Stromal Precursors in the Bone Marrow of Untreated Patients with Severe and Non-Severe Aplastic Anemia Differ in the Proliferative Potential

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 10-10
Author(s):  
Irina N. Shipounova ◽  
Alyona I. Dorofeeva ◽  
Nikolay M. Kapranov ◽  
Anton V. Luchkin ◽  
Zalina T. Fidarova ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Absolute Neutrophil Count ◽  
Neutrophil Count ◽  
Hematopoietic Cells ◽  
Proliferative Potential ◽  
Differentiation Potential ◽  
Stromal Precursors ◽  
Hematopoietic Microenvironment ◽  
Healthy Donors

Background. Aplastic anemia (AA) is a disorder characterized by pancytopenia, hypoplastic bone marrow (BM), and the absence of underlying malignancy. It is believed to be of autoimmune nature. However, some patients fail to respond to the immunosuppressive therapy. The impaired hematopoietic microenvironment could be another reason for BM failure. The severity of AA varies widely from mild, chronic pancytopenia to total hematopoietic failure. The diagnosis of severe (SAA) and non-severe AA (NAA) is based on an absolute neutrophil count as an essential criterion. The aim of the study was to analyze the multipotent mesenchymal stromal cells (MMSC) and fibroblasts colony forming units (CFU-F) in BM of untreated SAA and NAA patients. Methods. The study included 22 AA patients (8 with SAA and 14 with NAA) in the debut of the disease. In all patients BM was aspirated after informed consent at diagnostic punctures. The proportion of non-hematopoietic CD45-CD34-CD71-CD235-CD90+CD73+CD105+ cells was estimated by FACS. From the BM, MMSC were isolated by the standard method and the concentration of CFU-F was determined. Individual CFU-F-derived colonies were analyzed for their proliferative and differentiation potential. Adipogenic and osteogenic differentiation potential was analyzed with standard techniques. Relative expression level (REL) of several genes had been estimated with RT-PCR in Taqman modification. As a control 19 BM samples of healthy donors of according age were used. Results. The data are presented in the table. The proportion of non-hematopoietic cells was higher in the BM of AA patients than in healthy donors. We recalculated the proportion of CFU-F among non- hematopoietic cells; it was similar in the BM of AA patients and healthy donors. However, the concentration of -CFU-F was much higher in the BM of patients with SAA then in the BM of patients with NAA. Among NAA patients, 2 had PNG clone and unlike other NAA patients increased CFU-F concentration, comparable to patients with SAA. It seems that the character of stromal cell damage depends on the severity of AA. Individual CFU-F- derived clones from the BM of NAA patients had very limited proliferative potential, while those of SAA patients did not differ from colonies of healthy donors. The analysis of CFU-F-derived colonies differentiation ability revealed that the proportion of the precursors that did not respond to the differentiation induction was higher in the BM of AA patients than in donors. It reflects the involvement of a certain subpopulation of stromal precursors that are either pre-differentiated into fibroblasts, or, conversely, earlier precursors of the hematopoietic microenvironment, which were not able to differentiate into osteoblasts and/or adipocytes within standard time. The analysis of the MMSC growth characteristics revealed that the time required for MMSC from SAA and NAA patients to form a confluent monolayer after the initial seeding and the population doubling time, were significantly higher than in MMSC of healthy donors. Thus, the proliferation rate of MMSC of AA patients is reduced. Nevertheless, the total cell production for 3 passages did not differ in cultures of AA patients and healthy donors. Therefore, the proliferative potential of MMSC of AA patients is not altered. Probably MMSC being analyzed ex vivo can restore their function. However, the analysis of REL of genes regulating the proliferation (FGF2, FGFR1, FGFR2) in MSCs had revealed the differences in comparison with donors and between SAA and NAA. Moreover, the analysis of the polymorphism in CFH gene, participating in immunomodulation, showed that the distribution differs between NAA and SAA patients. Conclusions. Stromal precursors in BM of untreated NAA and SAA patients are impaired and differ between the two subtypes of AA. It seems that the differences between NAA and SAA may lay not only in the absolute neutrophil count but also in the BM stroma itself. This effect could participate in the pathogenesis of AA or be the consequence of compensatory reaction of stromal microenvironment to the hematopoiesis failure. This work was supported by the Russian Foundation for Basic Research, project no. 19-015-00280. Table Disclosures No relevant conflicts of interest to declare.

