title: Antibody-directed lentiviral gene transduction in early immature hematopoietic progenitor cells.
abstract: BACKGROUND
  The specific and efficient transduction of retroviral particles remains problematic for in vivo and ex vivo gene therapy studies, where the targeting cell population is a heterogeneous bulk population.
  
  
  METHODS
  Pseudotyping lentiviral particles with Sindbis virus envelope (Env) proteins modified with an immunoglobulin Fc-binding domain presents a method of selecting cells within a mixed population through antibody (Ab)-mediated targeting. Conditions were tested for targeted lentiviral gene delivery to hematopoietic progenitor cells via Ab-conjugated envelopes independent of CD34.
  
  
  RESULTS
  Conditions to optimize the efficiency of gene delivery were established using the ABCG2 multidrug resistance protein, associated with stem cell phenotypes, as the cell surface target. By varying the proportion of ABCG2 expressing cells in a population, ABCG2-targeted gene delivery was detectable by flow cytometry when ABCG2(+) cells comprised greater than 5% of the population. Conditions that increased the efficiency of gene transfer, including cholesterol independent Env proteins and pH, increased nonspecific gene delivery. The feasibility of this cell-Ab-virus sandwich system in targeting transduction in a mixed population was tested in cells derived from human cord blood (CB). Conjugation of viral particles with anti-CD133 and anti-ABCG2 hematopoietic stem cell-associated Ab resulted in targeted gene transfer into early immature hematopoietic progenitor cells. Enhancement was found when the hematopoietic progenitor cells were enriched from CB cells via the depletion of lineage(+) committed cells.
  
  
  CONCLUSIONS
  Gene transfer to lineage(-) early immature hematopoietic progenitors from human umbilical CB was obtained using CD133, ABCG2 or HLA-1 antibodies conjugated to lentiviruses pseudotyped with modified Sindbis viral Env proteins.
authors.affiliation: Department of Biochemistry, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.forename: Monica J
authors.initials: MJ
authors.lastname: Roth
mesh_terms: D000071916:AC133 Antigen; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000276:immunology; D000906:Antibodies / Q000627:therapeutic use; D015703:Antigens, CD / Q000276:immunology; D016503:Drug Delivery Systems / Q000379:methods*; D005312:Fetal Blood / Q000166:cytology; D015316:Genetic Therapy / Q000379:methods*; D006023:Glycoproteins / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D009363:Neoplasm Proteins / Q000276:immunology; D010455:Peptides / Q000276:immunology; D014161:Transduction, Genetic / Q000379:methods*; D014759:Viral Envelope Proteins / Q000276:immunology
chemical_list: C116614:ABCG2 protein, human; D000071916:AC133 Antigen; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D000906:Antibodies; D015703:Antigens, CD; D006023:Glycoproteins; D009363:Neoplasm Proteins; C000606023:PROM1 protein, human; D010455:Peptides; D014759:Viral Envelope Proteins