ABERRANT GAG PROTEIN-COMPOSITION OF A HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 VIF MUTANT - PRODUCED IN PRIMARY LYMPHOCYTES

Productive, spreading infection of peripheral blood lymphocytes (PBL) with human immunodeficiency virus type 1 (HIV-1) requires the viral pr otein Vif. To study the requirement for vif in this system, we infecte d PBL with a phenotypically complemented HIV-1 clone mutated in vif. P rogeny virus was produced which was noninfectious in PBL but replicate d in SupT1 cells. Analysis of metabolically labeled proteins of sedime ntable extracellular particles made in PBL by radioimmunoprecipitation with either serum from a patient with AIDS or a monoclonal antibody r eactive with HIV-1 Gag proteins revealed that vif-negative but not wil d-type particles carry higher levels of p55, p41, and p38 Gag-specific proteins compared with those of p24. Similar results were obtained wi th sucrose-purified virions. Our data indicate that vif plays a role i n Gag protein processing or in incorporation of processed Gag products into mature virions. The presence of unprocessed precursor Gag polypr otein (Pr55(gag)) and other Gag processing intermediates in PBL-derive d vif-negative extracellular particles may contribute to the reduced i nfectivity of this virus.