High Levels of Soluble Immunoregulatory Receptors in Patients with WaldenströM’s Macroglobulinemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4881-4881 ◽  
Author(s):  
Zachary R. Hunter ◽  
Andrew R. Branagan ◽  
Daniel Ditzel Santos ◽  
Olivier Tournilhac ◽  
Evdoxia Hatjiharissi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Mast Cells ◽  
Immune Responses ◽  
Pcr Analysis ◽  
P Value ◽  
Rt Pcr ◽  
T Cell Immune Responses ◽  
Immunoregulatory Receptors ◽  
Cell Disorder

Abstract CD25, CD27, CD30 and CD40 are receptors for IL-2, CD70, CD153 and CD154, respectively, which provide important signaling for both B- and T-cell immune responses. We therefore examined the sera of patients with Waldenstrom’s macroglobulinemia (WM), a B-cell disorder characterized by excess IgM secreting bone marrow lymphoplasmacytic cells (LPC) for the presence of soluble CD25, CD27, CD30, CD40, IL-2, CD153, and CD154. Sera were from patients with active disease and off-therapy. Sera from healthy age matched donors (HD) was used for controls. The results of these studies were as follows: WM ELISA Results HD ELISA Results p-value n= median range n= median range sCD25 pg/ml 2.647x10−6 41 3418.99 3–19756.2 20 573.6 184.96–891.03 IL-2 pg/ml 0.72385 41 22.96 3–76.83 20 11.07 5.64–64.7 sCD27 U/ml 2.4727x10−7 26 7.45 0–19.42 10 0 0–2.78 sCD70 ND ND ND ND ND ND ND sCD30 U/ml 0.00088 25 89.25 0–550.81 15 39.12 0–135.25 sCD153 ng/ml 0.68388 25 8.18 0–43.8 15 5.65 0–24.82 sCD40 pg/ml 0.02484 25 101.39 11.76–584.99 11 50.73 0–150.5 sCD154 pg/ml 0.81317 55 949.58 92–4973.16 17 1078.03 351.88–2323.38 Considering our recent studies demonstrating a role for mast cells (MC) in supporting WM cell growth (JCO 2004 22:571S), we examined bone marrow LPC along with MC from WM patients for expression of CD25, CD27 and CD40 and/or their ligands by flow cytometry and RT-PCR analysis. The results of these studies are as follows: Flow Cytometry RT-PCR WM MC WM MC CD25 4/10 (40%) 2/7 (29%) 7/9 (78%) 7/15 (47%) IL-2 ND ND ND ND CD27 5/12 (42%) 2/8 (25%) 7/7 (100%) 4/7 (57%) CD70 6/6 (100%) 10/11 (91%) 7/7 (100%) 2/7 (29%) CD30 1/21 (4.7%) ND ND ND CD153 3/7 (43%) 12/13 (92%) 2/2 (100%) 9/11 (82%) CD40 25/30 (83%) ND ND ND CD154 2/3 (67%) 9/13 (69%) 7/9 (78%) ND The above studies demonstrate high levels of circulating immunoregulatory receptors, and expression of these receptors and/or their ligands on WM tumor and mast cells. Studies addressing their role in immune dysregulation in WM are underway.

Constitutive Expression of CD40L on Bone Marrow Mast Cells Supports the Growth of Lymphoplasmacytic Cells in Patients with Waldenstrom’s Macroglobulinemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2350-2350 ◽  
Author(s):  
Olivier Tournilhac ◽  
Daniel Ditzel Santos ◽  
Lian Xu ◽  
Jeffery Kutok ◽  
Yu Tsu Tai ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Mast Cells ◽  
Cell Surface ◽  
Tumor Cells ◽  
Thymidine Uptake ◽  
Dependent Manner ◽  
Rt Pcr ◽  
Potent Inducer ◽  
Dose Dependent

