Successful Treatment of HU-Refractory Polycythemia Vera with Atorvastatin and Low Dose Hydroxyurea. Results from a Pilot Study in Bolivia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5621-5621
Author(s):  
Ricardo Amaru ◽  
Ariel Amaru ◽  
Hortensia Miguez ◽  
Gina Torres ◽  
Josue Mamani ◽  
...  
Keyword(s):  
Pilot Study ◽  
High Risk ◽  
Polycythemia Vera ◽  
Mononuclear Cells ◽  
Jak2v617f Mutation ◽  
World Health ◽  
La Paz ◽  
Healthy Donors

Abstract Background Polycythemia Vera (PV) is a clonal myeloproliferative neoplasm, characterized by the JAK2V617F mutation. The main goal of current therapies for PV is to prevent thrombotic events and delay transformation to Myelofibrosis (MF) or Acute Myeloid Leukemia (AML).Treatment for PV to keep an hematocrit (Hct) level <45 %, has been associated with a reduction in cardiovascular deaths and thrombotic events (Marchioli, R et al. NEJM 2013). Currently, low-risk PV patients (<60 years and no previous thrombotic events) are treated with aspirin and phlebotomy while high-risk patients require additional cytoreductive therapy, usually with Hydroxyurea (HU). Resistance to HU is associated with an increased risk of transformation and reduced survival. This is why for HU-refractory patients, second line treatments with interferon alpha, anagrelide or even ruxolitinib are recommended. In Latin America, because of high cost and drugs availability, this last group reflects difficulties to be treated. Because statins have been reported to modulate the erythroid clonogenic activity of normal BM erythroid colonies we performed a pilot study to investigate in vitro and in vivo the biologic and clinical activity of atorvastatin in PV patients Patients and Methods Ten high risk PV patients with a median age of 64.3 years (range 58-73) entered into this study. The diagnosis of PV was done according to the 2008 World Health Organization diagnostic criteria and patients were stratified according to an algorithm proposal provided by Griesshammer et al. (Ann Hematol, 2015). The definition of HU resistance (Barosi, G et al.: BJH 2009) was applicable to five patients (median age 63.9 years) failing to achieve a satisfactory hematologic response upon treatment with more than 2 g of HU, 100 mg of Aspirin and phlebotomies. The assessment of the JAK2V617F mutation was performed as previously described (Guerini et al.: Leukemia 2009). Colony assay, proliferation and apoptosis tests were performed with or without Simvastatin (3.5 uM), as previously described (Amaru, A, Experimental Hematology 2012), on cell lines (UKE1 and K562) and bone marrow mononuclear cells obtained from PV patients and healthy donors. Patients with HU refractory PV (n=5) and high risk PV with hypercholesterolemia (n=5) were eligible to receive Atorvastatin (20 mg/day) added on the top of the ongoing treatment with phlebotomies, Aspirin (100 mg/day) and cytoreductive HU therapy (500 mg/day). All treated patients were high altitude residents (> 3.600 m.a.s.l.) of La Paz (Bolivia) where the normal Hct level of healthy subjects is 48-57% for men and 44-54% for women. This pilot study was approved by the Review Board of the Hospital and the University of San Andres, La Paz. Results In a preliminary set of in vitro proliferation cell assays, simvastatin (3.5 uM), added for 5 days, induced a 33% inhibition of cell proliferation of UKE-1 (JAK2V617F mutated) as compared to 5 % of K562 (BCR/ABL positive). A comparable result was obtained in a 7-day clonogenic cell assay where the colony inhibition was 50 % for UKE-1 and 10 % for K562. On the basis of these results similar experiments were also performed using BM mononuclear cells derived from PV patients and healthy donors. In these experiments performed with the addition of simvastatin, it induced a 41% of inhibition in BFU-E colonies of PV patients and a 25% of inhibition in healthy donors. Furthermore, BFU-E colonies inhibited by simvastatin presented a decrease in hemoglobinization and the size of colonies. HU refractory PV patients and High-risk PV patients with hypercholesterolemia treated with the addition of Atorvastatin, Aspirin, cytoreductive HU and phlebotomies; after a follow-up of 2.6 years (1-7 years), induced a decrease of WBC from 16.500 to 9.270/ul, Hct 61.1 to 52.3% and PLT 457.900,000 to 324.7000/ul. The number of required phlebotomies is reduced in comparison to the required at starting treatment. None of the patients presented thrombotic or cardiopulmonary event. One patient died within two years of starting treatment, due to complications of diabetes mellitus. Conclusions In vitro and in vivo, statins showed some evidence of inhibitory activity of the hematopoiesis of PV patients. These preliminary results might indicate the opportunity to further investigate the potential clinical value of these molecules in the treatment of PV. Disclosures Off Label Use: Atorvastatin was used for its antiproliferative activity on myeloid progenitor cells shown by in vitro experiments.

