Structural analysis of the mouse chromosomal gene encoding interleukin 4 which expresses B cell, T cell and mast cell stimulating activities

Abstract

Based on homology with the mouse interleukin 4 (IL-4) cDNA that expresses B cell, T cell, and mast cell stimulating activities (Lee, F. et al., (1986) Proc. Natl. Acad. Sci. USA 83, 2061), we have isolated from a Balb/c mouse liver DNA library the mouse chromosomal gene and analyzed its overall structure. The gene occurs as a single copy in the haploid genome and contains four exons and three introns. The exon sequences almost completely match the cloned cDNA sequence. Interestingly, there is a fairly high degree of homology between mouse IL-4 and mouse IL-2 genes extending more than 200 bp upstream of a "TATA" like sequence located 20 bp upstream of the transcription initiation site. These sequences may play an important role in the regulated expression of this gene in concanavalin A or antigen-stimulated T lymphocytes. The supernatant of COS7 cells transfected with plasmid DNA containing the entire gene exhibited both T cell growth factor and mast cell growth factor activities.