About this item:

458 Views | 59 Downloads

Author Notes:

Corresponding author. Mailing address: Veterans Affairs Medical Center, 1670 Clairmont Rd., Medical Research 151H, Decatur, GA 30033. Phone: (404) 728-7711. Fax: (404) 728-7726. E-mail: rschina@emory.edu.

J.L. present address: Uppsala University, Department of Medical Sciences, 75185 Uppsala, Sweden.

R.F.S. is the inventor of DFC, (−)-FTC, and 3TC.

The royalties for (−)-FTC were sold to Gilead Sciences and Royalty Pharma in 2005.

However, R.F.S. continues to receive royalties from the sales of 3TC until 2011.

R.F.S. is also a major shareholder in RFS Pharma, LLC, a company that currently develops Amdoxovir for HIV-1 infections.


Research Funding:

This study was supported in part by Public Health Service grants 5R37-AI-0419801; and 5P30-AI-50409 (CFAR) and by the Department of Veterans Affairs.

Computational modeling was performed with assistance of the Emory School of Medicine Biomolecular Computing Resource (BIMCORE).

Hardware and software was supported in part through an Academic Excellence Grant from Sun Microsystems and an Academic Research Award from Accelrys Corp.

Selection and Characterization of HIV-1 with a Novel S68 Deletion in Reverse Transcriptase


Journal Title:

Antimicrobial Agents and Chemotherapy


Volume 55, Number 5


, Pages 2054-2060

Type of Work:

Article | Final Publisher PDF


Resistance to human immunodeficiency virus type 1 (HIV-1) represents a significant problem in the design of novel therapeutics and the management of treatment regimens in infected persons. Resistance profiles can be elucidated by defining modifications to the viral genome conferred upon exposure to novel nucleoside reverse transcriptase (RT) inhibitors (NRTI). In vitro testing of HIV-1LAI-infected primary human lymphocytes treated with β-d-2′,3′-dideoxy-2′,3′-didehydro-5-fluorocytidine (DFC; Dexelvucitabine; Reverset) produced a novel deletion of AGT at codon 68 (S68Δ) alone and in combination with K65R that differentially affects drug response. Dual-approach clone techniques utilizing TOPO cloning and pyrosequencing confirmed the novel S68Δ in the HIV-1 genome. The S68Δ HIV-1 RT was phenotyped against various antiviral agents in a heteropolymeric DNA polymerase assay and in human lymphocytes. Drug susceptibility results indicate that the S68Δ displayed a 10- to 30-fold increase in resistance to DFC, lamivudine, emtricitabine, tenofovir, abacavir, and amdoxovir and modest resistance to stavudine, β-d-2′,3′-oxa-5-fluorocytidine, or 9-(β-d-1,3-dioxolan-4-yl)guanine and remained susceptible to 3′-azido-3′-deoxythymidine, 2′,3′-dideoxyinosine (ddI), 1-(β-d-dioxolane)thymine (DOT) and lopinavir. Modeling revealed a central role for S68 in affecting conformation of the β3-β4 finger region and provides a rational for the selective resistance. These data indicate that the novel S68Δ is a previously unrecognized deletion that may represent an important factor in NRTI multidrug resistance treatment strategies.

Copyright information:

© 2011, American Society for Microbiology.

Export to EndNote