Intrahost and Interhost Variability of the HIV Type 1 nef Gene in Brazilian Children

Autor(es)

Cavalieri, Elizabeth ^[1] ; Florido, Camila ^[1] ; Leal, Elcio ^[1] ; Machado, Daisy Maria ^[1] ; Camargo, Michelle ^[1] ; Diaz, Ricardo S. ^[1] ; Janini, Luiz Mario ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: AIDS Research and Human Retroviruses; v. 25, n. 11, p. 1129-1140, NOV 2009.
• Citações Web of Science: 1

Resumo

Many aspects of HIV-1 pathogenesis are affected by Nef protein activity, and efforts have been made to study variation in the nef gene and how that variation relates to disease outcome. We studied the genetic diversity of the nef gene in distinct clones obtained from the same patient (intrahost) and in sequences obtained from different hosts (interhost). The set of sequences analyzed was obtained from HIV-1-infected Brazilian children and contained 112 clones from 25 children (intrahost samples), as well as 55 sequences from epidemiologically unlinked children (interhost samples). We found extensive site polymorphisms and amino acid length variations, mainly in the amino terminal region of the nef gene, between the myristoylation motif (MGxxxS) and the MHC-1 downregulation motif (Rxx). Analysis of the sequences deposited in the Los Alamos HIV sequences database (www.hiv.lanl.gov) indicated that the most frequent motif at the MHC-1 downregulation site in the subtype B strain is R(86%)A(64%)E(82%) (n = 1040) and R(78%)T(74%)E(56%) in the subtype C strain (n = 549). Conversely, the Brazilian subtype B isolates presented the motif R(81%)T(62%)E(67%) at this site (n = 64). A detailed analysis of selective pressures identified a concentration of codons under strong positive selection in the amino terminal region of the nef gene. We also determined that different sites are under positive selection in the subtype B and subtype C viruses. The amino acid composition in the MHC-1 downregulation motif of the nef gene in our sequences may indicate a distinct adaptive pattern of HIV-1 subtype B to the Brazilian host population. (AU)

• Processo FAPESP: 04/10372-3 - Dinâmica evolutiva do vírus da imunodeficiência humana, tipo 1 (HIV-1) em populações sob tratamento antiretroviral
• Beneficiário: Elcio de Souza Leal
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 05/53246-0 - Análise da diversidade genética no gene Nef do vírus da imunodeficiência humana, tipo 1 (HIV-1) em crianças e em adultos recém-infectados
• Beneficiário: Luiz Mário Ramos Janini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• 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
• Processo FAPESP: 04/12044-3 - Análise da diversidade genética no gene Nef do vírus da imunodeficiência humana, tipo 1 (HIV-1) em crianças e em adultos recém-infectados
• Beneficiário: Camila Florido
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 01/11086-6 - Fatores associados à supressão viral prolongada em crianças infectadas pelo vírus da imunodeficiência humana (HIV-1) em uso de drogas anti-retrovirais
• Beneficiário: Daisy Maria Machado
• Modalidade de apoio: Auxílio à Pesquisa - Regular