New α- and SIN γ-retrovectors for safe transduction and specific transgene expression in pancreatic β cell lines

• Published in: BMC biotechnology 2019-06, Vol.19 (1), p.35-35, Article 35
• Main Authors: Albagli, Olivier, Maugein, Alicia, Huijbregts, Lukas, Bredel, Delphine, Carlier, Géraldine, Martin, Patrick, Scharfmann, Raphaël
• Format: Article
• Language: English
• Subjects: Animals; Antigens; Avian cells; Biotechnology; BXV1 xenotropic retrovirus; Cell cycle; Cell Line; Cell Line, Tumor; Cell lines; Cloning; Deoxyribonucleic acid; DNA; EndoC-β H2 cells; Expression vectors; Gene Expression; Gene sequencing; Genetic control; Genetic Vectors - genetics; Genetic Vectors - metabolism; HEK293 Cells; HIV; Human immunodeficiency virus; Humans; Immunodeficiency; Insulin; Insulin-Secreting Cells - cytology; Insulin-Secreting Cells - metabolism; Life Sciences; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Mammals; Mice; Pancreas; Pancreatic β cell lines; Rat insulin promoter; Rats; Regulatory sequences; Retroviridae - classification; Retroviridae - genetics; Retroviridae - metabolism; SIN γ-retrovector; Transduction, Genetic; Transgenes; Transgenes - genetics; Variations; Vectors (Biology); Viruses; Xenotropic; α-Retrovector
• ISSN: 1472-6750; 1472-6750
• DOI: 10.1186/s12896-019-0531-9

Viral vectors are invaluable tools to transfer genes and/or regulatory sequences into differentiated cells such as pancreatic cells. To date, several kinds of viral vectors have been used to transduce different pancreatic cell types, including insulin-producing β cells. However, few studies have used vectors derived from « simple » retroviruses, such as avian α- or mouse γ-retroviruses, despite their high experimental convenience. Moreover, such vectors were never designed to specifically target transgene expression into β cells. We here describe two novel α- or SIN (Self-Inactivating) γ-retrovectors containing the RIP (Rat Insulin Promoter) as internal promoter. These two retrovectors are easily produced in standard BSL2 conditions, rapidly concentrated if needed, and harbor a large multiple cloning site. For the SIN γ-retrovector, either the VSV-G (pantropic) or the retroviral ecotropic (rodent specific) envelope was used. For the α-retrovector, we used the A type envelope, as its receptor, termed TVA, is only naturally present in avian cells and can efficiently be provided to mammalian β cells through either exogenous expression upon cDNA transfer or gesicle-mediated delivery of the protein. As expected, the transgenes cloned into the two RIP-containing retrovectors displayed a strong preferential expression in β over non-β cells compared to transgenes cloned in their non-RIP (CMV- or LTR-) regulated counterparts. We further show that RIP activity of both retrovectors mirrored fluctuations affecting endogenous INSULIN gene expression in human β cells. Finally, both α- and SIN γ-retrovectors were extremely poorly mobilized by the BXV1 xenotropic retrovirus, a common invader of human cells grown in immunodeficient mice, and, most notably, of human β cell lines. Our novel α- and SIN γ-retrovectors are safe and convenient tools to stably and specifically express transgene(s) in mammalian β cells. Moreover, they both reproduce some regulatory patterns affecting INSULIN gene expression. Thus, they provide a helpful tool to both study the genetic control of β cell function and monitor changes in their differentiation status.