Immunophenotypic profile of leukocytes in hyperandrogenemic female rat an animal model of polycystic ovary syndrome

The immune etiology of polycystic ovary syndrome (PCOS) is an intriguing area. However, whether there is alteration in the leukocyte populations in different tissues remain ambiguous.

AIM

To characterize the leukocyte populations of hyperandrogenemic female (HAF) rat tissues.

METHODS

Female Sprague Dawley rats at 3 weeks of age were implanted subcutaneously with dihydrotestosterone (DHT) or placebo pellets. The rats were aged to 14-15 weeks and tissues were collected.

RESULTS

Peripheral blood (PB) and renal CD4⁺ (P < 0.03, P < 0.007), Th17 (P < 0.05, P < 0.002), and CD4⁺CD28^null (P < 0.04, P < 0.001) were significantly increased in HAF rats compared to placebo, respectively, in spite of their lower percentage in the spleen. Although, the percentage of Treg T lymphocytes were significantly higher in the PB (P < 0.001) of HAF rats, the splenic (P < 0.01) and renal Treg cells (P < 0.03) were found to be significantly lower. Remarkably, HAF rats had higher renal mast cells (P < 0.00009) despite lower splenic (P < 0.002). The number of PB, renal, and splenic CD8⁺ T cells and IgM⁺-B cells in HAF rats remained unchanged.

CONCLUSION

Results from this study 1) provide the first evidence of significant alteration of T lymphocyte subsets and different leukocyte populations profile in a rat model of polycystic ovary syndrome, 2) demonstrate alteration of the immunological niche of blood, spleen, and kidney tissues in Hyperandrogenemia state in female rats, 3) imply potential immune system dysregulation in HAF rats which may suggest a link between excess androgen, chronic inflammation, and immune-mediated diseases in polycystic ovary syndrome patients.

Strategies and Techniques for NK Cell Phenotyping

Therapies based on activating the immune system, that is, immunotherapy, are now widely implemented in clinical praxis in patients with advanced cancer. Although cancer immunotherapy can result in long-lasting clinical responses, the majority of patients do not respond or develop resistance. Furthermore, cancer immunotherapy is being increasingly combined with other forms of immunotherapy or conventional cancer therapies. It is therefore much needed to identify biomarkers that can precisely classify what patients will benefit from the treatment without any major adverse events and to further develop the efficacy of cancer immunotherapy. While much attention has been focused on monitoring T cell responses in cancer immunotherapy, recent reports have shown that NK cells also play a major role in the response to cancer immunotherapy. The gold standard for immunoprofiling of NK cells is flow cytometry, but other technologies have emerged and include mass cytometry, multiplex immunohistochemistry, and single-cell RNA-sequencing. In this chapter we provide a detailed protocol to profile NK cells using flow cytometry, and a brief introduction to other techniques.

Flow Cytometry for Non-Hodgkin and Hodgkin Lymphomas

Multiparametric flow cytometry is a powerful diagnostic tool that permits rapid assessment of cellular antigen expression to quickly provide immunophenotypic information suitable for disease classification. This chapter describes a general approach for the identification of abnormal lymphoid populations by flow cytometry, including B, T, NK, and Hodgkin lymphoma cells suitable for the clinical and research environment. Knowledge of the common patterns of antigen expression of normal lymphoid cells is critical to permit identification of abnormal populations at disease presentation and for minimal residual disease assessment. We highlight an overview of procedures for processing and immunophenotyping non-Hodgkin B- and T-cell lymphomas and also describe our strategy for the sensitive and specific diagnosis of classical Hodgkin lymphoma and nodular lymphocyte predominant Hodgkin lymphoma.

One-Tube Multicolor Flow Cytometry Assay (OTMA) for Comprehensive Immunophenotyping of Peripheral Blood

Recent improvements in the flow cytometry technology allow the determination of the general immune status through the development of multicolor immunofluorescence panels. The one-tube multicolor flow cytometry assay (OTMA) that is presented here identifies 20 different, clinically relevant immune cell subsets and three common activation markers. Thereby, a comprehensive immune status that covers all major immune cells is easily obtained.The assay is suitable for every common three lasers and 10 color flow cytometer and includes the application of 15 different antibodies. Furthermore, the assay requires only 100 μL of EDTA-treated whole-blood and less than 40 min for sample preparation. By being easily adaptable to individual requirements and by additionally determining absolute cell counts, the assay is well-suited for translational research in clinical trials.

