Identification of a novel resistance (E40F) and compensatory (K43E) substitution in HIV-1 reverse transcriptase

<p>Abstract</p> <p>Background</p> <p>HIV-1 nucleoside reverse transcriptase inhibitors (NRTIs) have been used in the clinic for over twenty years. Interestingly, the complete resistance pattern to this class has not been fully elucidated. Novel mutations in RT appearing during treatment failure are still being identified. To unravel the role of two of these newly identified changes, E40F and K43E, we investigated their effect on viral drug susceptibility and replicative capacity.</p> <p>Results</p> <p>A large database (Quest Diagnostics database) was analysed to determine the associations of the E40F and K43E changes with known resistance mutations. Both amino acid changes are strongly associated with the well known NRTI-resistance mutations M41L, L210W and T215Y. In addition, a strong positive association between these changes themselves was observed. A panel of recombinant viruses was generated by site-directed mutagenesis and phenotypically analysed. To determine the effect on replication capacity, competition and <it>in vitro </it>evolution experiments were performed. Introduction of E40F results in an increase in Zidovudine resistance ranging from nine to fourteen fold depending on the RT background and at the same time confers a decrease in viral replication capacity. The K43E change does not decrease the susceptibility to Zidovudine but increases viral replication capacity, when combined with E40F, demonstrating a compensatory role for this codon change.</p> <p>Conclusion</p> <p>In conclusion, we have identified a novel resistance (E40F) and compensatory (K43E) change in HIV-1 RT. Further research is indicated to analyse the clinical importance of these changes.</p

Identification of a novel resistance (E40F) and compensatory (K43E) substitution in HIV-1 reverse transcriptase-1

four days and after 2, 4 and 6 passages the relative presence of both viruses in the culture was determined by sequencing. Shown are two representative experiments. The variability in each independent experiment is indicated by ± standard error of the mean (SEM). A: Pat A (E40F, M41L, K43E, M184V, L210W, T215Y and K219T) versus Pat A-WT43 (E40F, M41L, M184V, L210W, T215Y and K219T). B: wild type versus wild type+K43E. C: M41L+T215Y versus M41L+T215Y+K43E. D: M41L+T215Y+E40F versus M41L+T215Y+E40F+K43E.<p><b>Copyright information:</b></p><p>Taken from "Identification of a novel resistance (E40F) and compensatory (K43E) substitution in HIV-1 reverse transcriptase"</p><p>http://www.retrovirology.com/content/5/1/20</p><p>Retrovirology 2008;5():20-20.</p><p>Published online 13 Feb 2008</p><p>PMCID:PMC2276231.</p><p></p

Identification of a novel resistance (E40F) and compensatory (K43E) substitution in HIV-1 reverse transcriptase-0

four days and after 2, 4 and 6 passages the relative presence of both viruses in the culture was determined by sequencing. Shown are two representative experiments. The variability in each independent experiment is indicated by ± standard error of the mean (SEM). A: M41L+T215Y versus M41L+T215Y+E40F B: Pat A (E40F, M41L, K43E, M184V, L210W, T215Y and K219T) versus Pat A-WT40 (M41L, K43E, M184V, L210W, T215Y and K219T).<p><b>Copyright information:</b></p><p>Taken from "Identification of a novel resistance (E40F) and compensatory (K43E) substitution in HIV-1 reverse transcriptase"</p><p>http://www.retrovirology.com/content/5/1/20</p><p>Retrovirology 2008;5():20-20.</p><p>Published online 13 Feb 2008</p><p>PMCID:PMC2276231.</p><p></p