NASCENT HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 REVERSE TRANSCRIPTION OCCURS WITHIN AN ENVELOPED PARTICLE

Although a small amount of viral DNA has been shown to be enclosed wit hin human immunodeficiency virus type 1 (HIV-1) virions, the majority of full-length viral DNA is formed after this virus infects target cel ls. Hence, we undertook investigations to identify the physical charac teristics of the HIV-1 replication unit during the early events of inf ection. In these studies, nascent viral DNA synthesis was found to occ ur between 15 and 30 min after purified, DNase treated HIV-1 virions w ere added to HUT 78 cells. At Ih postinfection, a large amount of stro ng-stop viral DNA and some first-strand viral DNA had been synthesized . Several lines of evidence, including purification, nuclease digestio n, and immunoprecipitation, indicated that these nascent viral DNAs we re located within particles containing components such as reverse tran scriptase and p24(gag) and gp120(cnv) proteins and having physical cha racteristics similar to those of intact virions.