Biology subjects

Warren, A. L.

Publications and source records attributed to Warren, A. L..

2 recordsLinked to original sources

bioRxiv2017

Replication of early and recent Zika virus isolates throughout mouse brain development

Fetal infection with Zika virus (ZIKV) can lead to congenital Zika virus syndrome (cZVS), which includes cortical malformations and microcephaly. The aspects of cortical development that are affected during virus infection are unknown. Using organotypic brain slice cultures generated from embryonic mice of various ages, sites of ZIKV replication including the neocortical proliferative zone and radial columns, as well as the developing midbrain, were identified. The infected radial units are surrounded by uninfected cells undergoing apoptosis, suggesting that programmed cell death may limit viral dissemination in the brain and may constrain virus associated injury. Therefore, a critical aspect of ZIKV induced neuropathology may be defined by death of uninfected cells. All ZIKV isolates assayed replicated efficiently in early and mid-gestation cultures, and two isolates examined replicated in late-gestation tissue. Alteration of neocortical cytoarchitecture, such as disruption of the highly-elongated basal processes of the radial glial progenitor cells, and impairment of postmitotic neuronal migration were also observed. These data suggest that all lineages of ZIKV tested are neurotropic, and that ZIKV infection interferes with multiple aspects of neurodevelopment that contribute to the complexity of cZVS.\n\nSignificanceZika virus infection has been associated with multiple pathologies of the central nervous system (CNS) including microcephaly, Guillain-Barre syndrome, lissencephaly, the loss of white and grey matter volume and acute myelitis. Using organotypic brain slice cultures, we determined that ZIKV replicates across different embryonic developmental stages, and viral infection can disrupt proper brain development leading to congenital CNS complications. These data illustrate that all lineages of ZIKV tested are neurotropic, and that infection may disrupt neuronal migration during brain development. The results expand our understanding of neuropathologies associated with congenital Zika virus syndrome.

microbiology↗

bioRxiv2017

Neurotropism of enterovirus D68 isolates is independent of sialic acid and is not a recently acquired phenotype

Acute flaccid myelitis /acute flaccid paralysis (AFM/AFP) is a rare but serious illness of the nervous system, specifically affecting the grey matter of the spinal cord, motor controlling regions of the brain and the cranial nerve. Most cases of AFM/AFP are pathogen associated, typically with poliovirus and enterovirus infections, and occur in children under the age of 6 years old. Enterovirus D68 (EV-D68) was first isolated from children with pneumonia in 1962, but an association with AFM/AFP was not observed until the 2014 outbreak. Organotypic mouse brain slice cultures generated from postnatal day 1 to 10 mice were used to determine if neurotropism of EV-D68 is shared among virus isolates. Six of the seven EV-D68 isolates examined, including two from 1962 and four from the 2014 outbreak, replicated in neurons, and all replicated in astrocytes. Furthermore, a putative viral receptor, sialic acid, is not required for neurotropism of EV-D68, as both sialic acid dependent and independent viruses replicated within neurons. These observations demonstrate that EV-D68 is neurotropic independent of its genetic lineage, can infect both neurons and astrocytes, and that neurotropism is not a recently acquired characteristic as has been suggested.\n\nSignificanceRecently there has been an increase in the number of children infected with enterovirus D68 (EV-D68). Most infections are associated with mild flu-like symptoms, but neurological dysfunction may develop in a small number of children. How the biochemical and genetic differences among EV-D68 isolates relates to development of neurological disease remains an unanswered question. Assessing infection of multiple viral isolates in organotypic brain slice cultures from postnatal day 1 to 10 mice revealed that multiple isolates are neurotropic. Both neuraminidase sensitive and resistant viruses infected neurons, indicating that sialic acid binding does not play a role in EV-D68 neuropathogenesis. Establishment of a genetically and pharmacologically amenable system using organotypic brain slice cultures will provide insight into how EV-D68 neuropathologies develop.

microbiology↗