Expression of Gal4-VP16 and Gal4-DNA binding domain under the control of the T lymphocyte-specific Ick proximal promoter in transgenic mice

Abstract

Thymocyte-specific transcriptional regulatory systems can be used to better understand the relationship between transcription and V(D)J recombination during early T. cell development In this study, we generated transgenic mice expressing the transactivator Gal4-VP16 or the Gal4 DNA binding domain (Gal4-DBD) under the control of the Ick proximal promoter, which is only active in immature thymocytes. From these studies Gal4-VP16 and Gal4-DBD expression was shown to significantly alter thymic cellularity and differentiation without significantly changing the CD3+ thymocyte distribution. Furthermore, the presence of Gal4-VP16 or Gal4-DBD in the transgenic thymocytes retarded the mobility of the Gal4 DNA binding motif as determined by a gel mobility shift assay, suggesting that the developmental alteration did not affect the functional property of the transgenic proteins. These results indicated that Ick promoter-driven Gal4-VP16 or Gal4-DBD expression did not affect CD3+ mature thymocytes, thus this system can be applied to study transcriptional regulation of trans-responder genes in bigenic mouse model thymocytes.