Minimal Residual Disease Quantification in Chronic Lymphocytic Leukemia: Clinical Significance and Flow Cytometric Methods

The very sensitive quantification of leukemia cells that persist in chronic lymphocytic leukemia patients after successful therapy is steadily gaining interest with clinical scientists. Minimal residual disease (MRD) has demonstrated prognostic significance in the context of different treatment modalities leading to its approval as an intermediate endpoint for licensure in randomized trials by the European Medicine Agency. Data supporting the clinical impact of MRD as well as a highly standardized and broadly available method for MRD assessments by flow cytometry are described herein. Examples of gating strategies are provided with comprehensive explanations to allow the reader the application of the technology to blood and bone samples with high and very low level MRD, respectively. This chapter has a particular focus on samples acquired shortly after anti-CD20 treatment. The standardization developed by the EuroFlow consortium is additionally described as technical basis for reproducible and standardized flow cytometric MRD assessments.

A novel antibody combination to identify KIR2DS2high natural killer cells in KIR2DL3/L2/S2 heterozygous donors

The killer cell immunoglobulin-like receptor (KIR) KIR2DS2 induces natural killer (NK) cell activation upon ligation and in genetic studies is associated with protection against certain cancers and viral infections. One of the difficulties in understanding KIR2DS2 has been that ligands have been hard to define. In part, this is because the high sequence homology between KIR2DS2 and KIR2DL3/KIR2DL2 has made it difficult to make antibodies that specifically detect NK cells expressing KIR2DS2. Using transfected NK cell line (NKL) cells and primary human samples, we report the identification of a novel antibody combination which allows identification of NK cells with relatively high expression of KIR2DS2. This separation is sufficient to examine primary human NK cell activation in response to KIR2DS2 specific ligands.

Multiple myeloma secondary to acute lymphoblastic leukemia: A case report

RATIONALE

Acute lymphoblastic leukemia (ALL) secondary to multiple myeloma (MM) is rare. Here we report a rare case of secondary ALL transformed from MM.

PATIENT CONCERNS

A 64-year-old woman was diagnosed as MM IgG light chain type in 2001. She achieved complete remission after 2 cycles of therapy, and received maintenance therapy with thalidomide. The patient suffered from MM relapse in September 2011. Bone marrow examination showed that the percentage of primary lymphocytes was 59%, indicating ALL-L2 (Pre-B-ALL). The patient reached complete remission after 1 cycle of chemotherapy, and has been maintained for more than 6 years.

DIAGNOSES

Immunophenotyping analysis revealed that the abnormal cell population accounted for approximately 66% which expressed HLA-DR, CD4, CD22, CD33, CD34, and cCD79a. These results indicated acute B lymphoblastic leukemia. Chromosome presented 47, XX, +5, -7, +19. Leukemia fusion gene analysis demonstrated positive EVI1 and negative IgH and TCR gene rearrangement.

INTERVENTIONS

The patient accepted 1 cycle of VDCLP chemotherapy and reached complete remission, followed with consolidation therapies with VDCLP, MA, CAG and other chemotherapy regimens.

OUTCOMES

This patient has maintained CR1 of ALL for more than 6 years.

LESSONS

Even secondary lymphoblastic leukemia has been rarely reported in patients with MM, we still need perform bone marrow examination, flow cytology, and gene tests, especially during maintenance therapy.

Immunophenotyping of Circulating Endothelial Cells and Endothelial Microparticles

Flow-cytometric detection of circulating endothelial cells and endothelial microparticles is an essential tool in studies of vascular diseases. Here we describe the principles and detailed methods for human blood sample processing, storage, labeling, and gating of circulating endothelial elements.