Abstract CD40 ligand (CD40L) is a potent inducer of normal and malignant B-cell proliferation through interaction with CD40. We and others have observed excess mast cells (MC) in bone marrow (BM) biopsies of WM patients, which are commonly found admixed with tumor aggregates. (Tournilhac et al, JCO 2004, 22:571S). We therefore sought to clarify the role of MC in WM. Co-culture of 0.5% paraformaldehyde fixed, or sublethally irradiated HMC-1, LAD, and KU mast or basophilic cell lines and sorted BM lymphoplasmacytic cells (LPC) from 10 WM patients resulted in MC dose-dependent tumor colony formation and/or proliferation as assessed by 3H-thymidine uptake studies. As demonstrated by immunohistochemical, multicolor flow cytometric (CD117+FceRI+) and/or RT-PCR analysis, CD40L was expressed on BM MC from 29 of 31 (94%), 11 of 13 (85%), and 7 of 9 (78%) of WM patients, respectively. In contrast, cell surface CD40L expression was not detected by immunohistochemistry (p=0.00005) and flow cytometry (p=0.003) in 5 normal donors, and only faint expression for 1 of 5 normal donors by RT-PCR (p=0.09). Moreover, by multicolor flow cytometry, CD40 was expressed on BM tumor cells from 14/17 (83%) patients. CD40 functionality was confirmed either by the G28.5 CD40 agonistic antibody which induced dose dependent proliferation or by the rh-CD40L which partly prevented serum starvation-induced-apoptosis of WM LPC from 4/4 and 3/4 patients respectively. Importantly, expansion of tumor cells from 3 of 4 patients in mixed cultures with paraformaldehyde fixed MC was blocked in a dose dependent manner by use of a CD40L blocking protein (CD40:Fc). These studies demonstrate that CD40L is constitutively expressed on the cell surface of BM MC in WM and support the growth of WM tumor cells, and therefore provide the framework for therapeutic targeting of MC and MC-WM cell interactions in WM.

Regulation of the New CXCR7 Receptor in Plasma Cell Dyscrasias.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3527-3527
Author(s):  
Anne-Sophie Moreau ◽  
Xavier Leleu ◽  
Xiaoying Jia ◽  
Judith Runnels ◽  
Costas Pitsillides ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Tumor Cells ◽  
Cell Lines ◽  
The Other ◽  
Pcr Analysis ◽  
Boyden Chamber ◽  
Embryonic Cells ◽  
Rt Pcr ◽  
Migration Assay

Abstract Background: Multiple Myeloma (MM) and Waldenstrom Macroglobulinemia (WM) are characterized by widespread involvement of the bone marrow (BM) as the result of successful homing, engraftment and growth of tumor cells at that site. The receptor for SDF-1, CXCR4 has already been implicated by us and others in the migration and homing of tumor cells to the bone marrow. Recently, a new receptor for the chemokine SDF-1 has been described, namely CXCR7. To date, it has been implicated in the migration of embryonic cells during neurogenesis in zebrafish. It has been reported to be expressed in cancer cells but its function remains unknown. We have previously shown that disruption of the CXCR4/SDF-1 axis interferes with homing of MM cells to the BM. To better understand the homing and migration of MM and WM tumor cells, we sought to study the expression and function of CXCR7. Methods: MM (U266, MM1.S, RPMI, OPM2, OPM1, KMS12BM) and WM (BCWM.1 and WSU-WM) cell lines were used. CD19+ and CD138+ cells were extracted from patient bone marrow samples by microbeads selection after informed consent. To determine the expression of CXCR7 on MM and WM cell lines as well as primary samples, we used flow cytometry and RT-PCR analysis. The migration of tumor cells towards SDF-1 was studied using the transwell boyden chamber migration assay. The adhesion of tumor cells to fibronectin using a fluorometric assay. The CXCR7 inhibitor CCX-754 (ChemoCentryx Inc., Mountain View, CA) was used. Results: CXCR7 was expressed in all cell lines tested except WSU-WM by flow cytometry and RT-PCR. Interestingly, U266 cell line did not express surface CXCR4 and expressed CXCR7 and therefore was used in further experiments to determine the differential role of CXCR7 in SDF-1 related function. Primary WM (n=14) and MM (n=7) cells expressed low intensity CXCR7 by flow cytometry. Use of the above cells in experiments utilizing small molecule antagonists of both CXCR4 and CXCR7 suggested that inhibiting the binding of SDF-1 to one receptor could impact the signaling functions of the other. Experiments are ongoing to clarify the nature of the interaction between these two SDF receptors. Furthermore, adhesion of U266 cells to fibronectin was increased in presence of SDF-1, and inhibited in the presence of CCX-7754. Further analysis to examine CXCR7 and CXCR4 antagonism in adhesion are ongoing. Conclusion: we showed for the first time CXCR7 expression on MM and WM tumor cells. Our results lead us to conclude that through binding of a shared ligand, CXCR7 and CXCR4 may modulate the biological activity of the other.

