title: Identification of a rare mutation at reverse transcriptase Lys65 (K65E) in HIV-1-infected patients failing on nucleos(t)ide reverse transcriptase inhibitors.
abstract: OBJECTIVE
  The HIV reverse transcriptase (RT) mutation K65R confers resistance to nucleos(t)ide reverse transcriptase inhibitors (NRTIs). Here, analysing a large database, we report the selection of another rare K65E mutation in patients failing on NRTI-containing regimens.
  
  
  METHODS
  Clinical and virological characteristics of patients harbouring the K65E mutation were analysed using a large RT sequence database from treatment-experienced individuals. Structural analysis of the K65E RT mutant complex was performed by means of docking simulations. The replication capacity was assessed using viruses harbouring the K65E mutation introduced by site-directed mutagenesis (SDM) in pNL 4-3.
  
  
  RESULTS
  Overall, in 23 530 sequences from patients failing on antiretroviral therapy, the prevalence of substitutions at position K65 in RT was 2.4%. In addition to K65R (n = 395) and K65N (n = 9), another mutation, K65E, was found in 15 patients. In 11 out of 15 cases, tenofovir, abacavir, didanosine or stavudine were present at the time of K65E selection. The molecular recognition of RT containing K65E supports evidence for the role of this mutation in resistance to tenofovir. The SDM pNL4-3 K65E variant harboured a very low replicative capacity (5% versus wild-type).
  
  
  CONCLUSIONS
  We investigated the role of a novel rare NRTI mutation located at position Lys65 of RT (K65E), found in drug-experienced patients failing on NRTIs. The low frequency of this mutation is probably related to the high impairment of replicative capacity induced by this mutation. This study should have significant clinical implications, as these findings warn clinicians that other minor substitutions at Lys65 (such as K65E) play a role in NRTI resistance.
authors.affiliation: Inserm UMR S-943, Paris, France.
authors.forename: Slim
authors.initials: S
authors.lastname: Fourati
authors.forename: Benoit
authors.initials: B
authors.lastname: Visseaux
authors.forename: Daniele
authors.initials: D
authors.lastname: Armenia
authors.forename: Laurence
authors.initials: L
authors.lastname: Morand-Joubert
authors.forename: Anna
authors.initials: A
authors.lastname: Artese
authors.forename: Charlotte
authors.initials: C
authors.lastname: Charpentier
authors.forename: Peter
authors.initials: P
authors.lastname: Van Den Eede
authors.forename: Giosuè
authors.initials: G
authors.lastname: Costa
authors.forename: Stefano
authors.initials: S
authors.lastname: Alcaro
authors.forename: Marc
authors.initials: M
authors.lastname: Wirden
authors.forename: Carlo Federico
authors.initials: CF
authors.lastname: Perno
authors.forename: Francesca
authors.initials: F
authors.lastname: Ceccherini Silberstein
authors.forename: Diane
authors.initials: D
authors.lastname: Descamps
authors.forename: Vincent
authors.initials: V
authors.lastname: Calvez
authors.forename: Anne-Genevieve
authors.initials: AG
authors.lastname: Marcelin
mesh_terms: D015658:HIV Infections / Q000188:drug therapy* / Q000473:pathology / Q000821:virology*; D054303:HIV Reverse Transcriptase / Q000737:chemistry / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D062105:Molecular Docking Simulation; D020125:Mutation, Missense; D011487:Protein Conformation; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*; D017211:Treatment Failure; D019562:Viral Load; D014779:Virus Replication
chemical_list: D018894:Reverse Transcriptase Inhibitors; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase
keywords: HIV; drug resistance; nucleoside analogues