Cell transformation by avian defective leukaemia viruses

1980 ◽  
Vol 210 (1180) ◽  
pp. 397-409 ◽  
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Cell Transformation ◽  
Nucleic Acid Hybridization ◽  
Phenotypic Analysis ◽  
Amino Terminal ◽  
Cell Specificity ◽  
Core Proteins ◽  
Carboxy Terminal

A comparative study of seven independently isolated defective leukaemia viruses has been carried out. Phenotypic analysis of the chicken bone marrow cells transformed in vitro allowed the separation of these seven viruses into three groups based on the differentiation phenotype of the transformed cell. Nucleic acid hybridization studies revealed that these seven viruses had acquired cellular sequences. Interestingly, these studies also showed that the viruses within the same biological grouping had acquired related sequences. This indicates that viruses that have acquired the same or similar cellular sequences have very similar oncogenic capabilities. Analysis of proteins expressed in cells transformed by these viruses demonstrated that the cellular sequences were usually inserted within the gene for the viral core proteins, gag . Therefore the cellular sequences are expressed as a gag -related fusion protein which has an amino-terminal region derived from the gag gene and a carboxy-terminal half derived from the cellular sequences. Two exceptions to this are discussed. The general conclusion from these studies is that defective leukaemia viruses transform cells by virtue of acquired host cellular sequences. The ability of these viruses to transform cells and the target cell specificity of the transformation depends on these cellular sequences.

Gfi1-N382S Mutants from Human Severe Congenital Neutropenia Patients Function through a Transcriptional Dominant Negative Mechanism.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1185-1185
Author(s):  
Adrian P. Zarebski ◽  
Avinash M. Baktula ◽  
Sudeep Basu ◽  
John O. Trent ◽  
H. Leighton Grimes
Keyword(s):  
Bone Marrow ◽  
Dna Binding ◽  
Bone Marrow Cells ◽  
Severe Congenital Neutropenia ◽  
Wild Type ◽  
Congenital Neutropenia ◽  
Murine Bone Marrow ◽  
Amino Terminal ◽  
Marrow Cells

Abstract The Growth factor independence 1 (Gfi1) zinc finger transcriptional repressor is a T cell leukemia oncoprotein that also plays a crucial role in granulopoiesis in both mice and humans. A single point mutation in the amino terminal SNAG repressor domain (P2A) is able to ablate both Gfi1 transcriptional repression activity and linked oncogenic activity in T lymphoctyes. Mice deleted for Gfi1 are lymphopenic, but also lack mature neutrophils. Gfi1−/− mice display a profound block to myeloid differentiation and abnormal promyelocytes accumulate in the blood. Humans with Severe Congenital Neutropenia (SCN) with heterozygous mutations in Gfi1 have similar abnormal promyelocytes. We introduced the SCN patient Gfi1N382S DNA-binding-deficient mutation into murine Gfi1 and overexpressed it in primary murine bone marrow cells. While expression of the wild type Gfi1 resulted almost exclusively in mature granulocyte differentiation, forced expression of the N382S mutant resulted almost exclusively in monocytic differentiation. Flow cytometric analysis revealed a population of N382S-expressing cells with markers of both monocytes and neutrophils resembling the atypical Gfi1−/− promyelocytes. To determine if mutation of the N382 residue is uniquely able to block Gfi1 function, we constructed a virtual model of Gfi1 zinc fingers 3, 4 and 5 interacting with DNA. The model revealed several possible protein-DNA interactions. In order to validate the model we mutated those residues to alanine and performed EMSA with in vitro transcribed/translated proteins. The same alanine substitution mutants were expressed in primary murine bone marrow and tested for their ability to control myelopoiesis. Lack of DNA binding in EMSA tightly correlated with impaired granulopoesis in our in vitro model, suggesting the necessity of intact DNA binding for proper Gfi1 function. These data suggested that the non-DNA binding mutants were able to inhibit repression by wild type endogenous Gfi1, perhaps through the sequestration of limiting corepressor proteins. The Gfi1P2A mutant is unable to repress transcription. We therefore tested the effect of Gfi1P2A expression on myelopoiesis and found that it blocked granulopoiesis equivalently to Gfi1N382S. To rigorously determine whether the titration of limiting corepressors was the cause of N382S neutropenia, we constructed a compound mutant containing both N382S and P2A and expressed it in primary murine bone marrow cells. Expression of Gfi1P2A-N382S had little effect on myelopoiesis. We conclude that SCN patients with heterozygous Gfi1 mutations have blocked granulopoiesis because the non-DNA binding mutant protein competes with the wild type allele for titratable associated cofactors.

