5368
Injection of SEA to adult mice activates CD4+ T cells expressing certain T-cell receptor (TCR) variable region beta-chain families and induces strong and rapid production of interleukin 2 ( IL-2 ).
 ( cell type: T cells, None) , ( protein: SEA, None) , ( protein: T-cell receptor (TCR) variable region beta-chain families, None) , ( cell type: CD4+ T cells, None) , ( protein: IL-2, 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: T cells, None) , ( protein: SEA, None) , ( protein: T-cell receptor (TCR) variable region beta-chain families, None) , ( cell type: CD4+ T cells, None) , ( protein: IL-2, None) 