Can modulation of viral fitness represent a target for anti-HIV-1 strategies?
Prolonged use of anti-retroviral compounds in human immunodeficiency virus type 1 (HIV-1) infection selects for drug-resistant and often mutidrug-resistant viral variants. Drug-resistance mutations may also affect viral fitness. Interestingly, recent research has indicated that some of the unfit drug-resistant variants may be less pathogenic, suggesting that decreased viral fitness is beneficial for the host and may be driven by specific treatments during anti-HIV-1 infection. A second potential antiviral strategy starting with profound inteference with viral fitness aims at forcing viruses towards lethal mutagenesis (the so-called "error catastrophe"). This review summarizes the methods for addressing HIV-1 fitness in vitro and ex vivo, the current understanding of clinical implications of reduced HIV-1 fitness, and the potential use of anti-HIV-1 strategies aiming at modulating viral fitness. Finally, it is emphasized how the peculiar features of HIV-1 quasispecies (displaying two different forms of memory, a replicative and a non-replicative form) may sharply influence the design of future diagnostic methodologies for fitness analysis.
Università Vita-Salute San Raffaele, Milan, Italy.
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D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D009154:Mutation; D012641:Selection, Genetic; D014779:Virus Replication