@article{mbs:/content/journal/jgv/10.1099/vir.0.19123-0, author = "Weber, Jan and Rangel, Hector R. and Chakraborty, Bikram and Tadele, Mahlet and Martinez, Miguel A. and Martinez-Picado, Javier and Marotta, Michael L. and Mirza, Muneer and Ruiz, Lidia and Clotet, Bonaventura and Wrin, Terri and Petropoulos, Christos J. and Quiñones-Mateu, Miguel E.", title = "A novel TaqMan real-time PCR assay to estimate ex vivo human immunodeficiency virus type 1 fitness in the era of multi-target (pol and env) antiretroviral therapy", journal= "Journal of General Virology", year = "2003", volume = "84", number = "8", pages = "2217-2228", doi = "https://doi.org/10.1099/vir.0.19123-0", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.19123-0", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "Despite numerous studies on human immunodeficiency virus type 1 (HIV-1) fitness, many key conceptual and technical questions are still unsolved. For example, the proper system to determine virus fitness of HIV-1 is still unknown. In this study, an assay was developed to estimate HIV-1 fitness based on growth competition experiments and TaqMan real-time PCR. This novel technique was compared with several methods (i.e. virus growth kinetics, growth competition/heteroduplex-tracking analysis and single-cycle replication capacity assay) in order to analyse the impact of various genomic regions and overall genetic background on virus fitness. HIV-1 primary isolates and three different sets of recombinant viruses [i.e. recombinant clones carrying protease (PR), reverse transcriptase (RT) or the 3′ end of Gag, PR and RT (3′Gag/PR/RT), sequences amplified by PCR from the same primary isolates)] were evaluated. Here, it is demonstrated that, in spite of intrinsic differences, both growth competition/TaqMan and single-cycle replication assays detected a significant reduction in HIV-1 fitness as a consequence of drug-resistant mutations in pol. However, this new assay, based on HIV-1 isolates, may be useful to quantify replicative fitness in viruses from patients treated simultaneously with antiretroviral drugs targeting different genomic regions of HIV-1 (e.g. pol and env).", }