Surface Barcoding of Live PBMC for Multiplexed Mass Cytometry

Sample barcoding is a powerful method for harmonizing mass cytometry data. By assigning a unique combination of barcode labels to each cell sample, a set of individual samples can be pooled and further processed and acquired as a large, single sample. For assays that require uncompromised profiling of cell-surface markers on live cells, barcoding by metal-labeled antibodies targeting cell-surface epitopes is the barcoding approach of choice. Here we provide an optimized and validated protocol for cell-surface barcoding of ten PBMC samples with palladium-labeled β2-microglobulin (B2M) antibodies used in a 5-choose-2 barcoding scheme, for subsequent immune phenotyping by mass cytometry. We further provide details on the generation of palladium-labeled antibodies utilizing amine-reactive isothiocyanobenzyl-EDTA (ITCB-EDTA) that permits the implementation of antibody-based barcoding not interfering with lanthanide channels typically used for analyte detection in mass cytometry assays.

Method for Tagging Antibodies with Metals for Mass Cytometry Experiments

Mass cytometers are time-of-flight (TOF) mass spectrometer-coupled flow cytometers (known as CyTOFs) that quantify the abundance of metal-tagged antibodies (Abs) or other cellular probes within single cell suspensions or laser-ablated tissue sections. While many strategies exist for covalently crosslinking to proteins, the Fluidigm MaxPar^® process is currently the most widely used and involves first loading a metal-chelating polymer with an elementally and isotopically enriched metal. Once the chelation sites have been filled, a maleimide moiety on the polymer is reacted with the free thiol groups on the partially reduced monoclonal immunoglobulin G (IgG) Ab to form an irreversible covalent bond. Here we describe modifications to the Fluidigm MaxPar^® protocol that increase the quantity of Ab per reaction up to 150 μg, introduce an initial Ab quality control step, utilize metal labels not included in the Fluidigm catalog, and provide an option to perform two reactions in one centrifugal filter.

Immunophenotyping of Human B Lymphocytes in Blood and in Adipose Tissue

The human obese subcutaneous adipose tissue (SAT) contributes to systemic and B cell intrinsic inflammation, reduced B cell responses, and increased secretion of autoimmune antibodies. Immune cells are recruited to the SAT by chemokines released by both adipocytes and infiltrating immune cells. We describe here the characterization of B lymphocytes from the SAT and blood (control) of obese females undergoing weight reduction surgeries (breast reduction or panniculectomy). We show how to isolate the immune cells from the blood and SAT, how to characterize B cells and their subsets, and how to measure markers of activation and/or transcription factors in SAT-derived B cells and B cell subsets. We also show how to evaluate other immune cell types infiltrating the SAT, including T cells, NK cells, monocyte/macrophages, in order to measure relative proportions of these cell types as compared to the blood.

Scalable Conjugation and Characterization of Immunoglobulins with Stable Mass Isotope Reporters for Single-Cell Mass Cytometry Analysis

The advent of mass cytometry (CyTOF®) has permitted simultaneous detection of more than 40 antibody parameters at the single-cell level, although a limited number of metal-labeled antibodies are commercially available. Here we present optimized and scalable protocols for conjugation of lanthanide as well as bismuth ions to immunoglobulin (Ig) using a maleimide-functionalized chelating polymer and for characterization of the conjugate. The maleimide functional group is reactive with cysteine sulfhydryl groups generated through partial reduction of the Ig Fc region. Incubation of Ig with polymer pre-loaded with lanthanide ions produces metal-labeled Ig without disrupting antigen specificity. Antibody recovery rates can be determined by UV spectrophotometry and frequently exceeds 60%. Each custom-conjugated antibody is validated using positive and negative cellular control populations and is titrated for optimal staining at concentrations ranging from 0.1 to 10 μg/mL. The preparation of metal-labeled antibodies can be completed in 4.5 h, and titration requires an additional 3-5 h.

Protein Barcodes Enable High-Dimensional Single-Cell CRISPR Screens

CRISPR pools are being widely employed to identify gene functions. However, current technology, which utilizes DNA as barcodes, permits limited phenotyping and bulk-cell resolution. To enable novel screening capabilities, we developed a barcoding system operating at the protein level. We synthesized modules encoding triplet combinations of linear epitopes to generate >100 unique protein barcodes (Pro-Codes). Pro-Code-expressing vectors were introduced into cells and analyzed by CyTOF mass cytometry. Using just 14 antibodies, we detected 364 Pro-Code populations; establishing the largest set of protein-based reporters. By pairing each Pro-Code with a different CRISPR, we simultaneously analyzed multiple phenotypic markers, including phospho-signaling, on dozens of knockouts. Pro-Code/CRISPR screens found two interferon-stimulated genes, the immunoproteasome component Psmb8 and a chaperone Rtp4, are important for antigen-dependent immune editing of cancer cells and identified Socs1 as a negative regulator of Pd-l1. The Pro-Code technology enables simultaneous high-dimensional protein-level phenotyping of 100s of genes with single-cell resolution.

