Human Schwann cells are susceptible to infection with Zika and yellow fever viruses, but not dengue virus
Zika virus (ZIKV) is a re-emerged flavivirus transmitted by Aedes spp mosquitoes that has caused outbreaks of fever and rash on islands in the Pacific and in the Americas. These outbreaks have been associated with neurologic complications that include congenital abnormalities and Guillain-Barré syndrome (GBS). The pathogenesis of ZIKV-associated GBS, a potentially life-threatening peripheral nerve disease, remains unclear. Because Schwann cells (SCs) play a central role in peripheral nerve function and can be the target for damage in GBS, we characterized the interactions of ZIKV isolates from Africa, Asia and Brazil with human SCs in comparison with the related mosquito-transmitted flaviviruses yellow fever virus 17D (YFV) and dengue virus type 2 (DENV2). SCs supported sustained replication of ZIKV and YFV, but not DENV. ZIKV infection induced increased SC expression of IL-6, interferon (IFN)β1, IFN-λ, IFIT-1, TNFα and IL-23A mRNAs as well as IFN-λ receptors and negative regulators of IFN signaling. SCs expressed baseline mRNAs for multiple potential flavivirus receptors and levels did not change after ZIKV infection. SCs did not express detectable levels of cell surface Fcγ receptors. This study demonstrates the susceptibility and biological responses of SCs to ZIKV infection of potential importance for the pathogenesis of ZIKV-associated GBS.