HIV-1 has a high mutation rate, which contributes to its ability to evade the host immune system, limits the efficacy of antiretroviral drugs and drives the emergence of drug resistance. Drug resistance conferring mutations as well as other viral mutations are primarily attributed to the error-prone nature of reverse transcriptase (RT). An intentional increase in RT-mediated mutations decreases virus infectivity by increasing the mutation rate to a level that is not able to maintain survival of the virus population. The potency by which HIV-1 infectivity can be decreased by increasing RT-mediated errors has led to an initiative to discover small molecules that may increase the HIV-1 mutation rate. An interdisciplinary collaborative team has been assembled to 1) conduct discovery studies to identify new small molecules that increase RT-mediated errors, 2) use molecular analyses to identify the mechanism(s) by which small molecules increase the HIV mutation rate and result in virus extinction, and 3) to assess the mechanism of RT-mediated mutation using biochemical methods. Through preliminary studies, we have identified four small molecules that increase RT-mediated mutations. In order to elucidate the structure-activity relationship driving this increase and to optimize this activity, we will first pursue discovery studies to identify small molecules that can increase RT-mediated errors. The antiviral and mutagenic activities of these molecules will be assessed in cell culture. Second, we will examine the mechanism by which small molecules induce mutations and cause virus extinction in HIV-1 using cell culture methodologies. Here we will examine small molecules that we have already discovered as well as any lead molecules that we identify. Third, we will investigate the mechanism of action using biochemical methods to elucidate the mechanistic basis for increased RT-mediated mutation. Successful completion of these studies will provide deeper insight into the mechanisms of RT-mediated viral mutagenesis and its impact on viral replication and extinction.

Public Health Relevance

Reverse transcriptase (RT) is a critical enzyme in the HIV-1 life cycle and remains the most exploited target for antiretroviral drugs. Studies on the error-prone nature of HIV-1 RT will provide detailed information regarding the nature of mutations as well as the mechanisms by which mutations arise during viral DNA synthesis. This information will likely reveal new information regarding HIV-1 RT activity and it may assist in the development of novel therapeutic approaches directed at virus extinction.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM105876-01A1
Application #
8561668
Study Section
AIDS Molecular and Cellular Biology Study Section (AMCB)
Program Officer
Sakalian, Michael
Project Start
2013-09-15
Project End
2017-05-31
Budget Start
2013-09-15
Budget End
2014-05-31
Support Year
1
Fiscal Year
2013
Total Cost
$591,622
Indirect Cost
$171,015
Name
University of Minnesota Twin Cities
Department
Microbiology/Immun/Virology
Type
Schools of Dentistry
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
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Rawson, Jonathan M O; Daly, Michele B; Xie, Jiashu et al. (2016) 5-Azacytidine Enhances the Mutagenesis of HIV-1 by Reduction to 5-Aza-2'-Deoxycytidine. Antimicrob Agents Chemother 60:2318-25
Daly, Michele B; Roth, Megan E; Bonnac, Laurent et al. (2016) Dual anti-HIV mechanism of clofarabine. Retrovirology 13:20
Rawson, Jonathan M O; Landman, Sean R; Reilly, Cavan S et al. (2015) Lack of mutational hot spots during decitabine-mediated HIV-1 mutagenesis. Antimicrob Agents Chemother 59:6834-43
Rawson, Jonathan M O; Landman, Sean R; Reilly, Cavan S et al. (2015) HIV-1 and HIV-2 exhibit similar mutation frequencies and spectra in the absence of G-to-A hypermutation. Retrovirology 12:60
Clouser, Christine L; Bonnac, Laurent; Mansky, Louis M et al. (2014) Characterization of permeability, stability and anti-HIV-1 activity of decitabine and gemcitabine divalerate prodrugs. Antivir Chem Chemother 23:223-30
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