Successful Treatment of Refractory Idiopathic Aplastic Anemia with Rituximab

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4114-4114
Author(s):  
Sreedhar Katragadda ◽  
John C Nelson
Keyword(s):  
Bone Marrow ◽  
Platelet Count ◽  
Blood Cell ◽  
Aplastic Anemia ◽  
Cell Count ◽  
Absolute Neutrophil Count ◽  
Neutrophil Count ◽  
Red Blood Cell ◽  
Antithymocyte Globulin ◽  
Blood Cell Count

Abstract We report the first case of refractory idiopathic aplastic anemia who responded to Rituximab (anti-CD 20 monoclonal antibody). The patient is a 22 year old Hispanic male construction worker who presented with a two week history of weakness, dyspnea on exertion and gum bleeding was found to have a platelet count of 11 × 109/L, hemoglobin of 7.4 g/dL, and white blood cell count of 1.6 × 109/L with 30% neutrophils. A bone marrow biopsy showed hypocellular marrow with relative lymphocytosis of mixed B and T cells and a normal chromosome analysis. A paroxysmal nocturnal hemoglobinuria (PNH) panel was negative. Serological studies did not show any evidence of HBV, HCV, CMV or EBV infection, but did show previous infection with parvo B19. He was initially treated with horse antithymocyte globulin (ATG) at a dose of 40 mg/kg for four days and cyclosporine. After ten weeks of treatment he was still requiring weekly packed red blood cell and platelet transfusions and G-CSF support. At that time he was treated with rabbit antithymocyte globulin and cyclosporine was continued. He had a partial recovery with absolute neutrophil count remaining mostly above 1 × 109/L, but he was still requiring red blood cell and platelet transfusions with baseline hemoglobin of 6 gm/dL and platelet count of less than 20 × 109/L. A bone marrow biopsy done ten weeks after the rabbit ATG treatment showed hypocellular marrow (20% cellularity) with trilineage hematopoiesis, with no evidence of dysplasia. Due to his transfusion dependence after eight months from his rabbit ATG treatment, he received Rituximab at a dose of 375 mg/m2 weekly for four weeks. He had a dramatic improvement of hemoglobin to 11.5 gm/dL and white blood cell count to 3.5 × 109/L, with an absolute neutrophil count of 2 × 109/L, although his platelet count remained at 20 × 109/L. He remains transfusion independent for a follow-up period of 8 months after the Rituximab treatment. Review of literature showed partial to good responses with Rituximab in aplastic anemia patient who refused treatment with ATG and cyclosporine (Hansen PB et al), aplastic anemia associated with CLL (Bharwani L et al), severe aplastic anemia induced by fludarabine and cyclophosphamide in a patient with B-CLL (Castiglioni MG et al) and, refractory Diamond-Blackfan anemia (Morimoto A et al).

Poor Potential of Proliferation and Differentiation in Bone Marrow Mesenchymal Stem Cells Derived From Children with Severe Aplastic Anemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 5081-5081
Author(s):  
Ching-Tien Peng
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Aplastic Anemia ◽  
Severe Aplastic Anemia ◽  
Population Doubling ◽  
Bone Marrow Mscs ◽  
Proliferative Capacity ◽  
Differentiation Potential ◽  
Proliferation And Differentiation

