Production of HIV-1-based virus-like particles for vaccination: achievements and limits.

Over the past years, much knowledge has been gained about the HIV-1 virus structure and infection cycle. This knowledge has been used to conceive different types of potential vaccines and vaccination strategies. This review focuses on the characteristics of the virus and the vaccines that have been developed, particularly on those using virus-like particles, as well as on the developments for their production and purification. The production of HIV-1 VLPs has been investigated in different platforms such as, yeast, plants, insect and mammalian cells. Their purification follows the same rational as for viral vectors: clarification, nuclease treatment, concentration/capture, polishing, formulation and viral clearance. Analytical techniques to characterise the obtained productions will be of paramount relevance for their final application, considering that the raw production obtained in bioreactors comprises not only the VLPs of interest but also many other extracellular vesicles. Finally, it should also be considered that VLPs are prone to carry host cell proteins and DNA.