Erythropoiesis in Polycythemia Vera Is Hyper-Proliferative and Has Accelerated Differentiation during In Vitro Erythroid Expansion and Is Associated with Higher Expressions of cMYB and EPOR at Early Erythroid Progenitors

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1549-1549
Author(s):  
Hana Bruchova ◽  
Donghoon Yoon ◽  
Archana Agarwal ◽  
Eva Otahalova ◽  
Hyojin Kim ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Mononuclear Cells ◽  
Early Stage ◽  
Severe Disease ◽  
Erythroid Differentiation ◽  
Erythroid Progenitors ◽  
Peripheral Blood Mononuclear ◽  
Healthy Donors ◽  
Differentiation Stage

Abstract Erythroid differentiation is a dynamic process leading to the production of mature red blood cells. Even small variations in this process may result in severe disease phenotype. To study this process, we used a three-phase erythroid expansion system to expand homogeneous erythroid progenitors (EPs) from peripheral blood mononuclear cells (PB-MNCs) (Bruchova H. et al, 2007, Exp. Hematology, in press). We then characterized the expanded EPs from polycythemia vera (PV) patients and healthy donors at various points of maturation comparing cell proliferation and differentiation stage. EPs from PV patients outgrew controls up to day 14 (∼12 fold for PV and ∼4 fold for control compared to day 1). Differentiation was analyzed using both FACS analysis (with CD71/CD235a staining) and morphological evaluation (Wright-Giemsa staining), and demonstrated a more rapid differentiation of PV EPs when compared to controls up to day 14. We then evaluated apoptosis/cell cycle analysis by propidium iodide staining. Although PV EPs contained larger S phase population (45%) than controls (34%) at day 11, the apoptosis proportion of PV EPs was increased ∼2 fold to control from day 14. To understand the molecular mechanism of these differences between PV and controls, we analyzed the gene expression of several known regulators in erythropoiesis - BCL2, EPOR, cMYB, p27. Two transcripts (EPOR and cMYB) showed unique profiles on PV EPs. The EPOR transcript increased earlier in PV; i.e. from day 7 until day 21 and reached a plateau at day 11, compared to day 9 until day 19 and plateau at day 14 in controls. In addition, PV EPs contained higher levels of EPOR transcripts than control on most of timepoints. Interestingly, cMYB, which is known to augment early progenitor proliferation, was highly expressed from day 7 in PV, through day 11. Control EPs also expressed cMYB from day 9 through day 11; however, cMYB levels from any stages of control EPs were markedly lower than PV EPs at day 7. In this study, we demonstrate that PV erythropoiesis has unique features of hyperproliferation and an accelerated differentiation. These features are associated with earlier and higher expressions of cMYB and EPOR at the early stage of erythropoiesis.

Pilot study of a comprehensive precision medicine platform for children with high-risk cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10539-10539 ◽  
Author(s):  
Loretta Lau ◽  
Jennifer Byrne ◽  
Paul G Ekert ◽  
Tim Failes ◽  
Andrew Fellowes ◽  
...  
Keyword(s):  
Pilot Study ◽  
High Risk ◽  
Precision Medicine ◽  
Drug Testing ◽  
National Level ◽  
Genomic Analysis ◽  
Treatment Recommendations ◽  
Childhood Cancers