scholarly journals Effect of pseudotype on Abelson virus and Kirsten sarcoma virus-induced leukemia.

1978 ◽  
Vol 147 (4) ◽  
pp. 1044-1053 ◽  
Author(s):  
C D Scher
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Cell Transformation ◽  
Leukemia Virus ◽  
Helper Virus ◽  
Lymphoid Cells ◽  
Lymphoid Leukemia ◽  
Sarcoma Virus ◽  
Marrow Cells

Nonproducer cells transformed by Kirsten sarcoma virus (KiSV) or Abelson murine leukemia virus (A-MuLV) were infected with N- or NB-tropic helper viruses to rescue the defective transforming virus. The titer of the transforming viruses was determined on NIH/3T3 fibroblast-like cells and cell-free filtrates of virus stock were inoculated into newborn Fv-1nn mice. Friend, Moloney, and Rauscher group of MuLV (FMR) pseudotypes of KiSV induced an erythroid leukemia efficiently, while an endogenous helper (N35-MuLV) pseudotype of KiSV did not. FMR pseudotypes of A-MuLV induced the Abelson lymphoid leukemia, while the N35-MuLV or a Kirsten leukemia virus (Ki-MuLV) pseudotype did not. Pseudotypes of A-MuLV were used to infect bone marrow cells of Fv-1nn mice in vitro. The FMR pseudotypes transformed bone marrow cells at 40-100-fold higher frequency than the N35-MuLV or Ki-MuLV pseudotypes. Mixing experiments demonstrated that the addition of an effective helper, such as M-MuLV did not enhance lymphoid transformation by ineffective A-MuLV (N35-MuLV). The A-MuLV genome is responsible for hematopoietic cell transformation because a nonproducer clone of lymphoid cells, free of helper virus, was isolated. The data indicates that the pseudotype of A-MuLV determines its ability to transform hematopoietic cells.

scholarly journals Colony formation in vitro by leukemic cells in acute lymphoblastic leukemia (ALL)

Blood ◽  
1978 ◽  
Vol 52 (4) ◽  
pp. 712-718 ◽  
Author(s):  
SD Smith ◽  
EM Uyeki ◽  
JT Lowman
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Bone Marrow Cells ◽  
Lymphoblastic Leukemia ◽  
Lymphoid Cells ◽  
Assay System ◽  
Leukemic Cells ◽  
Specific Cell ◽  
Specific Cell Surface

Abstract An assay system in vitro for the growth of malignant lymphoblastic colony-forming cells (CFC) was established. Growth of malignant myeloblastic CFC has been previously reported, but this is the first report of growth of malignant lymphoblastic CFC. Established assay systems in vitro have been very helpful in elucidating the control of growth and differentiation of both normal and malignant bone marrow cells. Lymphoblastic CFC were grown from the bone marrow aspirates of 20 children with acute lymphoblastic leukemia. Growth of these colonies was established on an agar assay system and maintained in the relative hypoxia (7% oxygen) of a Stulberg chamber. The criteria for malignancy of these colonies was based upon cellular cytochemical staining characteristics, the presence of specific cell surface markers, and the ability of these lymphoid cells to grow without the addition of a lymphoid mitogen. With this technique, specific nutritional requirements and drug sensitivities can be established in vitro, and these data may permit tailoring of individual antileukemic therapy.