scholarly journals Discrepancy of Blast Percentage between the Bone Marrow Aspirate and Flow Cytometry and Its Impact on Survival Outcomes in Patients with Myelodysplastic Syndromes Excess Blast (MDS-EB)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5441-5441
Author(s):  
Meera Yogarajah ◽  
Phuong L. Nguyen ◽  
Rong He ◽  
Hassan B. Alkhateeb ◽  
Mithun Vinod Shah ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Small Sample Size ◽  
Scoring Systems ◽  
Standard Of Care ◽  
Risk Groups ◽  
Small Sample ◽  
International Prognostic Scoring System ◽  
P Value ◽  
Number Of Patients

Background MDS is a heterogeneous disease and the revised International Prognostic Scoring System (IPSS-R) is utilized in prognostication. The percentage (%) of blasts in the bone marrow is determined in the aspirate morphologically. Though the former is the standard of care the blast percentage is also reported by flow cytometry and biopsy which can many times be inconsistent. We previously presented the utilization of biopsy based blast percentage which showed meaningful prognostic groups compared to aspirate. In this study we compare the blasts as reported by the aspirate and flow cytometry in MDS-EB in calculating IPSS-R. Methods The MDS database was reviewed for cases of MDS-EB after due IRB approval at the Mayo clinic. We calculated IPSS-R scores based on the aspirate blast % (IPSS-RAsp) and flow blast% (IPSS-Rfl). The aspirate blast percentage was reported morphologically. Suboptimal aspirates were excluded from the study. The flow blast percentage was determined by immunophenotyping. The overall survival (OS) was determined by IPSS-RAsp and IPSS-RFl. OS estimates were calculated by Kaplan-Meier curves and log-rank testing using JMP v.13. Uno's concordance statistic was used to compare the 2 risk scoring systems. Results Of 1322 patients, 431 (33%) cases were identified with MDS-EB out of which 120 (29%) cases had blasts reported in the aspirate and flow. Based on aspirate MDS EB1: 54% (n=65), MDS EB2 46% (n=55). The hematological, cytogenetic and R-IPSS categories were compared between MDS-EB1 and MDS- EB 2. The blast percentage and hemoglobin levels was significantly different between MDS-EB1 and EB2 as seen in table 1, however the IPSS-R risk groups were not significantly different. The flow cytometry was concordant with aspirate in 66/120 (55%) cases. Out of the dis-concordant cases only 20% (11/54) was upstaged by flow cytometry with most of the patients being down staged as expected by the techniques used in processing the blood and hence not reliable when reported low (Figure 1). The OS outcomes based on the IPSS- R asp, IPSS-Rfl areshown in figure 2A,2B .The p value with aspirate based R-IPSS was more significant than flow cytometry based R-IPSS (p= 0.0007 vs 0.0174). We compared the two models for observed OS differences using the Uno model which was not statistically significant. (p= 0.6) Conclusions Both models did not show a difference which is likely due to the very small sample size. However flow cytometry did down stage more patients when disconcordant and may have less value in that setting. It would be ideal to compare all 3 models aspirate, biopsy and flow cytometry however we did not have enough number of patients to do the comparison. Disclosures Patnaik: Stem Line Pharmaceuticals.: Membership on an entity's Board of Directors or advisory committees. Al-Kali:Astex Pharmaceuticals, Inc.: Research Funding.

