title: Effect of natural polymorphisms in the HIV-1 CRF02_AG protease on protease inhibitor hypersusceptibility.
abstract: Hypersusceptibility (HS) to inhibition by different antiretroviral drugs (ARVs) among diverse HIV-infected individuals may be a misnomer because clinical response to treatment is evaluated in relation to subtype B infections while drug susceptibility of the infecting virus, regardless of subtype, is compared to a subtype B HIV-1 laboratory strain (NL4-3 or IIIB). Mounting evidence suggests that HS to different ARVs may result in better treatment outcome just as drug resistance leads to treatment failure. We have identified key amino acid polymorphisms in the protease coding region of a non-B HIV-1 subtype linked to protease inhibitor HS, namely, 17E and 64M in CRF02_AG. These HS-linked polymorphisms were introduced in the BD6-15 CRF02_AG molecular clone and tested for inhibition using a panel of protease inhibitors. In general, suspected HS-linked polymorphisms did increase susceptibility to specific protease inhibitors such as amprenavir and atazanavir, but the combination of the 17E/64M polymorphisms showed greater HS. These two mutations were found at low frequencies but linked in a sequence database of over 700 protease sequences of CRF02_AG. In direct head-to-head virus competitions, CRF02_AG harboring the 17E/64M polymorphisms also had higher replicative fitness than did the 17E or the 64M polymorphism in the CFR02_AG clone. These findings suggest that subtype-specific, linked polymorphisms can result in hypersusceptibility to ARVs. Considering the potential benefit of HS to treatment outcome, screening for potential HS-linked polymorphisms as well as preexisting drug resistance mutations in treatment-naïve patients may guide the choice of ARVs for the best treatment outcome.
authors.affiliation: Laboratório de Virologia Humana, Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: André F A
authors.initials: AF
authors.lastname: Santos
authors.forename: Denis M
authors.initials: DM
authors.lastname: Tebit
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Lalonde
authors.forename: Ana B
authors.initials: AB
authors.lastname: Abecasis
authors.forename: Annette
authors.initials: A
authors.lastname: Ratcliff
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: Camacho
authors.forename: Ricardo S
authors.initials: RS
authors.lastname: Diaz
authors.forename: Ottmar
authors.initials: O
authors.lastname: Herchenröder
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: Soares
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Arts
mesh_terms: D019943:Amino Acid Substitution; D000069446:Atazanavir Sulfate; D002219:Carbamates / Q000494:pharmacology; D024882:Drug Resistance, Viral / Q000235:genetics; D005663:Furans; D057809:HEK293 Cells; D016333:HIV Protease / Q000235:genetics*; D017320:HIV Protease Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D006801:Humans; D009154:Mutation; D009842:Oligopeptides / Q000494:pharmacology; D016366:Open Reading Frames; D010957:Plasmids; D011110:Polymorphism, Genetic; D011725:Pyridines / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D014162:Transfection
chemical_list: D002219:Carbamates; D005663:Furans; D017320:HIV Protease Inhibitors; D009842:Oligopeptides; D011725:Pyridines; D013449:Sulfonamides; D000069446:Atazanavir Sulfate; C095108:amprenavir; D016333:HIV Protease; C514803:p16 protease, Human immunodeficiency virus 1