Identification of upstream conserved noncoding sequences for the analysis of transcriptional activation on IL-7 receptor alpha gene

Official URL: http://risc01.sabanciuniv.edu/record=b1143162 (Table of Contents)

Interleukin-7 (IL-7) is a key cytokine in the development of B- and Tlymphocytes. Responsiveness of lymphocyte populations to IL-7 is controlled by the temporal and cell specific expression of the IL-7 receptor (IL-7R). Although there are studies on the transcriptional regulation of IL-7R expression, these findings are insufficient to explain the tight regulation on IL-7R expression. In this study, we identified conserved upstream sequences at the mouse IL-7R alpha locus. We aligned murine and human genomic sequences using a pairwise global alignment approach and found seven noncoding genomic regions with more than 85 percent conservation. We amplified the conserved sequences from a specific bacterial artificial chromosome and constructed luciferase reporter vectors representing these mouse genomic sequences. Here we investigate a reporter gene strategy to identify the transcriptional activation properties of these mouse sequences in a mouse T-lymphoma cell line. We evaluated the efficiency of luciferase assay system in a human kidney fibroblast cell line and a mouse CD4 single positive T-lymphocyte cell line. Due to the distinct expression properties of IL-7R, the present study can be expanded for cells representing the different stages of B- and T-lymphocyte development. Analysis of the transcriptional responses of different cell lineages to the conserved sequences will facilitate the studies on the investigation of the tight regulation on IL-7R expression.