Develop and Evaluate the Efficacy of Nanoformulated siBeclin1 Delivered Intranasally to Eliminate HIV in the Brain. The overall hypothesis is that small interfering (si) RNAs targeting the autophagy pathway can act as a synergistic therapeutic agent with antiretroviral drugs to eliminate central nervous system (CNS) HIV reservoirs and viral associated inflammatory responses in perivascular macrophages, microglia [1,2] and astrocytes [3]. To this end, we will synthesize a siBeclin1 siRNA- polyethylenimine (PEI) polyplex [4] to facilitate intranasal delivery to the brain [4]. The nanoformulated siBeclin1 which transiently diminishes expression of host protein Beclin1, will be tested for its efficacy in eliminating brain cell HIV reservoirs in humanized mice. Efficient intranasal delivery (Figure 1), deployment of mannose decorated particles (Figure 2) and quantitative measures of viral replication will be employed (Figure 3). In the first two sub aims (a &b) of Aim 1, we will quantitatively measure the pharmacokinetics and bio-distribution of siBeclin1 in brain, lung, heart, liver and kidney by reverse transcription polymerase chain reaction (RT-PCR) and liquid chromatography- tandem mass spectrometry (LC-MS/MS) methodologies. Since cell toxicity is a problem encountered with many antiretroviral therapies, in Aim 1c, morphological changes due to cytotoxicity in the brain will be assessed by histology using Hematoxylin and eosin (H&E) and Nissl staining to detect for neuronal damages. Followed by immunohistochemical labeling of neuronal nuclei (NeuN) or microtubule-associated protein 2 (MAP2) to assess for the surviving neuronal cells in the brain. The cell marker, ionized calcium binding adaptor molecule 1 (Iba-1) or CD68 specific for microglia and glial fibrillary acidic protein (GFAP) specific for astrocytes will be used to detect Glial activation (gliosis). Inflammatory responses will be measured by cytokine and chemokine membrane-based antibody arrays and confirmed by colorimetric sandwich enzyme-linked immunosorbent assay (ELISA). Chemistry analysis on the levels of blood urea nitrogen and alanine transaminase activity, will indicate toxicity of the kidneys and liver, respectively.
In Aim 2 a, we will determine the efficacy of the nanoformulated siBeclin1 on the different aspects of CNS pathology induced by HIV antiretroviral drugs including (1) viral replication (measured by PCR-based assays); (2) secretion of immune responses (measured by ELISA-based assays); (3) glial activation and (4) neuronal health (measured by histological and immunohistochemical based assays). Special emphasis will be placed on the hippocampus and the basal ganglia as these regions are most affected by HIV disease and are critical for brain development, learning and memory processes and sensory motor function.
In aim 2 b, behavioral changes elicited by HIV infection alone or in combination with antiretroviral drug regimen nanoformulated siBeclin1 will be assessed using the novel object recognition test as an indicator of short-term memory and the Morris water maze to measure spatial memory. The sensory motor test will be assessed by using the Rota-rod, grip-strength and horizontal bar.
In response to the funding opportunity announcement number PA-18-350, our proposal addresses two high priority research areas listed under the division of AIDS research (DAR), including: (a) the development of next generation HIV therapies with better safety and ease of brain delivery and (b) research toward a cure and development of novel therapeutic approaches to mitigate central nervous system complications of HIV infection.
