GROWTH ABILITY OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 AUXILIARY GENE MUTANTS IN PRIMARY BLOOD MACROPHAGE CULTURES

A strain of human immunodeficiency virus type 1 that is strictly tropi c for primary human blood cell cultures was constructed in vitro. Muta tional studies on the vif, vpr, vpu and nef genes of this virus were p erformed to evaluate their biological functions in natural target cell s. For this purpose, replication properties of mutant viruses in perip heral blood mononuclear cells (PBMCs) and macrophages (PBMPs) were det ermined. Three phenotypes with respect to virus replication were notic ed: normal or mildly retarded growth (nef and vpr mutants), impaired g rowth (vpu mutant), and no growth (vif mutant). These results suggest that the Vif and Vpu proteins are more important than the Nef and Vpr proteins for virus replication in PBMCs and PBMPs.