IL-2 promoter-driven lacZ expression as a monitoring tool for IL-2 expression in primary T cells of transgenic mice.
A transgenic mouse system has been established to follow the pattern of IL-2 expression at the level of single T cells. This was achieved by introducing a human IL-2 promoter-driven reporter gene (Escherichia coli lacZ) into the germline of mice and monitoring its product, beta-galactosidase (beta-gal), by FACS analysis. Ex vivo experiments confirmed that the regulated expression of the transgene is comparable with that of the endogenous IL-2 gene. Transgene expression is inducible by mitogens, restricted to T cells, and diminished by immunosuppressive agents, such as cyclosporin A, at concentrations known to suppress IL-2 transcription. Depending on the mitogens used, 30-50% of peripheral T cells produced IL-2 with an asynchronous induction pattern, as measured by transgenic beta-gal activity. Both helper (CD4+CD8-) and cytotoxic T cells (CD4-CD8+) respond with comparable heterogenous expression levels but they show different frequencies of beta-gal production. Transgenic beta-gal-producing T cells were detectable as early as 2 h after mitogen stimulation. These cells represent a transitional IL-2 secreting, IL-2 receptor alpha-chain negative T cell population, which occurs in the autocrine process of T cell activation. Administration of staphylococcal enterotoxin A (SEA), a bacterial superantigen, resulted in a T cell specific (Thy-1.2) increase (2.5-fold) of reporter gene expression in vivo. In summary, we could demonstrate that IL-2 promoter-driven reporter gene expression in transgenic mice is a sensitive tool to characterize IL-2 expressing cells phenotypically.(ABSTRACT TRUNCATED AT 250 WORDS)
Brombacher
F
F
Sandoz Pharma Ltd, Basel, Switzerland.
Schäfer
T
T
Weissenstein
U
U
Tschopp
C
C
Andersen
E
E
Bürki
K
K
Baumann
G
G
D000818:Animals; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D007376:Interleukin-2 / Q000235:genetics*; D007763:Lac Operon; D051379:Mice; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D001616:beta-Galactosidase / Q000096:biosynthesis*
D007376:Interleukin-2; D001616:beta-Galactosidase