scholarly journals Interleukin-3 is significantly more effective than other colony- stimulating factors in long-term maintenance of human bone marrow- derived colony-forming cells in vitro

Blood ◽  
1989 ◽  
Vol 73 (7) ◽  
pp. 1836-1841 ◽  
Author(s):  
M Kobayashi ◽  
BH Van Leeuwen ◽  
S Elsbury ◽  
ME Martinson ◽  
IG Young ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cultured Cells ◽  
Bone Marrow Cells ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Interleukin 3 ◽  
Gm Csf ◽  
Factor G ◽  
Marrow Cells

Abstract Human bone marrow cells cultured for 21 days in the presence of recombinant human interleukin-3 (IL-3) produced up to 28 times more colony-forming cells (CFC) than could be obtained from cultures stimulated with granulocyte colony stimulating factor (G-CSF) or granulocyte-macrophage CSF (GM-CSF). IL-3-cultured cells retained a multipotent response to IL-3 in colony assays but were restricted to formation of granulocyte colonies in G-CSF and granulocyte or macrophage colonies in GM-CSF. Culture of bone marrow cells in IL-3 also led to accumulation of large numbers of eosinophils and basophils. These data contrast with the effects of G-CSF, GM-CSF, and IL-3 in seven-day cultures. Here both GM-CSF and IL-3 amplified total CFC that had similar multipotential colony-forming capability in either factor. G-CSF, on the other hand, depleted IL-3-responsive colony-forming cells dramatically, apparently by causing these cells to mature into granulocytes. The data suggest that a large proportion of IL-3- responsive cells in human bone marrow express receptors for G-CSF and can respond to this factor, the majority becoming neutrophils. Furthermore, the CFC maintained for 21 days in IL-3 may be a functionally distinct population from that produced after seven days culture of bone marrow cells in either IL-3 or GM-CSF.

scholarly journals Antioxidant Fusion Protein SOD1-Tat Increases the Engraftment Efficiency of Total Bone Marrow Cells in Irradiated Mice

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3395
Author(s):  
Ting Bei ◽  
Xusong Cao ◽  
Yun Liu ◽  
Jinmei Li ◽  
Haihua Luo ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Fusion Protein ◽  
Bone Marrow Cells ◽  
Standard Procedure ◽  
Severe Infection ◽  
Copper Zinc Superoxide Dismutase ◽  
Donor Cells ◽  
Total Bone Marrow ◽  
Marrow Cells

Total body irradiation is a standard procedure of bone marrow transplantation (BMT) which causes a rapid increase in reactive oxygen species (ROS) in the bone marrow microenvironment during BMT. The increase in ROS reduces the engraftment ability of donor cells, thereby affecting the bone marrow recovery of recipients after BMT. In the early weeks following transplantation, recipients are at high risk of severe infection due to weakened hematopoiesis. Thus, it is imperative to improve engraftment capacity and accelerate bone marrow recovery in BMT recipients. In this study, we constructed recombinant copper/zinc superoxide dismutase 1 (SOD1) fused with the cell-penetrating peptide (CPP), the trans-activator of transcription (Tat), and showed that this fusion protein has penetrating ability and antioxidant activity in both RAW264.7 cells and bone marrow cells in vitro. Furthermore, irradiated mice transplanted with SOD1-Tat-treated total bone marrow donor cells showed an increase in total bone marrow engraftment capacity two weeks after transplantation. This study explored an innovative method for enhancing engraftment efficiency and highlights the potential of CPP-SOD1 in ROS manipulation during BMT.