Abstract 5081 Introduction Idiopathic severe aplastic anemia (SAA), characterized by failure of hematopoiesis, is rare and potentially life-threatening to children. However, the pathogenesis has not been completely understood, and insufficiency in the hematopoietic microenvironment can be an important factor. Mesenchymal stem cells (MSCs) play an important role in maintaining bone marrow microenvironment. Therefore, we aimed at the intrinsic defects of bone marrow MSCs derived from SAA children. Materials and Methods Bone marrow MSCs were obtained from 5 SAA children and 5 controls. The morphology, immunophenotyping, proliferative capacity and differentiation potential of MSCs from SAA children were determined and compared with those of MSCs from controls. Results In vitro, MSCs of SAA and control group shared a similar spindle-shaped morphology. Both revealed a consistent immunophenotypic profile which was negative for CD45, CD14 and CD34, and positive for CD105, CD73, and CD44. However, SAA MSCs had slower expansion rate and smaller cumulative population doubling from passage 4 to 6 (1.83± 1.21 vs 3.36± 0.87; p = 0.046), indicating lower proliferative capacity. Besides, only 3 of 5 cultures of SAA group retained the ability to continue expansion till 80%-90% confluent cell layer beyond passage 6, suggesting earlier senescence of SAA MSCs. After osteogenic induction, SAA MSCs showed lower alkaline phosphatase activity (1.46± 0.04 vs 2.27± 0.32; p = 0.013), less intense von Kossa staining and lower gene expression of core binding factora1 (0.0015± 0.0005 vs 0.0056± 0.0017; p = 0.013). Following adipogenic induction, SAA MSCs showed less intense Oil red O staining (0.86± 0.22 vs 1.73± 0.42; p = 0.013) and lower lipoproteinlipase expression (0.0105± 0.0074 vs 0.0527± 0.0254; p = 0.013).The results of real time-PCR analysis for the assessment of lineage-specific genes were consistent with the findings of histochemical stains, and both indicated that SAA MSCs had poor osteogenic and adipogenic potential. Conclusions In this study, we demonstrated that bone marrow MSCs from children with SAA had poor potential of proliferation and differentiation. These alterations in MSCs may contribute to the failure of hematopoiesis, and lead to the development of the disease. Further studies are needed to elucidate the relationship between MSCs and SAA. Disclosures No relevant conflicts of interest to declare.

Stathmin 1 Is Involved In The Highly Proliferative Phenotype Of High-Risk Myelodysplastic Syndromes and Acute Leukemia Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 861-861
Author(s):  
João Agostinho Machado-Neto ◽  
Paula de Melo Campos ◽  
Patricia Favaro ◽  
Mariana Lazarini ◽  
Irene Lorand-Metze ◽  
...  
Keyword(s):  
Bone Marrow ◽  
High Risk ◽  
Bone Marrow Cells ◽  
Hematopoietic Cells ◽  
Leukemia Cell ◽  
Low Risk ◽  
Leukemia Cells ◽  
Healthy Donors ◽  
Stathmin 1 ◽  
Marrow Cells

