The objective of our proposal is to characterize the window of opportunity for CD8-induced killing of cells infected but not yet producing SIV in rhesus macaques (RM). To this end we will compare treatment of SIV infection in control animals and CD8-depleted animals. Although similar experiments were done before (in part) by us and others, those used RTI therapy (PMPA and FTC). Here, we propose that using an integrase strand transfer inhibitor (raltegravir - RAL), we will obtain qualitatively and quantitatively different results that will alow probing of the strength of the immune response during cell infection but before viral production (i.e., before integration). We will extend the standard and successful models of viral therapy to analyze the case of RAL monotherapy, because we expect that the behavior of the decay of virus is different. Analyzing viral load under RAL therapy (and its suspension) in CD8 depleted macaques will provide the best conditions to probe the effect of CD8s on controlling the virus. In addition, we will analyze the number of infected cells, with different forms of HIV DNA (integrated, unintegrated, 2LTR circles) to gain precious insights into the long-term dynamics of viral reservoirs, especially latently infected cells.
Our specific aims are:
Aim 1. Quantify the dynamics of SIV during RAL monotherapy in rhesus macaques (RM). Hypothesis: The profile of viral load under RAL monotherapy is due to decay of cells infected by virus that have not completed integration but which leak through and become productively infected. We will develop new models of viral dynamics, which take into account the specific mode of action of RAL. Thus, we will quantify the kinetics of cellular reservoirs with unintegrated HIV DNA.
Aim 2. Quantify the effect of CD8+ T-cells in killing cells infected with SIVmac before they become productively infected (i.e., before proviral integration). Hypothesis: Most of the CD8+ T cell effect on killing infected cells occurs before the start of viral production by the infected cell. We will quantify te effect of CD8 on killing of cells with unintegrated DNA.
Aim 3. Quantify and model the fate of different cellular/viral reservoirs during long-term SIV treatment. Hypothesis: Modeling of long-term combination therapy including structured RAL treatment interruptions will permit a characterization of the decay and maintenance of different cellular/viral reservoirs. We will measure cells with integrated and unintegrated viral DNA (eg., 2-LTR circles), latently infected cells and follicular dendritic cell-associated viruses. We will develop models of these cellular compartments to quantify their decay and understand whether they are replenished throughout treatment or if they continuously decrease. These studies will better characterize the strength of CD8+ T-cells in controlling infection and the long-term decay of different viral reservoirs. Thus, our results will have implications to HIV control (by vaccines and therapy) and probe the limits of the immune response in eradicating the virus.

Public Health Relevance

HIV/AIDS is an infectious disease with large mortality and morbidity worldwide. Although, it can be controlled with therapeutic agents, we still don't understand why the immune system cannot control it. In this project, we will quantify the effect of immune cells in killing infected cells in vivo. We will also use a similar experimental strategy to probe the long-term decay of different cellular reservoirs of virus.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI104373-02
Application #
8707963
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Stansell, Elizabeth H
Project Start
2013-08-01
Project End
2017-07-31
Budget Start
2014-08-01
Budget End
2015-07-31
Support Year
2
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Los Alamos National Lab
Department
Type
DUNS #
City
Los Alamos
State
NM
Country
United States
Zip Code
87545
Perelson, Alan S; Ribeiro, Ruy M (2018) Introduction to modeling viral infections and immunity. Immunol Rev 285:5-8
Romero-Severson, Ethan O; Ribeiro, Ruy M; Castro, Mario (2018) Noise Is Not Error: Detecting Parametric Heterogeneity Between Epidemiologic Time Series. Front Microbiol 9:1529
Brocca-Cofano, Egidio; Xu, Cuiling; Wetzel, Katherine S et al. (2018) Marginal Effects of Systemic CCR5 Blockade with Maraviroc on Oral Simian Immunodeficiency Virus Transmission to Infant Macaques. J Virol 92:
Policicchio, Benjamin Bruno; Sette, Paola; Xu, Cuiling et al. (2018) Emergence of resistance mutations in simian immunodeficiency virus (SIV)-infected rhesus macaques receiving non-suppressive antiretroviral therapy (ART). PLoS One 13:e0190908
Vaidya, Naveen K; Ribeiro, Ruy M; Liu, Pinghuang et al. (2018) Correlation Between Anti-gp41 Antibodies and Virus Infectivity Decay During Primary HIV-1 Infection. Front Microbiol 9:1326
Cardozo, Erwing Fabian; Apetrei, Cristian; Pandrea, Ivona et al. (2018) The dynamics of simian immunodeficiency virus after depletion of CD8+ cells. Immunol Rev 285:26-37
Policicchio, Benjamin B; Cardozo, Erwing Fabian; Sette, Paola et al. (2018) Dynamics of Simian Immunodeficiency Virus Two-Long-Terminal-Repeat Circles in the Presence and Absence of CD8+ Cells. J Virol 92:
Cardozo, E Fabian; Andrade, Adriana; Mellors, John W et al. (2017) Treatment with integrase inhibitor suggests a new interpretation of HIV RNA decay curves that reveals a subset of cells with slow integration. PLoS Pathog 13:e1006478
Ke, Ruian; Cong, Mian-Er; Li, David et al. (2017) On the Death Rate of Abortively Infected Cells: Estimation from Simian-Human Immunodeficiency Virus Infection. J Virol 91:
Schechter, Melissa E; Andrade, Bruno B; He, Tianyu et al. (2017) Inflammatory monocytes expressing tissue factor drive SIV and HIV coagulopathy. Sci Transl Med 9:

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