Open AccessCharacterization of the R263K Mutation in HIV-1 Integrase That Confers Low-Level Resistance to the Second-Generation Integrase Strand Transfer Inhibitor Dolutegravir
Author(s) -
Peter K. Quashie,
Thibault Mésplède,
Ying-Shan Han,
Maureen Oliveira,
Diane N. Singhroy,
Tamio Fujiwara,
Mark Underwood,
Mark A. Wainberg
Publication year - 2012
Publication title -
journal of virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.617
H-Index - 292
eISSN - 1070-6321
pISSN - 0022-538X
DOI - 10.1128/jvi.06591-11
Subject(s) - integrase , dolutegravir , biology , integrase inhibitor , mutagenesis , mutation , dna , raltegravir , virology , viral replication , reverse transcriptase , genetics , microbiology and biotechnology , virus , gene , viral load , polymerase chain reaction , antiretroviral therapy
Integrase (IN) strand transfer inhibitors (INSTIs) have been developed to inhibit the ability of HIV-1 integrase to irreversibly link the reverse-transcribed viral DNA to the host genome. INSTIs have proven their high efficiency in inhibiting viral replicationin vitro and in patients. However, first-generation INSTIs have only a modest genetic barrier to resistance, allowing the virus to escape these powerful drugs through several resistance pathways. Second-generation INSTIs, such as dolutegravir (DTG, S/GSK1349572), have been reported to have a higher resistance barrier, and no novel drug resistance mutation has yet been described for this drug. Therefore, we performedin vitro selection experiments with DTG using viruses of subtypes B, C, and A/G and showed that the most common mutation to emerge was R263K. Further analysis by site-directed mutagenesis showed that R263K does confer low-level resistance to DTG and decreased integration in cell culture without altering reverse transcription. Biochemical cell-free assays performed with purified IN enzyme containing R263K confirmed the absence of major resistance against DTG and showed a slight decrease in 3′ processing and strand transfer activities compared to the wild type. Structural modeling suggested andin vitro IN-DNA binding assays show that the R263K mutation affects IN-DNA interactions.