Longitudinal study of viral pro subpopulations under the
selective pressure of protease inhibitors in vitro and
in vivo. (A) The MSS HTA of nine
different passages of a virus culture that was subjected to increasing
concentrations of saquinavir. The stepwise shift of the MSS HTA bands
to higher positions can be seen and this shift correlates with an
increasing number of resistance mutations seen in bulk sequences
derived from proviral DNA. Positions highlighted in gray are target
positions of the MSS probe. Two amino acids indicate a mixed
population. hd, heteroduplex; dsP, double-stranded probe.
(B) Patient 1005 was followed during a trial of
ritonavir from the start of monotherapy (St, day 1), through to the
first timepoint of rebound of viral RNA after initial response (Re, day
114), to the endpoint of the trial (E, day 228). The pro
sequences of molecular clones corresponding to different populations
are indicated (L, lower band; U, upper band). Again, the target
positions of the MSS HTA probe are highlighted in gray. Note that the
L63C mutation represents a change of three nucleotides (CTC to TGT)
which likely leads to a mobility shift.