Evaluation of immunophenotyping, proliferation and osteogenic differentiation potential of SSEA-4 positive stem cells derived from pulp of deciduous teeth

OBJECTIVES

Despite the increased interest in stem cells isolated from remnant pulp of deciduous teeth, no specific marker has been yet established for them. The present study aimed to investigate whether SSEA-4 (stage-specific embryonic antigen) would be a suitable marker to isolate stem cells from Human Exfoliated Deciduous teeth (SHEDs) in order to increase its differentiation potential toward osseous tissue.

DESIGN

The SHEDs were isolated and the expression patterns of mesenchymal, hematopoietic and embryonic stem cell markers were assessed. The cells were then divided into two groups of SSEA-4(+) and unsorted SHEDs and the cell proliferation rate and population-doubling-time (PDT) were calculated. Subsequently, the differentiation potentials were examined through alizarin-red staining and Quantitative real time-PCR (qRT-PCR).

RESULTS

Isolated cells were spindle-shaped with a high expression of mesenchymal stem cell markers and weak expression of hematopoietic markers. The mean expression of Oct-4 was 68.77%±1.28. Despite similar proliferation rates between SSEA-4(+) and unsorted SHEDs, because of differences in the shape of the growth curves, PDT was lower in unsorted SHEDs (P = 0.2 × 10^-4). Alizarin-red staining showed similar calcium deposition in both groups. Upon differentiation, the expression of osteocalcin was higher in unsorted SHEDs (P = 0.043), while, the expression of alkaline phosphatase was lower (P<0.001). The parathyroid hormone receptor (PTHR) expression was not significantly different (P = 0.0625).

CONCLUSIONS

The results of the present study revealed that SHEDs have high differentiation potentials even in the unsorted cells. Although the SSEA-4-positive SHEDs showed slightly better osteogenic potential, the differences were not abundant to link SSEA-4 expression with superior differentiation potency.

Data mining of digitized health records in a resource-constrained setting reveals that timely immunophenotyping is associated with improved breast cancer outcomes

BACKGROUND

Organizations that issue guidance on breast cancer recommend the use of immunohistochemistry (IHC) for providing appropriate and precise care. However, little focus has been directed to the identification of maximum allowable turnaround times for IHC, which is necessary given the diversity of hospital settings in the world. Much less effort has been committed to the development of digital tools that allow hospital administrators to monitor service utilization histories of their patients.

METHODS

In this retrospective cohort study, we reviewed electronic and paper medical records of all suspected breast cancer patients treated at one secondary-care hospital of the Mexican Institute of Social Security (IMSS), located in western Mexico. We then followed three years of medical history of those patients with IHC testing.

RESULTS

In 2014, there were 402 breast cancer patients, of which 30 (7.4% of total) were tested for some IHC biomarker (ER, PR, HER2). The subtyping allowed doctors to adjust (56.7%) or confirm (43.3%) the initial therapeutic regimen. The average turnaround time was 56 days. Opportune IHC testing was found to be beneficial when it was available before or during the first rounds of chemotherapy.

CONCLUSIONS

The use of data mining tools applied to health record data revealed that there is an association between timely immunohistochemistry and improved outcomes in breast cancer patients. Based on this finding, inclusion of turnaround time in clinical guidelines is recommended. As much of the health data in the country becomes digitized, our visualization tools allow a digital dashboard of the hospital service utilization histories.