Classical and Molecular Cytogenetic Abnormalities in 124 Pediatric Patients with Acute Lymphocyte Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4419-4419
Author(s):  
Yihuan Chai ◽  
Hui Lv ◽  
Jun Lu ◽  
Peifang Xiao ◽  
Jianqing Li
Keyword(s):  
Bone Marrow ◽  
Multiplex Pcr ◽  
Cytogenetic Analysis ◽  
Chromosomal Abnormalities ◽  
Molecular Diagnostic ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Childhood All ◽  
Cytogenetic Abnormalities ◽  
Conventional Cytogenetic Analysis

Abstract In childhood acute lymphocyte leukemia (ALL), cytogenetics plays an important role in diagnosis, allocation of treatment and prognosis. On base of the conventional cytogenetic analysis, molecular methods have inproved our ability to accurately and rapidly risk-stratify patient with childhood ALL in the last few years. Our aim was to assess the demography of cytogenetic abnormalities in childhood ALL. The study sample consisted of 124 newly diagnosed ALL patients younger than 16 years, who were diagnosed at the Department of Pediatric Hematology/Oncology, Soochow University Children’s Hospital. The diagnosis and FAB subtypes of ALL was determined by Wright-Giemsa-stained bone marrow smears and cytochemicalstaining. Immunophenotyping of the bone marrow samples was performed by flow cytometry. Multiplex reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed to detect the 29 most common leukemia translocations for routine molecular diagnostic hematopathology practice, and complement the information gained from conventional cytogenetic analysis. Cytogenetic analysis was successful in 112 of 124 children with ALL. Sixty-eight (60%)of them had clonal chromosomal abnormalities. Numerical imbalances consisted of hyperdipoild(>47 chromosomes, 36 cases), hypodipoild(<46 chromosomes, 14 cases), pseudodiploidy(18 cases). Chromosomal translocations were observed in 13 patients by conventional cytogenetic analysis. Three cases were found positive for t (4;11), 3 cases for t (9;22), 1 case for t (1;19) and 6 cases for other rare translocations. RT-PCR analysis detected 116 of the 124 ALL patients. Thirteen cases of TEL-AML1, 10 cases of rearrangement in the MLL gene, 4 cases of E2A-PBX1, 4 cases of E2A-HLF, 3 cases of BCR-ABL, 2 cases of TLS-ERG, 32 cases of HOX11, were detected by RT-PCR in B-lineage leukemias. SIL-TAL1 had been found in 4 of 7 of T-lineage leukemias. Sixty-eight cases of ALL show chromosomal aberrations. Multiplex PCR positivity was detected in 59(50%)of the 116 ALL patients studied. Multiplex PCR combined with chromosome analysis uncovered Chromosomal abnormalities in 95 of 124(77%) of ALL patients and supplemented each other in detecting Chromosomal abnormalities. It provides reliable evidence for the diagnosis, classification and prognosis.

Study on Mechanism of Human Marrow Mesenchymal Stem Cell in Treating Patients with Aplastic Anemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4099-4099
Author(s):  
Zhenhua Qiao ◽  
Xiujuan Zhao
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
T Cells ◽  
Aplastic Anemia ◽  
Hematopoietic Cell ◽  
Control Group ◽  
Rt Pcr ◽  
Tnf Α ◽  
Ifn Γ ◽  
Tgf Β1

