[p<0.001]/36%[p<0.0001]), after standard Ficoll gradient isolation, cell apoptosis was more pronounced already after 24h delay, and viability did not further decrease after 48h (64%/44%[p<0.0001]/40%[p<0.0001]). Conclusions: In conclusion, our data suggests that post-centrifugation delays of up to 48h might have only a minor effect on cell yield and purity. However, at the same time, a relevant decrease in cell viability was observed, which could be partially compensated by the use of CPT if the isolation was resumed latest the day after blood withdrawal.

scholarly journals Impact of SARS-CoV-2 infection on the recovery of peripheral blood mononuclear cells by density gradient

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria D. I. Manunta ◽  
Giuseppe Lamorte ◽  
Francesca Ferrari ◽  
Elena Trombetta ◽  
Mario Tirone ◽  
...  
Keyword(s):  
Density Gradient ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Early Phase ◽  
Mononuclear Cells ◽  
Early Stage ◽  
Gradient Centrifugation ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells ◽  
Circulating Lymphocytes

AbstractSARS-CoV-2 virus infection is responsible for coronavirus disease (COVID-19), which is characterised by a hyperinflammatory response that plays a major role in determining the respiratory and immune-mediated complications of this condition. While isolating peripheral blood mononuclear cells (PBMCs) from whole blood of COVID-19 patients by density gradient centrifugation, we noticed some changes in the floating properties and in the sedimentation of the cells on density medium. Investigating this further, we found that in early phase COVID-19 patients, characterised by reduced circulating lymphocytes and monocytes, the PBMC fraction contained surprisingly high levels of neutrophils. Furthermore, the neutrophil population exhibited alterations in the cell size and in the internal complexity, consistent with the presence of low density neutrophils (LDNs) and immature forms, which may explain the shift seen in the floating abilities and that may be predictive of the severity of the disease. The percentage of this subset of neutrophils found in the PBMC band was rather spread (35.4 ± 27.2%, with a median 28.8% and IQR 11.6–56.1, Welch’s t-test early phase COVID-19 versus blood donor healthy controls P < 0.0001). Results confirm the presence of an increased number of LDNs in patients with early stage COVID-19, which correlates with disease severity and may be recovered by centrifugation on a density gradient together with PBMCs.

Phase 1/2 study of eprenetapopt (APR-246) in combination with pembrolizumab in patients with solid tumor malignancies.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. TPS3161-TPS3161
Author(s):  
Ecaterina Elena Dumbrava ◽  
Amit Mahipal ◽  
Xin Gao ◽  
Geoffrey Shapiro ◽  
Jason S. Starr ◽  
...  
Keyword(s):  
Solid Tumors ◽  
Mononuclear Cells ◽  
Phase 1 ◽  
Objective Response ◽  
Progression Free Survival ◽  
Maximum Tolerated Dose ◽  
Tumor Growth Inhibition ◽  
Advanced Solid Tumors ◽  
Peripheral Blood Mononuclear

TPS3161 Background: The p53 pathway has been implicated in antitumor immunity, including antigen presentation and T-cell proliferation. Loss of p53 function can increase resistance to immunotherapy across many tumor types. Eprenetapopt (eprenet) is a small molecule that stabilizes the folded structure of p53, resulting in activation of mutant p53 and stabilization of wild-type (WT) p53. It also targets the cellular redox homeostasis, resulting in induction of apoptosis in tumor cells. In vivo, mice carrying supernumerary copies of the TP53 gene harbor a pro-inflammatory tumor microenvironment, an effect recapitulated in TP53 normal-copy mice treated with eprenetapopt. Combining eprenetapopt and anti-PD1 or anti-CTLA4 therapy resulted in enhanced tumor growth inhibition and improved survival in TP53 WT mice inoculated with B16 melanoma and MC38 colon adenocarcinoma cells . Based on these results, we hypothesized that eprenet-induced p53 stabilization may augment response to immunotherapy. To test this hypothesis, we are conducting a phase 1b/2 study of eprenet in combination with pembrolizumab (eprenet+pembro) in pts with solid tumors. Methods: The primary objectives are to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) and to assess the safety and tolerability of eprenet+pembro in pts with advanced solid tumors. The secondary objectives are to estimate the anti-tumor activity and to describe the pharmacokinetics of the combination. Exploratory objectives include assessing predictive and pharmacodynamic markers of response. The study includes a safety lead-in with a 3+3 dose de-escalation design for pts with advanced solid tumors with known tumor TP53 mutation status ( TP53 WT is acceptable) (max 18 pts), followed by expansion cohorts in pts with NSCLC, gastric/GEJ and urothelial cancer (max 100 pts). In expansion, pts with urothelial and gastric cancers must be naïve to anti-PD-1/ L1 therapy. Eprenet is given IV once daily on Days 1–4 while pembro is administered on Day 3 of each 21-day cycle. The RP2D of eprenet+pembro is considered the dose at which ≤ 1 of 6 pts in a cohort has a dose-limiting toxicity (DLT). Primary endpoints are occurrence of DLTs, adverse events (AEs) and serious AEs with eprenet+pembro. Key secondary endpoints are best objective response, progression free survival and overall survival. Exploratory endpoints include gene mutations by next generation sequencing (including TP53), mRNA expression, multiplex immunohistochemistry and transcriptomics, multiplex flow cytometry on peripheral blood mononuclear cells and cytokines in serum. Continuous monitoring of toxicity will be conducted. The trial opened in May 2020 and is actively enrolling patients. Clinical trial information: NCT04383938.