10539 Background: Genomic analyses can identify actionable mutations in a subset of childhood cancers. However it has been challenging to translate actionable mutations into substantial benefits for adult cancers despite high mutation frequency. Methods: To test whether we could enhance identification of personalised therapies for high risk (HR) childhood cancers we conducted a pilot study (TARGET) evaluating a novel, comprehensive precision medicine platform incorporating molecular profiling, in vitro and in vivo drug testing. Results: We evaluated the first 29 patients with HR cancer (expected survival < 30%) enrolled prospectively over 15 months. Samples were collected from 15 CNS tumors, 10 solid tumors and 4 leukemias. All samples underwent targeted DNA sequencing. Pathogenic or likely pathogenic mutations were found in 59% (17/29) of tumors. 41% (12/29) had potentially actionable mutations. RNA-sequencing was performed on 27 samples. Previously described fusions were identified in 19% (5/27; 1 targetable, 1 clinical relevant and 3 diagnostic fusions). 37% (10/27) of samples also had actionable aberrations related to copy number changes or RNA expression. In vitro culture and establishment of patient-derived xenograft (PDX) were attempted in 19 and 21 fresh samples, respectively. The success rate of establishing a primary culture was 42% (8/19) and PDX engraftment rate was 67% (14/21). At least 1 drug hit was identified in 5 (56%) of the 9 samples screened using a high throughput drug screen of up to 165 compounds. Drug testing has been completed in 4 PDXs and was informative in all 4 cases allowing prioritisation of treatment recommendations. Genomic analysis in combination with RNA-seq, in vitro drug screening and PDX drug testing enriched the analysis and increased the ability to make personalised treatment recommendations from 41% (targeted panel alone) to 66%. Conclusions: This pilot study demonstrates that this novel, comprehensive platform is feasible and has the potential to improve outcome for HR childhood cancers. A multicentre study testing the implementation of the platform on a national level (PRISM trial) will open for Australian children with HR cancer under the Zero Childhood Cancer Program in 2017.

Pure Heterozygous and Mixed JAK2 V617F Genotypes Result in Distinct Mechanisms of Erythrocytosis in Polycythemia Vera.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 662-662
Author(s):  
Sabrina Dupont ◽  
Aline Masse ◽  
Chloe James ◽  
Nicole Casadevall ◽  
William Vainchenker ◽  
...  
Keyword(s):  
Polycythemia Vera ◽  
Progenitor Cells ◽  
Mononuclear Cells ◽  
Fold Increase ◽  
Jak2 V617f ◽  
Molecular Event ◽  
Erythroid Progenitors ◽  
Low Frequencies

Abstract The JAK2 V617F mutation is present in most patients with polycythemia vera (PV) and half with essential thrombocythemia (ET). Using real-time quantitative PCR, we analyzed the levels of JAK2 V617F in granulocytes and/or bone marrow mononuclear cells from 159 PV and 149 ET patients. High JAK2 V617F levels were correlated with higher leukocyte, granulocyte, hemoglobin values and higher endogenous erythroid colony formation. Thus, the phenotype of PV and ET may be closely linked to the JAK2 V617F level, which may reflect the clonal genotypic pattern of hematopoietic progenitor cells. It is thought that the occurrence of the mitotic recombination, which generates homozygous JAK2 V671F clones, is a key molecular event for the onset of PV. In this work, we aimed to study the consequences of the clonal JAK2 V617F genotype on the amplification properties and erythropoietin (EPO) hypersensitivity of PV (n=14) and ET (n=6) progenitors. Analysis of clonal genotypic patterns shows that ET patients harbor a mix of heterozygous and normal progenitors. Interestingly, we distinguish pure heterozygous PV profiles (3/14 patients) with no homozygous progenitors from homozygous PV profiles (11/14 patients) with normal, heterozygous and homozygous progenitors. Similar low frequencies of mutated immature progenitors, comprising long-term culture-initiating cells and lympho-myeloid progenitors, are found in ET and PV. In contrast, PV patients with pure heterozygous PV profiles have striking higher proportions (&gt;90%) of mutated committed progenitors than other PV and ET patients. This result suggests a selective amplification of heterozygous cells in the early phases of hematopoiesis. Furthermore, by using increasing concentrations of EPO, homozygous mutated erythroid progenitors are demonstrated to be more sensitive to EPO than heterozygous ones, a majority of the former (69,5%) being EPO independent. Moreover, we demonstrate a two to three fold increase in in vitro amplification of ET and PV progenitor cells when compared to normal ones in serum free liquid culture containing IL3, Stem Cell Factor, Dexamethasone and 1 IU/mL EPO. In addition, the quantification of the mutated allele in immature CD34+CD38- cells, in CD34+CD38+ committed progenitor cells, in mature erythroblasts (GPA+) and in granulocytes shows a marked in vivo selective advantage of mutated cells in late stages of hematopoiesis. These results suggest that in PV, erythrocytosis results from two distinct mechanisms: a terminal erythroid amplification advantage triggered by homozygosity or a two-step process including the upstream amplification of heterozygous cells that may involve additional molecular event(s).

