1882
Results were statistically correlated with those of CD4+ cell counts (17 out of 17) and with anti- EBV antibody titres (13 out of 17) assessed using standard immunofluorescence method and enzyme-linked immunosorbent assay procedure using recombinant ZEBRA protein and synthetic peptides as antigens .
 ( protein: recombinant ZEBRA protein, None) , ( protein: CD4+, None) , ( protein: antigens, None) , ( protein: ZEBRA, 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: recombinant ZEBRA protein, None) , ( protein: CD4+, None) , ( protein: antigens, None) , ( protein: ZEBRA, None) 