5568
MHC class II density on the APC was modified using DQ2 homo -and hetero zygous B-LCLs as APCs , however this variation of MHC concentration had no effect on T cell proliferation .
 ( protein: MHC class II, None) , ( cell type: APC, None) , ( cell type: APCs, None) , ( cell type: T cell, 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: MHC class II, None) , ( cell type: APC, None) , ( cell type: APCs, None) , ( cell type: T cell, None) 