Interferon-gamma-induced factor binding to the interleukin-4-responsive element of CD23b promoter in human tonsillar mononuclear cells: role in transient up-regulation of the interleukin-4-induced CD23b mRNA.
Stimulation of human tonsillar mononuclear cells with interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) rapidly induced the activation of distinct nuclear factors with different mobilities, both of which bind the IL-4 response element (IL-4RE) of CD23b promoter as examined by electrophoretic mobility shift assays (EMSA). Co-treatment of IL-4 and IFN-gamma induced, in addition to the two distinct complexes, a new complex with an intermediate mobility. The IL-4-induced complex reacted with anti-STAT (signal transducers and activators of transcription) 6, resulting in a supershift whereas the formation of the IFN-gamma-induced complex was inhibited by anti-STAT 1. The intermediate complex appeared to react with both anti-STAT 6 and anti-STAT 1. Although IFN-gamma alone did not induce CD23 mRNA transcription, Northern blot analysis revealed a transient up-regulation of the IL-4-induced CD23 mRNA by IFN-gamma within 2 h of IFN-gamma treatment in these tonsillar cells. The results suggest that the IL-4RE of the IL-4-inducible gene can accommodate both IL-4- and IFN-gamma-activated factors, such as STAT 6 and STAT 1, either in homodimeric or heterodimeric forms and the binding of these different proteins to the respective promoter may play a potential regulatory role in the IL-4-inducible gene expression.
Park
H J
HJ
Department of Biology and Institute of Basic Science, College of Natural Science, Sung Kyun Kwan Univ. Suwon, Korea.
So
E Y
EY
Lee
C E
CE
D000818:Animals; D000906:Antibodies / Q000276:immunology; D004268:DNA-Binding Proteins / Q000276:immunology; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000235:genetics; D007073:Immunoglobulin E / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007371:Interferon-gamma / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D014066:Palatine Tonsil / Q000166:cytology* / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000502:physiology; D017455:Receptors, IgE / Q000187:drug effects* / Q000235:genetics*; D050794:STAT1 Transcription Factor; D015534:Trans-Activators / Q000276:immunology; D015854:Up-Regulation / Q000502:physiology
D000906:Antibodies; D004268:DNA-Binding Proteins; D007127:Immunoglobulin Constant Regions; D007143:Immunoglobulin Heavy Chains; D012333:RNA, Messenger; D017455:Receptors, IgE; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; C494080:Stat1 protein, mouse; D015534:Trans-Activators; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma