13110
Two chronically HIV-1 -infected cell lines , U1 (monocytic) and ACH-2 (T lymphocytic), were stimulated with TNF-alpha or PMA and cultured in the presence of various concentrations of the compound.
 ( protein: TNF-alpha, None) , ( cell line: ACH-2, None) , ( cell line: chronically HIV-1 -infected cell lines, None) , ( cell line: U1, 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: TNF-alpha, None) , ( cell line: ACH-2, None) , ( cell line: chronically HIV-1 -infected cell lines, None) , ( cell line: U1, None) 