Regulation of immunoglobulin gene expression in trans by phorbol esters.
Lipopolysaccharide-stimulated B cell cultures treated with phorbol-12,13-dibutyrate have been shown to down-regulate their steady state levels of microseconds RNA while the microns RNA remained constant. In contrast, the steady state levels of delta RNA was up-regulated by the same treatment. By using mice transgenic for a rearranged mu or delta gene, it could be shown that the down-regulatory effect acts in trans on a defined DNA stretch and is independent of isotype. Thus, the positive effect on endogenous delta RNA steady-state levels must be regulated at the level of RNA processing. In addition, a DNA construct containing 1.5 kb of a kappa promoter 5' of, and an IgH enhancer 3' of, a chloramphenicol acetyl transferase reporter gene could be down-regulated in trans by anti-mu- or phorbol-12,13-dibutyrate treatment, showing that transcriptional control of Ig promoter elements can readily be observed in non-transformed B lymphocytes.
Mårtensson
I L
IL
Department of Immunology, University of Uppsala Biomedical Center, Sweden.
Iglesias
A
A
Leanderson
T
T
D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects*; D005803:Genes, Immunoglobulin; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D051379:Mice; D010703:Phorbol Esters / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects
D007143:Immunoglobulin Heavy Chains; D010703:Phorbol Esters; D012333:RNA, Messenger