At present, there are ~37 million people living with human immunodeficiency virus type-1 (HIV) infection worldwide. Although AIDS and severe dementia have become uncommon with ART, minor cognitive motor disorder (MCMD) remains an important manifestation of HIV infection affecting 10-30% of persons living with HIV which may be increasing as the number of HIV-infected individuals in their 50s and 60s rises. Additionally, though ART has led to significant virologic suppression and improvement in immune function, persistent viral reservoirs remain that have been refractory to intensified antiviral therapy including macrophages and microglial cells within the brain. Numerous strategies have been proposed to eradicate HIV persistence (both latent and low level replicating virus). Most prominent has been the ?shock and kill? approach that attempts to reactivate virus with the hope of decreasing the reservoir size while preventing new cells from becoming infected. This approach, however, could be detrimental to the CNS where viral reactivation including release of viral components could exacerbate inflammation and neuronal dysfunction resulting in increased cognitive impairment. Our previous research has indicated that autophagy is essential for the maintenance of cellular homeostasis and persistence of HIV in viral reservoirs. However, despite being an essential survival mechanism, excessive levels of autophagy are able to induce cell death. Recently, we have shown that an autophagy- dependent non-apoptotic form of cell death, autosis, can be triggered by autophagy-inducing peptides through the induction of Na+/K+-ATPase leading to HIV inhibition and the potential to preferentially kill HIV latently/persistently infected cells including macrophages. In the research proposed, these peptides will be loaded into lipid-coated polymeric nanoparticles that combine the positive attributes of both liposomes and polymeric nanoparticles and optimized to allow passage across the blood-brain-barrier, This proposal will leverage the unique experience of our research team in elucidating the molecular interactions of HIV and autophagy, and in the development and use of nanoparticles to optimize drug delivery.
The Specific Aims of this proposal are:
Aim 1 : Preferential killing of HIV-infected macrophages, microglia and astrocytes without viral reactivation.
Aim 2 : In vitro optimization of HIV eradication in macrophages, microglia and astrocytes resulting in the least toxicity to neurons.
Aim 3 : Synthesis and optimization of peptide loaded sub-25 nm nanoparticles for improved delivery to the CNS;
and Aim 4 : Elimination of HIV infected cells within the CNS in the murine model of HIV encephalitis. This research will address the fundamental roadblocks to achieving HIV elimination within the brain by: developing nanoparticles that facilitate peptide entry across the BBB; preferential killing of HIV- infected cells within the CNS through induction of Na+K+-ATPase dependent autosis; preventing the reactivation of virus and infection of uninfected bystander cells; and development of a broadly applicable approach that can be applied to all populations of HIV-infected patients with sustained viral suppression on ART.
Although antiretroviral therapy has led to significant virologic suppression and improvement in immune function, HIV infection is not eliminated and minor cognitive impairment continues to be present in 10-30% of HIV-infected persons. In the research proposed, we will utilize nanoparticles loaded with specific peptides that we have shown can inhibit HIV and can preferentially kill HIV-infected cells without reactivation of virus or neurotoxicity. This proposal will leverage the considerable experience of our research team in modulating autophagy to inhibit HIV, and in the development and use nanoparticles to optimize drug delivery, and provide a novel and broadly applicable strategy to eradicate HIV from the CNS without viral reactivation or neurotoxicity.
| Campbell, Grant R; Bruckman, Rachel S; Herns, Shayna D et al. (2018) Induction of autophagy by PI3K/MTOR and PI3K/MTOR/BRD4 inhibitors suppresses HIV-1 replication. J Biol Chem 293:5808-5820 |
| Zhang, Gang; Luk, Brian T; Hamidy, Morcel et al. (2018) Induction of a Na+/K+-ATPase-dependent form of autophagy triggers preferential cell death of human immunodeficiency virus type-1-infected macrophages. Autophagy 14:1359-1375 |
| Campbell, Grant R; Bruckman, Rachel S; Chu, Yen-Lin et al. (2018) SMAC Mimetics Induce Autophagy-Dependent Apoptosis of HIV-1-Infected Resting Memory CD4+ T Cells. Cell Host Microbe 24:689-702.e7 |
| Rawat, Pratima; Spector, Stephen A (2017) Development and characterization of a human microglia cell model of HIV-1 infection. J Neurovirol 23:33-46 |