Thrombopoietin-Induced Stimulation of Megakaryocyte- Enriched Bone Marrow Cultures

1979 ◽  
Author(s):  
K. L. Kellar ◽  
B. L. Evatt ◽  
C. R. McGrath ◽  
R. B. Ramsey
Keyword(s):  
Bone Marrow ◽  
Dna Synthesis ◽  
Bone Marrow Cells ◽  
Rabbit Plasma ◽  
Bone Marrow Cultures ◽  
Plasma Fractions ◽  
Marrow Cultures ◽  
Stimulation Of

Liquid cultures of bone marrow cells enriched for megakaryocytes were assayed for incorporation of 3H-thymidine (3H-TdR) into acid-precipitable cell digests to determine the effect of thrombopoietin on DNA synthesis. As previously described, thrombopoietin was prepared by ammonium sulfate fractionation of pooled plasma obtained from thrombocytopenic rabbits. A control fraction was prepared from normal rabbit plasma. The thrombopoietic activity of these fractions was determined in vivo with normal rabbits as assay animals and the rate of incorporation of 75Se-selenomethionine into newly formed platelets as an index of thrombopoietic activity of the infused material. Guinea pig megakaryocytes were purified using bovine serum albumin gradients. Bone marrow cultures containing 1.5-3.0x104 cells and 31%-71% megakaryocytes were incubated 18 h in modified Dulbecco’s MEM containing 10% of the concentrated plasma fractions from either thrombocytopenic or normal rabbits. In other control cultures, 0.9% NaCl was substituted for the plasma fractions. 3H-TdR incorporation was measured after cells were incubated for 3 h with 1 μCi/ml. The protein fraction containing thrombopoietin-stimulating activity caused a 25%-31% increase in 3H-TdR incorporation over that in cultures which were incubated with the similar fraction from normal plasma and a 29% increase over the activity in control cultures to which 0.9% NaCl had been added. These data suggest that thrombopoietin stimulates DNA synthesis in megakaryocytes and that this tecnique may be useful in assaying thrombopoietin in vitro.

In vitro proliferative advantage of bone marrow cells with tetrasomy 8 in Ewing sarcoma

1996 ◽  
Vol 90 (2) ◽  
pp. 176-178 ◽  
Author(s):  
Luba Trakhtenbrot ◽  
Yoram Neumann ◽  
Matilda Mandel ◽  
Amos Toren ◽  
Nelly Gipsh ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Ewing Sarcoma ◽  
Bone Marrow Cells ◽  
Tetrasomy 8 ◽  
Proliferative Advantage ◽  
Marrow Cells

scholarly journals Effects of point mutations in the cytidine deaminase domains of APOBEC3B on replication and hypermutation of hepatitis B virus in vitro

2007 ◽  
Vol 88 (12) ◽  
pp. 3270-3274 ◽  
Author(s):  
Marianne Bonvin ◽  
Jobst Greeve
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Point Mutations ◽  
Alternative Mechanism ◽  
Amino Terminal ◽  
Hbv Replication ◽  
B Virus ◽  
Carboxy Terminal ◽  
Deaminase Domain

APOBEC3 cytidine deaminases hypermutate hepatitis B virus (HBV) and inhibit its replication in vitro. Whether this inhibition is due to the generation of hypermutations or to an alternative mechanism is controversial. A series of APOBEC3B (A3B) point mutants was analysed in vitro for hypermutational activity on HBV DNA and for inhibitory effects on HBV replication. Point mutations inactivating the carboxy-terminal deaminase domain abolished the hypermutational activity and reduced the inhibitory activity on HBV replication to approximately 40 %. In contrast, the point mutation H66R, inactivating the amino-terminal deaminase domain, did not affect hypermutations, but reduced the inhibition activity to 63 %, whilst the mutant C97S had no effect in either assay. Thus, only the carboxy-terminal deaminase domain of A3B catalyses cytidine deaminations leading to HBV hypermutations, but induction of hypermutations is not sufficient for full inhibition of HBV replication, for which both domains of A3B must be intact.

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