2073
We tested the effects of BHA , a phenolic, lipid-soluble, chain-breaking antioxidant , and NAC , a known glutathione precursor with some direct free-radical scavenging properties as well, on the regulation of HIV -1 expression in latently infected U1 cells and in productively and chronically infected U937 cells .
 ( cell line: U937 cells, None) , ( cell line: U1 cells, 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 line: U937 cells, None) , ( cell line: U1 cells, None) 