Correlation of cGAS, STING, INF-α and INF-β gene expression with Zika virus kinetics in primary culture of microglia and neurons from BALB/c mice

Abstract

Pattern recognition receptors participate in the innate immune response. Among PRRs, the cGAS/STING pathway is known to detect cytosolic DNA and cyclic dinucleotides, but it’s also important in RNA virus infection. We aimed to evaluate the gene expression of some important genes of cGAS/STING pathway and to correlate this expression with Zika virus kinetics in mice microglia and neurons. Cells were infected by MOI = 1.0. Indirect immunofluorescence, plaque titration of supernatant, extraction, and quantification of total intracellular RNA, RT-qPCR and Western blotting were performed. Plaque titration profile in microglia and neurons was similar, including higher titers of plaque forming units at 24, 48, 72 and 96 hpi, respectively. ZIKV kinetics evaluated by RT-qPCR was similar in both cells, with highest viral titers at 48, 72, 24 and 96 hpi, respectively. Expression profile of cGAS, STING, INF-α and INF-β was quite different between the cells, including gene suppression, as observed for cGAS in neurons. Our results showed a differentiated expression profile of cGAS/STING pathway genes in mice microglia and neurons, which can be explained by the different mechanisms that ZIKV uses to bypass the immune response of these cells. Furthermore, each cell type responds differently to combat the viral infection.

Key words
cGAS/STING pathway; INF-α; INF-β; primary cell cultures of CNS; viral kinetics; Zika virus