title: Immune reconstitution in HIV-1 infected children with discordant response to antiretroviral therapies: patterns of HIV-1 env gene evolution driven by restoration of thymic function.
abstract: The evolution of human immunodeficiency virus type 1 (HIV-1) env gp120 region was addressed in HIV-1 infected children showing virological failure to antiretroviral therapy (ART). Sequence analysis of the replicating plasma virus at baseline and after one year of therapy documented evolution of gp120 in all subjects but one. Analysis of the host's selective pressure showed that the values of Ka/Ks ratios were higher in the V3 sequence than in the whole C2-V5 region in 4 of 5 children with improvement of thymic output. Moreover, in 2 of the 4 chidren, the V3 evolution paralleled with a reverse shift of the viral phenotype (from CXCR4-tropic to CCR5-tropic). These results suggest that, under ART, the V3 evolution towards less pathogenic viral variants may be driven by the host's increased selective pressure following restoration of thymic function and immune reconstitution.
authors.affiliation: Istituto di Microbiologia e Scienze Biomediche, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Vecchi
authors.forename: N
authors.initials: N
authors.lastname: Burighel
authors.forename: D
authors.initials: D
authors.lastname: Bellanova
authors.forename: S
authors.initials: S
authors.lastname: Menzo
authors.forename: A
authors.initials: A
authors.lastname: De Rossi
authors.forename: M
authors.initials: M
authors.lastname: Clementi
authors.forename: P
authors.initials: P
authors.lastname: Bagnarelli
mesh_terms: D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002648:Child; D018076:DNA, Complementary; D019143:Evolution, Molecular; D015752:Genes, env; D015699:HIV Envelope Protein gp120 / Q000235:genetics*; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010446:Peptide Fragments / Q000235:genetics; D017434:Protein Structure, Tertiary; D012367:RNA, Viral / Q000097:blood / Q000302:isolation & purification; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D019380:Anti-HIV Agents; D018076:DNA, Complementary; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D012367:RNA, Viral