Antiviral CD8 T cells induce Zika-virus-associated paralysis in mice.

Abstract

Zika virus (ZIKV) is an emerging, mosquito-borne RNA virus. The rapid spread of ZIKV within the Americas has unveiled microcephaly1 and Guillain-Barré syndrome 2,3 as ZIKV-associated neurological complications. Recent reports have further indicated other neurological manifestations to be associated with ZIKV including myelitis 4, meningoencephalitis 5 and fatal encephalitis6. Here, we investigate the neuropathogenesis of ZIKV infection in IFNAR knockout (Ifnar1−/−) mice, an infection model that exhibits high viral burden within the central nervous system (CNS). We show that systemic spread of ZIKV from the site of infection to the brain requires Ifnar1-deficiency in the hematopoietic compartment. However, spread of ZIKV within the CNS is supported by Ifnar1-deficient non-hematopoietic cells. Within this context, ZIKV infection of astrocytes results in breakdown of the blood-brain barrier and a large influx of CD8+ effector T cells. Further, we find antiviral activity of CD8+ T cells within the brain markedly limits ZIKV infection of neurons, but as a consequence instigates ZIKV-associated paralysis. Taken together, our study uncovers mechanisms underlying ZIKV-neuropathogenesis within a susceptible mouse model and suggests BBB breakdown and T cell mediated neuropathology as potential underpinnings of ZIKV-associated neurological complications in humans.