This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Southgate, T. D. Articles by Castro, M. G. Search for Related Content PubMed PubMed Citation Articles by Southgate, T. D. Articles by Castro, M. G.

Long-Term Transgene Expression within the Anterior Pituitary Gland in Situ: Impact on Circulating Hormone Levels, Cellular and Antibody-Mediated Immune Responses¹

Molecular Medicine and Gene Therapy Unit, School of Medicine, University of Manchester, Manchester M13 9PT, United Kingdom

Address all correspondence and requests for reprints to: Professor Maria Castro, Molecular Medicine and Gene Therapy Unit, School of Medicine, University of Manchester, Stopford Building, Room 1.302, Oxford Road, Manchester M13 9PT, United Kingdom. E-mail: mcastro{at}fs1.scg.man.ac.uk

Adenoviral vectors have been identified as useful tools for gene transfer to the pituitary gland with the aim of providing therapeutic treatments for pituitary diseases. Although successful adenovirus-mediated gene transfer to the pituitary has been shown, the duration of transgene expression, local immune responses and consequences on circulating pituitary hormone levels have not been investigated. These are critical not only for the successful implementation of these gene transfer techniques both for physiological and/or therapeutic applications but also for assessing the safety of these approaches. We have therefore assessed duration and levels of transgene expression 3 days, 14 days, 1, 2, and 3 months after delivery of adenoviruses expressing herpes simplex virus type 1 thymidine kinase (HSV1-TK), under the control of the major immediate early human cytomegalovirus (RAd-hCMV/TK) or human PRL (RAd-hPrl/TK) promoters, to the anterior pituitary (AP) gland in situ. The presence of vector genome and cellular immune infiltrates within the AP gland were also studied along with the levels of circulating anti-adenovirus neutralizing antibodies and AP hormones in sera. Ubiquitous or cell-type specific expression of HSV1-TK within the AP gland was seen from RAd-hCMV/TK and RAd-hPrl/TK respectively at all time points, although a reduction in expression was seen over time. PCR amplification of HSV1-TK specific sequences showed the persistence of adenoviral genomes for up to 3 months. Analysis of the AP showed the presence of a virus-induced inflammation that peaked around day 14 and was resolved between 2–3 months. ED1-positive macrophages, CD8-positive T-cells and CD161-positive NK cells were identified up to 1 month after virus administration. A virus-induced humoral immune response was also present as anti-adenovirus neutralizing antibodies were detected from 14 days after virus administration. Levels of circulating pituitary hormones were unaffected by virus administration with the exception of the stress hormone ACTH which was increased at 3 days but normalized by 14 days. In conclusion, our data indicates that adenovirus-mediated delivery to the AP gland in situ may be a useful tool for the treatment of pituitary diseases as no major cytotoxicity or disruption of AP hormonal functions are seen. Despite of this, further developments to this approach still need to be made to combat the reduced transgene expression seen over time and the induction of virus-induced immune responses.

This article has been cited by other articles:

				M Candolfi, G Jaita, D Pisera, L Ferrari, C Barcia, C Liu, J Yu, G Liu, M G Castro, and A Seilicovich Adenoviral vectors encoding tumor necrosis factor-{alpha} and FasL induce apoptosis of normal and tumoral anterior pituitary cells. J. Endocrinol., June 1, 2006; 189(3): 681 - 690. [Abstract] [Full Text] [PDF]

				W. Xiong, S. Goverdhana, S. A. Sciascia, M. Candolfi, J. M. Zirger, C. Barcia, J. F. Curtin, G. D. King, G. Jaita, C. Liu, et al. Regulatable Gutless Adenovirus Vectors Sustain Inducible Transgene Expression in the Brain in the Presence of an Immune Response against Adenoviruses J. Virol., January 1, 2006; 80(1): 27 - 37. [Abstract] [Full Text] [PDF]

				E. J. Lee and J L. Jameson Gene therapy of pituitary diseases J. Endocrinol., June 1, 2005; 185(3): 353 - 362. [Abstract] [Full Text] [PDF]

				C. Roche, A. J Zamora, D. Taieb, E. Lavaque, R. Rasolonjanahary, H. Dufour, C. Bagnis, A. Enjalbert, and A. Barlier Lentiviral vectors efficiently transduce human gonadotroph and somatotroph adenomas in vitro. Targeted expression of transgene by pituitary hormone promoters J. Endocrinol., October 1, 2004; 183(1): 217 - 233. [Abstract] [Full Text] [PDF]

				J. R. Smith-Arica, J. C. Williams, D. Stone, J. Smith, P. R. Lowenstein, and M. G. Castro Switching On and Off Transgene Expression within Lactotrophic Cells in the Anterior Pituitary Gland in Vivo Endocrinology, June 1, 2001; 142(6): 2521 - 2532. [Abstract] [Full Text] [PDF]