Abstract Objective: To explore mechanism of human marrow mesenchymal stem cells (MSCs) in treating patients with aplastic anemia(AA). Methods: MSCs in patients with aplastic anemia(AA) and the control group were separated with Percoll(1.073g/m L) and cultured in low glucose DMEM. Then, observed their morphologies,checked their molecule surface antigen by flow cytometry and examined the process of adipogenic differention. The mononuclear cells (MNC)of marrow in patients with AA were enriched based 1.077g/L density centrifuge and cultured in the 1640 medium. (1)MSC in control group and MNC in AA group were co-cultured with or without cytokines. The function of supporting hematopoiesis for MSC was to be observed in single confluence layer after plating by counting the total cells and the clones in every well every week. Then analyzed the dynamics of proliferation. T cells were harvested by using nylon column. MSC in control group and T cells in AA group were co-cultured. The proliferation of T cell was measured by MTT method. The CD25,CD69,CD4,CD8,Annexin-V expression rates of CD3+T cells were analyzed by flow cytometry .The gene and protein of IL-2, IL-4,IL-10,TNF-α,IFN-γ,TGF-β1 were examined by RT-PCR and ELISA respectively. MSC treated to the model of AA, by the examination of peripheral hemogram, bone marrow biopsy, pathological section of spleen. Results: There was no significant difference between control group MSC and AA-MSC in morphologies but adipogenic differentiation in AA patients is earlier than controls. The clones of CFU-GM in group(MSC)(78.46±3.58)/2×105 cells, after 14 days cultured was significantly higher than(9.21±4.32)/2×105 cells in group(CK + DMEM medium), while lower than (99.32±4.34)/2×105 cells in group(MSC+CK). (1)the Treg cells (TCD4+CD25+) in AA group (2.01±1.21)/ 2×105 was significantly lower than (4.43±1.67)/2×105 cells in control group, while(5.43±2.31) / 2×105 in group (MSC+AAT) was no more than (4.43±1.67)/2×105 cells in control group. (2) MSCs significantly inhibited T cell proliferation (P< 0. O5)by MTT. (3) RT-PCR and ELISA analysis showed that MSCs induced the expression of IL-4, IL-10, TGF-β1 and decreased significantly the expression of IL-2, TNF-α, IFN -γ in T cells of AA. the model of AA treated by MSCs showed improvements in 3 blood components greatly(p<0.05), Bone marrow proliferated and restored to the normal level, hematopoietic cell increased obviously (hematopoietic cell capacity was more than 40%), and atrophied spleen restore to normality. Conclusions: morphologies of AA’MSC had no evident different with the control but was more easy adipogenic differention. aplastic anemia belongs to autoimmune diseases in which T cells effect organ-specific destruction. The fundamental mechanism of MSC in treating AA should be potential to promote hematopoietic cell proliferation by adjusting immunity.

CXCR7 Regulates SDF-1 Induced Adhesion and Homing in Multiple Myeloma.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1674-1674 ◽  
Author(s):  
Nicholas Burwick ◽  
Anne-Sophie Moreau ◽  
Xiaoying Jia ◽  
Xavier Leleu ◽  
Judith Runnels ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Flow Cytometry ◽  
Cell Adhesion ◽  
Cell Lines ◽  
Cxcr4 Expression ◽  
Rt Pcr ◽  
Growth And Survival ◽  
Tumor Types

