title: Correction of proliferative responses in purine nucleoside phosphorylase (PNP)-deficient T lymphocytes by retroviral-mediated PNP gene transfer and expression.
abstract: Purine nucleoside phosphorylase (PNP; EC 2.4.2.1) deficiency is associated with a fatal T cell immunodeficiency in children, a candidate condition for gene therapy by introduction of functional PNP sequences into either T lymphocytes or more primitive progenitor cells in the bone marrow. To test the effectiveness of PNP gene transfer in T lymphocytes, a retroviral vector (LmPSN-2) was designed and constructed to express the murine PNP cDNA under transcriptional regulation of the Moloney murine leukemia virus long terminal repeat. LmPSN-2 was first used to mediate gene transfer and expression of electrophoretically distinct murine PNP in normal (PNP-positive) human PBL. Peripheral blood leukocytes were then obtained from a PNP deficient patient and characterized phenotypically. Despite their paucity and general mitogenic unresponsiveness, T lymphocytes from this patient were successfully grown in culture by using anti-CD3 with rIL-2 and then transduced with LmPSN-2. Elevated PNP enzyme activity was observed in the transduced cell population. Mitogenic and allogeneic responses, normally depressed in PNP-deficient patients' cells, were partially corrected in the transduced cell population relative to nontransduced cells. These results suggest the possibility of effecting improved immunologic function in PNP-deficient T lymphoid cells by retroviral-mediated gene transfer as therapy for PNP deficiency.
authors.affiliation: Institute of Human Genetics, University of Minnesota, Minneapolis.
authors.forename: D M
authors.initials: DM
authors.lastname: Nelson
authors.forename: K A
authors.initials: KA
authors.lastname: Butters
authors.forename: M L
authors.initials: ML
authors.lastname: Markert
authors.forename: N L
authors.initials: NL
authors.lastname: Reinsmoen
authors.forename: R S
authors.initials: RS
authors.lastname: McIvor
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002478:Cells, Cultured; D005822:Genetic Vectors; D006801:Humans; D016130:Immunophenotyping; D008213:Lymphocyte Activation / Q000502:physiology*; D008297:Male; D051379:Mice; D011683:Purine-Nucleoside Phosphorylase / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics*; D012190:Retroviridae; D013601:T-Lymphocytes / Q000201:enzymology*; D014162:Transfection / Q000235:genetics*
chemical_list: D011683:Purine-Nucleoside Phosphorylase