title: Recombinant fowlpox virus for in vitro gene delivery to pancreatic islet tissue.
abstract: The feasibility of using avipox virus as a vector for gene delivery to islet tissue (adult islets and fetal proislets) was examined using a recombinant fowlpox virus (FPV) engineered to express the reporter gene LacZ (FPV-LacZ). The efficiency of in vitro transduction was dose-dependent and influenced by the donor species and maturation status of the islet tissue. Reporter gene expression in FPV-LacZ-transduced islet grafts was transient (3-7 days) in immunoincompetent nude mice and was not prolonged by in vivo treatment with anti-IFN-gamma mAb. In contrast, FPV-LacZ-transduced NIT-1 cells (a mouse islet beta cell line) expressed the LacZ gene beyond 18 days in vitro. Silencing of transgene expression therefore appeared to occur in vivo and was T cell- and IFN-gamma-independent. Isografts of FPV-LacZ-transduced islets in immunocompetent mice underwent immunological destruction by 7 days, suggesting that either FPV proteins or the reporter protein beta-galactosidase induced an adaptive immune response. Co-delivery of the rat bioactive immunoregulatory cytokine gene TGF-beta to islets using FPV-TGF-beta led to enhanced expression of TGF-beta mRNA in isografts but no long-term protection. Nevertheless, compared to control islet isografts at 5 days, FPV-transduced islets remained embedded in the clotted blood used to facilitate implantation. This phenomenon was TGF-beta transgene-independent, correlated with lack of cellular infiltration, and suggested that the FPV vector transformed the blood clot into a temporary immunological barrier.
authors.affiliation: Division of Immunology and Genetics, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia.
authors.forename: Michelle F
authors.initials: MF
authors.lastname: Solomon
authors.forename: Ian A
authors.initials: IA
authors.lastname: Ramshaw
authors.forename: Charmaine J
authors.initials: CJ
authors.lastname: Simeonovic
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004274:DNA, Recombinant / Q000235:genetics*; D017930:Genes, Reporter / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics*; D007515:Islets of Langerhans / Q000166:cytology / Q000378:metabolism* / Q000821:virology*; D016381:Islets of Langerhans Transplantation; D007763:Lac Operon / Q000235:genetics; D051379:Mice; D008819:Mice, Nude; D011212:Poxviridae / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D014161:Transduction, Genetic; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
chemical_list: D004274:DNA, Recombinant; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta