14291
In the present study, analysis of the interleukin-2 ( IL-2 ) gene activation shows that naive human helper T cells ( cord blood CD4+ T cells , adult CD4+CD45RO- T cells ) regulate IL-2 transcription by a mechanism involving both a silencer and an activator acting on the purine-rich IL-2 promoter elements ( NF-AT binding sites ).
 ( cell type: adult CD4+CD45RO- T cells, None) , ( protein: interleukin-2, None) , ( protein: IL-2, None) , ( DNA: interleukin-2 ( IL-2 ) gene, None) , ( protein: IL-2, None) , ( DNA: NF-AT binding sites, None) , ( cell type: naive human helper T cells, None) , ( cell type: cord blood CD4+ T cells, None) , ( DNA: silencer, None) , ( DNA: purine-rich IL-2 promoter elements, None) , ( DNA: activator, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( cell type: adult CD4+CD45RO- T cells, None) , ( protein: interleukin-2, None) , ( protein: IL-2, None) , ( DNA: interleukin-2 ( IL-2 ) gene, None) , ( protein: IL-2, None) , ( DNA: NF-AT binding sites, None) , ( cell type: naive human helper T cells, None) , ( cell type: cord blood CD4+ T cells, None) , ( DNA: silencer, None) , ( DNA: purine-rich IL-2 promoter elements, None) , ( DNA: activator, None) 