Persistent HIV-1 infection of tissue macrophage and CNS microglia can be observed throughout pathogenesis, and these cell types have been considered as key long-living HIV-1 reservoirs in the infected patients. We recently observed that human primary macrophages infected with M-tropic HIV-1 display a greatly elevated survival capability upon cellular insults. Considering the various cytotoxic environments caused by HIV-1 infection, which are well explained in the CNS model, it is a logical speculation that HIV-1 may have evolved to display self-protective responses in macrophage and microglia reservoirs against the HIV-1 induced cytotoxic insults and to achieve the long term survival of these HIV-1 infected cell types and persistent HIV-1 production. However, the viral factors responsible for this extended survival phenotype of HIV-1 infected non-dividing target cells and the cellular mechanisms involved in this long-term survival phenotype have never been envisioned. Due to the limited access of human primary microglia, we have recently established a human microglial cell line system that also displays the greatly enhanced survival capability upon HIV-1 infection. This model system enabled us to reveal both the mechanisms underlying HIV-1 induced cell survival and intracellular Tat as a key viral factor responsible for the cytoprotective phenotype of HIV-1. Our preliminary data also suggest that the well characterized PI3K/Akt survival pathway is mechanistically involved in the cytoprotective effect of HIV-1 infection and intracellular Tat expression. Using our model system as well as primary human macrophages, we identified several key host factors regulated by Tat expression, which will guide us in pinpointing the cytoprotective mechanism of action elicited by intracellular HIV-1 Tat. More interestingly, employing several PI3K/Akt inhibitors, which had been developed as anti-cancer agents, we revealed that the inhibition of the PI3K/Akt pathway can lead to the abolishment of the long-term survival phenotype of HIV-1 infected macrophages and eventually to the inhibition of HIV-1 production from the infected macrophages. In this proposal, we seek to 1) understand the cellular mechanisms and host/viral factors involved in the cytoprotective effect of HIV-1 infection in primary human macrophages and microglia, and 2) test the anti-HIV effect of the PI3K/Akt inhibitors by specifically eradicating macrophages and microglia HIV-1 reservoirs. This proposed work will shed light on understanding the molecular and cellular mechanisms involved in the long term survival of HIV-1 infected macrophage and microglia and the establishment of the HIV-1 reservoirs in the infected patients. The goal of the research is to develop new strategies to specifically eradicate the long- living HIV-1 reservoirs.

Public Health Relevance

Long term infection of HIV-1 in tissue macrophage and central nerve system reservoirs leads to persistent viral production and clinical complications such as HIV-1 associated dementia. Due to lack of antiviral therapy inhibiting viral production from long-living HIV-1 reservoirs that have been already infected, the viral spreading initiated from the HIV-1 reservoirs is currently beyond control. This application proposes to identify new antiviral strategies to specifically eradicate long-living HIV-1 reservoirs, which can minimize persistent viral production and infection in the HIV-1 infected patients.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI077401-01A2
Application #
7622243
Study Section
AIDS Discovery and Development of Therapeutics Study Section (ADDT)
Program Officer
Salzwedel, Karl D
Project Start
2009-01-01
Project End
2012-12-31
Budget Start
2009-01-01
Budget End
2009-12-31
Support Year
1
Fiscal Year
2009
Total Cost
$346,500
Indirect Cost
Name
University of Rochester
Department
Microbiology/Immun/Virology
Type
Schools of Dentistry
DUNS #
041294109
City
Rochester
State
NY
Country
United States
Zip Code
14627
Kretschmer, Stefanie; Wolf, Christine; König, Nadja et al. (2015) SAMHD1 prevents autoimmunity by maintaining genome stability. Ann Rheum Dis 74:e17
Nguyen, Laura A; Kim, Dong-Hyun; Daly, Michele B et al. (2014) Host SAMHD1 protein promotes HIV-1 recombination in macrophages. J Biol Chem 289:2489-96
Amie, Sarah M; Daly, Michele B; Noble, Erin et al. (2013) Anti-HIV host factor SAMHD1 regulates viral sensitivity to nucleoside reverse transcriptase inhibitors via modulation of cellular deoxyribonucleoside triphosphate (dNTP) levels. J Biol Chem 288:20683-91
Hollenbaugh, Joseph A; Gee, Peter; Baker, Jonathon et al. (2013) Host factor SAMHD1 restricts DNA viruses in non-dividing myeloid cells. PLoS Pathog 9:e1003481
Amie, Sarah M; Bambara, Robert A; Kim, Baek (2013) GTP is the primary activator of the anti-HIV restriction factor SAMHD1. J Biol Chem 288:25001-6
Amie, Sarah M; Noble, Erin; Kim, Baek (2013) Intracellular nucleotide levels and the control of retroviral infections. Virology 436:247-54
Goujon, Caroline; Schaller, Torsten; Galão, Rui Pedro et al. (2013) Evidence for IFN?-induced, SAMHD1-independent inhibitors of early HIV-1 infection. Retrovirology 10:23
Kennedy, Edward M; Amie, Sarah M; Bambara, Robert A et al. (2012) Frequent incorporation of ribonucleotides during HIV-1 reverse transcription and their attenuated repair in macrophages. J Biol Chem 287:14280-8
Gavegnano, Christina; Kennedy, Edward M; Kim, Baek et al. (2012) The Impact of Macrophage Nucleotide Pools on HIV-1 Reverse Transcription, Viral Replication, and the Development of Novel Antiviral Agents. Mol Biol Int 2012:625983
Mock, David J; Hollenbaugh, Joseph A; Daddacha, Waaqo et al. (2012) Leishmania induces survival, proliferation and elevated cellular dNTP levels in human monocytes promoting acceleration of HIV co-infection. PLoS Pathog 8:e1002635

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