Semliki Forest Virus Expression System

Abstract

The Semliki Forest virus (SFV) expression system utilises the efficient replication of SFV to transiently express foreign proteins in eukaryotic cells. In the basic version, cells are infected with a recombinant SFV where the part of the viral ribonucleic acid (RNA) genome that encodes the virus structural proteins is replaced by a gene of interest (transgene). On infection the viral genome is amplified and efficiently translated in the host cell cytoplasm, resulting in high‐level expression of the transgene. Recombinant virus is produced by co‐transfection of recombinant viral genomes and a helper genome that provides the virus structural proteins. Alternatively, infection is initiated by transfection with viral RNA genomes produced in vitro. Further developments, aiming for vaccine and therapeutic applications, include a deoxyribonucleic acid (DNA) vector where the recombinant SFV genome is placed under a cytomegalovirus promoter. This allows transgene expression without involving the structural virus proteins, and avoids RNA work in vitro.

Key Concepts:

  • A polylinker is a short DNA sequence containing multiple unique restriction sites.

  • A packaging signal is a motif in the viral genome that specifically interacts with the capsid forming protein of the virus. This will ensure efficient genome incorporation.

  • Replicon RNA is self‐replicating RNA that directs efficient production of protein.

  • Recombinant SFV is a suicide virus that infect cells and delivers replicon RNA but cannot produce new virions.

  • An autoprotease is a single use enzyme that is synthesised as part of a polyprotein and will release itself from the growing polypeptide chain.

Keywords: alphavirus; protein production; mammalian cells; virus‐like particle; vector RNA; replicon

Figure 1.

Replication of Semliki Forest virus.

Figure 2.

Outline of the Semliki Forest virus expression system.

close

References

Atkins GJ, Fleeton MN and Sheahan BJ (2008) Therapeutic and prophylactic applications of alphavirus vectors. Expert Reviews in Molecular Medicine 10: e33. doi:10.1017/S1462399408000859.

Berglund P, Sjöberg M, Garoff H et al. (1993) Semliki forest virus expression system: production of conditionally infectious recombinant particles. Biotechnology 11: 916–920.

Berglund P, Smerdou C, Fleeton MN, Tubulekas I and Liljeström P (1998) Enhancing immune responses using suicidal DNA vaccines. Nature Biotechnology 16: 562–565.

Carroll TD, Matzinger SR, Barro M et al. (2011) Alphavirus replicon‐based adjuvants enhance the immunogenicity and effectiveness of Fluzone® in rhesus macaques. Vaccine 29: 931–940.

Fu Y, Chen Z, Li C and Liu G (2012) Protective immune responses in ducklings induced by a suicidal DNA vaccine of the VP1 gene of duck hepatitis virus type 1. Veterinary Microbiology 160: 314–318.

Herweijer H, Latendresse JS, Williams P et al. (1995) A plasmid‐based self‐amplifying Sindbis virus vector. Human Gene Therapy 6: 1161–1167.

Johansson DX, Ljungberg K, Kakoulidou M and Liljeström P (2012) Intradermal electroporation of naked replicon RNA elicits strong immune responses. PLoS One 7: e29732.

Li KJ and Garoff H (1996) Production of infectious recombinant Moloney murine leukemia virus particles in BHK cells using Semliki Forest virus‐derived RNA expression vectors. Proceedings of the National Academy of Sciences of the USA 93: 11658–11663.

Liljeström P and Garoff H (1991) A new generation of animal cell expression vectors based on the Semliki Forest virus replicon. Nature Biotechnology 9: 1356–1361.

Ljungberg K, Whitmore AC, Fluet ME et al. (2007) Increased immunogenicity of a DNA‐launched Venezuelan equine encephalitis virus‐based replicon DNA vaccine. Journal of Virology 81: 13412–13423.

Lulla V, Kim DY, Frolova EI and Frolov I (2013) The amino‐terminal domain of alphavirus capsid protein is dispensable for viral particle assembly, but regulates RNA encapsidation through cooperative function of its subdomains. Journal of Virology 87: 12003–12019.