Abstract BACKGROUND: Multiple myeloma (MM) is a plasma cell malignancy that depends on interactions with the bone marrow (BM) microenvironment for growth and survival. In turn, adhesion of MM cells to the BM stroma provides a mechanism of resistance from standard chemotherapeutic agents. Recently, our lab has shown that by disrupting this adhesion using a selective CXCR4 inhibitor named AMD3100, MM cells are more sensitive to the proteasome inhibitor Bortezomib (Ghobrial lab, unpublished data). CXCR4 has been a particularly attractive target because its ligand SDF-1 is known to induce p42/44 MAPK, AKT, and the down-stream anti-apoptotic protein bad in MM cells, leading to increased MM growth and survival. Until recently, CXCR4 was thought to be a canonical receptor for the SDF-1 ligand. However, a second chemokine receptor for SDF-1 was subsequently discovered and named CXCR7. CXCR7 is a novel chemokine receptor that is important in cell adhesion, growth and survival in several tumor types. However, the role of CXCR7 in multiple myeloma (MM) has yet to be explored. Furthermore, the ability of SDF-1 ligand to regulate MM function via CXCR7 has not been studied. METHODS: The MM cell lines (U266, MM1.S, RPMI, OPM2, OPM1) were used. After informed consent was obtained, primary bone marrow samples from MM patients were collected. CD138 positive mononuclear cells were isolated by microbead selection. The expression of CXCR7 on MM cell lines and patient samples was confirmed using flow cytometry and RT-PCR analysis. For functional in vitro and ex-vivo assays, the CXCR7 selective antagonist 733 was used (ChemoCentryx Inc., Mountain View, CA). RESULTS: Here we show that CXCR7 was expressed on all tested MM cell lines and primary patient samples as demonstrated by flow cytometry and RT-PCR. Furthermore, CXCR7 was found to regulate SDF-1 induced MM cell adhesion, as demonstrated by in vitro assays using a small molecule compound specific for CXCR7 (733). The CXCR7 antagonist showed significant inhibition of adhesion of MM cell lines and patient samples to fibronectin, endothelial cells and stromal cells, with 50% reduction of adhesion at 5nM of the CXCR7 inhibitor, and with similar activity compared to 20uM of AMD3100 (CXCR4 inhibitor). However, unlike CXCR4, CXCR7 did not effect trans-well migration to SDF-1 chemokine. Interestingly, both receptors were found to be important for trans-endothelial migration of MM cells. Moreover, pre-treatment with 733 reduced homing of MM cells to the BM niche in vivo. Previous studies have failed to show signaling in response to CXCR7 in many tumor types. Here, we demonstrate that treatment with 733 inhibited SDF-1 induced pERK and pAKT, ribosomal pS6Kinase, pGSK3, pSTAT3, pFAK and pPAK signaling pathways, confirming a role for CXCR7 in facilitating SDF-1 signaling. This effect was further confirmed using immunofluorescence. To investigate whether CXCR7 and CXCR4 interact directly, we examined the effect of 733 and AMD3100 on CXCR4 expression and found that AMD3100 significantly inhibited CXCR4 expression, while 733 had no effect on CXCR4 expression, even in the presence of SDF-1. The CXCR7 inhibitor had no effect on the survival of MM cells using MTT and flow cytometry analysis, while high doses of 733 (1uM) had modest inhibition of proliferation. Interestingly, 733 prevented the growth advantage induced by 30nM SDF-1 at 24 hrs. CONCLUSION: Together, these results demonstrate the importance of CXCR7 in regulating MM adhesion and homing, and highlight the differential effects of CXCR4 and CXCR7 in regulating SDF-1 signaling in MM, thus providing a rationale for targeting the SDF-1/CXCR7 axis in MM.

Real-Time RT-PCR Analysis of Individual Osteolineage Cells within the Hematopoietic Stem Cell Niche

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2389-2389
Author(s):  
Lev Silberstein ◽  
Masatake Osawa ◽  
Charles Lin ◽  
Peter Kharchenko ◽  
Cristina Lo Celso ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Pcr Analysis ◽  
Rna Seq ◽  
Rt Pcr ◽  
Hematopoietic Stem ◽  
Chi Squared ◽  
The Individual ◽  
Osteolineage Cells ◽  
Angiopoietin 1

Abstract Abstract 2389 Osteolineage cells (OLCs) have been shown to participate in a regulatory bone marrow microenvironment for the hematopoietic stem and progenitor cells (HSPCs) – the endosteal niche. Our previous experiments using live animal imaging have demonstrated that single transplanted HSPCs preferentially home in close proximity to the individual OLCs. We hypothesized that these HSPC-proximal cells represent a distinct subpopulation of OLCs, which is specifically involved in a non-cell autonomous regulation of HSPC quiescence and self-renewal. To test this hypothesis, we developed a novel experimental platform, which allows visualization of HSPC-OLC cell pairs in-vivo and retrieval of the individual OLCs for molecular analysis. We intravenously injected DiI labeled adult bone marrow-derived FACS-sorted Lin−Sca1+c-kit+CD34−Flk2− HSPCs into irradiated newborn collagen 2.3GFP mouse recipients; in this transgenic strain, the majority of the OLCs are labeled with green fluorescent protein (GFP). 48 hours later, we sacrificed the animals and obtained fresh unfixed sections of femoral trabecular bone. Using a combination of differential interference contrast fluorescent microscopy, in-situ enzymatic digestion and micromanipulation, we harvested individual GFP-positive OLCs located within 2 cell diameters (“niche” OLCs) or greater than 5 cell diameters (“control” OLCs) from single DiI-bright HSPCs. Following reverse transcription and cDNA amplification with 29 cycles of PCR, as per the single cell RNA-Seq protocol (Tang et al, Nature Protocols 2010), we performed real-time RT-PCR analysis of 31 samples – 15 niche cells and 16 controls - for the OLC signature genes (osteocalcin, osterix) and for the genes implicated in playing a functional role in the HSPC-OLC cell interaction (osteopontin, CXCL12, angiopoietin 1). Transcripts for GAPDH, collagen 1 and GFP served as positive controls for the amplification. As expected, all cells were positive for GFP and over 85% cells expressed collagen 1. Osteopontin and CXCL12 were expressed at a similar level and frequency in the niche and control OLCs. However, we found that angiopoietin 1 transcripts were detected exclusively in the niche OLCs (3/15 versus 0/16, p <0.05 by Chi-squared). Moreover, niche OLCs were enriched for the osterix-positive cells (7/15 versus 2/16, p <0.05 by Chi-squared) and expressed a lower level of osteocalcin, as normalized for GAPDH expression (1.13 vs. 0.97, p< 0.05 by t-test). Our results suggest that niche OLCs may have a distinct molecular signature and reside within a population of very immature OLCs, as evidenced by the osterix + osteocalcin low phenotype. Further unbiased transcriptome characterization of these cells using genome-wide RNA-Seq assay is therefore likely to provide more evidence in support of our hypothesis and reveal novel non-cell autonomous regulators of HSPC quiescence. To our knowledge, this approach represents the first attempt to define molecular heterogeneity in-vivo at a single cell level using the micro-anatomical relationship between two heterologous cell types. Disclosures: Scadden: Fate Therapeutics: Equity Ownership.

