Lipoplexes Carrying mRNA Encoding Gag Protein Modulate Dendritic Cells to Stimulate HIV-Specific Immune Responses

Abstract

Aim: Cationic lipids (Lipofectamine™ [Invitrogen, Merelbeke, Belgium] and 1,2-dioleoyl-3-trimethylammonium-propane/1,2-dioleoyl-sn-glycero-3-phosphoethanolamine) and polymers (jetPEI™ and in vivo-jetPEI™ [Polyplus-transfection, Illkirch, France]) were evaluated for their potential to deliver mRNA to monocyte-derived dendritic cells. Materials & methods: Lipoplexes and polyplexes, containing mRNA encoding GFP or Gag protein, were incubated with human monocyte-derived dendritic cells and transfection efficiencies were assessed by flow cytometry. Results: Lipofectamine was by far the most efficient in mRNA delivery, therefore it was used in further experiments. Incubation of monocyte-derived dendritic cells isolated from HIV-1-positive donors with mRNA encoding Gag protein complexed to Lipofectamine resulted in 50% transfection. Importantly, coculture of these Gag-transfected dendritic cells with autologous T cells induced an over tenfold expansion of IFN-γ- and IL-2-secreting CD4⁺ and CD8⁺ T cells. Conclusion: Cationic lipid-mediated mRNA delivery may be a useful tool for therapeutic vaccination against HIV-1. This approach can be applied to develop vaccination strategies for other infectious diseases and cancer.

Original submitted 26 January 2012; Revised submitted 17 April 2012; Published online 14 August 2012

Keywords::

• cationic lipid
• dendritic cell
• HIV-1
• immunostimulation
• immunotherapy
• mRNA delivery
• nanoparticle

Financial & competing interests disclosure

This work was supported by grants from Inter-University Attraction Poles (IUAP; P6/41 of the Belgian government), Fund for Scientific Research Flanders (FWO; project no. G.0226.10), Secondary Research Funding Institute of Tropical Medicine (SOFI-B) and European Vaccines and Microbicides Enterprise (Europrise; contract no. 037611). W De Haes is a predoctoral fellow of the Agency for Innovation by Science and Technology in Flanders. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Acknowledgements

The authors thank the HIV-positive persons for donating their blood and the personnel of the AIDS reference clinic and laboratory of the authors’ Institute for the recruitment of the patients and collecting the samples. The authors are grateful to the NIH AIDS Research and Reference Reagent Program for providing the peptides.

Additional information

Funding

This work was supported by grants from Inter-University Attraction Poles (IUAP; P6/41 of the Belgian government), Fund for Scientific Research Flanders (FWO; project no. G.0226.10), Secondary Research Funding Institute of Tropical Medicine (SOFI-B) and European Vaccines and Microbicides Enterprise (Europrise; contract no. 037611). W De Haes is a predoctoral fellow of the Agency for Innovation by Science and Technology in Flanders. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.