Relaxation of Adaptive Evolution during the HIV-1 Infection Owing to Reduction of CD4+T Cell Counts

Autor(es)

Leal, Elcio ^[1] ; Casseb, Jorge ^[2] ; Hendry, Michael ^[3] ; Busch, Michael P. ^{[4, 5, 6]} ; Diaz, Ricardo Sobhie ^[7]

Afiliação do(s) autor(es)

^[1] Fed Univ Para, Inst Biotechnol, BR-66059 Belem, Para - Brazil

^[2] Univ Sao Paulo, Inst Trop Med, Sao Paulo, SP - Brazil

^[3] CDC, Ctr Dis Control & Prevent, Branch Lab, Atlanta, GA 30333 - USA

^[4] Blood Syst Res Inst, San Francisco, CA - USA

^[5] Univ Calif San Francisco, Dept Lab Med, San Francisco, CA 94143 - USA

^[6] Blood Syst Inc, San Francisco, CA - USA

^[7] Univ Fed Sao Paulo, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 7, n. 6 JUN 29 2012.
• Citações Web of Science: 2

Resumo

Background: The first stages of HIV-1 infection are essential to establish the diversity of virus population within host. It has been suggested that adaptation to host cells and antibody evasion are the leading forces driving HIV evolution at the initial stages of AIDS infection. In order to gain more insights on adaptive HIV-1 evolution, the genetic diversity was evaluated during the infection time in individuals contaminated by the same viral source in an epidemic cluster. Multiple sequences of V3 loop region of the HIV-1 were serially sampled from four individuals: comprising a single blood donor, two blood recipients, and another sexually infected by one of the blood recipients. The diversity of the viral population within each host was analyzed independently in distinct time points during HIV-1 infection. Results: Phylogenetic analysis identified multiple HIV-1 variants transmitted through blood transfusion but the establishing of new infections was initiated by a limited number of viruses. Positive selection (d(N)/d(S)>1) was detected in the viruses within each host in all time points. In the intra-host viruses of the blood donor and of one blood recipient, X4 variants appeared respectively in 1993 and 1989. In both patients X4 variants never reached high frequencies during infection time. The recipient, who X4 variants appeared, developed AIDS but kept narrow and constant immune response against HIV-1 during the infection time. Conclusion: Slowing rates of adaptive evolution and increasing diversity in HIV-1 are consequences of the CD4+ T cells depletion. The dynamic of R5 to X4 shift is not associated with the initial amplitude of humoral immune response or intensity of positive selection. (AU)

• Processo FAPESP: 07/52841-8 - Análise bayesiana de aspectos filogenética e seletivos do HIV-1 na epidemia brasileira
• Beneficiário: Elcio de Souza Leal
• Modalidade de apoio: Bolsas no Exterior - Pesquisa