Stimulatory and inhibitory action of cytokines on the regulation of hCMV-IE promoter activity in human endothelial cells

Viral promoters are commonly used as regulatory elements in gene therapy ve ctors due to their strong activity in various cell lines in vitro. However, transgene expression under the control of viral promoters in vivo has been shown to be limited to a short period of time. Several mechanisms for the transient expression of the delivered transgene may be important including deletion of transduced cells or promoter downregulation, Recently we report ed that cytokines may either decrease or increase the activity of the human cytomegalovirus (hCMV) promoter in monocytes depending on the differentiat ion status of the transduced cells. For many applications, the gene of inte rest has to be delivered into an inflammatory milieu (tumour, ischaemia/rep erfusion, vector-induced inflammation etc.). In this report we investigated the influence of various inflammatory cytokines on the hCMV-IE promoter ac tivity in transduced human primary endothelial cells (Huvec) in vitro, whic h may be the first target cells after gene transfer into different organs. Cultured cells were infected with an E1-deleted adenoviral vector encoding for E. coli beta-galactosidase (Adp-gal) driven by the hCMV-IE promoter and incubated either with or without various cytokines, Our results indicate t hat interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) downregulate pr omoter activity in endothelial cells whereas, in contrast, tumour necrosis factor (TNF-alpha), interleukin 1 beta (IL-1 beta) and interleukin 4 (IL-4) increased the promoter activity, These results suggest that inflammatory p rocesses influence the in vivo expression of transferred viral promoter con trolled genes of interest. (C) 2000 Academic Press.