A trypsin-based method for isolating leukocytes from human choriodecidua suitable for immunophenotyping and transcriptome studies

Leukocytes found at the human maternal-fetal interface participate in the inflammatory process associated with both preterm and term labor; therein, effective methods for their isolation that allow further phenotypic and functional analyses are necessary. Leukocyte isolation is usually carried out through scraping or enzyme digestion of the choriodecidua, however both methods usually limit the use of downstream immunophenotyping or transcriptomic techniques. Here we describe an isolation method based on gentle trypsin digestion that yields a leukocyte-enriched cell mixture with high lymphocyte viability, although less viable myeloid cells. We show that the method does not compromise cell surface markers since isolated leukocytes are suitable for flow cytometry; and that high quality RNA can be obtained from these cells for qRT-PCR and microarray analyses.

Concomitant T-cell prolymphocytic leukemia and visceral leishmaniasis: A case report

RATIONALE

T-cell prolymphocytic leukaemia (T-PLL) is a rare aggressive lymphoid disease featured by a significant increased lymphocyte count and obvious hepatosplenomegaly with poor prognosis. The concomitant presentation of T-PLL and visceral leishmaniasis (VL) has not previously been reported.

PATIENT CONCERNS

The patient initially suffered from anorexia, skin pigmentation, fever and hepatosplenomegaly. Bone marrow smear described leishmania and antibody test was positive. VL was diagnosed and he was given antimony gluconate therapy. His symptoms recurred.

DIAGNOSIS

A combination of serological rk39 test, morphologic evaluation and immunophenotyping by flow cytometry finally supported the diagnosis of concomitant VL and T-PLL.

OUTCOMES

Amphotericin B was used for the treatment of VL first and a referral for treating T-PLL after recovery from VL was suggested. Unfortunately, the patient requested to be discharged. Telephone follow-up indicated that he died a few days after leaving the hospital.

LESSONS

Due to the rarity of the disease combination, the pathogenesis association of T-PLL and VL is unclear. However, a duly diagnosis is crucial for treatment. In immunosuppressed patients due to malignancies and treatment, VL should be considered as an opportunistic infection. In VL infections, the clinical manifestations mimicking hematological malignancies may cover up the underlying disease. Under such conditions, a complete work-up based on laboratory test is necessary to achieve a correct diagnosis.

Lymphocytes as Biomarkers of Therapeutic Response in Rheumatic Autoimmune Diseases, Is It a Realistic Goal?

Many therapies are available for patients with rheumatoid arthritis (RA) while biological therapies have limited effects in patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS). In both cases, biomarkers predicting drug response would be very useful to guide clinicians in their choice. We performed a systematic review to evaluate the value of lymphocyte phenotyping as a marker of therapeutic response. Of the 1063 articles retrieved, 39 fulfilled inclusion criteria and were included in the present review (25 for RA, 10 for SLE, and 4 for pSS). Lymphocyte phenotyping was described as a biomarker of therapeutic response in many studies, but most results could not be confirmed by independent teams using multivariate analysis. The most consistent result might be the association between rituximab response and the levels of memory B cells before therapy, although some studies were controversial. Thus, lymphocyte phenotyping cannot yet be proposed as a biomarker of response in rheumatic autoimmune diseases. The lack of reproducibility between studies may be explained by technical issues influencing lymphocyte phenotyping so standardization procedures should be developed for future studies. The patients' characteristics vary between studies, and large population studies, including a wide range of patients' characteristics and biomarkers, are required to provide predictive models for clinical outcomes. The use of new flow cytometry techniques such as single-cell mass cytometry technology might also help finder reliable biomarkers in the future.

Innate lymphoid cells at the human maternal-fetal interface in spontaneous preterm labor

PROBLEM

Pathological inflammation is causally linked to preterm labor and birth, the leading cause of neonatal morbidity and mortality worldwide. Our aims were to investigate whether (i) the newly described family of innate lymphoid cells (ILCs) was present at the human maternal-fetal interface and (ii) ILC inflammatory subsets were associated with the pathological process of preterm labor.

METHODS OF STUDY

Decidual leukocytes were isolated from women with preterm or term labor as well as from gestational age-matched non-labor controls. ILCs (CD15- CD14- CD3- CD19- CD56- CD11b- CD127+ cells) and their subsets (ILC1, T-bet+ ILCs; ILC2, GATA3+ ILCs; and ILC3, RORγt+ ILCs) and cytokine expression were identified in the decidual tissues using immunophenotyping.

