CD8A and infection: We confirmed these results by infection with a full-length native EBNA1-GFP adenoviral expression construct, Ad-E1-GFP, which also showed low T cell proliferation, whilst infection with an adenoviral EBNA1-GFP expression vector where the GAr was deleted, Ad-E1-ΔGA-GFP, resulted in enhanced proliferation of antigen-specific CD8+ T cells (data not shown).