scholarly journals Corticotropin-Releasing Hormone and Its Structurally Related Urocortin Are Synthesized and Secreted by Human Mast Cells

Endocrinology ◽  
2004 ◽  
Vol 145 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Duraisamy Kempuraj ◽  
Nikoletta G. Papadopoulou ◽  
Michael Lytinas ◽  
Man Huang ◽  
Kristiana Kandere-Grzybowska ◽  
...  
Keyword(s):  
Mast Cells ◽  
Immune Responses ◽  
Restraint Stress ◽  
Acute Stress ◽  
Rt Pcr ◽  
Human Cord Blood ◽  
Potential Source ◽  
First Time ◽  
Pituitary Adrenal Axis ◽  
Stimulation Of

Abstract Stress activates the hypothalamic-pituitary-adrenal axis through CRH, leading to production of glucocorticoids that down-regulate immune responses. However, acute stress also has proinflammatory effects. We previously showed that restraint stress, as well as CRH and its structurally related urocortin (Ucn), could activate mast cells and trigger mast cell-dependent vascular permeability. Here we show for the first time that human cord blood-derived cultured mast cells (hCBMC) at 10 wk, but not at 2 wk, are immunocytochemically positive for CRH and Ucn; human leukemic mast cells are weakly positive for both peptides. The ability of these mast cells to synthesize CRH and Ucn was confirmed by showing mRNA expression with RT-PCR. hCBMC (8–14 wk) synthesize and store 1–10 ng/106 cells (10–20 μg/g) of both CRH and Ucn detected by ELISA of cell homogenates. Stimulation of IgE-sensitized hCBMC with anti-IgE results in secretion of most CRH and Ucn. These findings indicate that mast cells are not only the target, but also a potential source of CRH and Ucn that could have both autocrine and paracrine functions, especially in allergic inflammatory disorders exacerbated by stress.

scholarly journals Cutaneous Mastocytosis in a 61-year-old Female from a Dermatological and Histopathological Perspective

2020 ◽  
pp. 01-06
Author(s):  
Erisa Kola ◽  
Jorida Memini ◽  
Ina Kola ◽  
Daniela Nakuci ◽  
John Ekladous ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Lymph Nodes ◽  
Systemic Mastocytosis ◽  
World Health ◽  
Systemic Involvement ◽  
Cutaneous Mastocytosis ◽  
Health Organization ◽  
Cell Disorder

