Changes in human immunodeficiency virus type 1 fitness and genetic diversity during disease progression

J Virol. 2005 Jul;79(14):9006-18. doi: 10.1128/JVI.79.14.9006-9018.2005.


This study examined the relationship between ex vivo human immunodeficiency virus type 1 (HIV-1) fitness and viral genetic diversity during the course of HIV-1 disease. Primary HIV-1 isolates from 10 patients at different time points were competed against control HIV-1 strains in peripheral blood mononuclear cell (PBMC) cultures to determine relative fitness values. Patient HIV-1 isolates sequentially gained fitness during disease at a significant rate that directly correlated with viral load and HIV-1 env C2V3 diversity. A loss in both fitness and viral diversity was observed upon the initiation of antiretroviral therapy. A possible relationship between genotype and phenotype (virus replication efficiency) is supported by the parallel increases in ex vivo fitness and viral diversity during disease, of which the correlation is largely based on specific V3 sequences. Syncytium-inducing, CXCR4-tropic HIV-1 isolates did have higher relative fitness values than non-syncytium-inducing, CCR5-tropic HIV-1 isolates, as determined by dual virus competitions in PBMC, but increases in fitness during disease were not solely powered by a gradual switch in coreceptor usage. These data provide in vivo evidence that increasing HIV-1 replication efficiency may be related to a concomitant increase in HIV-1 diversity, which in turn may be a determining factor in disease progression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acquired Immunodeficiency Syndrome / drug therapy
  • Acquired Immunodeficiency Syndrome / immunology
  • Acquired Immunodeficiency Syndrome / virology*
  • Adult
  • Anti-HIV Agents / therapeutic use
  • CD4 Lymphocyte Count
  • Disease Progression
  • Genetic Variation
  • HIV-1 / classification
  • HIV-1 / genetics*
  • Heteroduplex Analysis
  • Humans
  • Middle Aged
  • Receptors, HIV / physiology
  • Viral Load


  • Anti-HIV Agents
  • Receptors, HIV