¹Gene Therapy and Therapeutics Branch, National Institute of Dental and Craniofacial Research, Department of Health and Human Services, National Institutes of Health, Bethesda, MD 20892-1190, USA

Correspondence: Bruce J. Baum, Building 10, Room 1N113, MSC-1190, GTTB/NIDCR/NIH, 10 Center Drive, Bethesda, MD 20892-1190, USA. Fax: (301) 402 1228. E-mail: bbaum@dir.nidcr.nih.gov

Received 6 August 2004; Accepted 1 March 2005.

Abstract

To optimize vectors for salivary gland gene transfer, we screened viral [cytomegalovirus (CMV; human immediate early), Rous sarcoma virus (RSV), simian virus 40, and Moloney murine leukemia virus long terminal repeat] and mammalian [elongation factor 1 (EF1), cytokeratin 18 (K18), cytokeratin 19 (K19), kallikrein (Kall), and amylase (AMY), all human, and rat aquaporin-5 (rAQP5), and derivative elements] promoters driving luciferase activity in vitro and in vivo. In adenoviral vectors, the CMV promoter showed highest activity, with the EF1 and RSV promoters slightly less powerful, in rat submandibular glands (SMGs). The K18 2.5-kb, K19 3.0-kb, and rAQP5 0.4-kb and Kall promoters had intermediate activity, while the AMY promoter exhibited lowest activity. To localize transgene expression, enhanced green fluorescence protein was used. The CMV, RSV, EF1, K18 2.5-kb, K19 3.0-kb, rAQP5 0.4-kb, and AMY promoters were not cell-type specific in SMGs; however, the Kall promoter was primarily active in ductal cells. These data will facilitate optimal expression cassette design for salivary gland gene transfer.