Engineering a Recombinant Zika Virus for Immune Modulation in Microglia 

Chronic activation of microglia is a hallmark of neurodegenerative disease. Transcriptomic analysis of microglia from human patient samples show activation patterns that include classical inflammation response pathways and transcriptional regulators like STAT1 and NF-kB. Suppression of these regulators to reprogram microglia from chronic activation to basal function is an attractive therapeutic strategy for treating neurodegeneration, but small molecule inhibitors of these mechanisms have failed to show efficacy. Studies of Zika virus non structural (NS) proteins demonstrate inhibition of STATs and STING-NF-kB pathways by targeted degradation or direct proteolysis. Zika proteins may affect even more crucial mediators of immune response, offering a valuable resource for therapeutic bioactivity and new strategies to address neurodegeneration.
We will build an experimental platform to survey the bioactivity of the Zika NS proteins in human microglia. We used the HMC3 human microglial cell line for assay development and ESC derived microglia for final analysis. Zika NS genes were cloned into inducible lentiviral vectors to generate ESC and HMC3 cells stably expressing NS1-5. To assay bioactivity, cells are stimulated chemically through the IP3/DAG, TLR4 and TLR3 pathways. Control and NS protein inducible cells are induced, immune stimulated, and harvested for RNAseq analysis.
We will validate the known bioactivity of the Zika NS proteins, including degradation of STAT2, using differential expression analysis across conditions. Novel Zika NS bioactivity will be identified by the disruption of established post-stimulation gene signatures.