Chronic Lymphocytic Leukemia Cells Promote Increased BAFF Expression in Monocytes Partially through TNF-Alpha Leading to Increased CLL Cell Survival

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3154-3154
Author(s):  
Davorka Messmer ◽  
Hsu-Hsiang Chang ◽  
Thomas J. Kipps
Keyword(s):  
B Cells ◽  
Cell Survival ◽  
Mononuclear Cells ◽  
Lymphocytic Leukemia ◽  
Conditioned Media ◽  
Healthy Donors ◽  
Accessory Cells ◽  
High Level

Abstract The tumor microenvironment plays a critical role in growth, metastasis, and survival of tumors. Chronic lymphocytic leukemia (CLL) B cells of many patients can rapidly undergo apoptosis in vitro unless co-cultured with accessory cells, which elaborate factors that promote CLL-cell survival. A major type of such accessory cells is nurse-like cells (NLC), which prior studies demonstrated could differentiate from CD14+ blood mononuclear cells when exposed to CLL B cells in vitro, and presumably in vivo. In the absence of CLL cells, blood mononuclear CD14+ cells typically differentiate into macrophages that have a distinctive morphology from that of NLC. We found that, compared with macrophages, NLCs consistently expressed significantly higher levels of B-cell activating factor (BAFF) (n=11), a tumor-necrosis-factor (TNF)-related ligand that promotes survival of B cells, including CLL B cells. To investigate the influence of CLL cells on the differentiation of NLC in vitro, purified CLL B cells or B cells of healthy donors were cultured for 24h to generate conditioned media. When CD14+ blood mononuclear cells of healthy donors were cultured for 7 days in media conditioned by CLL cells, but not in non-conditioned media or in media conditioned by normal B cells, the cells assumed the morphology of NLC, acquired high-level expression of BAFF, and developed an enhanced capacity to support CLL cell survival in vitro. Similar activity was also found in the sera of CLL patients, but not in the sera of healthy control donors. The capacity of either CLL-conditioned media (n=4) or CLL-patient sera (n=9) to induce NLC differentiation leading to increased expression of BAFF was significantly reduced by a decoy receptor for TNF-a, suggesting that TNF-a contributes to the differentiation of NLC in vitro. However, TNF-a alone was not sufficient to induce high-level expression of BAFF on blood mononuclear CD14+ cells, suggesting that additional factors are involved. The results show a previously unrecognized symbiosis between CLL cells and accessory cells in their microenvironment. Because the survival of neoplastic B cells in vivo potentially depends upon NLC found in the lymphoid tissues of patients with CLL, identification of the factor(s) involved in inducing their differentiation could provide a novel target for therapy of patients with this disease.

scholarly journals Human Polyomavirus Type 1 (BK Virus) Agnoprotein Is Abundantly Expressed but Immunologically Ignored

2007 ◽  
Vol 14 (8) ◽  
pp. 959-968 ◽  
Author(s):  
David Leuenberger ◽  
Per Arne Andresen ◽  
Rainer Gosert ◽  
Simone Binggeli ◽  
Erik H. Ström ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Bk Virus ◽  
Gamma Interferon ◽  
Human Polyomavirus ◽  
Large Tumor ◽  
Peripheral Blood Mononuclear ◽  
Healthy Donors ◽  
Cellular Immune

