Natl Conf Hum Retroviruses Relat Infect (1st). 1993 Dec 12-16;:126.

Using a one-step cell-to-cell transmission infection model, the structure and protein composition of early Human Immunodeficiency Virus (HIV) replication intermediates were investigated. Early replication intermediates refer to the structures associated with the synthesis of unintegrated viral DNA. It was found that unintegrated HIV DNA isolated from the cytoplasm sedimented as part of a discrete complex of approximately 320S. This replication complex was not associated with cell membranes and could not be dissociated into smaller discrete subunits using detergents. PCR detection of the DNA component of immunoprecipitated HIV early replication intermediates showed that the cytoplasmic intermediates were associated with the viral enzymes integrase, reverse transcriptase, protease, the matrix protein (p17) and histones. Nuclear intermediates were found to be associated only with integrase, protease and histones, lacking the viral enzyme reverse transcriptase and the matrix protein (p17). Transportation of HIV early replication intermediates from the cytoplasm to the nucleus was also accompanied by a reduction of the sedimentation coefficient from 320S to approximately 80S. Reverse transcription, the conversion of the single-stranded RNA genome into double-stranded DNA molecule, is a major event in the life cycle of retroviruses. The stages of reverse transcription in HIV infection were investigated in our cell-to-cell infection model. The minus strong-stop DNA and the first template transfer were detected as early as 1.5 hours after infection, with completion of the full-length double-stranded DNA molecule by 3.5 hours, as detected by PCR. Evidence suggests that reverse transcription can proceed from initiation to completion within the 320S nucleoprotein complex.

HIV/*PHYSIOLOGY Polymerase Chain Reaction RNA-Directed DNA Polymerase/GENETICS Templates *Transcription, Genetic Viral Matrix Proteins/GENETICS Virus Replication ABSTRACT