title: Targeting transgene expression to antigen-presenting cells derived from lentivirus-transduced engrafting human hematopoietic stem/progenitor cells.
abstract: Hematopoietic stem cells (HSCs) represent an important target for the treatment of various blood disorders. As the source of critical cells within the immune system, genetic modification of HSCs can also be used to modulate immune responses. The effectiveness of HSC-mediated gene therapy largely depends on efficient gene delivery into long-term repopulating progenitors and targeted transgene expression in an appropriate progeny of the transduced pluripotent HSCs. Self-inactivating (SIN) lentiviral vectors have been demonstrated to be capable of transducing mitotically inactive cells, including HSCs, and accommodating a nonviral promoter to control the transgene expression in transduced cells. In this study, we constructed 2 SIN lentiviral vectors, EF.GFP and DR.GFP, to express the green fluorescent protein (GFP) gene controlled solely by the promoter of either a housekeeping gene EF-1alpha or the human HLA-DRalpha gene, which is selectively expressed in antigen-presenting cells (APCs). We demonstrated that both vectors efficiently transduced human pluripotent CD34+ cells capable of engrafting nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. When the EF.GFP vector was used, constitutive high-level GFP expression was obtained in all the human HSC progeny detectable in NOD/SCID mice and in subsequent in vitro differentiation assays, indicating that engrafting human HSCs have been transduced. In contrast, the DR.GFP vector mediated transgene expression specifically in human HLA-DR+ cells and highly in differentiated dendritic cells (DCs), which are critical in regulating immunity. Furthermore, human DCs derived from transduced and engrafted human cells potently stimulated allogeneic T-cell proliferation. This study demonstrated successful targeting of transgene expression to APCs/DCs after stable gene transduction of pluripotent HSCs.
authors.affiliation: Division of Immunology and Hematopoiesis, Johns Hopkins Oncology Center, Johns Hopkins University, Baltimore, MD 21231, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cui
authors.forename: Jonathan
authors.initials: J
authors.lastname: Golob
authors.forename: Erin
authors.initials: E
authors.lastname: Kelleher
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Ye
authors.forename: Drew
authors.initials: D
authors.lastname: Pardoll
authors.forename: Linzhao
authors.initials: L
authors.lastname: Cheng
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000276:immunology; D002454:Cell Differentiation; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism*; D005240:Feasibility Studies; D005786:Gene Expression Regulation / Q000276:immunology; D017930:Genes, Reporter; D005813:Genes, Synthetic; D005822:Genetic Vectors / Q000235:genetics*; D006085:Graft Survival; D049452:Green Fluorescent Proteins; D006684:HLA-DR Antigens / Q000235:genetics*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism* / Q000821:virology; D006801:Humans; D007519:Isoantigens / Q000276:immunology; D016086:Lentivirus / Q000235:genetics*; D007963:Leukocytes, Mononuclear / Q000378:metabolism / Q000821:virology; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008213:Lymphocyte Activation; D008264:Macrophages / Q000166:cytology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D020648:Peptide Elongation Factor 1 / Q000235:genetics*; D011401:Promoter Regions, Genetic; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014162:Transfection; D019076:Transgenes
chemical_list: D006684:HLA-DR Antigens; D007519:Isoantigens; D008164:Luminescent Proteins; D020648:Peptide Elongation Factor 1; D049452:Green Fluorescent Proteins