4446
The proliferative responses of purified CD4+ or CD8+ T cells are suppressed more strongly by TPCK when anti-CD28 rather than the phorbol ester PMA is used as the mitogenic coactivator .
 ( protein: coactivator, None) , ( protein: anti-CD28, 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:
 ( protein: coactivator, None) , ( protein: anti-CD28, None) 