ABSTRACT Impaired BK virus (BKV)-specific immunity is a key risk factor of polyomavirus-associated nephropathy. We hypothesized that BKV agnoprotein might constitute an important immune target, as it is highly expressed after infection in vitro. We demonstrate abundant expression of BKV agnoprotein in vivo by immunostaining of kidney transplant (KT) biopsy specimens. Antibody responses to the recombinant affinity-purified BKV agnoprotein, large tumor (LT), and VP1 antigens in 146 sera from 38 KT patients and in 19 sera from 16 healthy donors (HD) were compared by enzyme immunoassay. In HD, low titers of anti-agnoprotein immunoglobulin G (IgG) were found in 15% of sera, compared to 41% for anti-LT antigen and 63% for anti-VP1. No anti-BKV IgM was detectable. In KT patients, anti-agnoprotein IgG and IgM were found in 8% and 3.6% of sera, compared to 63% and 18% for anti-LT IgG and IgM and 80% and 41% for anti-VP1 IgG and IgM, respectively. Anti-LT antigen and anti-VP1, but not anti-agnoprotein, activities increased during and after BKV viremia in KT patients. To investigate specific cellular immune responses, we compared levels of gamma interferon production in peripheral blood mononuclear cells (PBMC) of 10 HD and 30 KT patients by enzyme-linked immunospot assay. In HD, the median numbers of gamma interferon spot-forming units per million PBMC for the agnoprotein, LT antigen, and VP1 peptides were 1, 23, and 25, respectively, whereas the responses in KT patients were 2, 24, and 99, respectively. We conclude that BKV agnoprotein, though abundantly expressed in vivo, is poorly recognized immunologically.

Expanded Natural Killer (NK) Cells for Immunotherapy: Fresh and Made to Order

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1912-1912
Author(s):  
Susann Szmania ◽  
Natalia Lapteva ◽  
Tarun K. Garg ◽  
Joshuah D Lingo ◽  
Amy D Greenway ◽  
...  
Keyword(s):  
High Risk ◽  
Nk Cells ◽  
Mononuclear Cells ◽  
Nk Cell ◽  
Conflicts Of Interest ◽  
K562 Cells ◽  
Clinical Grade ◽  
Additional Advantage

Abstract Abstract 1912 Introduction Remarkable increases in the dose and activity of NK cells can be achieved by co-culture with the HLA class I deficient cell line K562 that has been genetically modified to express membrane-bound IL15 and the co-stimulatory molecule 41BB-ligand (K562-mb15-41BBL; Fujisaki et al. Cancer Res. 2009;69:4010–4017). We are conducting a clinical trial utilizing these ex-vivo expanded NK cells (ENK) which are produced at the Center for Cell and Gene Therapy (CAGT) at Baylor and then shipped to the University of Arkansas for Medical Sciences (UAMS) for infusion to high-risk relapsed multiple myeloma (MM) patients using the NHLBI-PACT mechanism. Here we report on the characteristics of the ENK cell products sent fresh versus frozen. Methods Apheresis products were collected from MM patients or healthy donors (HD), cryopreserved, and then shipped to CAGT for GMP grade production, as described (Lapteva et al. Cytotherapy 2012; in press). Briefly, mononuclear cells from thawed and ficolled apheresis products were cultured in Stem Cell Growth Medium (CellGenix) supplemented with 10% fetal bovine serum and 10 U/mL IL2 with stimulator cells at a ratio of 1 NK cell to 10 irradiated K562-mb15-41BBL cells (developed at St. Jude Children's Research Hospital, Memphis, TN). Cells were harvested on day 8–9; products from HD were CD3-depleted. Clinical-grade products were shipped to UAMS overnight either cryopreserved in a dry shipper (n=7) or fresh in 5% human serum albumin on cold packs at 1–11°C (n=4). Cell purity, expression of activating molecules, and viability by 7AAD exclusion was assessed by flow cytometry. Standard 4h chromium-release assays were used to assess potency against K562 cells at a 20:1 ENK: K562 ratio. Student's t-Test was used to determine significance. Results From 0.9–1.5×107 starting NK cells, the total number of ENK cells produced was 5.4×109 (range 1.8–24×109). The fold NK-cell expansion was significantly lower for MM patients (n=5, median 22, 12–70 fold) than for HD (n=6, median 95, 31–160 fold; p<0.05). At harvest, median CD3+/CD56+ NK cell purity was 70% (52–88); CD3 depletion of HD products increased CD3+/CD56+ purity to 93% (86–95) resulting in a median CD3+/CD56- T cell content of 0.02% (0.04–1.02). Overall, median viability was 93% (67–98) and potency (defined as lysis of K562 cells at a 20:1 E:T ratio) was 74% (26–92). One product derived from a patient with 21% CD138+ MM cells in the apheresis collection had low expansion (12-fold), viability (66.7%) and potency (26%). For cryopreserved products, viability immediately after thawing was acceptable (median 94%, 75–99) but recovery of viable cells varied from 61% to 100% and thawed ENK failed to lyse K562 cells unless rested overnight. Further, recovery was extremely poor after overnight incubation (median 16%, 10–21). We therefore validated shipment of fresh ENK products. In contrast with frozen NK cells, the median recovery for fresh clinical products post-shipping was 101% (87–151). We confirmed that NK purity, viability, potency and expression of the key activating molecules NKG2D, NKp30, NKp44 and CD226 were retained up to 48h after transfer. ENK further increased by 34% after 72h in vitro incubation in the presence of IL2. Significant in vivo expansion of ENK was observed after infusion of fresh ENK cell products (n=3) but not after infusion of thawed products (n=3, see separate abstract). An additional advantage was that the fresh cells arrived ready to infuse and changes in release criteria relying on rapid and in process testing significantly reduced the time from apheresis collection to ENK infusion, an important consideration when treating high-risk MM patients who can experience rapid disease progression. Conclusion We conclude that large numbers of clinical grade ENK cells can be generated from both MM patient and HD derived apheresis products by co-culture with IL2 and K562-mb15-41BBL although less vigorous expansion was observed with patient-derived cells. Upon thawing, cryopreserved ENK cells exhibited inferior recovery and potency, and survived poorly during further in vitro culture. In contrast, freshly formulated and shipped ENK cells have excellent recovery and retain cytolytic ability. Robust in vivo expansion was only seen after infusion of fresh ENK cells. Production assistance by CAGT allowed for the rapid implementation of a novel therapy utilizing fresh ENK cells for poor prognosis MM patients. Disclosures: No relevant conflicts of interest to declare.

