Diversity of HIV-1 subtype B: implications to the origin of BF recombinants
| Autor: | Élcio Leal, Fabiola Villanova |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Phenylalanine
Science HIV Infections V3 loop Biology Genetic analysis Computational Biology/Molecular Genetics Tetramer Phylogenetics Humans Gene Phylogeny Genetics Multidisciplinary Phylogenetic tree Tryptophan env Gene Products Human Immunodeficiency Virus Genetics and Genomics/Bioinformatics Virology Virology/Virus Evolution and Symbiosis Evolutionary Biology/Microbial Evolution and Genomics HIV-1 Medicine Research Article |
| Zdroj: | PLoS ONE, Vol 5, Iss 7, p e11833 (2010) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | BackgroundThe HIV-1 subtype B epidemic in Brazil is peculiar because of the high frequency of isolates having the GWGR tetramer at V3 loop region. It has been suggested that GWGR is a distinct variant and less pathogenic than other subtype B isolates.Methodology/principal findingsNinety-four percent of the HIV-1 subtype B worldwide sequences (7689/8131) obtained from the Los Alamos HIV database contain proline at the tetramer of the V3 loop of the env gene (GPGR) and only 0.74% (60/8131) have tryptophan (GWGR). By contrast, 48.4% (161/333) of subtype B isolates from Brazil have proline, 30.6% (102/333) contain tryptophan and 10.5% (35/333) have phenylalanine (F) at the second position of the V3 loop tip. The proportion of tryptophan and phenylalanine in Brazilian isolates is much higher than in worldwide subtype B sequences (chi-square test, p = 0.0001). The combined proportion of proline, tryptophan and phenylalanine (GPGR+GWGR+GFGR) of Brazilian isolates corresponds to 89% of all amino acids in the V3 loop. Phylogenetic analysis revealed that almost all subtype B isolates in Brazil have a common origin regardless of their motif (GWGR, GPGR, GGGR, etc.) at the V3 tetramer. This shared ancestral origin was also observed in CRF28_BF and CRF29_BF in a genome region (free of recombination) derived from parental subtype B. These results imply that tryptophan substitution (e.g., GWGR-to-GxGR), which was previously associated with the change in the coreceptor usage within the host, also occurs at the population level.Conclusions/significanceBased on the current findings and previous study showing that tryptophan and phenylalanine in the V3 loop are related with coreceptor usage, we propose that tryptophan and phenylalanine in subtype B isolates in Brazil are kept by selective mechanisms due to the distinct coreceptor preferences in target cells of GWGR, GFGR and GFGR viruses. |
| Databáze: | OpenAIRE |
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