The mechanisms underlying Zika virus (ZIKV)-related microcephaly and other neurodevelopment defects remain poorly understood. Here, we describe the derivation and characterization, including ...single-cell RNA-seq, of neocortical and spinal cord neuroepithelial stem (NES) cells to model early human neurodevelopment and ZIKV-related neuropathogenesis. By analyzing human NES cells, organotypic fetal brain slices, and a ZIKV-infected micrencephalic brain, we show that ZIKV infects both neocortical and spinal NES cells as well as their fetal homolog, radial glial cells (RGCs), causing disrupted mitoses, supernumerary centrosomes, structural disorganization, and cell death. ZIKV infection of NES cells and RGCs causes centrosomal depletion and mitochondrial sequestration of phospho-TBK1 during mitosis. We also found that nucleoside analogs inhibit ZIKV replication in NES cells, protecting them from ZIKV-induced pTBK1 relocalization and cell death. We established a model system of human neural stem cells to reveal cellular and molecular mechanisms underlying neurodevelopmental defects associated with ZIKV infection and its potential treatment.
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•Derivation of human neocortical and spinal cord neuroepithelial stem (NES) cells•Zika virus (ZIKV) infects NES cells and radial glia, impairing mitosis and survival•ZIKV induces mitochondrial sequestration of centrosomal phospho-TBK1•Nucleoside analogs inhibit ZIKV replication, protecting NES cells from cell death
Onorati et al. establish neuroepithelial stem (NES) cells as a model for studying human neurodevelopment and ZIKV-induced microcephaly. Together with analyses in human brain slices and microcephalic human fetal tissue, they find that ZIKV predominantly infects NES and radial glial cells, reveal a pivotal role for pTBK1, and find that nucleoside analogs inhibit ZIKV replication, protecting NES cells from cell death.
Neurologic sequelae can be devastating complications of respiratory viral infections. We report the presence of virus in neural and capillary endothelial cells in frontal lobe tissue obtained at ...postmortem examination from a patient infected with severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2). Our observations of virus in neural tissue, in conjunction with clinical correlates of worsening neurologic symptoms, pave the way to a closer understanding of the pathogenic mechanisms underlying central nervous system involvement by SARS‐CoV‐2.
Highlights
The clinical spectrum of COVID-19 has expanded to include neurologic manifestations such as anosmia, ageusia, ataxia and seizures, suggesting that SARS-CoV-2 may also be neurotropic.
Ultrastructural analysis of tissue from this case revealed the presence of viral-like particles in brain and capillary endothelium, which was further confirmed by molecular testing for SARS-CoV-2.
This case provides first evidence for the potential direct propagation and presence of SARS-CoV-2 in human brain tissue.
These findings have direct implications for neurologic clinical practice and should raise awareness amongst physicians managing SARS-CoV-2-infected patients with CNS symptoms.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus with high nucleotide identity to SARS-CoV and to SARS-related coronaviruses that have been detected in horseshoe ...bats, has spread across the world and had a global effect on healthcare systems and economies
. A suitable small animal model is needed to support the development of vaccines and therapies. Here we report the pathogenesis and transmissibility of SARS-CoV-2 in golden (Syrian) hamsters (Mesocricetus auratus). Immunohistochemistry assay demonstrated the presence of viral antigens in nasal mucosa, bronchial epithelial cells and areas of lung consolidation on days 2 and 5 after inoculation with SARS-CoV-2, followed by rapid viral clearance and pneumocyte hyperplasia at 7 days after inoculation. We also found viral antigens in epithelial cells of the duodenum, and detected viral RNA in faeces. Notably, SARS-CoV-2 was transmitted efficiently from inoculated hamsters to naive hamsters by direct contact and via aerosols. Transmission via fomites in soiled cages was not as efficient. Although viral RNA was continuously detected in the nasal washes of inoculated hamsters for 14 days, the communicable period was short and correlated with the detection of infectious virus but not viral RNA. Inoculated and naturally infected hamsters showed apparent weight loss on days 6-7 post-inoculation or post-contact; all hamsters returned to their original weight within 14 days and developed neutralizing antibodies. Our results suggest that features associated with SARS-CoV-2 infection in golden hamsters resemble those found in humans with mild SARS-CoV-2 infections.
Coronaviruses are enveloped RNA viruses capable of causing respiratory, enteric, or systemic diseases in a variety of mammalian hosts that vary in clinical severity from subclinical to fatal. The ...host range and tissue tropism are largely determined by the coronaviral spike protein, which initiates cellular infection by promoting fusion of the viral and host cell membranes. Companion animal coronaviruses responsible for causing enteric infection include feline enteric coronavirus, ferret enteric coronavirus, canine enteric coronavirus, equine coronavirus, and alpaca enteric coronavirus, while canine respiratory coronavirus and alpaca respiratory coronavirus result in respiratory infection. Ferret systemic coronavirus and feline infectious peritonitis virus, a mutated feline enteric coronavirus, can lead to lethal immuno-inflammatory systemic disease. Recent human viral pandemics, including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and most recently, COVID-19, all thought to originate from bat coronaviruses, demonstrate the zoonotic potential of coronaviruses and their potential to have devastating impacts. A better understanding of the coronaviruses of companion animals, their capacity for cross-species transmission, and the sharing of genetic information may facilitate improved prevention and control strategies for future emerging zoonotic coronaviruses. This article reviews the clinical, epidemiologic, virologic, and pathologic characteristics of nine important coronaviruses of companion animals.
