Delivery of HIV-1 Nef linked to heat shock protein 27 using a cationic polymer is more effective than cationic lipid in mammalian cells

BACKGROUND: Different adjuvants and delivery systems have been used to enhance the potency of DNA vaccines against viral diseases. Among them, heat shock proteins (HSPs) are stress proteins that have multiple roles such as chaperon activity and anti-apoptotic and adjuvant properties. The goal of this study was to compare the expression of HIV-1 Nef, Hsp27 and Hsp27-Nef genes transfected in HEK-293T mammalian cells by TurboFect and Lipofectamine as a cationic polymer and lipid, respectively. METHODS: At first, the pEGFP eukaryotic vectors encoding HIV-1 Nef, Hsp27 and Hsp27-Nef genes were generated and transfected in HEK-293T using TurboFect and Lipofectamine delivery systems. Then, the expression of proteins was evaluated and compared using fluorescent microscopy, flow cytometry and western blotting 48 hr after transfection. RESULTS: The accuracy of the DNA constructs was confirmed on agarose gel electrophoresis to be ~ 720 bp, ~ 648 bp, and ~ 1368 bp bands for Hsp27, Nef, and Hsp-Nef, respectively. The expression analysis in the transfected cells showed that the delivery of genes using TurboFect was significantly higher than that using Lipofectamine. Furthermore, transfection of Hsp27 gene was more effective than that of Nef gene using both delivery systems. Hsp27 linked to Nef could also increase its delivery and expression in HEK-293T cells. CONCLUSION: Generally, Hsp27 can be used as a suitable carrier in DNA vaccine design against HIV-1 infections (Fig. 5, Ref. 28).