Abstract Introduction : Stathmin 1, also known as Oncoprotein 18 (OP18) or Leukemia-associated phosphoprotein p18 (LAP18), is an important cytoplasmic microtubule-destabilizing protein that plays a critical role in the process of mitosis, proliferation and accurate chromosome segregation through regulation of microtubule dynamics. High levels of Stathmin 1 have been reported in solid tumors and have been associated with poor prognosis in various types of cancers. The identification of overactive proteins in leukemia cells, compared to normal hematopoietic cells, as well as understanding the molecular and cellular basis of the disease may provide new therapeutic opportunities. Aims: To evaluate Stathmin 1 expression in proliferating and non-proliferating hematopoietic cells, in bone marrow cells from healthy donors and from patients with myelodysplastic syndromes (MDS), acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL). In addition, we evaluated the effect of Stathmin 1 silencing on proliferation and apoptosis in the U937 acute myeloid leukemia cell line. Materials and Methods: A panel of human leukemia cell lines that included myeloid (K562, KU812, NB4, HL60, P39, HEL, U937, KG1 and THP1) and lymphoid cells (Jurkat, MOLT4, Daudi, Raji, Namalwa and Karpas 422) in exponential growth was used. Peripheral blood lymphocytes (PBL) were induced, or not, to proliferate upon PHA stimulation for 72 hours. A total of 30 healthy donors and 117 patients at diagnosis (MDS=52 [low-risk=36, high-risk=16], AML=49, and ALL=16) were included in the study. Stathmin 1 gene and protein expression was evaluated by qPCR and Western blot. Stathmin 1 was stably knocked down with specific shRNA-expressing lentiviral vector and cell growth was examined by MTT assay, clonogenicity by colony formation and apoptosis by AnnexinV/PI. Appropriate statistical analyses were performed; results are expressed as median (minimum- maximum). Results: A higher expression of Stathmin 1 was observed in all leukemia cell lines, when compared with normal non-proliferating hematopoietic cells. We also observed a marked increase in Stathmin 1 expression in PBL induced to proliferate with PHA after 72 hours. Stathmin 1 transcripts were significantly increased in total bone marrow cells from patients with AML (2.01 [0.35-8.88]; p=.0009) and ALL (2.94 [1.16-10.82]; p=.0004), compared with healthy donors (1.01 [0.38-4.08]). No difference in Stathmin 1 expression was observed between healthy donors and MDS patients. When the MDS group was stratified by the WHO classification into low and high-risk MDS, Stathmin 1 expression was significantly higher in the high-risk, when compared with low-risk MDS (1.62 [0.42–3.28] vs. 1.13 [0.36–2.61], p=.03). Similar results were found in isolated CD34+ bone marrow cells, Stathmin 1 transcripts were significantly increased in CD34+ AML cells compared with CD34+ normal cells, and in high-risk compared with low-risk MDS (all p≤.02). Interestingly, 3 out of 5 MDS patients showed a significant increase in Stathmin 1 transcripts after disease progression. Also, a significant positive correlation was observed between percentage of bone marrow blasts and Stathmin 1 expression in MDS patients (p=.03; r=.31). In U937 leukemia cells, Stathmin 1 silencing significantly reduced cell proliferation (p=.02) and clonal growth (p<.0001), but did not modulate apoptosis. Conclusions: Stathmin 1 is overexpressed in high-risk MDS and acute leukemia cells, and is upregulated during MDS progression, suggesting that Stathmin 1 plays a role in the highly proliferative phenotype. Our study adds new insights to the role of Stathmin 1 in leukemogenesis. Future studies are necessary to validate whether Stathmin 1 is a predictive marker for MDS progression, and to determinate whether Stathmin 1 is a “driver” or a “passenger” during malignant transformation. Disclosures: No relevant conflicts of interest to declare.

Partial Tandem Duplications of the MLL Gene Are Detectable in Peripheral Blood and Bone Marrow of Nearly All Healthy Donors

Blood ◽  
1998 ◽  
Vol 92 (5) ◽  
pp. 1728-1734 ◽  
Author(s):  
Susanne Schnittger ◽  
Bernhard Wörmann ◽  
Wolfgang Hiddemann ◽  
Frank Griesinger
Keyword(s):  
Bone Marrow ◽  
Peripheral Blood ◽  
Hematopoietic Cells ◽  
Chromosome 11 ◽  
Rt Pcr ◽  
Blood Samples ◽  
Mll Gene ◽  
Oncogenic Mutations ◽  
Healthy Donors ◽  
American Society