Lundstrom K (2003) Novel semliki forest virus vectors with reduced cytotoxicity and temperature sensitivity for long‐term enhancement of transgene expression. Molecular Therapy 7: 202–209.

Morse MA, Hobeika AC, Osada T et al. (2010) An alphavirus vector overcomes the presence of neutralizing antibodies and elevated numbers of Tregs to induce immune responses in humans with advanced cancer. Journal of Clinical Investigation 120: 3234–3241.

Quetglas JI, Rodriguez‐Madoz JR, Bezunartea J et al. (2013) Eradication of liver‐implanted tumors by semliki forest virus expressing IL‐12 requires efficient long‐term immune responses. Journal of Immunology 190: 2994–3004.

Schlesinger S (2001) Alphavirus vectors: development and potential therapeutic applications. Expert Opinion on Biological Therapy 1(2): 177–191. doi:10.1517/14712598.1.2.177.

Sjöberg EM and Garoff H (1996) The translation‐enhancing region of the Semliki Forest virus subgenome is only functional in the virus‐infected cell. Journal of General Virology 77(Part 6): 1323–1327.

Sjöberg M, Suomalainen M and Garoff H (1994) A significantly improved semliki forest virus expression system based on translation enhancer segments from the viral capsid gene. Biotechnology 12: 1127–1131.

Smerdou C and Liljeström P (1999) Two‐helper RNA system for production of recombinant Semliki forest virus particles. Journal of Virology 73: 1092–1098.

Vähä‐Koskela MJV, Tuittila MT, Nygårdas PT et al. (2003) A novel neurotropic expression vector based on the avirulent A7(74) strain of Semliki Forest virus. Journal of NeuroVirology 9: 1–15.

Vander Veen RL, Harris DLH and Kamrud KI (2012) Alphavirus replicon vaccines. Animal Health Research Reviews 13: 1–9.

Weaver SC, Osorio JE, Livengood JA, Chen R and Stinchcomb DT (2012) Chikungunya virus and prospects for a vaccine. Expert Review of Vaccines 11: 1087–1101.

Weclewicz K, Ekström M, Kristensson K and Garoff H (1998) Specific interactions between Retrovirus Env and Gag proteins in rat neurons. Journal of Virology 72: 2832–2845.

Yang Y, Xiao F, Lu Z et al. (2013) Development of a novel adenovirus–alphavirus hybrid vector with RNA replicon features for malignant hematopoietic cell transduction. Cancer Gene Therapy 20: 429–436.

Zhao H‐P, Sun J‐F, Li N et al. (2009) Prime‐boost immunization using alphavirus replicon and adenovirus vectored vaccines induces enhanced immune responses against classical swine fever virus in mice. Veterinary Immunology and Immunopathology 131: 158–166.

Further Reading

Ekström M, Garoff H and Andersson H (2006) Semliki forest virus expression system. In: Celis JE (ed.) Cell Biology: A Laboratory Handbook, 3rd edn, vol. 4, pp. 63–67. London, UK: Elsevier Academic Press.

Karlsson GB and Liljeström P (2004) Delivery and expression of heterologous genes in mammalian cells using self‐replicating alphavirus vectors. Methods in Molecular Biology (Clifton, NJ) 246: 543–557.

Lundstrom K (2012a) Determination of alphaviral titers. Cold Spring Harbor Protocols 2012(7): 835–837. doi:10.1101/pdb.prot070177.

Lundstrom K (2012b) Generation of recombinant alphaviral vectors. Cold Spring Harbor Protocols 2012(7): 825–831. doi:10.1101/pdb.prot070151.

Lundstrom K (2012c) Purification and concentration of alphavirus. Cold Spring Harbor Protocols 2012(7): 832–834. doi:10.1101/pdb.prot070169.

Sjöberg M and Garoff H (2006) Growth of Semliki Forest Virus. In: Celis JE (ed.) Cell Biology: A Laboratory Handbook, 3rd edn, vol. 1, pp. 419–423. London, UK: Elsevier Academic Press.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Sjöberg, Mathilda(Jul 2014) Semliki Forest Virus Expression System. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0002661.pub3]