AAC
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wei, X.
Right arrow Articles by Kappes, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wei, X.
Right arrow Articles by Kappes, J. C.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, June 2002, p. 1896-1905, Vol. 46, No. 6
0066-4804/02/$04.00+0     DOI: 10.1128/AAC.46.6.1896-1905.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Emergence of Resistant Human Immunodeficiency Virus Type 1 in Patients Receiving Fusion Inhibitor (T-20) Monotherapy

Xiping Wei,1 Julie M. Decker,1 Hongmei Liu,2 Zee Zhang,2 Ramin B. Arani,3 J. Michael Kilby,2 Michael S. Saag,2 Xiaoyun Wu,2 George M. Shaw,1,2,4 and John C. Kappes2,3,5*

Howard Hughes Medical Institute, Departments of,1 Medicine,2 Microbiology,4 Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama 35294,3 Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama 352335

Received 7 September 2001/ Returned for modification 5 December 2001/ Accepted 21 March 2002

The synthetic peptide T-20 (enfuvirtide) represents the first of a new class of antiretroviral compounds to demonstrate in vivo potency by targeting a step in viral entry. T-20 inhibits a conformational change in the human immunodeficiency virus type 1 (HIV-1) transmembrane glycoprotein (gp41) that is required for fusion between HIV-1 and target cell membranes. The initial phase I clinical trial of T-20 treatment for HIV-infected patients thus provided a unique opportunity to evaluate the emergence of resistant virus in vivo to this novel class of antiretroviral agents. All four patients who received an intermediate dose of T-20 (30 mg twice daily) had an initial decline in plasma viral load over the first 10 days but a rising trend by day 14, suggestive of selection for resistant virus. Plasma virus derived from patients enrolled in all dosage groups of the phase I T-20 trial was analyzed by population sequencing before and after treatment. While no mutations were found within a highly conserved 3-amino-acid sequence (GIV) known to be critical for fusion at baseline, after 14 days of therapy, virus from one patient in the 30-mg dose group (30-1) developed a mutation in this motif, specifically an aspartic acid (D) substitution for glycine (G) at position 36. Multiple env clones were derived from the plasma virus of all four patients in the 30-mg dosage group. Sequence analysis of 49 clones derived from the plasma of patient 30-1 on day 14 revealed that 25 clones contained the G36D mutation, while 8 contained the V38A mutation. Dual mutations involving G36D and other residues within the HR1 domain were also identified. In 5 of the 49 env clones, other mutations involving residues 32 (Q32R or Q32H) and 39 (Q39R) were found in combination with G36D. Cloned env sequences derived from the plasma virus of subject 30-3 also had single mutations in the GIV sequence (V38M and I37V) detectable following therapy with T-20. The plasma virus from subjects 30-2 and 30-4 did not contain changes within the GIV sequence. To analyze the biological resistance properties of these mutations, we developed a novel single-cycle HIV-1 entry assay using JC53BL cells which express ß-galactosidase and luciferase under control of the HIV-1 long terminal repeat. Full-length env clones were derived from the plasma virus of patients 30-1 and 30-3 and used to generate pseudotyped virus stocks. The mean 50% inhibition concentrations (IC50s) for mutants G36D and V38A (patient 30-1) were 2.3 µg/ml and 11.2 µg/ml, respectively, statistically significant increases of 9.1- and 45-fold, respectively, compared with those of wild-type Env. The IC50 for the V38 M mutation (patient 30-3) was 7.6 µg/ml, an 8-fold increase compared with that of the wild type. The I37V mutation resulted in an IC50 3.2-fold greater than that of the wild type. Envs with double mutations (Q32R plus G36D and Q32H plus G36D) exhibited a level of resistance similar to that of G36D alone. These findings provide the first evidence for the rapid emergence of clinical resistance to a novel class of HIV-1 entry inhibitors and may be relevant to future treatment strategies involving these agents.

* Corresponding author. Mailing address: University of Alabama at Birmingham, Department of Medicine, LHRB 613, 701 19th St. South, Birmingham, AL 35294. Phone: (205) 934-0051. Fax: (205) 975-7300. E-mail: kappesjc{at}uab.edu.

Antimicrobial Agents and Chemotherapy, June 2002, p. 1896-1905, Vol. 46, No. 6
0066-4804/02/$04.00+0     DOI: 10.1128/AAC.46.6.1896-1905.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Clin. Vaccine Immunol. Clin. Microbiol. Rev.
J. Clin. Microbiol. ALL ASM JOURNALS

Copyright © 2002 by the American Society for Microbiology. All rights reserved.