Deterministic Model of the Dynamics of Resistant Viruses under the One-Drug, One-Mutant, One-Cell Version of Our Target-Cell Model

<div><p>(A) Slow turnover rates for CD4⁺ target cells (<i>m</i> = 0.02, <i>k</i> = 0.0005).</p><p>(B) Rapid turnover rates for CD4⁺ target cells (<i>m</i> = 0.32, <i>k</i> = 0.008).</p><p>Here <i>m</i> and <i>k</i> were increased proportionately so as to isolate the effect of changing turnover rate without altering pre-therapy viral load. Blue lines, WT virus; red lines, drug-resistant virus; green lines, target cells. These simulations assume a high cost of resistance (<i>w</i>₁ = <i>k</i>₁/<i>k</i> = 0.6). Other parameters are as in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.0030133#pcbi-0030133-t002" target="_blank">Table 2</a> assuming a single population of short-lived infected cells. Interpretation: these simulations illustrate previous theoretical studies showing the concentration of drug-resistant viruses declines transiently following the initiation of therapy.</p>