title: TGFbeta plasmid construction and delivery for the prevention of type 1 diabetes.
abstract: Studies of animals with spontaneous autoimmune diabetes have revealed that autoreactive T cells that mediate islet beta cell destruction can be manipulated by the administration of Th(2) cytokines. Using gene delivery to express the targeted protein, we can overcome the need for frequent administration of cytokines on account of their short half-lives. In this study, the effect of hTGFbeta gene delivery was evaluated both in vitro and in vivo using an adenovirus vector (Ad) constructed with an hTGFbeta cDNA. In vitro transfection assays of the construct in HepG2, beta cell lines, and islets showed good expression levels of hTGFbeta and activation of smad3. Ad-hTGFbeta enhanced differentiation and proliferation in the beta cell line or islets without causing apoptosis. Of interest, Ad-hTGFbeta transduction in CD4(+)CD25(-) T cells resulted in a significant enhanced expression of CD25 and a regulatory T cell-specific transcription factor, Foxp3. To evaluate in vivo efficacy, Ad-hTGFbeta was intravenously injected into 7-week-old NOD mice and compared to the transduction using the vector only. The Ad-hTGFbeta group had persistent gene expression for longer than 5 weeks, and high TGFbeta serum level was secreted. There was no difference in the degree of insulitis between the Ad-hTGFbeta group and controls. Although we found favorable in vitro results, such as decrease in islet apoptosis, enhanced proliferation and differentiation, and increase in the level of CD4(+)CD25(+) regulatory T cells, there was no difference in reduction of the development of T1D between controls and Ad-hTGFbeta-injected mice. Nevertheless, if we find the appropriate mode and timing of TGFbeta gene transduction, Ad-hTGFbeta gene therapy might be useful in therapeutic cytokine delivery for the treatment of T1D.
authors.affiliation: Department of Internal Medicine & Bioengineering, College of Engineering, Hanyang University, Seoul, Korea.
authors.forename: Leejin
authors.initials: L
authors.lastname: Park
authors.forename: Eunjig
authors.initials: E
authors.lastname: Lee
authors.forename: Sangkyung
authors.initials: S
authors.lastname: Lee
authors.forename: Minsu
authors.initials: M
authors.lastname: Lim
authors.forename: Hekyung
authors.initials: H
authors.lastname: Hong
authors.forename: Geewook
authors.initials: G
authors.lastname: Shin
authors.forename: Yongsoo
authors.initials: Y
authors.lastname: Park
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002478:Cells, Cultured; D003001:Cloning, Molecular; D003921:Diabetes Mellitus, Experimental / Q000517:prevention & control; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000517:prevention & control*; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D010957:Plasmids / Q000235:genetics; D051900:Smad3 Protein / Q000235:genetics; D051906:Smad7 Protein / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000235:genetics*
chemical_list: D051900:Smad3 Protein; C497791:Smad3 protein, mouse; D051906:Smad7 Protein; C497807:Smad7 protein, mouse; D016212:Transforming Growth Factor beta