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Sindbis virus expression has been used for in vitro investi-50% of transfected cells. Cells were then cotransfected gations of antigen processing, presentation and epitope with DH-BB helper sequences that enabled the recombimapping. The recent development of a replication-deficient nant Sindbis virus RNA packaging. Nonreplicative Sindbis recombinant Sindbis virus expression vector has made in viral stock was collected 24 h after transfection. BHK cells vivo expression possible with minimal pathogenic risk.were then infected with viral stock and histochemistry Advantages of Sindbis virus over other available viral sysanalysis was performed. Again, approximately 50% of the tems include a comparatively smaller genome size making cells expressed ␤-gal. The same viral stock was infused it possible to clone larger inserts, the ability to infect a wide into the nucleus caudatus/putamen and nucleus accumrange of host cell types with reduced pathogenicity for bens septi and histochemical analysis on frozen sections humans. These features suggest the possible utility of from the relevant brain areas confirmed that ␤-gal was Sindbis virus for the in vivo delivery of genes to neural expressed in neurons in a time-dependent manner. ␤-Gal cells. We used the recombinant Sindbis viral expression was detected at 24 h after inoculation and was present for system to target delivery of the lacZ gene to neuronal cells at least 14 days, with maximum expression at 48 h. These of mice by stereotactic surgery. Sindbis viral mRNA results suggest that a nonreplicative Sindbis virus obtained by in vitro transcription was used to transfect baby expression system may be useful for delivery of foreign hamster kidney (BHK) cells. As shown by histochemistry, genes into the central nervous system (CNS). ␤-galactosidase (␤-gal) was expressed in approximately

Resident cells of the respiratory and gastrointestinal tracts, including epithelial and fibroblast cells, are the initial sites of entry for many viral pathogens. We investigated the role that these cells play in the inflammatory process in response to infection with reovirus 1/L. In A549 human bronchial or HT-29 human colonic epithelial cells, interferon (IFN)-beta, regulated on activation T cell expressed and secreted (RANTES), IFN-gamma-inducible protein (IP)-10, and interleukin-8 were upregulated regardless of whether cells were infected with replication-competent or replication-deficient reovirus 1/L. However, in CCD-34Lu human lung fibroblast cells, IFN-beta, IP-10, and RANTES were expressed only after infection with replication-competent reovirus 1/L. Expression of interleukin-8 in CCD-34Lu fibroblast cells was viral replication independent. This differential expression of IFN-beta, RANTES, and IP-10 was shown to be due to the lack of induction of IFN regulatory factor-1 and -2 in CCD-34Lu fibroblast cells treated with replication-deficient reovirus 1/L. We have shown that cytokine and/or chemokine expression may not be dependent on viral replication. Therefore, treatment of viral infections with inhibitors of replication may not effectively alleviate inflammatory mediators because most viral infections result in the generation of replication-competent and replication-deficient virions in vivo.

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