Partial tandem duplication within the MLL gene has recently been described as a novel genetic alteration in acute myeloid leukemia (AML). It has been associated with trisomy of chromosome 11, but was also identified in AML patients with normal karyotypes. The current study was performed to investigate whether MLL duplications are restricted to AML, and hence whether they may also occur in normal hematopoietic cells. MLL-duplication transcripts were analyzed by nested reverse-transcriptase polymerase chain reaction (RT-PCR) in peripheral blood in two groups of 45 and 20 patients, respectively, as well as in two bone marrow samples from healthy volunteers. Duplications were detected in two independent nested RT-PCR experiments in the peripheral blood samples of 38 of 45 (84%) and 20 of 20 (100%) of the two groups and in both bone marrow samples. On this basis, MLL duplications seem to occur frequently in a subset of cells in normal hematopoiesis. The type of partially duplicated MLL transcripts varied substantially. Three transcripts were identical to those known from AML. In addition, four new transcripts were characterized. Three of these four were in frame and potentially translatable. MLL duplications were also detected by seminested genomic PCR with intron 9– and intron 1–specific primers in 20 of 20 peripheral blood samples studied, indicating that the duplications are genomically fixed at the DNA level and are not an RT-PCR artifact. In summary, MLL duplications are regularly generated by homologous ALU recombination in a small number of hematopoietic cells of most or even all healthy donors. These data suggest that MLL duplications are not implicated in the malignant transformation in AML, or alternatively, that only a few cells will acquire additional oncogenic mutations necessary to establish the malignant phenotype of AML. © 1998 by The American Society of Hematology.

Recombinant humanized anti-IL-2 receptor antibody (daclizumab) produces responses in patients with moderate aplastic anemia

Blood ◽  
2003 ◽  
Vol 102 (10) ◽  
pp. 3584-3586 ◽  
Author(s):  
Jaroslaw P. Maciejewski ◽  
Elaine M. Sloand ◽  
Olga Nunez ◽  
Carol Boss ◽  
Neal S. Young
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
Aplastic Anemia ◽  
Neutrophil Count ◽  
Bone Marrow Failure ◽  
Interleukin 2 ◽  
Immunosuppressive Agent ◽  
Solid Organ ◽  
Bone Marrow Failure Syndrome ◽  
Humanized Monoclonal Antibody

AbstractIn contrast to severe aplastic anemia (sAA), the appropriate management of patients with moderate pancytopenia is unclear. In this study, we examined the efficacy of a humanized monoclonal antibody recognizing interleukin-2 receptor (daclizumab), which has proven to be a successful immunosuppressive agent in solid organ and bone marrow transplantation. We treated 17 patients with moderate aplastic anemia (mAA) with 1 mg/kg every 2 weeks for 3 months. mAA was defined as depression of 2 of the 3 blood counts: absolute neutrophil count 1200/mm3 or less, platelet count 70 000/mm3 or less, hemoglobin level 8.5 g/dL or lower, and absolute reticulocyte count 60 000/mm3 or less. The primary end point of our protocol was a hematologic response in at least one affected peripheral blood value. Daclizumab had little toxicity. Six of the 16 (38%) evaluable patients responded to treatment. Two patients with previously chronic disease showed complete return of normal counts, which were sustained for more than 2 years following treatment. Four patients had single-lineage responses. Two previously transfusion-dependent patients became transfusion independent; one patient with many neutropenia-related infections had a normal neutrophil count following treatment. Daclizumab appears safe; its efficacy in this pilot protocol suggests that expanded study of this monoclonal antibody in immune-mediated bone marrow failure syndrome is warranted. (Blood. 2003; 102:3584-3586)

scholarly journals Human extramedullary bone marrow in mice: a novel in vivo model of genetically controlled hematopoietic microenvironment

Blood ◽  
2012 ◽  
Vol 119 (21) ◽  
pp. 4971-4980 ◽  
Author(s):  
Ye Chen ◽  
Rodrigo Jacamo ◽  
Yue-xi Shi ◽  
Rui-yu Wang ◽  
Venkata Lokesh Battula ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Critical Role ◽  
Hematopoietic Cells ◽  
Leukemic Cells ◽  
In Vivo Model ◽  
Hematopoietic Microenvironment ◽  
Cell Engraftment

