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Different evolutionary patterns are found within human immunodeficiency virus type 1-infected patients
Concepción Casado1, Soledad García2, Carmen Rodríguez2
1Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Majadahonda, Madrid 28220, Spain1.
The Journal of General Virology
|September 20, 2001
Summary
Human immunodeficiency virus type 1 (HIV-1) evolution in patients shows diverse genetic patterns. Viral quasispecies analysis reveals distinct evolutionary pathways within individuals, even with normal clinical progression.
Area of Science:
- Virology
- Molecular Evolution
- Immunology
Background:
- Human immunodeficiency virus type 1 (HIV-1) infection is a complex disease with ongoing viral evolution.
- Understanding in vivo HIV-1 evolution is crucial for developing effective treatment and prevention strategies.
- Previous studies have focused on clinically progressing patients, leaving the evolutionary dynamics in typical cases less explored.
Purpose of the Study:
- To investigate the in vivo evolution of HIV-1 in patients with normal clinical progression.
- To analyze the genetic variability and evolutionary patterns of HIV-1 quasispecies within individual patients.
- To identify potential differences in evolutionary forces acting on distinct viral clades within the same host.
Main Methods:
- Selection of six HIV-1 infected patients with normal clinical evolution, followed for 1-4 years.
- Analysis of viral genetic variability using heteroduplex mobility assay and RNase A mismatch cleavage.
- Nucleotide sequencing of the C2-fusion domain of the env gene to study virus quasispecies.
- Phylogenetic analysis, calculation of genetic distances, divergence, heterogeneity, and K(a)/K(s) ratios.
- Recombination analysis to identify recombinant variants.
Main Results:
- Patients exhibited diverse HIV-1 genetic variability, ranging from homogeneous populations to complex quasispecies.
- Three patients displayed a consistent phylogenetic tree topology with independent clades.
- Recombinant variants were identified in patients with independent clades.
- Differential selective pressures (K(a)/K(s) ratios) were observed in distinct viral clades within a single patient, indicating simultaneous divergent evolutionary forces.
Conclusions:
- HIV-1 evolution in patients with normal clinical progression can follow multiple distinct patterns.
- The presence of independent clades and recombinant variants highlights the complex evolutionary dynamics within a host.
- Simultaneous divergent selective pressures on different viral clades suggest intricate host-virus interactions and adaptation.