scholarly journals Resistance Mutations in Protease and Reverse Transcriptase Genes of Human Immunodeficiency Virus Type 1 Isolates from Patients with Combination Antiretroviral Therapy Failure

1998 ◽  
Vol 178 (5) ◽  
pp. 1497-1501 ◽  
Author(s):  
Benjamin Young ◽  
Steven Johnson ◽  
Minoo Bahktiari ◽  
David Shugarts ◽  
Russell K. Young ◽  
...  
2009 ◽  
Vol 53 (11) ◽  
pp. 4667-4672 ◽  
Author(s):  
Hongtao Xu ◽  
Yudong Quan ◽  
Bluma G. Brenner ◽  
Tamara Bar-Magen ◽  
Maureen Oliveira ◽  
...  

ABSTRACT Etravirine (ETR) is a second-generation nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) active against common human immunodeficiency virus type 1 (HIV-1) drug-resistant strains. This study was designed to determine the extent to which each of the Y181C or G190A mutations in RT might confer resistance to ETR and other members of the NNRTI family of drugs. Recombinant HIV-1 RT enzymes containing either the Y181C or the G190A mutation, or both mutations in tandem, were purified. Both RNA- and DNA-dependent DNA polymerase assays were performed in order to determine the extent to which each of these mutations might confer resistance in cell-free biochemical assays against each of ETR, efavirenz, and nevirapine. Both the biochemical and the cell-based phenotypic assays confirmed the susceptibility of G190A-containing enzymes and viruses to ETR. The results of this study indicate that the G190A mutation is not associated with resistance to ETR.


2000 ◽  
Vol 74 (2) ◽  
pp. 1023-1028 ◽  
Author(s):  
Tomozumi Imamichi ◽  
Tanima Sinha ◽  
Hiromi Imamichi ◽  
Yi-Ming Zhang ◽  
Julie A. Metcalf ◽  
...  

ABSTRACT A variant of human immunodeficiency virus type 1 (HIV-1) possessing a deletion in the reverse transcriptase (RT) gene at codon 67 was identified in a patient who had failed combination antiretroviral therapy. This deletion initially emerged under the selective pressure of combination therapy with 3′-azido-3′-deoxythymidine (AZT) plus 2′,3′-dideoxyinosine. It has persisted for more than 3 years in association with the accumulation of a variety of other well-described drug resistance mutations and an uncharacterized mutation at RT codon 69 (T69G). Phenotypic studies demonstrated that the codon 67 deletion by itself had little effect on AZT sensitivity. However, in the context of the T69G mutation and three other mutations known to be associated with AZT resistance (K70R, T215F, and K219Q), this deletion led to a increase in AZT resistance from 8.5-fold to 445-fold. A further increase in resistance (up to 1,813-fold) was observed when two mutations associated with nonnucleoside RT inhibitor resistance (K103N and L74I) were added to the deletion T69G K70R T215F K219Q construct. Hence, these results establish that a deletion at RT codon 67 may be selected for in the presence of antiretroviral therapy and may lead to high-level resistance to AZT.


2004 ◽  
Vol 20 (11) ◽  
pp. 1166-1172 ◽  
Author(s):  
Said H.S. Al Dhahry ◽  
Euan M. Scrimgeour ◽  
Abdul Raouf Al Suwaid ◽  
Mohammed R.M.Y. Al Lawati ◽  
Hussein S. El Khatim ◽  
...  

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