Immunoglobulin-Like Transcript 5 Inhibits Macrophage-Mediated Bacterial Killing and Antigen Presentation During Sepsis

2019 ◽  
Vol 220 (10) ◽  
pp. 1688-1699
Author(s):  
Siqi Ming ◽  
Musheng Li ◽  
Minhao Wu ◽  
Jianhui Zhang ◽  
Haibo Zhong ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Underlying Mechanism ◽  
Peripheral Blood Mononuclear ◽  
Bacterial Killing ◽  
In Vivo Experiments ◽  
Healthy Donors ◽  
Antigen Presenting ◽  
Species Production

Abstract Background Immunosuppression contributes to the mortality of sepsis. However, the underlying mechanism remains unclear. Methods In the present study, we investigated the role of inhibitory receptor immunoglobulin-like transcript 5 (ILT5) in sepsis. We first screened the expression of ILT family members, and we found that ILT5 was dramatically up-regulated in the peripheral blood mononuclear cells from sepsis patients versus healthy donors. Results Knockdown of ILT5 by small interfering ribonucleic acid increased bacterial killing and reactive oxygen species production in THP-1 and RAW264.7 cells. Moreover, ILT5-expressing monocytes/macrophages exhibited lower expression of antigen-presenting molecules including major histocompatibility complex-II and CD80. In the in vitro coculture system with monocytes/macrophages, blockage of ILT5 facilitated Th1 proliferation and differentiation of CD4+ T cells. Furthermore, in vivo experiments demonstrated that pretreatment with ILT5 blocking peptide improved the survival and pulmonary pathology of septic mice. Conclusions Together, our study identified ILT5 as an immunosuppressive regulator during sepsis, which may provide potential therapeutic strategy for sepsis.

scholarly journals The dominant negative β isoform of the glucocorticoid receptor is uniquely expressed in erythroid cells expanded from polycythemia vera patients

Blood ◽  
2011 ◽  
Vol 118 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Lilian Varricchio ◽  
Elena Masselli ◽  
Elena Alfani ◽  
Angela Battistini ◽  
Giovanni Migliaccio ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Polycythemia Vera ◽  
Mononuclear Cells ◽  
Therapeutic Agents ◽  
Dominant Negative ◽  
Erythropoietin Treatment ◽  
Low Levels ◽  
Stimulation Of

