JAC Advance Access published online on August 20, 2008
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dkn335
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Original research |
HIV-2 integrase gene polymorphism and phenotypic susceptibility of HIV-2 clinical isolates to the integrase inhibitors raltegravir and elvitegravir in vitro
1 AP-HP, Groupe hospitalier Bichat-Claude Bernard, Laboratoire de Virologie, Paris F-75018, France 2 Université Denis Diderot-Paris 7, Paris, France 3 INSERM U552, Paris, France 4 AP-HP, Groupe hospitalier Bichat-Claude Bernard, Service de Maladies Infectieuses et Tropicales, Paris F-75018, France 5 AP-HP, Groupe hospitalier Bichat-Claude Bernard, Pharmacie, Paris F-75018, France 6 INSERM U897, Bordeaux, France 7 AP-HP, Groupe hospitalier Saint Antoine, Service de Maladies Infectieuses et Tropicales, Paris F-75012, France
Received 3 June 2008; returned 14 July 2008; revised 18 July 2008; accepted 24 July 2008
* Correspondence address. Laboratoire de Virologie, Hôpital Bichat Claude Bernard, 46 rue Henri Huchard, 75877 Paris Cedex 18, France. Tel: +33-1-40256150; Fax: +33-1-40256769; E-mail: diane.descamps{at}bch.aphp.fr
Objectives: We investigated the in vitro phenotypic susceptibility of HIV-2 isolates from integrase inhibitor (INI)-naive patients to INIs and its relation to HIV-2 integrase gene polymorphism.
Methods: We determined the phenotypic susceptibility to raltegravir and elvitegravir of co-cultured isolates obtained from the HIV-2 ROD reference strain and from 14 clinical isolates. IC50 values were compared with those for HIV-1 reference strains. HIV-2 integrase gene polymorphism was assessed in isolates from 52 INI-naive patients enrolled in the French HIV-2 cohort.
Results: Median raltegravir and elvitegravir IC50 values for the 14 clinical HIV-2 isolates were 2.4 and 0.7 nM, respectively, and were similar to those observed for HIV-2 ROD and HIV-1 reference strains. Overall, 38% of HIV-2 integrase amino acids were polymorphic. The catalytic triad DDE and the HHCC and RKK motifs were fully conserved, at the same genomic positions as described in HIV-1. In subtype B isolates, the total length of the integrase gene varied, owing to the presence of stop codons at positions 288, 294, 297 and 302. Fourteen of the positions associated with substitutions conferring INI resistance in HIV-1 were polymorphic in HIV-2.
Conclusions: Despite 40% heterogeneity between the HIV-1 and HIV-2 integrase genes, the phenotypic susceptibility of clinical HIV-2 isolates to INIs was similar to that of HIV-1. This new class of antiretroviral drugs thus represents a novel therapeutic possibility for HIV-2-infected patients who otherwise have few treatment options.
Key Words: HIV/AIDS , resistance , mutations , human immunodeficiency virus type 2