Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The efficiency of retroviral-mediated gene transfer into hematopoietic stem cells (HSC) is dependent on the survival and self-renewal of HSC in vitro during retroviral infection. We have examined the effect of prestimulation of bone marrow with various cytokines, including the product of the Steel gene, Steel factor or stem cell factor (SCF) (the ligand for the c-kit receptor) on the efficiency of retroviral transduction of the human adenosine deaminase (hADA) cDNA into murine HSC. Bone marrow cells were prestimulated for 48 hours with hematopoietic growth factors, then cocultivated with the packaging cell line producing the ZipPGK-ADA simplified retrovirus for an additional 48 hours with continued growth factor exposure. Nonadherant cells from these cocultures were injected into lethally irradiated recipients. The content of day 12 colony-forming unit-spleen (CFU-S12) in SCF/interleukin 6 (IL-6)-prestimulated and cocultured bone marrow was more than threefold greater than that of IL-3/IL-6-prestimulated bone marrow cells. All mice receiving bone marrow cells infected with the PGK-ADA virus after prestimulation with IL-3/IL-6 or SCF/IL-6 demonstrated hADA expression in the peripheral blood after full hematopoietic reconstitution. While all recipients of IL-3/IL-6-prestimulated bone marrow expressed hADA at 4 months posttransplant, in three independent experiments examining a total of 33 mice, in most recipients of SCF/IL-6-prestimulated and infected bone marrow cells, the expression of human enzyme was higher than IL-3/IL-6 mice. Southern blot analysis of DNA from hematopoietic tissues from these same mice prepared at least 4 months posttransplantation also demonstrated a higher infection efficiency of HSC as measured by proviral integration patterns and genome copy number analysis. These results suggest that the higher level of hADA expression seen in mice receiving marrow prestimulated with SCF/IL-6 before retroviral infection is due to more efficient infection of reconstituting HSC. Other growth factor combinations were also studied; however, prestimulation with SCF/IL-6 or IL-3/IL-6 appeared optimal. Using retroviral-mediated gene transfer and viral integration patterns, Steel factor (SCF) in combination with IL-6 appears to increase the survival and self-renewal of reconstituting hematopoietic stem cells and proves useful in effecting expression of foreign genes in transplant recipients. Such pretreatment may also be useful in the application of retroviral transfer methods to human cells.
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PMID:Stem cell factor, interleukin-3, and interleukin-6 promote retroviral-mediated gene transfer into murine hematopoietic stem cells. 137 19

An amphotropic retroviral vector, LgAL(delta Mo + PyF101) containing a human adenosine deaminase (ADA) cDNA was used to optimize procedures for the lasting genetic modification of the hematopoietic system of mice. The highest number of retrovirally infected cells in the hematopoietic tissues of long-term reconstituted mice was observed after transplantation of bone marrow (BM) cells that had been cocultured in the presence of both interleukin-1 alpha (IL-1 alpha) and IL-3. A significantly lower number was detected when IL-1 alpha was omitted from such cocultures. The yield of cells that generate spleen colony-forming cells (CFU-S) in the BM of lethally irradiated recipients (MRA-CFU-S) significantly improved on inclusion of the adherent cell fraction of cocultures in the transplant. Retroviral integration patterns in MRA-CFU-S-derived spleen colonies showed that an MRA-CFU-S can produce many CFU-S during BM regeneration. Expression of hADA was detected in the circulating white blood cells of long-term reconstituted animals, demonstrating that the LgAL(delta Mo + PyF101) vector is capable of directing the sustained expression of hADA, and in approximately 35% of the transduced MRA-CFU-S-derived spleen colonies. These results should facilitate the development of gene therapy protocols for the treatment of severe combined immunodeficiency caused by a lack of functional ADA.
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PMID:Factors affecting the transduction of pluripotent hematopoietic stem cells: long-term expression of a human adenosine deaminase gene in mice. 767 68

Diamond Blackfan Anaemia (DBA) is a congenital disease characterised by defective erythroid progenitor maturation. It is usually diagnosed during the first year of life. The main clinical sign is profound isolated normochromic or macrocytic anaemia, with normal numbers and function of the other haemopoietic cells. Reticulocyte counts in patients with DBA are very low. Bone marrow reflects the defective erythropoiesis, showing a very low number of erythropoietic precursors and a reduction of erythroid burst-forming unit progenitor cells. The proliferation and differentiation of the other lineages are normal. More than one-third of patients have malformations, most often involving the upper limbs and head, and the urogenital or cardiovascular systems. However, the link between these malformations and defective erythropoiesis is unclear and a defect in a molecule acting on both early embryonic development and haematopoiesis has been proposed. Whereas most cases are sporadic, inheritance is observed in 10% of patients, with a dominant or, more rarely, recessive pattern. One locus on chromosome 19q13.2 encoding ribosomal protein S19 accounts for a quarter of patients with either the dominant or the sporadic form. Families not linked with this locus have also been described. The diagnosis of DBA may be difficult and differential diagnoses include Fanconi's anaemia and acquired erythroid aplasias. Erythrocyte adenosine deaminase levels are generally high in DBA patients, which may help in the diagnosis, but they are not pathognomic. Corticosteroids are the main treatment option in DBA and these agents induce erythropoiesis in over 60% of patients. Some patients achieve complete remission, which may be either corticosteroid-induced or spontaneous. The increased in vitro erythropoiesis occasionally induced by the addition of specific cytokines, namely interleukin (IL)-3 and stem cell factor (SCF), has suggested their use in vivo. However, few patients have responded to IL-3, whereas SCF administration, though interesting in theory, has not yet been attempted. Patients who do not respond to corticosteroids and those who have to discontinue treatment because of adverse events must rely on long term transfusions, and are thus exposed to all of the associated complications. Bone marrow or cord blood transplantation has been performed in some patients. The former approach is burdened with severe complications and high mortality.
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PMID:Diamond-Blackfan Anaemia: an overview. 1102 96

To improve maintenance and gene transfer of human lymphoid progenitors for clinical use in gene therapy of adenosine deaminase (ADA)-deficient SCID we investigated several gene transfer protocols using various stem cell-enriched sources. The lymphoid differentiation potential was measured by an in vitro clonal assay for B/NK cells and in the in vivo SCID-hu mouse model. Ex vivo culture with the cytokines TPO, FLT3-ligand, and SCF (T/F/S) plus IL-3 or IL-7 substantially increased the yield of transduced bone marrow (BM) CD34(+) cells purified from ADA-SCID patients or healthy donors, compared to T/F/S alone. Moreover, the use of IL-3 or IL-7 significantly improved the maintenance of in vitro B cell progenitors from ADA-SCID BM cells and allowed the efficient transduction of B and NK cell progenitors. Under these optimized conditions transduced CD34(+) cells were efficiently engrafted into SCID-hu mice and gave rise to B and T cell progeny, demonstrating the maintenance of in vivo lymphoid reconstitution capacity. The protocol based on the T/F/S + IL-3 combination was included in a gene therapy clinical trial for ADA-SCID, resulting in long-term engraftment of stem/progenitor cells. Remarkably, gene-corrected BM CD34(+) cells obtained from one patient 4 and 11 months after gene therapy were capable of repopulating the lymphoid compartment of SCID-hu hosts.
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PMID:IL-3 or IL-7 increases ex vivo gene transfer efficiency in ADA-SCID BM CD34+ cells while maintaining in vivo lymphoid potential. 1556 41