415
Antigen complexed with major histocompatibility complex class I or II molecules on the surface of antigen presenting cells interacts with the T cell receptor ( TCR ) on the surface of T cells and initiates an activation cascade.
 ( protein: T cell receptor, None) , ( cell type: T cells, None) , ( protein: TCR, None) , ( cell type: antigen presenting 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:
 ( protein: T cell receptor, None) , ( cell type: T cells, None) , ( protein: TCR, None) , ( cell type: antigen presenting cells, None) 