Matches in SemOpenAlex for { <https://semopenalex.org/work/W2554553387> ?p ?o ?g. }
Showing items 1 to 78 of
78
with 100 items per page.
- W2554553387 abstract "Abstract Abstract 3570 Poster Board III-507 For the hemoglobin disorders, hematopoietic stem cell gene transfer is potentially curative, yet this strategy requires high-level β-globin gene expression among erythroid cells. Position effects, which are imparted by chromosomal position and chromatin structure, induce clonal variability of transgene expression. Recent work demonstrates that the chicken HS4 insulator element reduces position effects, resulting in consistently high-level expression of a therapeutic β-globin gene in the MEL cell line. In this study, we evaluated the effects of HS4 insulators on lentiviral vector titers and transgene expression among transduced human hematopoietic cells. We constructed various types of insulated lentiviral vectors using a reverse oriented GFP under the control of the MSCV-LTR promoter (rMpGFP) or a conventional reverse oriented β-globin expression cassette, in which the globin gene was changed to GFP (BGpGFP). A full-length HS4 insulator (1.2 kb HS4), tandem HS4 core insulator (2 × 250 b HS4), and a single core insulator (250 b HS4) were inserted into the 3′ LTR. The insulator elements were inserted in both forward (F) and reverse (R) orientations. Vector titers were significantly decreased by insertion of the 1.2 kb HS4 and 2 × 250 b HS4 in both orientations and both vector constructs, compared to uninsulated vectors (p<0.05), with the degree dependent on fragment size. Interestingly, reverse-oriented insulators showed better vector titers when compared to forward-oriented insulators for all types of insulator fragments except the 2 × 250 b HS4 in rMpGFP vectors (p<0.05). We next evaluated GFP expression from various insulated rMpGFP vectors in GPA+ human erythroid cells that originated from transduced CD34+ cells (MOI=3) (Figure). The %GFP was decreased by 1.2 kb HS4 and 2 × 250 b HS4 insulators in both orientations, compared to the uninsulated vector (p<0.05). All insulated vector constructs had a tendency to lower CVs, there was no significant difference except for the 1.2 kb HS4 F vector (p<0.05). There was no significant difference of MFIs between all types of insulated and uninsulated vectors. In order to evaluate insulator function for the BGpGFP vectors in human hematopoietic cells, we practically chose the 250 b HS4 R because it did not decrease vector titers and the 1.2 kb HS4 showed 5-fold lower transduction efficiency in human erythroid cells. During erythorid culture of transduced human erythroid cells, %GFP and MFIs decreased whereas CVs increased,showing chromosomal position effects. The 250 b HS4 R insulator showed lower %GFP and lower MFIs (MOI=20) (p<0.05 on day 13 and 20), compared to those of the uninsulated vector. There was no significant difference in CVs. After MOI escalation of BGpGFP vectors (day13), the insulated vector showed lower %GFP at MOI 10, 25, and 50 (p<0.05) and lower overall GFP expression (%GFP x MFI) at MOI 25 and 50 (p<0.05) compared to uninsulated vector. These data demonstrated that inclusion of HS4 insulator elements decreases GFP expression, which is not overcome by increasing MOI. We then performed transduced hematopoietic stem cell transplantation in a human xenograft mouse model using a 250 b HS4 R insulated rMpGFP vector. In the human CD45+ fraction of mouse peripheral blood cells, the insulator element decreased both %GFP and MFIs at 4 and 8 weeks after transplantation (p<0.05). There was no significant difference of CVs among the insulated and uninsulated vector at all time points. These data demonstrate that the inclusion of HS4 insulator elements lowers viral titers, reduces efficiency of transduction and produces minimal effects on transgene expression among human hematopoietic cells in vitro and in vivo Disclosures: No relevant conflicts of interest to declare." @default.
- W2554553387 created "2016-11-30" @default.
- W2554553387 creator A5001134935 @default.
- W2554553387 creator A5028422235 @default.
- W2554553387 creator A5063279617 @default.
- W2554553387 creator A5066512942 @default.
- W2554553387 date "2009-11-20" @default.
- W2554553387 modified "2023-09-27" @default.
- W2554553387 title "Chicken HS4 Insulators Have Minimal Functions in Human Hematopoietic Cells That Were Transduced with An HIV1-Based Lentiviral Vector." @default.
