A regulatable adenovector for simultaneous expression of thymulin and GFP genes in muscle and brain

REGGIANI PC; POCH B; RIMOLDI OJ; GOYA RG

Puerto Madryn

Congreso; XLVI Reunión Anual SAIB.; 2010

SAIB

Thymulin (FTS) is a thymic peptide possessing hypophysiotropic activity and antiinflammatory effects in the brain. In order to regulate FTS expression tightly in gene therapy studies, we built a two-adenovector Tet-Off regulatable system in which transgene expression can be turned off at the transcriptional level by doxycycline (DOX). It consists of two adenoviral vectors: RAd-(GFPtreFTS)bd, expressing the genes for green fluorescent protein (GFP) and FTS under the control of a bidirectional regulatable promoter, and RAd-tTA, constitutively expressing the transactivator protein tTA. We also constructed a control system expressing only GFP. Different cell lines were co-transduced with both RAd’s. High expression of GFP and FTS was observed, whereas both genes were silenced by addition of Dox. Male rats received ICV injections of either both RAd’s or RAd-(GFPtreFTS)bd alone (control). After 48 hs thymulin levels rose in the CSF (24±4.6 fg/ml) of animals injected with both RAds relative to controls (4±0.3 fg/ml). This system was also administered i.m. to rats. Initially, serum FTS levels rose (384±74 fg/ml), but fell to basal levels (102±16 fg/ml) after addition of DOX to the drinking water. This regulatable gene expression system constitutes a suitable tool to further investigate the role of thymulin in the maturation of the neuroendocrine system during postnatal life in rodents.