GENERATION AND CHARACTERIZATION OF A HOST CELL-DEPENDENT GAG GENE MUTANT OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1

An in-frame gag gene mutant of human immunodeficiency virus type 1, wh ich carries two amino acid substitutions in the center of the p24 codi ng region, was constructed in vitro, and its replication properties in several cell lines were examined. In CD4-negative SW480 cells transfe cted with the mutant clone, synthesis and processing of viral gag, pol , and env proteins occurred normally, and viral particles were produce d. Virions derived from the transfection displayed a severe replicatio n defect when inoculated into some CD4-positive cell lines (H9 and Mol t4 clone 8), but in other lines (A3.01 and M8166), the mutant virus gr ew fairly well. The mutant was demonstrated to be defective at an earl y infection phase (from adsorption to integration) in Molt4, clone 8 c ells but was normal in A3.01 cells. These results indicated that the G ag-p24 protein of human immunodeficiency virus type 1 plays an importa nt role at the early infection phase in a cell-dependent manner. (C) 1 995 Academic Press, Inc.