To clarify the role of CCR5 host genetic background and disease progression on viral evolutionary patterns , we obtain gp120 envelope sequences from clonal HIV-1 variants isolated at multiple time points in the course of infection from populations of HIV-1-infected individuals who only harbored CCR5-using HIV-1 variants at all time points .
O O O O O B-GeneOrGeneProduct O O O O O O O O O O O O O B-GeneOrGeneProduct O O O O B-OrganismTaxon O O O O O O O O O O B-DiseaseOrPhenotypicFeature O O O B-DiseaseOrPhenotypicFeature O O O O B-GeneOrGeneProduct B-OrganismTaxon O O O O O O