- W2554553387 doi "https://doi.org/10.1182/blood.v114.22.3570.3570" @default.
- W2554553387 hasPublicationYear "2009" @default.
- W2554553387 type Work @default.
- W2554553387 sameAs 2554553387 @default.
- W2554553387 citedByCount "0" @default.
- W2554553387 crossrefType "journal-article" @default.
- W2554553387 hasAuthorship W2554553387A5001134935 @default.
- W2554553387 hasAuthorship W2554553387A5028422235 @default.
- W2554553387 hasAuthorship W2554553387A5063279617 @default.
- W2554553387 hasAuthorship W2554553387A5066512942 @default.
- W2554553387 hasConcept C100012643 @default.
- W2554553387 hasConcept C101762097 @default.
- W2554553387 hasConcept C102230213 @default.
- W2554553387 hasConcept C104317684 @default.
- W2554553387 hasConcept C109159458 @default.
- W2554553387 hasConcept C150194340 @default.
- W2554553387 hasConcept C153911025 @default.
- W2554553387 hasConcept C159047783 @default.
- W2554553387 hasConcept C199491388 @default.
- W2554553387 hasConcept C28328180 @default.
- W2554553387 hasConcept C32470452 @default.
- W2554553387 hasConcept C39981086 @default.
- W2554553387 hasConcept C40767141 @default.
- W2554553387 hasConcept C54355233 @default.
- W2554553387 hasConcept C86803240 @default.
- W2554553387 hasConcept C92087593 @default.
- W2554553387 hasConceptScore W2554553387C100012643 @default.
- W2554553387 hasConceptScore W2554553387C101762097 @default.
- W2554553387 hasConceptScore W2554553387C102230213 @default.
- W2554553387 hasConceptScore W2554553387C104317684 @default.
- W2554553387 hasConceptScore W2554553387C109159458 @default.
- W2554553387 hasConceptScore W2554553387C150194340 @default.
- W2554553387 hasConceptScore W2554553387C153911025 @default.
- W2554553387 hasConceptScore W2554553387C159047783 @default.
- W2554553387 hasConceptScore W2554553387C199491388 @default.
- W2554553387 hasConceptScore W2554553387C28328180 @default.
- W2554553387 hasConceptScore W2554553387C32470452 @default.
- W2554553387 hasConceptScore W2554553387C39981086 @default.
- W2554553387 hasConceptScore W2554553387C40767141 @default.
- W2554553387 hasConceptScore W2554553387C54355233 @default.
- W2554553387 hasConceptScore W2554553387C86803240 @default.
- W2554553387 hasConceptScore W2554553387C92087593 @default.
- W2554553387 hasLocation W25545533871 @default.
- W2554553387 hasOpenAccess W2554553387 @default.
- W2554553387 hasPrimaryLocation W25545533871 @default.
- W2554553387 hasRelatedWork W1482385628 @default.
- W2554553387 hasRelatedWork W1514053797 @default.
- W2554553387 hasRelatedWork W2001953227 @default.
- W2554553387 hasRelatedWork W2025332622 @default.
- W2554553387 hasRelatedWork W2050371150 @default.
- W2554553387 hasRelatedWork W2138403036 @default.
- W2554553387 hasRelatedWork W2183107596 @default.
- W2554553387 hasRelatedWork W2363782604 @default.
- W2554553387 hasRelatedWork W2384055889 @default.
- W2554553387 hasRelatedWork W2406536330 @default.
- W2554553387 hasRelatedWork W2551095098 @default.
- W2554553387 hasRelatedWork W2556696512 @default.
- W2554553387 hasRelatedWork W2561397902 @default.
- W2554553387 hasRelatedWork W2566535473 @default.
- W2554553387 hasRelatedWork W2570152511 @default.
- W2554553387 hasRelatedWork W2586565232 @default.
- W2554553387 hasRelatedWork W2589137604 @default.
- W2554553387 hasRelatedWork W2980369329 @default.
- W2554553387 hasRelatedWork W3031656559 @default.
- W2554553387 hasRelatedWork W3150012257 @default.
- W2554553387 isParatext "false" @default.
- W2554553387 isRetracted "false" @default.
- W2554553387 magId "2554553387" @default.
- W2554553387 workType "article" @default.