Genetic characterization of the nef gene from human immunodeficiency virus type 1 group M strains representing genetic subtypes A, B, C, E, F, G, and H

1999

Article

Jubier-Maurin Véronique, Saragosti S., Perret J.L., Mpoudi Ngolé E., Esu-Williams E., Mulanga Claire, Liégeois Florian, Ekwalanga M., Delaporte Eric, Peeters Martine

AIDS Research and Human Retroviruses, 1999, 15 (1), p. 23-32 ISSN 0889-2229

Most efforts to characterize sequence variation of HIV isolates has been directed toward the structural envelope gene. Few studies have evaluated the sequence variability of auxiliary genes such as nef. In this study 41 new HIV-1 strains, representing the majority of the described envelope subtypes of HIV-1 (A to H), were genetically characterized in the nef region. Phylogenetic analysis showed that 34 strains could be classified in the same subtype in nef and env, and 7 (19%) of the 41 new virus were recombinants. From two of the seven strains, recombination occurred upstream of the nef gene, whereas for five of the seven strains recombination occurred withn the nef gene with a crossover close to the 5' end of the LTR (long terminal repeat). The low intersubtype distance between subtype B and D in the nef gene confirms previous observations in the pol env, and gag genes, which suggest a commn ancestor for these subtypes. The majority of all the previously described functional domains in the nef gene were relatively conserved among the different subtypes, with only minor differences being observed. The myristoylation signal among the different subtypes, with only minor differences being observed. The myristoylation signal was less conserved for subtype C, with one or more amino acid changes being observed at positions 3, 4, and 5. The highly conserved acidic region (positions 62 to 65), critical for the enhancement of viral synthesis with an increased virus growth rate, was less conserved among the subtype G strains from our study. At least three epitopic regions of the nef gene have been defined and each can be recognized by CTLs under a variety of HLA restrictions ; all were also relatively well conserved between the different genetic subtypes. Despite the relatively important genetic variation in nef sequences obtained among the different genetic subtypes, functional domains and CTL epitopes were relatively well conserved... (D'après résumé d'auteur)

Maladies sexuellement transmissibles [052MALTRA03]

SIDA ; VIRUS ; ANALYSE GENETIQUE ; DISTANCE GENETIQUE ; VARIABILITE GENETIQUE ; PHYLOGENIE ; GENE NEF ; RECOMBINAISON

Fonds IRD [F B010017856]

fdi:010017856