While the advent of antiretroviral therapy (ART) has dramatically reduced the morbidity and mortality associated with HIV infection, viral eradication is not achievable due to the persistence of latently-infected cells during treatment. ART must therefore be taken on a lifelong basis. Accumulating data suggest that HIV- infected individuals often experience persistent immune dysregulation, chronic inflammation, and accelerated aging even in the setting of ART-mediated viral suppression. These realities have created a pronounced interest in developing strategies to eradicate HIV in infected individuals. Identifying host determinants governing viral latency and reservoir size in vivo will be critical in developing effective strategies to clear the latent reservoir and cure HIV infection. Several cell-intrinsic immune factors have been discovered that restrict HIV infection in the absence of antiretroviral drugs. We recently demonstrated that the elevated expression of two particular restriction factors, p21 (inhibitor of HIV transcription) and schlafen 11 (codon usage-based inhibitor of HIV protein synthesis), was strongly associated with decreased HIV latent reservoir size in ART-suppressed individuals. We further demonstrated that select cell-intrinsic immune responses were enhanced in subjects who initiated ART during early versus chronic infection, likely contributing to the reduced reservoir size observed in these individuals. In this R01 project, we will extend our in vivo observations by performing single cell-level analyses, as well as ex vivo and in vitro experiments to characterize the effects of select host restriction factors on the establishment and reversal of HIV latency.
In Aim 1, we will apply novel PCR-Activated Cell Sorting (PACS) technology to clinical samples from HIV-infected, ART-suppressed individuals to interrogate single CD4+ T cells for the presence of HIV DNA and RNA. We will then measure the expression of p21 and schlafen 11 in single cells harboring transcriptionally active and inactive proviruses to elucidate the role of these factors in regulating viral latency.
In Aim 2, w will use lentiviral transduction to overexpress and silence select cell- intrinsic immune factors i primary cells and human lymphoid aggregate cultures (HLAC). A dual-reporter HIV construct will then be used to examine the effects of these cell-intrinsic immune factors on the establishment of latent HIV infection. Lastly, in Aim 3, we will manipulate p21 and schlafen 11 expression in a cell line model of HIV latency and in HIV-infected primary cells. Cells will then be treated with a comprehensive panel of latency reversal agents, to examine the effects of p21 and schlafen 11 manipulation on the efficacy of these agents and on the dynamics of viral reactivation. This study will yield valuable insights into how cell-intrinsic immunity may serve as a foundation of novel curative strategies for HIV infection.

Public Health Relevance

While the advent of antiretroviral therapy (ART) has significantly decreased the morbidity and mortality associated with HIV infection, a cure is not achieved due to the persistence of latently HIV-infected cells during treatment. ART must therefore be taken on a lifelong basis, and treated individuals often experience drug toxicity, persistent immune dysregulation, chronic inflammation, and accelerated aging. In this project, we investigate the ability of antiviral proteins naturally produced in human cells known as 'host restriction factors' to modulate HIV latent infection, with the ultimate goal of manipulating these cell-intrinsic immune defenses to cure HIV infection.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM117901-04S1
Application #
9736974
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Sakalian, Michael
Project Start
2015-09-01
Project End
2020-08-31
Budget Start
2018-09-01
Budget End
2019-08-31
Support Year
4
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Blood Systems Research Institute
Department
Type
DUNS #
006902498
City
San Francisco
State
CA
Country
United States
Zip Code
94118
Battivelli, Emilie; Dahabieh, Matthew S; Abdel-Mohsen, Mohamed et al. (2018) Distinct chromatin functional states correlate with HIV latency reactivation in infected primary CD4+ T cells. Elife 7:
Krarup, A R; Abdel-Mohsen, M; Schleimann, M H et al. (2018) The TLR9 agonist MGN1703 triggers a potent type I interferon response in the sigmoid colon. Mucosal Immunol 11:449-461
Pillai, Satish K; Deeks, Steven G (2017) Signature of the Sleeper Cell: A Biomarker of HIV Latency Revealed. Trends Immunol 38:457-458
Keating, Sheila M; Pilcher, Christopher D; Jain, Vivek et al. (2017) HIV Antibody Level as a Marker of HIV Persistence and Low-Level Viral Replication. J Infect Dis 216:72-81
Togarrati, Padma Priya; Sasaki, Robson T; Abdel-Mohsen, Mohamed et al. (2017) Identification and characterization of a rich population of CD34+ mesenchymal stem/stromal cells in human parotid, sublingual and submandibular glands. Sci Rep 7:3484
Vibholm, Line; Schleimann, Mariane H; Højen, Jesper F et al. (2017) Short-Course Toll-Like Receptor 9 Agonist Treatment Impacts Innate Immunity and Plasma Viremia in Individuals With Human Immunodeficiency Virus Infection. Clin Infect Dis 64:1686-1695
Henrich, Timothy J; Deeks, Steven G; Pillai, Satish K (2017) Measuring the Size of the Latent Human Immunodeficiency Virus Reservoir: The Present and Future of Evaluating Eradication Strategies. J Infect Dis 215:S134-S141
Jacobs, Evan S; Keating, Sheila M; Abdel-Mohsen, Mohamed et al. (2017) Cytokines Elevated in HIV Elite Controllers Reduce HIV Replication In Vitro and Modulate HIV Restriction Factor Expression. J Virol 91:
Abdel-Mohsen, Mohamed; Chavez, Leonard; Tandon, Ravi et al. (2016) Human Galectin-9 Is a Potent Mediator of HIV Transcription and Reactivation. PLoS Pathog 12:e1005677