We are proud to announce that the peer-reviewed journal Biologicals has now published our work on the high yield expression of an HIV envelope protein.
Despite numerous advances in the understanding of HIV and AIDS, the search for a potent anti-HIV vaccine continues. The envelope glycoproteins found on the surface of the HIV virus are prime targets for HIV vaccine development efforts. Researchers have shown high promise for gp145 as a vaccine candidate against HIV in various preclinical studies. However, further development has remained largely hindered due to low yields of biologically active recombinant HIV gp145. This was further complicated by the extensive glycosylation pattern that decorates the protein.
With Batavia’s STEP®-protein technology, our team was able to develop a stable cell line, able to express high yields of the HIV gp145 protein. The developed CHO cell lines expressed HIV gp145 with significantly higher overall expression yields than currently accessible. Additionally, it produced high product quality that could potentially be suitable for future studies assessing the efficacy and safety of gp145-based HIV vaccines.
STEP®-protein is a cell line development technology which is especially suitable for the efficient expression of difficult to express proteins.
The STEP technology is comprised of an adaptable, stringent antibiotic (zeocin) selection system and expression enhancing DNA elements. Stringency of selection pressure is introduced by a functionally impaired selection marker (FI-Zeo), thus introducing a minimum threshold for expression of the transgene and selection marker protein in transfected cells.
Only cells with sufficiently high expression levels can survive the selection pressure. The gene of interest (GOI) is expressed on the same mRNA as the selection marker. They are translationally coupled to the upstream GOI via an IRES. Therefore, high expression of the selection marker results in high expression levels of the GOI.
The expression cassette is flanked by two expression enhancing DNA elements. These elements increase expression levels and thereby also facilitate the use of high selection stringency.