Plasmids used for protein expression in DCs. Plasmids were constructed using standard recombinant DNA techniques, and all constructs were sequenced for potential errors. Plasmid pG encodes GFP alone. Plasmids pOG and pGO encode for OVA-GFP and GFP-OVA fusion proteins, respectively. To obtain more efficient CD4 T-cell activation, plasmids pGOL2tail and psigGOL1tail were done: pGOL2 has a carboxyl-terminal sequence of LIMP-2 protein attached to GFP-OVA fusion, whereas psigGOL1tail has both amino- and carboxyl-terminal signal sequences of LAMP-1 protein connected to GFP-OVA fusion.