Highly efficient gene transfer in naive human T cells with a murine leukemia virus-based vector

Retroviral vectors based on the Moloney murine leukemia virus (MULV) have b ecome the primary tool for gene delivery into hematopoietic cells, but clin ical trials have been hampered by low transduction efficiencies. Recently, we and others have shown that gene transfer of MuLV-based vectors into T ce lls can be significantly augmented using a fibronectin-facilitated protocol . Nevertheless, the relative abilities of naive (CD45RA(+)) and memory (CD4 5RO(+)) lymphocyte subsets to be transduced has not been assessed, Although naive T cells demonstrate a restricted cytokine profile following antigen stimulation and a decreased susceptibility to infection with human immunode ficiency virus, it was not clear whether they could be efficiently infected with a MuLV vector. This study describes conditions that permitted gene tr ansfer of an enhanced green fluorescent protein-expressing retroviral vecto r in more than 50% of naive umbilical cord (UC) blood and peripheral blood (PB)T cells following CD3/CD28 ligation, Moreover, treatment of naive T cel ls with interleukin-7 resulted in the maintenance of a CD45RA phenotype and gene transfer levels ap preached 20%, Finally, it was determined that para meters for optimal transduction of CD45RA+ T cells isolated from PB UC bloo d differed: transduction of the UC cells was significantly increased by the presence of autologous mononuclear cells (24.5% versus 56.5%), Because nai ve T cells harbor a receptor repertoire that allows them to respond to nove l antigens, the development of protocols targeting their transduction is cr ucial for gene therapy applications, This approach will also allow the func tions of exogenous genes to be evaluated in primary nontransformed naive T cells, (C) 2000 by The American Society of nematology.