title: Gene therapy targeting cord blood-derived CD34+ cells from HIV-exposed infants: preclinical studies.
abstract: Hematopoietic CD34+ cells from placental and umbilical cord blood (PUCB) can be valuable vehicles for gene therapy of immunodeficiencies and genetic disorders. We have conducted preclinical studies towards the treatment of HIV-1-infected infants with genetically 'immunized' CD34+ cells derived from PUCB using anti-HIV-1 hairpin ribozyme genes. PUCB was collected from 10 newborns of HIV-1-positive mothers. CD34+ cells were enriched with a modified procedure using Dynal immunomagnetic beads and chymopapain, stimulated with stem cell factor (SCF), IL-3 and IL-6, and transduced using cell-free recombinant retroviral vector (MJT) expressing a ribozyme against the U5 region of HIV-1. No significant differences were observed in the growth pattern of CD34+ cells from normal infants, HIV-1 exposed infants or infants confirmed to be infected by HIV-1. The transduction efficiency of the CD34+ cells from all the infants was also comparable. MJT-transduced CD34+ cells from an HIV-1-infected infant were maintained in a liquid culture system for 4 weeks, and the progeny macrophage cells were challenged with the monocyte-tropic laboratory strain, HIV-Bal, or the HIV-1 isolate from the infant's mother. Significant inhibition of virus replication was observed in ribozyme-transduced cells. Thus, we have demonstrated efficient and stable gene transfer into progenitor cells from the cord blood of HIV-1-exposed or -infected infants and shown that protection from HIV-1 infection was conferred to the progeny cells produced by CD34+ cells transduced with the anti-HIV ribozyme gene construct.
authors.affiliation: Department of Medicine, University of California, La Jolla, CA, USA.
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: A
authors.initials: A
authors.lastname: Gervaix
authors.forename: D
authors.initials: D
authors.lastname: Kang
authors.forename: P
authors.initials: P
authors.lastname: Law
authors.forename: S A
authors.initials: SA
authors.lastname: Spector
authors.forename: A D
authors.initials: AD
authors.lastname: Ho
authors.forename: F
authors.initials: F
authors.lastname: Wong-Staal
mesh_terms: D018952:Antigens, CD34; D002478:Cells, Cultured; D005312:Fetal Blood / Q000276:immunology; D015870:Gene Expression; D018390:Gene Targeting; D015316:Genetic Therapy / Q000379:methods*; D015658:HIV Infections / Q000276:immunology / Q000517:prevention & control*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D016337:RNA, Catalytic; D013234:Stem Cells / Q000276:immunology
chemical_list: D018952:Antigens, CD34; D016337:RNA, Catalytic