RESUMO
The findings that BF intersubtype recombinant human immunodeficiency type 1 viruses (HIV-1) with coincident breakpoints in pol are circulating widely in Argentina and that non-recombinant F subtype viruses have failed to be detected in this country were reported recently. To analyse the mosaic structures of these viruses and to determine their phylogenetic relationship, near full-length proviral genomes of eight of these recombinant viruses were amplified by PCR and sequenced. Intersubtype breakpoints were analysed by bootscanning and examining the signature nucleotides. Phylogenetic relationships were determined with neighbour-joining trees. Five viruses, each with predominantly subtype F genomes, exhibited mosaic structures that were highly similar. Two intersubtype breakpoints were shared by all viruses and seven by the majority. Of the consensus breakpoints, all nine were present in two viruses, which exhibited identical recombinant structures, and four to eight breakpoints were present in the remaining viruses. Phylogenetic analysis of partial sequences supported both a common ancestry, at least in part of their genomes, for all recombinant viruses and the phylogenetic relationship of F subtype segments with F subtype viruses from Brazil. A common ancestry of the recombinants was supported also by the presence of shared signature amino acids and nucleotides, either unreported or highly unusual in F and B subtype viruses. These results indicate that HIV-1 BF recombinant viruses with diverse mosaic structures, including a circulating recombinant form (which are widespread in Argentina) derive from a common recombinant ancestor and that F subtype segments of these recombinants are related phylogenetically to the F subtype viruses from Brazil.
Assuntos
Variação Genética , Genoma Viral , Infecções por HIV/virologia , HIV-1/genética , Mosaicismo , Recombinação Genética , Proteínas Virais , Argentina , Sequência de Bases , DNA Viral , Feminino , Produtos do Gene gag/genética , Produtos do Gene gag/fisiologia , Produtos do Gene rev/genética , Produtos do Gene rev/fisiologia , Antígenos HIV/genética , Antígenos HIV/fisiologia , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/fisiologia , Transcriptase Reversa do HIV/genética , Transcriptase Reversa do HIV/fisiologia , HIV-1/classificação , Proteínas do Vírus da Imunodeficiência Humana , Humanos , Masculino , Dados de Sequência Molecular , Filogenia , Estrutura Terciária de Proteína , Análise de Sequência de Proteína , Análise de Sequência de RNA , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/fisiologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana , Produtos do Gene rev do Vírus da Imunodeficiência HumanaRESUMO
One of the most intriguing aspects concerning the pathogenesis of AIDS is the long period of latency of the HIV in human cells, not causing any cytopatic effect in some and, on the other hand, causing cell destruction, at short periods, in others. The various agents and the mechanisms they adopt to reactivate the latente HIV, were described. Also the frequent epidemiological observation on the presence of both such agents and the HIV in AIDS patients allowed the authors to speculate on the probable important role of a cohort of co-factors which determine the destiny of such individuals. Special considerations were made in respect to the hepatitis B virus, cytomegalovirus, herpesviruses (HHV-1, e and 6), EB virus, HTLV-1 and 2 retroviruses, group B arbovirus Maguary, malaria and other endemic infectious diseases which victimize millions of Brazilians. Accepting the importance of such co-factors acting on the viral gens that regulate the HIV expression in the host cell, it was speculated on the possible role of vaccines, such as the hepatitis B vaccine, and some antiviral drugs which could be useful in the indirect prevention of AIDS-disease in both HIV-carriers and those practising AIDS-high-risk-activities.