RESULTS

(i) The proportion of total ILCs was increased in the decidua parietalis of women with preterm labor; (ii) ILC1s were a minor subset of decidual ILCs during preterm and term gestations; (iii) ILC2s were the most abundant ILC subset in the decidua during preterm and term gestations; (iv) the proportion of ILC2s was increased in the decidua basalis of women with preterm labor; (v) the proportion of ILC3s was increased in the decidua parietalis of women with preterm labor; and (vi) during preterm labor, ILC3s had higher expression of IL-22, IL-17A, IL-13, and IFN-γ compared to ILC2s in the decidua.

CONCLUSION

ILC2s were the most abundant ILC subset at the human maternal-fetal interface during preterm and term gestations. Yet, during preterm labor, an increase in ILC2s and ILC3s was observed in the decidua basalis and decidua parietalis, respectively. These findings provide evidence demonstrating a role for ILCs at the maternal-fetal interface during the pathological process of preterm labor.

Lymphocyte and monocyte subpopulations in severe aortic stenosis at the time of surgical intervention

INTRODUCTION

Aortic stenosis (AS) is the most common acquired valvular heart disease in adults. Immune system involvement becomes evident during AS development. We sought to investigate the role of different circulating lymphocyte and monocyte subpopulations, with focus on CD4⁺CD8⁺ and natural killer T (NKT) cells, in AS.

MATERIAL AND METHODS

Blood samples and aortic valves were obtained from patients undergoing elective aortic valve surgery. Valves were dissected and underwent genetic analyses and calcium content assessment. Lymphocytes and monocytes subsets were assessed by flow cytometry.

RESULTS

Thirty-eight AS patients were studied. Maximal transvalvular pressure gradient (PG_max) as well as mean transvalvular pressure gradient (PG_mean) correlated with the CD4⁺CD8⁺ lymphocyte count (r=0.35, P=.03 and r=0.43, P=.006, respectively) and fraction (r=0.43, P=.007 and r=0.48, P=.002, respectively). PG_max and PG_mean correlated with CD16⁺CD56⁺CD3⁺ NKT cell count (r=0.39, P=.01 and r=0.43, P=.007, respectively) and fraction (r=0.49, P=.002 and r=0.47, P=.003, respectively). The classical monocyte subpopulation increased after the surgery by 68% (P<.0001). Patients after mini-sternotomy surgery had 47% lower nonclassical monocyte counts than those with full-sternotomy (P=.03). Patients treated with statins had significantly lower postoperative levels of both classical (-25%, P=.04) and nonclassical monocytes (-37%, P=.004) than nontreated individuals.

CONCLUSIONS

In patients with severe isolated AS, CD4⁺CD8⁺ T cells and CD16⁺CD56⁺CD3⁺ NKT cells are associated with AV pressure gradients. Postoperative monocyte levels are affected by procedure invasiveness and use of statins.

A Practical Cryopreservation and Staining Protocol for Immunophenotyping in Population Studies

Large population-based cohort studies, through their prospective collection of a broad range of health information, represent an invaluable resource for novel insights into the pathogenesis of human diseases. Collection and cryopreservation of viable cells from blood samples is becoming increasingly common in large cohorts as these cells are a valuable resource for immunophenotyping and functional studies. The cryopreservation of peripheral blood mononuclear cells (PBMCs), thawing, and immunophenotyping protocols used to immunophenotype 9938 participants in the Health and Retirement Study (HRS) are described. The extensive quality control involved in a large-scale immunophenotyping epidemiological study is also outlined. The existing literature on the effect of cryopreservation on various immune cell subsets including T, B, NK cells, monocytes, and dendritic cells is provided. © 2018 by John Wiley & Sons, Inc.

High throughput automated analysis of big flow cytometry data

The rapid expansion of flow cytometry applications has outpaced the functionality of traditional manual analysis tools used to interpret flow cytometry data. Scientists are faced with the daunting prospect of manually identifying interesting cell populations in 50-dimensional datasets, equalling the complexity previously only reached in mass cytometry. Data can no longer be analyzed or interpreted fully by manual approaches. While automated gating has been the focus of intense efforts, there are many significant additional steps to the analytical pipeline (e.g., cleaning the raw files, event outlier detection, extracting immunophenotypes). We review the components of a customized automated analysis pipeline that can be generally applied to large scale flow cytometry data. We demonstrate these methodologies on data collected by the International Mouse Phenotyping Consortium (IMPC).