Abstract The interactions between hematopoietic cells and the bone marrow (BM) microenvironment play a critical role in normal and malignant hematopoiesis and drug resistance. These interactions within the BM niche are unique and could be important for developing new therapies. Here, we describe the development of extramedullary bone and bone marrow using human mesenchymal stromal cells and endothelial colony-forming cells implanted subcutaneously into immunodeficient mice. We demonstrate the engraftment of human normal and leukemic cells engraft into the human extramedullary bone marrow. When normal hematopoietic cells are engrafted into the model, only discrete areas of the BM are hypoxic, whereas leukemia engraftment results in widespread severe hypoxia, just as recently reported by us in human leukemias. Importantly, the hematopoietic cell engraftment could be altered by genetical manipulation of the bone marrow microenvironment: Extramedullary bone marrow in which hypoxia-inducible factor 1α was knocked down in mesenchymal stromal cells by lentiviral transfer of short hairpin RNA showed significant reduction (50% ± 6%; P = .0006) in human leukemic cell engraftment. These results highlight the potential of a novel in vivo model of human BM microenvironment that can be genetically modified. The model could be useful for the study of leukemia biology and for the development of novel therapeutic modalities aimed at modifying the hematopoietic microenvironment.

scholarly journals Oligoclonal Expansion and T-Cells Subpopulations in Patients with Aplastic Anemia at Different Stages of the Disease

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3864-3864
Author(s):  
Anastasia V. Abramova ◽  
Elena A. Mikhaylova ◽  
Zalina T. Fidarova ◽  
Yuliya O. Davydova ◽  
Nikolay M. Kapranov ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Aplastic Anemia ◽  
Memory T Cells ◽  
Clonal Expansion ◽  
Th Cells ◽  
Healthy Donors ◽  
Oligoclonal Expansion

Abstract Background. The main mechanism of the bone marrow (BM) failure in idiopathic aplastic anemia (AA) has an immunomediated character. Researching the T-cell clone's effect in the AA pathogenesis is very relevant at the present time. Oligoclonal expansion of T cells is frequent in AA and the identification of immunodominant T-cell clones can correlate with the disease activity and may possibly serve as response predictor to immunosuppressive therapy (IST). The aim. To identify T-cells subpopulations, expression of PD-1 and PD-L1 on T-cells and TCR-Vβ repertoires by flow cytometry in different groups of AA patients. Methods. Thirty AA patients (pts) with median age of 30.5 (19-71), m/f ratio 1:1,3 were divided in 3 groups: pts with newly diagnosed (ND) AA (n=13), pts with overall response to IST (OR) (n=10), non-response pts (NR) for 2 and more lines of IST (n=7). Flow cytometry was performed with BD FACS Canto II. We used commercial kit (IOTest® Beta Mark TCR Vb Repertoire) for evaluation of TCR-Vβ repertoire in the bone marrow (BM) of these patients. We performed analysis of BM samples from healthy donors as a control group (n=8). Due to low amount of donor samples the maximal value each of the 24 subclones (for CD4+ (T-helpers - Th) and CD8+ cells (T-cytotoxic cells - TCL)) was accepted as threshold. We concluded the presence of clonal expansion if TCR subclone exceeded this threshold. We identified different T-cell subpopulations in all 3 groups of AA and healthy donors by flow cytometry: double positive T-cells (CD3+CD4+CD8+), double negative T-cells (CD3+CD4- CD8-), Th (CD3+CD4+), TCL (CD3+CD8+), NK-T-cells (CD3+CD56+) out of CD3+ cells. Among Th and TCL cells was determined naive T-cells (CD28+CD95-), effector T-cells (CD28-CD95+), memory T-cells (CD28+CD95+), regulatory T-cells (CD4+CD127-CD25high) and subpopulations Th and TCL co-expressed PD-1 and PD-L1. Multiple comparisons were assessed by ANOVA or Kruskal Wallis test by GraphPad Prism software. Results. In our study all 30 AA patients had an immunodominant TCR-Vβ clones among Th and/or TCL cells. We identified the most common clonotypes in comparison with healthy donors - Vβ1, Vβ2, Vβ3 among the Th cells and Vβ3, Vβ9, Vβ13.1 among the TCL cells. In ND group Vβ1 was highly expanded in 5 (38.5%), Vβ3 - in 7 (53.8%) pts among Th, and Vβ3 - in 3 (23.1%) and Vβ9 - in 4 (30.8%) out of 13 pts among TCL. In OR group Vβ2 expansion was in 4 (40%) and Vβ3 - in 5 (50%) pts among Th; Vβ3 in 6 (60%) and Vβ9 in 6 (60%) out of 10 pts among TCL. In NR group the most frequent was Vβ13.1 clone in TCL - in 3 (42.9%) out of 7 pts. In NR group in overall clonal expansion was less frequent than in ND and OR groups. We also analyzed the previously mentioned subpopulations of T-cells in patients with AA in three groups (ND, OR, NR) compared to healthy donors (table 1). We obtained significant differences in the count of naive Th and TCL cells, memory T-cells in all three groups of AA patients compared to donors: proportion of naive Th and TCL cells was significantly higher and proportion of memory Th cells was lower in the donor group than in AA pts. The percent of TCL effectors was higher in ND AA pts compare to donors. We also found that cell count of activated Th (CD4+CD25+) was higher in the group of refractory pts. In OR pts proportion of PD-1-positive Th was higher than in donors. In NR pts Th and TCL co-expressed with PD-L1 were lower compare to donors (table 1). Conclusions. In our study we found immunodominant clonotypes in different AA pts and depletion of the pool of naive T cells. Dynamic observation of changes in the most common clonotypes in AA pts during treatment will provide suitable therapy tactics (allogenic bone marrow transplantation or IST). Disclosures No relevant conflicts of interest to declare.

