Development of an in vitro 3D brain organoid model of Human Immunodeficiency Virus Type 1 (HIV-1) to study latency in the CNS

Nearly 38 million individuals are currently infected with human immunodeficiency virus type 1 (HIV-1). Of the individuals living with HIV-1, up to 50% will develop HIV-associated neurocognitive disorder (HAND), characterized by cognitive, mood, and motor impairments. The development of HAND seems to arise due to virus-induced immune activation in the central nervous system (CNS) and persists even when individuals adhere to strict antiretroviral therapies (ART). This is thought to be due in part to the limited ability of antiretrovirals crossing the blood-brain barrier (BBB). While receiving ART, the virus within the brain is thought to reside in a latent state and does not actively replicate. Previously, our laboratory developed a triculture 3D brain organoid model to study HIV-1 induced neuroinflammation. Generated from fetal cortical tissue, this model is complicated by changing regulations pertaining to the use of fetal tissue, as well as complex and time-consuming propagation methods. To overcome these difficulties, we sought to develop a new model utilizing a commercially available, immortalized human cell line, ReNcell®-VM. Additionally, there is no current physiologically relevant in vitro model of HIV-1 latency in the brain. As such, we sought to use antiretroviral drugs to recapitulate the latent HIV-1 state found in the brains of HIV-1+ individuals when receiving ART to advance studies towards understanding the mechanisms contributing to the development of HAND. This model would also serve as a means for exploring alternative therapeutics with greater efficacy in traversing the BBB. Use of this model would provide a more biologically relevant method of studying the therapeutic potential of new antiretroviral and anti-inflammatory molecules. Results from this study support the generation of 3D brain organoids using the ReNcell®-VM cell line and show evidence of cellular differentiation into the major cell types of the brain – neurons and astrocytes. Infection of the organoid model was possible through incorporation of HIV-1 infected microglia cells. However, establishment of the latent-like state using antiretroviral drugs necessitates additional study before the in vitro latency model can be achieved