Reassessing the human immunodeficiency virus type 1 life cycle through age-structured modeling: lifespan of infected cells, viral generation time and R0. - Related Articles
Reassessing the human immunodeficiency virus type 1 life cycle through age-structured modeling: lifespan of infected cells, viral generation time and R0.
J Virol. 2009 May 20;
Authors: Althaus CL, De Vos AS, De Boer RJ
The rapid decay of viral load after drug treatment in patients infected with human immunodeficiency virus type 1 (HIV-1) has been shown to result from the rapid loss of infected cells due to their high turnover with a generation time of around 1-2 days. Traditionally, viral decay dynamics after drug treatment is investigated using models of differential equations in which both the death rate of infected cells and the viral production rate are assumed to be constant. Here, we describe an age-structured model of the viral decay dynamics in which viral production rates and death rates depend on the age of the infected cell. In order to investigate the effects of age-dependent rates, we compare these models with earlier descriptions of the viral load decay and fit them to previously published data. We find no supporting evidence for increasing infected cell death rates but we cannot reject the possibility of increasing viral production rates with the age of the cell. In particular, we demonstrate that an exponential increase in viral production with infected cell age is perfectly consistent with the data. Since an exponential increase in virus production can compensate for the exponential loss of infected cells, the death rates of HIV-1-infected cells might be higher than previously anticipated. We discuss the implications of these findings on the lifespan of infected cells, the viral generation time and the basic reproductive number R0.
PMID: 19457999 [PubMed - as supplied by publisher] [PubMed-HIV]