scholarly journals Identification of a Hematopoietic Cell Population Emerging From Mouse Bone Marrow With Proliferative Potential In Vitro and Immunomodulatory Capacity

2021 ◽  
Vol 12 ◽  
Author(s):  
Catalina-Iolanda Marinescu ◽  
Mihai Bogdan Preda ◽  
Carmen Alexandra Neculachi ◽  
Evelyn Gabriela Rusu ◽  
Sinziana Popescu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stromal Cells ◽  
Hematopoietic Cells ◽  
Tumor Rejection ◽  
Proliferative Potential ◽  
Mouse Bone Marrow ◽  
Positive Outcomes ◽  
Immunomodulatory Properties

There is continuing interest in therapeutic applications of bone marrow-derived mesenchymal stromal cells (MSC). Unlike human counterparts, mouse MSC are difficult to propagate in vitro due to their contamination with adherent hematopoietic cells that overgrow the cultures. Here we investigated the properties of these contaminating cells, referred to as bone marrow-derived proliferating hematopoietic cells (BM-PHC). The results showed that both BM-PHC and MSC had strong immunomodulatory properties on T cells in vitro, with PGE2 and NO involved in this mechanism. However, BM-PHC were stronger immunomodulators than MSC, with CCL-6 identified as putative molecule responsible for superior effects. In vivo studies showed that, in contrast to BM-PHC, MSC endorsed a more rapid xenograft tumor rejection, thus indicating a particular context in which only MSC therapy would produce positive outcomes. In conclusion, bone marrow contains two cell populations with immunomodulatory properties, which are valuable sources for therapeutic studies in specific disease-relevant contexts.

scholarly journals Endogenous TGF-beta1 Mediated Osteogenic Impairment of Medullar Mesenchymal Stromal Cells in Primary Myelofibrosis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1873-1873
Author(s):  
Christophe Martinaud ◽  
Christophe Desterke ◽  
Johanna Konopacki ◽  
Lisa Pieri ◽  
Rachel Golub ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasm ◽  
Hematopoietic Cells ◽  
Primary Myelofibrosis ◽  
Osteogenic Potential ◽  
Healthy Donors

