RESUMO
Fusion inhibitors are antiretroviral (ARV) drugs that prevent HIV-1 entry into host cells. Enfuvirtide (ENF) is the only ARV drug marketed in this class and, like other HIV drugs, it has been associated with the emergence and selection of therapeutic-resistant HIV-1 strains. The aims of this work were to develop a computational tool capable of identifying and classifying mutations associated with resistance to Enfuvirtide and to evaluate the prevalence of these mutations among the HIV-1 sequences deposited in public databases. The HIVfird (HIV-1 fusion inhibitor resistance detector) was developed using the PHP programming language, using 30 DNA bases obtained from the HIV-1 HXB2 gp41 protein as a reference. To assess the level of resistance in HIV-1 populations, sequences were retrieved from the Los Alamos National Laboratory (LANL) database. The HIVfird is hosted at www.hivfird.ics.ufba.br, fully functional and available for public use. Twenty-five amino acid substitutions and 15 combinations were found to be associated with some level of resistance to ENF. These mutations are located at positions 36-45 of gp41, with 36, 38, 43, and 44 having the greatest diversity and frequency of variations associated with drug resistance. Resistance mutations were found in 3.16% and 4.67% of the circulating HIV-1 isolates in the world and Brazil, respectively. Subtype B showed a significantly higher ENF resistance rate (4.9%) compared to other genetic forms, while subtype C presented the lowest rate (0.9%). We present here HIVfird, an online tool that might assist in the therapeutic management of HIV-1 patients with multiple drug failure and in population-based analysis of drug resistance.
Assuntos
Análise Mutacional de DNA/métodos , DNA Viral/genética , Farmacorresistência Viral , Enfuvirtida/farmacocinética , Proteína gp41 do Envelope de HIV/genética , Inibidores da Fusão de HIV/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Mutação , Software , Sequência de Aminoácidos , Substituição de Aminoácidos , Sequência de Bases , Bases de Dados Genéticas , Farmacorresistência Viral/genética , Enfuvirtida/uso terapêutico , Saúde Global , Proteína gp41 do Envelope de HIV/fisiologia , Inibidores da Fusão de HIV/uso terapêutico , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/genética , HIV-1/isolamento & purificação , Humanos , Internet , Mutação de Sentido Incorreto , Alinhamento de Sequência , Homologia de Sequência do Ácido NucleicoRESUMO
HIV therapy with anti-retroviral drugs is limited by the poor exposure of viral reservoirs, such as lymphoid tissue, to these small molecule drugs. We therefore investigated the effect of PEGylation on the anti-retroviral activity and subcutaneous lymphatic pharmacokinetics of the peptide-based fusion inhibitor enfuvirtide in thoracic lymph duct cannulated rats. Both the peptide and the PEG were quantified in plasma and lymph via ELISA. Conjugation to a single 5â¯kDa linear PEG decreased anti-HIV activity three-fold compared to enfuvirtide. Whilst plasma and lymphatic exposure to peptide mass was moderately increased, the loss of anti-viral activity led to an overall decrease in exposure to enfuvirtide activity. A 20â¯kDa 4-arm branched PEG conjugated with an average of two enfuvirtide peptides decreased peptide activity by six-fold. Plasma and lymph exposure to enfuvirtide, however, increased significantly such that anti-viral activity was increased two- and six-fold respectively. The results suggest that a multi-enfuvirtide-PEG complex may optimally enhance the anti-retroviral activity of the peptide in plasma and lymph.
