Semliki Forest virus

From these data, it is tempting to conclude that the inactivation of cap-dependent translation which seems to occur in poliovirus-infected HeLa cells, and perhaps in reovirus-infected L cells, also occurs in neuroblastoma cells infected with SFV. Although the relevance of a redirection of the protein-synthesizing system towards noncapped mRNAs is obvious for uncapped poliovirus or for uncapped reovirus mRNAs, the rationale for SFV-infected cells is obscured because SFV mRNAs, when isolated from infected cells, appear to be capped (Pettersson et al., 1980). In addition, further analyses of initiation factors from SFV-infected cells suggest that the mechanisms operative in the shift in specificity might be different from the biochemical lesion(s) induced by poliovirus. 

The first major difference emerged when both eIF-4B and 24-CBP were partially purified from SFV-infected neuroblastoma cells and compared with uninfected cell factors for activity in translation 

Efforts to identify the inhibitory component in infected cell ribosomal salt wash yielded a protein of Mr 33,0(X) daltons, which comigrated with the SFV capsid protein on SDS-polyacrylamide gels and which reacted with antibodies raised against viral capsid protein (H. Van Steeg, personal communication). This protein, purified from infected cell ribosomal salt wash, selectively inhibited translation in vitro of host and early viral mRNA, but had no effect on translation of late viral mRNA or EMC virus RNA. The mechanism by which SFV capsid protein interferes with translation initiation of some mRNAs is not understood, nor is it clear how SFV late mRNA eludes the inhibition, or what role cap recognition plays in this scheme. However, the overall strategies followed by SFV and poliovirus may be quite similar, despite differences in underlying mechanisms. 

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Alphaviruses, such as Sindbis virus and Semliki Forest virus, are a group of mosquito-borne, enveloped RNA viruses that can cause encephalitis, fever, arthritis and rashes in mammals. These viruses have two protein shells—an outer glycoprotein layer and an inner core— which are separated by a lipid bilayer, a membrane. Studies by cryoelectron microscopy have shown that... 

Helenius, A., Kartenbech, J., Simons, K., and Fries, E. (1980) On the entry of Semliki forest virus into BHK-21 cells./. Cell Biol. 84, 404. 

Semliki Forest virus Rapid virus production Broad host range Extreme yields of receptors Large-scale technology established Safety concerns... 

Semliki Forest virus Easy Extreme/easy High Short/easy Of concern High... 

Simmen U, Schweitzer C, Burkard W, Schaffner W, Lundstrom K. (1998). Hypericum perforatum inhibited the binding of mu- and kappa-opioid receptor expressed with the Semliki Forest virus system. Pharm Acta Helv. 73 53-56. 

One experimental tool in this direction is provided by some enveloped animal viruses which mature at the cell surface of infected cells (K Sri inen and Renkonen, 1977 Lenard, 1978). Such viruses include influenza virus, Semliki Forest virus (SFV), Sindbis virus, and vesicular stomatitis virus (VSV). They are extremely simple in makeup and hence are very well characterized. They can be tagged with biochemical probes in many different ways. They infect many animal cells in culture, and after infection turn the cells into factories for the production of virus progeny. The protein-synthesizing machinery of the host cell is programmed by the viral RNA to make viral proteins exclusively and these include the viral surface glycoproteins. These are synthesized with signal peptides and inserted into the ER membrane (Katz et ai, 1977 Garoff et... 

We wish to thank Henrik Garofl, Ari Helenius, Carl-Henrik von Bonsdorff, and Maija Pesonen for a critical reading of the manuscript. One of us (K. S.) would like to express a special word of thanks to Hilkka Virta for unfailing and devoted technical support through all stages of the Semliki Forest virus studies both in Helsinki and in Heidelberg. 

Semliki Forest Virus A Probe for Membrane Traffic in the... 

Marsh M, Helenius A. Adsorptive endocytosis of Semliki Forest virus. J Mol Biol 1980 142(3) 439 54. 

Introduction of a gene of interest into the host cell line by viral infection is a convenient method since a large number of cells can be infected simultaneously. Systems employing Semliki Forest Virus, Vaccinia Virus, and Retoviral vectors are used. However, drawbacks include the requirement for special precautions when engineering and preparing the viral... 

Welsh, J. K., Skurrie, 1. J., and May, J. T. (1978). Use of Semliki forest virus to identify lipid-mediated antiviral activity and anti-alphavirus immunoglobulin A in human milk. Infect. Immun. 19, 395 01. 

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