Glycosaminoglycan Compositional Analysis of Relevant Tissues in ZIKV Pathogenesis and in vitro Evaluation of Heparin as Antiviral Against ZIKV Infection.

Zika virus (ZIKV) is an enveloped RNA virus from the flavivirus family that can cause fetal neural abnormalities in pregnant women. Previously, we established that ZIKV-EP (envelope protein) binds to human placental chondroitin sulfate (CS), suggesting that CS may be a potential host cell surface receptor in ZIKV pathogenesis. In this study, we further characterized GAG disaccharide composition in other biological tissues (i.e., mosquitoes, fetal brain cells, eye tissues) in ZIKV pathogenesis to investigate the role of tissue specific GAGs. Heparan sulfate (HS) was the major GAG and levels of HS-6-sulfo (6S), HS 0S (unsulfated HS), and CS 4S disaccharides were main difference in the GAG composition of Aedes aegypti and albopictus mosquitoes. In human fetal neural progenitor and differentiated cells, HS 0S and CS 4S were the main disaccharides. A change in disaccharide composition levels was observed between undifferentiated and differentiated cells. In different regions of the bovine eyes, CS was the major GAG, and the amounts of hyaluronic acid (HA) or keratan sulfate (KS) varied depending on the region of the eye. Next, we examined heparin (HP) of various structures to investigate their potential in vitro antiviral activity against ZIKV and dengue virus (DENV) infection in Vero cells. All compounds effectively inhibited DENV replication, however, they surprisingly promoted ZIKV replication. HP of longer chain lengths exhibited greater promotional activity in ZIKV replication. This study further expands our understanding of role of GAGs in ZIKV pathogenesis and carbohydrate-based antivirals against flaviviral infection.