Following the severe acute respiratory syndrome coronavirus (SARS‐CoV) and Middle East respiratory syndrome coronavirus (MERS‐CoV), another highly pathogenic coronavirus named SARS‐CoV‐2 (previously ...known as 2019‐nCoV) emerged in December 2019 in Wuhan, China, and rapidly spreads around the world. This virus shares highly homological sequence with SARS‐CoV, and causes acute, highly lethal pneumonia coronavirus disease 2019 (COVID‐19) with clinical symptoms similar to those reported for SARS‐CoV and MERS‐CoV. The most characteristic symptom of patients with COVID‐19 is respiratory distress, and most of the patients admitted to the intensive care could not breathe spontaneously. Additionally, some patients with COVID‐19 also showed neurologic signs, such as headache, nausea, and vomiting. Increasing evidence shows that coronaviruses are not always confined to the respiratory tract and that they may also invade the central nervous system inducing neurological diseases. The infection of SARS‐CoV has been reported in the brains from both patients and experimental animals, where the brainstem was heavily infected. Furthermore, some coronaviruses have been demonstrated able to spread via a synapse‐connected route to the medullary cardiorespiratory center from the mechanoreceptors and chemoreceptors in the lung and lower respiratory airways. Considering the high similarity between SARS‐CoV and SARS‐CoV2, it remains to make clear whether the potential invasion of SARS‐CoV2 is partially responsible for the acute respiratory failure of patients with COVID‐19. Awareness of this may have a guiding significance for the prevention and treatment of the SARS‐CoV‐2‐induced respiratory failure.
Research Highlights
SARS‐CoV2 causes epidemic pneumonia characterized by acute respiratory distress.
This novel coronavirus is similar to SARS‐CoV in sequence, pathogenesis, and cellular entry.
Some coronaviruses can invade brainstem via a synapse‐connected route from the lung and airways.
The potential invasion of SARS‐CoV2 may be one reason for the acute respiratory failure.
Awareness of this will have guiding significance for the prevention and treatment.
Although antiretroviral therapy for HIV infection prevents AIDS-related complications and prolongs life, it does not fully restore health. Long-term treated patients remain at higher than expected ...risk for a number of complications typically associated with aging, including cardiovascular disease, cancer, osteoporosis, and other end-organ diseases. The potential effect of HIV on health is perhaps most clearly exhibited by a number of immunologic abnormalities that persist despite effective suppression of HIV replication. These changes are consistent with some of the changes to the adaptive immune system that are seen in the very old ("immunosenescence") and that are likely related in part to persistent inflammation. HIV-associated inflammation and immunosenescence have been implicated as causally related to the premature onset of other end-organ diseases. Novel therapeutic strategies aimed at preventing or reversing these immunologic defects may be necessary if HIV-infected patients are to achieve normal life span.
Coronavirus disease 2019 (COVID-19) is an acute infection of the respiratory tract that emerged in late 2019
. Initial outbreaks in China involved 13.8% of cases with severe courses, and 6.1% of ...cases with critical courses
. This severe presentation may result from the virus using a virus receptor that is expressed predominantly in the lung
; the same receptor tropism is thought to have determined the pathogenicity-but also aided in the control-of severe acute respiratory syndrome (SARS) in 2003
. However, there are reports of cases of COVID-19 in which the patient shows mild upper respiratory tract symptoms, which suggests the potential for pre- or oligosymptomatic transmission
. There is an urgent need for information on virus replication, immunity and infectivity in specific sites of the body. Here we report a detailed virological analysis of nine cases of COVID-19 that provides proof of active virus replication in tissues of the upper respiratory tract. Pharyngeal virus shedding was very high during the first week of symptoms, with a peak at 7.11 × 10
RNA copies per throat swab on day 4. Infectious virus was readily isolated from samples derived from the throat or lung, but not from stool samples-in spite of high concentrations of virus RNA. Blood and urine samples never yielded virus. Active replication in the throat was confirmed by the presence of viral replicative RNA intermediates in the throat samples. We consistently detected sequence-distinct virus populations in throat and lung samples from one patient, proving independent replication. The shedding of viral RNA from sputum outlasted the end of symptoms. Seroconversion occurred after 7 days in 50% of patients (and by day 14 in all patients), but was not followed by a rapid decline in viral load. COVID-19 can present as a mild illness of the upper respiratory tract. The confirmation of active virus replication in the upper respiratory tract has implications for the containment of COVID-19.
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