Modification of a salmonid alphavirus replicon vector for enhanced expression of heterologous antigens.
A salmonid alphavirus (SAV) replicon has been developed to express heterologous antigens but protein production was low to modest compared with terrestrial alphavirus replicons. In this study, we have compared several modifications to a SAV replicon construct and analysed their influence on foreign gene expression. We found that an insertion of a translational enhancer consisting of the N-terminal 102 nt of the capsid gene, together with a nucleotide sequence encoding the foot-and-mouth disease virus (FMDV) 2A peptide, caused a significant increase in EGFP reporter gene expression. The importance of fusing a hammerhead (HH) ribozyme sequence at the 5' end of the viral genome was also demonstrated. In contrast, a hepatitis D virus ribozyme (HDV-RZ) sequence placed at the 3' end did not augment expression of inserted genes. Taken together, we have developed a platform for optimized antigen production, which can be applied for immunization of salmonid fish in the future.
Norwegian University of Life Sciences, Department of Basic Sciences and Aquatic Medicine, P.O. Box 8146 Dep., N-0033 Oslo, Norway.
Tz-Chun
TC
Guo
Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
Daniel X
DX
Johansson
Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
Peter
P
Liljeström
Norwegian University of Life Sciences, Department of Basic Sciences and Aquatic Medicine, P.O. Box 8146 Dep., N-0033 Oslo, Norway.
Øystein
Ø
Evensen
Norwegian University of Life Sciences, Department of Basic Sciences and Aquatic Medicine, P.O. Box 8146 Dep., N-0033 Oslo, Norway.
Øyvind
Ø
Haugland
D000524:Alphavirus / Q000235:genetics*; D000818:Animals; D000956:Antigens, Viral / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003588:Cytopathogenic Effect, Viral; D018076:DNA, Complementary; D004279:DNA, Viral; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D005822:Genetic Vectors / Q000235:genetics* / Q000502:physiology; D012093:Replicon / Q000235:genetics*; D014776:Virus Cultivation
D000956:Antigens, Viral; D018076:DNA, Complementary; D004279:DNA, Viral