Kuhmann SE, Pugach P, Kunstman KJ, Taylor J, Stanfield RL, Snyder A, Strizki JM, Riley J, Baroudy BM, Wilson IA, Korber BT, Wolinsky SM, Moore JP; HIV DRP Symposium Antiviral Drug Resistance (4th: 2003: Chantilly, Va.).
Program Abstr HIV DRP Symp Antivir Drug Resist. 2003 Dec 7-10; 4: Abstract no. 11.
Dept. of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY
We have described previously the generation of an escape variant of human immunodeficiency virus type 1 (HIV-1), under the selection pressure of AD101, a small molecule inhibitor that binds the CCR5 coreceptor (Trkola, A., et al., 2002. Proc. Natl. Acad. Sci. USA 99:395-400). The escape mutant, CC101.19, continued to use CCR5 for entry, but unlike the parental virus, CC1/85, it was at least 20,000-fold resistant to AD101. We have now cloned the env genes from the parental and escape mutant isolates, and used them to make chimeric infectious molecular clones that fully recapitulate the phenotypes of the corresponding isolates. Sequence analysis of the evolution of the escape mutants suggested that the most relevant changes were likely to be in the V3 loop region of the gp120 glycoprotein. We therefore made a series of mutant viruses, and found that full AD101 resistance was conferred by four amino acid changes in V3. Each of these changes individually caused partial resistance when they were introduced into the V3 loop of a CC1/85 clone, but their impact was dependent upon the gp120 context in which they were made. We assume that these amino acid changes in the V3 loop alter how the HIV-1 Env complex interacts with CCR5. Perhaps unexpectedly, given the dependence of the escape mutant on CCR5 for entry, monomeric gp120 proteins expressed from clones of the fully resistant isolate failed to bind to CCR5 on the surface of L1.2-CCR5 cells, under conditions where gp120 proteins from the parental virus and a partially AD101-resistant virus bound strongly. Hence the full impact of the V3 substitutions is only apparent at the level of the native Env complex. A structure-based model of the V3 loops of the parental and escape mutant viruses suggests that one of the V3 substitutions, H308P, might have a significant effect on the architecture of the V3 loop. Acknowledgements: This work was funded by NIH grants AI41420 (JPM), GM46192 (IAW, RLS), HD37356 (SMW), Immunology training grant T32 AI07621 (SEK and PP); by IAVI (JPM and IAW); and by Schering Plough Research Institute (JPM). BK is an Elizabeth Glaser Scientist of the Pediatric AIDS Foundation. JPM is a Stavros S. Niarchos Scholar. The Department of Microbiology and Immunology at the Weill Medical College gratefully acknowledges the support of the William Randolph Hearst Foundation. Los Alamos National Laboratory la-ur-03-5893.
Publication Types:
Keywords:
- Child
- Genes, env
- HIV Envelope Protein gp120
- HIV-1
- Humans
- Phenotype
- Receptors, CCR5
- genetics
- immunology
Other ID:
UI: 102268436
From Meeting Abstracts