scholarly journals Drug Resistance and Predicted Virologic Responses to Human Immunodeficiency Virus Type 1 Protease Inhibitor Therapy

2000 ◽  
Vol 182 (3) ◽  
pp. 758-765 ◽  
Author(s):  
Jon H. Condra ◽  
Christos J. Petropoulos ◽  
Rainer Ziermann ◽  
William A. Schleif ◽  
Malathi Shivaprakash ◽  
...  
2011 ◽  
Vol 55 (11) ◽  
pp. 5090-5098 ◽  
Author(s):  
Sanggu Kim ◽  
Yun-Cheol Kim ◽  
Hangfei Qi ◽  
Kunkai Su ◽  
Sherie L. Morrison ◽  
...  

ABSTRACTEmergence of drug-resistant mutant viruses during the course of antiretroviral therapy is a major hurdle that limits the success of chemotherapeutic treatment to suppress human immunodeficiency virus type 1 (HIV-1) replication and AIDS progression. Development of new drugs and careful patient management based on resistance genotyping data are important for enhancing therapeutic efficacy. However, identifying changes leading to drug resistance can take years of clinical studies, and conventionalin vitroassays are limited in generating reliable drug resistance data. Here we present an efficientin vitroscreening assay for selecting drug-resistant variants from a library of randomly mutated HIV-1 strains generated by transposon-directed base-exchange mutagenesis. As a test of principle, we screened a library of mutant HIV-1 strains containing random mutations in the protease gene by using a reporter T-cell line in the presence of the protease inhibitor (PI) nelfinavir (NFV). Analysis of replicating viruses from a single round of infection identified 50 amino acid substitutions at 35 HIV-1 protease residue positions. The selected mutant viruses showed specific resistance to NFV and included most of the known NFV resistance mutations. Therefore, the new assay is efficient for identifying changes leading to drug resistance. The data also provide insights into the molecular mechanisms underlying the development of drug resistance.


2003 ◽  
Vol 77 (8) ◽  
pp. 4836-4847 ◽  
Author(s):  
Thomas D. Wu ◽  
Celia A. Schiffer ◽  
Matthew J. Gonzales ◽  
Jonathan Taylor ◽  
Rami Kantor ◽  
...  

ABSTRACT Although many human immunodeficiency virus type 1 (HIV-1)-infected persons are treated with multiple protease inhibitors in combination or in succession, mutation patterns of protease isolates from these persons have not been characterized. We collected and analyzed 2,244 subtype B HIV-1 isolates from 1,919 persons with different protease inhibitor experiences: 1,004 isolates from untreated persons, 637 isolates from persons who received one protease inhibitor, and 603 isolates from persons receiving two or more protease inhibitors. The median number of protease mutations per isolate increased from 4 in untreated persons to 12 in persons who had received four or more protease inhibitors. Mutations at 45 of the 99 amino acid positions in the protease—including 22 not previously associated with drug resistance—were significantly associated with protease inhibitor treatment. Mutations at 17 of the remaining 99 positions were polymorphic but not associated with drug treatment. Pairs and clusters of correlated (covarying) mutations were significantly more likely to occur in treated than in untreated persons: 115 versus 23 pairs and 30 versus 2 clusters, respectively. Of the 115 statistically significant pairs of covarying residues in the treated isolates, 59 were within 8 Å of each other—many more than would be expected by chance. In summary, nearly one-half of HIV-1 protease positions are under selective drug pressure, including many residues not previously associated with drug resistance. Structural factors appear to be responsible for the high frequency of covariation among many of the protease residues. The presence of mutational clusters provides insight into the complex mutational patterns required for HIV-1 protease inhibitor resistance.


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