title: T-lymphocyte function after retroviral-mediated thymidine kinase gene transfer and G418 selection.
abstract: Generation of an efficient graft-versus-leukemia (GVL) effect in patients with hematological malignancies who relapse after allogeneic bone marrow transplantation depends in part upon the number of infused T lymphocytes. Currently, a GVL reaction cannot be achieved without inducing concomitant graft-versus-host disease (GVHD); thus, one strategy is to try to modulate this GVL/GVHD ratio. We engineered human T lymphocytes with herpes simplex virus-thymidine kinase and neomycin resistance genes, with an LXSN-derived vector that confers a ganciclovir-specific sensitivity to the transduced T cells. We analyzed proliferation, interleukin-2 production, alloreactivity in a mixed lymphocyte culture, and clonogenicity during the different stages of retroviral infection and G418 selection. Our results confirm that a sufficient number of transduced T lymphocytes can be obtained after selection for clinical studies. Their proliferative activity, alloresponsiveness, and ability to produce and respond to interleukin-2 were retained. Compared with control populations, their clonogenicity, as assessed by limiting dilution assays, was reduced after retroviral infection and G418 selection by 1.6 and 2.9 logs, respectively, with both viral supernatant incubation and coculture procedures. This study shows that infection and selection with the thymidine kinase-neomycin resistance gene retroviral vector significantly reduces the number of functional T lymphocytes. This finding should be taken into account when establishing the dose of T lymphocytes necessary to trigger a modulated GVL/GVHD effect.
authors.affiliation: Sections of Haematology and Clinical Immunology, Department of Clinical and Experimental Medicine, Perugia University, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Di Ianni
authors.forename: S
authors.initials: S
authors.lastname: Di Florio
authors.forename: G
authors.initials: G
authors.lastname: Venditti
authors.forename: C
authors.initials: C
authors.lastname: Liberatore
authors.forename: F
authors.initials: F
authors.lastname: Lucheroni
authors.forename: F
authors.initials: F
authors.lastname: Falzetti
authors.forename: A
authors.initials: A
authors.lastname: Terenzi
authors.forename: C C
authors.initials: CC
authors.lastname: Stella
authors.forename: F
authors.initials: F
authors.lastname: Spinozzi
authors.forename: P
authors.initials: P
authors.lastname: Mannoni
authors.forename: M F
authors.initials: MF
authors.lastname: Martelli
authors.forename: A
authors.initials: A
authors.lastname: Tabilio
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D002478:Cells, Cultured; D017931:DNA Primers / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D015774:Ganciclovir / Q000494:pharmacology; D018014:Gene Transfer Techniques; D005839:Gentamicins / Q000494:pharmacology*; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology; D016133:Polymerase Chain Reaction; D012190:Retroviridae / Q000235:genetics; D018139:Simplexvirus / Q000201:enzymology; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology*; D013937:Thymidine Kinase / Q000096:biosynthesis / Q000235:genetics*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D000945:Antigens, Differentiation, T-Lymphocyte; D017931:DNA Primers; D005839:Gentamicins; D007376:Interleukin-2; C010680:antibiotic G 418; D013937:Thymidine Kinase; D015774:Ganciclovir