Plasmids

The pGag-EGFP plasmid (NIHARP cat #11468) used to prepare HIV-1 VLP, which directs Rev-independent expression of HIV-1 Gag-EGFP fusion protein (tier 1 clade B) to form VLP, was obtained from Dr. Marilyn Resh through the NIH AIDS Reagent Program, Division of AIDS, NIAID, NIH. The pGag-EGFP plasmid was constructed by cloning Gag from pCMV55M1-10 (22) into the pEGFP-N1 plasmid (Clontech) (23). Plasmid DNA was amplified in Escherichia coli DH5α; DH5α-containing pGag plasmid was grown in LB medium supplemented with 25 µg/mL kanamycin. The pHXB2 envelope plasmid (NIHARP cat#1069), containing HXB2 gp160 under an SV40 promoter, was obtained from Dr. Kathleen Page and Dr. Dan Littman through the NIH AIDS Reagent Program, Division of AIDS, NIAID, NIH. Plasmid DNA was amplified in E. coli DH5α; DH5α-containing pHXB2 env plasmid was grown in LB medium supplemented with 50 µg/mL ampicillin. Plasmid purification used the BenchPro 2100 Plasmid Purification System (Invitrogen).