Abstract Glucocorticoid receptor (GR) agonists increase erythropoiesis in vivo and in vitro. To clarify the effect of the dominant negative GRβ isoform (unable to bind STAT-5) on erythropoiesis, erythroblast (EB) expansion cultures of mononuclear cells from 18 healthy (nondiseased) donors (NDs) and 16 patients with polycythemia vera (PV) were studied. GRβ was expressed in all PV EBs but only in EBs from 1 ND. The A3669G polymorphism, which stabilizes GRβ mRNA, had greater frequency in PV (55%; n = 22; P = .0028) and myelofibrosis (35%; n = 20) patients than in NDs (9%; n = 22) or patients with essential thrombocythemia (6%; n = 15). Dexamethasone stimulation of ND cultures increased the number of immature EBs characterized by low GATA1 and β-globin expression, but PV cultures generated great numbers of immature EBs with low levels of GATA1 and β-globin irrespective of dexamethasone stimulation. In ND EBs, STAT-5 was not phosphorylated after dexamethasone and erythropoietin treatment and did not form transcriptionally active complexes with GRα, whereas in PV EBs, STAT-5 was constitutively phosphorylated, but the formation of GR/STAT-5 complexes was prevented by expression of GRβ. These data indicate that GRβ expression and the presence of A3669G likely contribute to development of erythrocytosis in PV and provide a potential target for identification of novel therapeutic agents.

Involvement of various hematopoietic-cell lineages by the JAK2V617F mutation in polycythemia vera

Blood ◽  
2006 ◽  
Vol 108 (9) ◽  
pp. 3128-3134 ◽  
Author(s):  
Takefumi Ishii ◽  
Edward Bruno ◽  
Ronald Hoffman ◽  
Mingjiang Xu
Keyword(s):  
Polycythemia Vera ◽  
Hematopoietic Cells ◽  
Jak2v617f Mutation ◽  
Cell Lineages ◽  
Healthy Donors ◽  
Cd34 Cells ◽  
Polymerase Chain ◽  
B And T Lymphocytes

AbstractThe JAK2V617F mutation has been shown to occur in the overwhelming majority of patients with polycythemia vera (PV). To study the role of the mutation in the excessive production of differentiated hematopoietic cells in PV, CD19+, CD3+, CD34+, CD33+, and glycophorin A+ cells and granulocytes were isolated from the peripheral blood (PB) of 8 patients with PV and 3 healthy donors mobilized with G-CSF, and the percentage of JAK2V617F mutant allele was determined by quantitative real-time polymerase chain reaction (PCR). The JAK2V617F mutation was present in cells belonging to each of the myeloid lineages and was also present in B and T lymphocytes in a subpopulation of patients with PV. The proportion of hematopoietic cells expressing the JAK2V617F mutation decreased after differentiation of CD34+ cells in vitro in the presence of optimal concentrations of SCF, IL-3, IL-6, and Epo. These data suggest that the JAK2V617F mutation may not provide a proliferative and/or survival advantage for the abnormal PV clone. Although the JAK2V617F mutation plays an important role in the biologic origins of PV, it is likely not the sole event leading to PV.

scholarly journals Infection of human lymphomononuclear cells by SARS-CoV-2

2020 ◽  
Author(s):  
Marjorie C Pontelli ◽  
Italo A Castro ◽  
Ronaldo B Martins ◽  
Flávio P Veras ◽  
Leonardo La Serra ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Severe Infection ◽  
Peripheral Blood Mononuclear ◽  
Healthy Donors ◽  
B And T Lymphocytes

AbstractAlthough SARS-CoV-2 severe infection is associated with a hyperinflammatory state, lymphopenia is an immunological hallmark, and correlates with poor prognosis in COVID-19. However, it remains unknown if circulating human lymphocytes and monocytes are susceptible to SARS-CoV-2 infection. In this study, SARS-CoV-2 infection of human peripheral blood mononuclear cells (PBMCs) was investigated both in vitro and in vivo. We found that in vitro infection of whole PBMCs from healthy donors was productive of virus progeny. Results revealed that monocytes, as well as B and T lymphocytes, are susceptible to SARS-CoV-2 active infection and viral replication was indicated by detection of double-stranded RNA. Moreover, flow cytometry and immunofluorescence analysis revealed that SARS-CoV-2 was frequently detected in monocytes and B lymphocytes from COVID-19 patients, and less frequently in CD4+T lymphocytes. The rates of SARS-CoV-2-infected monocytes in PBMCs from COVID-19 patients increased over time from symptom onset. Additionally, SARS-CoV-2-positive monocytes and B and CD4+T lymphocytes were detected by immunohistochemistry in post mortem lung tissue. SARS-CoV-2 infection of blood circulating leukocytes in COVID-19 patients may have important implications for disease pathogenesis, immune dysfunction, and virus spread within the host.

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