Abstract Primary myelofibrosis (PMF) is myeloproliferative neoplasm characterized by clonal myeloproliferation, dysmegakaryopoiesis, extramedullary hematopoiesis associated with myelofibrosis and altered stroma in bone marrow and spleen. Mesenchymal stromal cells (MSCs) are reported to play a pivotal role in fibrosis and stromal changes are considered as a reactive counterpart of the cytokine production by clonal hematopoietic cells. The present study shows that MSCs from patients demonstrate functional abnormalities that are unexpectedly maintained ex-vivo, in culture. Material and Methods: we studied MSCs and bone marrow sections from PMF patients (n=12) as compared to healthy donors (HDs) (n=6). We tested their proliferation, immunophenotype, hematopoiesis supporting capacities, differentiation abilities, in-vivo osteogenic assays, and performed secretome and transcriptome analysis. Results: We found that PMF-MSCs exhibit similar proliferative capacity and long-term hematopoiesis supporting abilities as compare to healthy donors. They overproduce interleukin 6, VEGF, RANTES, PDGF, BMP-2 and surprisingly TGF-beta1. MSCs from fibrotic PMF patients express high levels of glycosaminoglycans. Adipocytes and chondrocytes differentiation abilities were not different as compared to HDs but PMF-MSCs exhibit an increased in vitro potential. Implementation on scaffold in nude mice confirmed, in vivo, this increased osteogenic potential. We then looked into gene expression and discovered that PMF-MSCs show an original transcriptome signature related to osteogenic lineage and TGF-beta1. Indeed, osteogenic genes such as Runx2, Dlx5, Twist1, Noggin, Sclerostin, GDF5 and Serpine1 are deregulated and suggest a potential osteoprogenitor priming of PMF-MSCs. These molecular results also advocated for a TGF-beta1 impregnation that prompted us to study its impact on PMF-MSCs osteogenic differentiation. First, we then showed that Smad2 is intrinsically over-activated in PMF-MSC and that stimulation by TGF-beta1 is associated with an increase phospho-Smad2 level and an enhancement of bone master gene regulator Runx2 expression. Then, we inhibited TGF-beta1 pathway by by SB-431542 and evidenced a specific behavior of osteogenic MSCs differentiation in patients, suggesting involvement of TGF-beta1 in osteogenic impairment. Conclusion: Altogether, our results identify a signature of PMF-MSCs and suggest that they participate in PMF osteogenic dysregulation independently from in vivo local stimulation by clonal hematopoietic cells Disclosures No relevant conflicts of interest to declare.

scholarly journals A Study of Prednisone Therapy in Chronic Lymphocytic Leukemia

Blood ◽  
1961 ◽  
Vol 17 (2) ◽  
pp. 182-195 ◽  
Author(s):  
RICHARD K. SHAW ◽  
DANE R. BOGGS ◽  
HAROLD R. SILBERMAN ◽  
EMIL FREI
Keyword(s):  
Bone Marrow ◽  
Chronic Lymphocytic Leukemia ◽  
Absolute Neutrophil Count ◽  
Neutrophil Count ◽  
Advanced Disease ◽  
Bone Marrow Failure ◽  
Lymphocytic Leukemia ◽  
Subjective Improvement ◽  
Prednisone Therapy ◽  
Circulating Lymphocytes

Abstract A study of prednisone therapy in 18 patients with chronic lymphocytic leukemia is reported. 1. Antileukemic effects consisting of subjective improvement, decrease in organ infiltration, improvement in hemoglobulin and absolute neutrophil count occurred. 2. These effects were transient. 3. An increase, often marked, in the number of circulating lymphocytes occurred in 16 of the 18 patients. 4. The administration of prednisone was attended by an increase in the severity of infections. Some increase in the frequency of infections was also observed, but this was not statistically significant (p > 0.05). It is concluded that corticosteroids should not be used electively in patients with chronic lymphocytic leukemia except in the presence of hemolytic anemia, significant thrombocytopenia or in the presence of advanced disease associated with bone marrow failure.

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