L. Karageorgos et al., CHARACTERIZATION OF HIV REPLICATION COMPLEXES EARLY AFTER CELL-TO-CELL INFECTION, AIDS research and human retroviruses, 9(9), 1993, pp. 817-823
In this study, we have characterized the HIV DNA-containing replicatio
n complexes present in cells early after cell-to-cell infection, using
sucrose gradient sedimentation and immunoprecipitation. Six hours aft
er cell-to-cell infection, a cytoplasmic HIV replication complex sedim
ented as a large structure (320S). This replication complex was precip
itated by antisera to three virus-coded enzymes (reverse transcriptase
, integrase, protease), to the matrix protein (p17), and to cellular h
istones but not to the major capsid protein (p24). This replication co
mplex was not associated with cell membranes and could not be dissocia
ted into smaller discrete subunits, using detergents. Nuclear extracts
from the same cell-to-cell infection contained a smaller (80S) comple
x that lacked reverse transcriptase and matrix protein (p17). Cytoplas
mic replication complexes from a cell-free virus infection sedimented
as 160S structures under identical conditions, as previously reported.
Our results indicate that, following cell-to-cell transmission of HIV
, all the HIV pol gene products, the matrix protein p17, and cellular
histones are present in cytoplasmic replication complexes that are tak
ing part in or have completed reverse transcription. Transportation of
the cytoplasmic replication complex to the nucleus is associated with
structural changes, including a reduction in size and altered protein
composition.