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The selection and evolution of viral quasispecies in HIV-1 infected children
P Nowak1, A C Karlsson, L Naver
1Divisions of Clinical Virology, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden. Piotr.Nowak@impi.ki.se
Insights
Children infected with human immunodeficiency virus type 1 (HIV-1) can acquire diverse viral strains from their mothers. Maternal HIV-1 variants may re-emerge years later, potentially from a reservoir established during initial infection.
Area of Science:
- Virology
- Immunology
- Genetics
Background:
- Vertical transmission of Human Immunodeficiency Virus type 1 (HIV-1) is a significant concern.
- Understanding the dynamics of viral populations during mother-to-child transmission is crucial for developing effective interventions.
Purpose of the Study:
- To analyze the diversity and divergence of HIV-1 viral populations in mother-child pairs over time.
- To investigate patterns of HIV-1 transmission and potential viral re-emergence in children.
Main Methods:
- Longitudinal sampling of peripheral blood mononuclear cells from three mothers and their children (up to 7 years).
- Polymerase chain reaction amplification, cloning, and sequencing of the HIV-1 V3 region.
- Phylogenetic analysis for HIV-1 DNA sequence comparisons.
Main Results:
- Initial viral populations were homogenous in two children and heterogeneous in one.
- Observed three transmission patterns: prevalent maternal strain, minor maternal strain, and multiple maternal strains.
- Noted a potential reappearance of a maternal sequence in one child at 34 months.
Conclusions:
- Children can be infected with various maternal HIV-1 strains, including minor variants or multiple quasispecies.
- Maternal viral variants may reappear in children years after initial infection.
- Re-emerging variants could originate from a reservoir of founder quasispecies established during primary HIV-1 infection.
Objectives:
To analyse the diversity and divergence of the viral populations in three mother-child pairs in longitudinally obtained samples for up to 7 years.
Methods:
Peripheral blood mononuclear cells were obtained from three mothers at delivery and three to four samples were obtained from each of their children from 1.5 months up to 78 months of age. The V3 region of HIV-1 was amplified by polymerase chain reaction, cloned and sequenced. HIV-1 DNA sequence comparisons were performed by phylogenetic analysis.
Results:
The viral population was initially homogenous in two children but highly heterogeneous in one child. Three patterns of vertical transmission seemed to have occurred: transmission of the most prevalent maternal strain, of a minor maternal strain and of multiple maternal strains. In one child, a possible reappearance of a maternal sequence was observed at 34 months of age.
Conclusions:
Children may become infected with the most prevalent maternal strain, a minor maternal variant or multiple maternal quasispecies. Maternal viral variants may reappear in children after several years of infection and could possibly be derived from a reservoir of founder quasispecies established during the children's primary HIV-1 infection.