Replication of lactic dehydrogenase virus and Sindbis virus in mouse peritoneal macrophages. Induction of interferon and phenotypic mixing

Abstract

Mouse peritoneal macrophages stimulated by thioglycollate can proliferate in culture for over 2 wk. Sindbis virus replicates in these cells, but not in the initial exudate culture. Lactic dehydrogenase virus (LDV) also produces higher yields in the exponentially growing cells. Proliferating macrophages infected with LDV induce a factor that inhibits the replication of Sindbis virus. The factor was identified as interferon by its species specificity and its acid stability. Macrophages that have been in culture for only 24 hr do not produce interferon. Replication of Sindbis virus in LDV-infected macrophages leads to phenotypic mixing between the two virions. We have detected both pure pseudotypes—virions containing the RNA of Sindbis virus and the envelope of LDV—and particles containing the envelope proteins of both virions. Our results demonstrate that the restricted host range of LDV is not due to the inability of the virus to adsorb to cells other than macrophages.