Absolute lymphocyte counts at end of induction correlate with distinct immune cell compartments in pediatric B cell precursor acute lymphoblastic leukemia

Several retrospective studies in children with B cell precursor (BCP) acute lymphoblastic leukemia (ALL) provided clinical evidence that higher absolute lymphocyte counts (ALC) early into treatment significantly correlated with improved relapse-free and overall survival. It still remains unknown, however, whether the predictive role of higher ALCs reflects general bone marrow recovery or a more specific attribute of immune function. To investigate this question, we implemented a prospective observational cohort study in 20 children with BCP ALL on day 29 (D29) of induction chemotherapy and immunophenotyped their lymphoid (T, B and natural killer cells) and myeloid (neutrophils, monocytes, dendritic cells) compartments. In a first evaluation of a cohort treated with Children's Oncology Group-based induction chemotherapy, the immune cell compartments were differentially depleted at D29. Neither gender, risk status, minimal residual disease, nor bone marrow recovery markers correlated with D29 ALC. In contrast, both CD3+ T cell and dendritic cell compartments, which did not correlate with age, significantly correlated with D29 ALC (p < 0.0001). In addition, subset complexity of cellular immune compartments was preserved at D29. This study reveals that D29 ALC significantly correlates with distinct immune cell compartments but not with bone marrow recovery markers, suggesting that higher D29 ALCs may contribute to leukemia control by inducing specific host immune activity.

Frequent Detection and Immunophenotyping of Prostate-Derived Cell Clusters in the Peripheral Blood of Prostate Cancer Patients

Background

Recent scientific studies have failed to determine parameters for the assessment of prostate cancer aggressiveness. The present study deals with the detection of blood-borne cancer cells based on polymerase chain reaction (PCR) and cell enrichment methods. The contradictory results reported in the literature have called into question the clinical usefulness of this diagnostic method in the preoperative staging of clinically localized prostate cancer.

Methods

We established a combined method of density gradient centrifugation and immunomagnetic separation using epithelium-specific antibodies, i.e. cytokeratins, to isolate prostate-derived circulating cells from the peripheral blood of patients with prostate cancer. Isolated cells were characterized by DNA staining and immunocytochemistry using antibodies for the detection of prostate-specific antigen (PSA), proliferation-associated proteins (MIB-1, H1 and H3) and apoptosis-associated proteins (M30, c-FasR).

Results

We applied these methods to 68 prostate cancer patients and were able to isolate cell clusters in 98%. Immunophenotypic and morphological characterization of PSA-positive prostate-derived cell clusters found in the peripheral blood of prostate cancer patients showed two main populations: 1) in 35% of the investigated prostate cancer patients we detected rounded cell aggregates of probable cancer cells expressing proliferation-associated proteins and lacking apoptosis-associated protein expression; 2) in all cases there was a high frequency of circulating dysmorphic cell clusters positive for apoptosis-associated protein expression.

Conclusion

Our results demonstrate the existence of at least two different types of blood-borne prostate-derived circulating cell clusters. Of these, only the less frequent, round, small cell clusters harbor features that are probably necessary for the cells to survive for metastatic spread.

Broad Immune Monitoring and Profiling of T Cell Subsets with Mass Cytometry

Mass cytometry (cytometry by time-of-flight, CyTOF) is a high-dimensional single-cell analytical technology that allows for highly multiplexed measurements of protein or nucleic acid abundances by bringing together the detection capacity of atomic mass spectroscopy and the sample preparation workflow typical of regular flow cytometry. In 2014 the mass cytometer was adapted for the acquisition of samples from microscopy slides (termed imaging mass cytometry), greatly increasing the applicability of this technology with the inclusion of spatial information. By using antibodies (or other probes) labeled with purified metal isotopes, mass cytometers are currently able to detect more than 50 different parameters at a single-cell level, exceeding the dimensionality of any other flow cytometry methodology currently on the market. This capability licenses unprecedented possibilities in many areas dealing with complex cellular mixtures (immunology, cell biology, and beyond), improving biomarker discovery and moving us closer to affordable personalized medicine than before.