Abstract 20: Resolution Phenotype of Monocytes and Macrophages is Altered in Peripheral Arterial Disease

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Melinda S Schaller ◽  
Laura Menke ◽  
Mian Chen ◽  
Warren J Gasper ◽  
S. Marlene Grenon ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Cell Surface ◽  
Phagocytic Activity ◽  
Mononuclear Cells ◽  
Gradient Centrifugation ◽  
Arterial Disease ◽  
Surface Markers ◽  
Cell Surface Markers ◽  
Peripheral Blood Mononuclear ◽  
Peripheral Arterial

Introduction: Peripheral arterial disease (PAD) is a chronic disease characterized by systemic inflammation. Monocytes (Mo) and macrophages play a central role in vascular inflammation and its resolution. We hypothesize that impaired resolution in PAD results in poor clinical outcomes. Methods: Resolution phenotype was assessed by phagocytic activity of leukocytes, Mo cell surface markers, and cytokine profiling of Mo-derived macrophages (MDM). Phagocytosis and cell-surface markers were determined by flow cytometry. MDMs were generated from peripheral blood mononuclear cells via density gradient centrifugation. Cytokines were measured by ELISA following MDM differentiation and subsequent stimulation with LPS. Results: Circulating Mo and neutrophils (PMN) isolated from PAD patients (n=9) demonstrated significantly lower phagocytic activity (Mo: >30%, p<.001; PMN: >25%, p<.01, Fig. 1) as compared to healthy subjects (HS) (n=14). Cell-surface marker analysis demonstrated a higher proportion of the pro-inflammatory intermediate Mo subset (CD14 ++ 16 + , 1.8-fold, p=.04) in PAD compared to HS. MDM from PAD subjects retain their intrinsic inflammatory program by producing more IL-6 (PAD 3138±2676 ng/mL, HS 731±854 ng/mL p=.03) and IL-1β (PAD 244±236 ng/mL, HS 24.1±23.8 ng/mL p=.04) than those from HS. Upon stimulation with LPS, MDM from PAD subjects secrete more IL-6 (PAD 23353±22483 ng/mL, HS 5097±5836 ng/mL p=.05) than those from HS. Conclusions: Circulating Mo and PMN in patients with PAD have substantially lower phagocytic activity as well as a greater proportion of the pro-inflammatory intermediate Mo subset compared to HS. MDM preserve their elevated inflammatory state throughout culture and retain a heightened response upon latter stimulatory cues. Collectively these data demonstrate a heightened inflammatory and impaired resolution phenotype in PAD that has potential implications for disease progression and response to interventions.

scholarly journals Cyclin E overexpression in relapsed adult acute lymphoblastic leukemias of B-cell lineage

Blood ◽  
1996 ◽  
Vol 87 (8) ◽  
pp. 3360-3367 ◽  
Author(s):  
R Scuderi ◽  
KA Palucka ◽  
K Pokrovskaja ◽  
M Bjorkholm ◽  
KG Wiman ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Lymphoblastic Leukemia ◽  
Cyclin E ◽  
Cell Lineage ◽  
Cyclin A ◽  
Mean Value ◽  
Peripheral Blood Mononuclear ◽  
Protein Levels

Using Western blot analysis, we examined cyclin E and cyclin A protein levels in 19 patients with acute lymphoblastic leukemia ([ALL] 15 B-ALL and four T-ALL). Whereas normal, nonproliferating peripheral blood mononuclear cells (PBMCs) expressed low levels of the 50-kD cyclin E, ALL blasts in the peripheral blood, although showing low-level or no proliferation as judged by FACS/cell-cycle analysis and cyclin A protein levels, expressed high levels of cyclin E, with a mean value similar to that of the proliferating Burkitt's lymphoma cell line, Akata. The accumulation of a protein shown to shorten the G1 phase of the cell cycle, cyclin E, in growth-delayed leukemic blasts may reflect the malignant status of these cells. Before treatment, B-ALL cells expressed predominantly the 50-kD cyclin E. T-ALL samples displayed the 50-kD cyclin E protein and a smaller, approximately 43-kD cyclin E species. In paired B-ALL samples taken before treatment and at relapse, we found a significant overexpression of the 50-kD protein in relapsed samples (P < .006), plus the presence of up to four additional smaller- molecular-weight species of cyclin E, illustrating clear diagnosis versus relapse differences. Cyclin E expression in ALL blasts may correlate to the relative malignant status of the cells, with higher protein levels reflecting a more advanced stage of the disease and a greater potential to proliferate under permissive conditions.

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