Characterization of a Chinese hamster ovary cell line developed by retroviral insertional mutagenesis that is resistant to Sindbis virus infection

The alphavirus Sindbis virus (SV) has a wide host range and infects many ty pes of cultured cells in vitro. The outcome of infection is dependent on th e strain of virus used for infection and the properties of the cells infect ed. To identify cellular determinants of susceptibility to SV infection we mutagenized Chinese hamster ovary (CHO) cells by retroviral insertion with a vector containing the neomycin resistance gene that allowed selection for integration into transcriptionally active genes. Cells were then selected for survival after infection with SV. The most resistant cell line (CHO-18. 4m) exhibited delayed virus replication and virus-induced cell death, had a single retroviral insertion, and was defective in SV binding to the cell s urface. Further analysis revealed that CHO-18.4m cells were deficient in th e expression of the sulfated glycosaminoglycans heparan sulfate and chondro itin sulfate. This further confirms the importance of heparan sulfate as an attachment molecule for SV in vitro and demonstrates the usefulness of thi s technique for identifying cellular genes that are important for virus rep lication.