First described by Nettleship et al. in 1869 [1], mastocytoses are a heterogeneous group of disorders characterized by the pathologic accumulation of mast cells in various tissues [2-5]. Mastocytosis can be confined to the skin as in cutaneous mastocytosis (CM), or it can involve extracutaneous tissues such as the liver, spleen, bone marrow and lymph nodes, as in systemic mastocytosis [6]. Mastocytosis is a World Health Organization-defined clonal mast cell disorder characterized by significant clinicopathologic heterogeneity [7]. Keywords: Cutaneous mastocytosis; Systemic mastocytosis; Systemic involvement; Mast cells; Mastocytosis.

scholarly journals AK002, a Novel Humanized Monoclonal Antibody to Siglec-8, Inhibits Mast Cell Activity and Depletes Eosinophils in Ex Vivo Bone Marrow Tissue from Patients with Systemic Mastocytosis

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1104-1104 ◽  
Author(s):  
Bradford A Youngblood ◽  
Emily C Brock ◽  
John Leung ◽  
Alan T Chang ◽  
Christopher Bebbington ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
Flow Cytometry ◽  
Mast Cell ◽  
Mast Cells ◽  
Ex Vivo ◽  
Systemic Mastocytosis ◽  
Cell Activity ◽  
Receptor Expression ◽  
Long Term Treatment

Abstract INTRODUCTION: Systemic Mastocytosis (SM) is a rare disease characterized by the clonal proliferation and accumulation of mast cells in the bone marrow, respiratory and gastrointestinal tracts, and organs such as the skin, liver, spleen, and brain. Common symptoms include pruritus, flushing, headache, cognitive impairment, fatigue, diarrhea, abdominal pain, hypotension and skin lesions, as well as an increased risk for osteoporosis and anaphylaxis. SM is currently managed with antihistamines, cromolyn sodium, and leukotriene blocking agents, which lack specificity and efficacy. In addition, glucocorticoids can provide temporary relief in some cases; however long-term treatment with steroids is not appropriate due to their many side effects. Siglec-8 is an inhibitory receptor selectively expressed on human mast cells and eosinophils, and therefore represents a novel target for the treatment of SM. Antibodies to Siglec-8 have been shown to inhibit mast cell activity and induce apoptosis of eosinophils. AK002 is a novel, humanized, non-fucosylated IgG1 monoclonal antibody to Siglec-8. This study evaluates the expression of Siglec-8 and ex vivo activity of AK002 on mast cells and eosinophils in bone marrow biopsies from patients with SM. METHODS: Bone marrow aspirates were obtained from patients clinically diagnosed with SM and processed to remove red blood cells. Multi-color flow cytometry was used to quantify eosinophils and mast cells and to evaluate the activation state of mast cells. The ex vivo activity of AK002 against eosinophils and mast cells was evaluated by flow cytometry. The inhibitory activity of AK002 agaist mast cells was also examined by quantifying cytokine levels in cultured bone marrow aspirate supernatants. RESULTS: All mast cells and eosinophils in bone marrow aspirates from SM patients displayed high Siglec-8 receptor expression (Figure 1). These mast cells also expressed the SM specific markers, CD25 (Figure 1) and CD30 and increased levels of cell surface degranulation markers. The expression of CD25 on mast cells significantly decreased following overnight treatment with AK002. AK002 also significantly reduced the level of mast cell-associated cytokines produced in cultured bone marrow supernatants, including IL-6, IL-8, and TNFα (Figure 2A). These changes in mast cell activity after AK002 treatment were not due to a reduction in mast cell numbers. In contrast, overnight incubation of AK002 significantly reduced the number of bone marrow eosinophils compared to an isotype control (Figure 2B). CONCLUSIONS: Bone marrow aspirates from patients with SM had activated mast cells and eosinophils that displayed robust expression of Siglec-8. AK002 demonstrated SM mast cell inhibition in ex vivo bone marrow aspirates. AK002 also had depleting effects on eosinophils, which may be valuable to SM patients with associated eosinophilia. These encouraging results could represent a novel approach for the treatment of SM. Disclosures Youngblood: Allakos, Inc.: Employment. Brock:Allakos, Inc.: Employment. Leung:Allakos, Inc.: Employment. Chang:Allakos, Inc.: Employment. Bebbington:Allakos, Inc.: Employment. Tomasevic:Allakos, Inc.: Employment.

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