EXPRESSION OF FOREIGN GENES IN CULTURED HUMAN PRIMARY MACROPHAGES USING RECOMBINANT VACCINIA VIRUS VECTORS

Recombinant vaccinia viruses (re-VVs) provide an extremely versatile m ethod for the expression of foreign genes in a wide range of cultured cell types of different lineages and species. In the present report, w e examine the utility of re-VV vectors for re-protein production in cu ltured human primary macrophages obtained through in vitro differentia tion of peripheral blood monocytes. Primary macrophages supported earl y stages of the VV infection cycle, including morphologic cytopathic e ffect, shut-off of host protein synthesis and activation of early vira l protein synthesis; however, late stages of infection were blocked, i ncluding synthesis of late viral proteins, replication of viral DNA, a nd production of infectious progeny virions. Abortive infection was ob served with several independent VV strains. Using re-VVs containing Es cherichia coli lacZ as a reporter gene, we assayed the activities of d ifferent classes of VV promoters. Consistent with the results noted ab ove, human primary macrophages supported reporter gene expression driv en by an early or intermediate VV promoter, but not by a late promoter ; expression was obtained with synthetic bifunctional promoters contai ning early and/or intermediate components. Primary macrophages also su pported the VV/bacteriophage T7 RNA polymerase hybrid gene expression system. The utility of re-VV vectors for production of proteins of bio logical interest in human primary macrophages was demonstrated using r e-VVs encoding human CD4 and the human immunodeficiency virus type-1 e nvelope glycoprotein.