RESUMO
Inherited deficiency of the RNA lariat-debranching enzyme 1 (DBR1) is a rare etiology of brainstem viral encephalitis. The cellular basis of disease and the range of viral predisposition are unclear. We report inherited DBR1 deficiency in a 14-year-old boy who suffered from isolated SARS-CoV-2 brainstem encephalitis. The patient is homozygous for a previously reported hypomorphic and pathogenic DBR1 variant (I120T). Consistently, DBR1 I120T/I120T fibroblasts from affected individuals from this and another unrelated kindred have similarly low levels of DBR1 protein and high levels of RNA lariats. DBR1 I120T/I120T human pluripotent stem cell (hPSC)-derived hindbrain neurons are highly susceptible to SARS-CoV-2 infection. Exogenous WT DBR1 expression in DBR1 I120T/I120T fibroblasts and hindbrain neurons rescued the RNA lariat accumulation phenotype. Moreover, expression of exogenous RNA lariats, mimicking DBR1 deficiency, increased the susceptibility of WT hindbrain neurons to SARS-CoV-2 infection. Inborn errors of DBR1 impair hindbrain neuron-intrinsic antiviral immunity, predisposing to viral infections of the brainstem, including that by SARS-CoV-2.
Assuntos
Tronco Encefálico , COVID-19 , Neurônios , SARS-CoV-2 , Humanos , Masculino , SARS-CoV-2/genética , COVID-19/genética , COVID-19/virologia , Tronco Encefálico/patologia , Tronco Encefálico/virologia , Tronco Encefálico/metabolismo , Adolescente , Neurônios/metabolismo , Neurônios/patologia , Encefalite Viral/genética , Encefalite Viral/patologia , Encefalite Viral/virologia , Fibroblastos/metabolismo , Rombencéfalo/metabolismoRESUMO
Astroviruses have been found in cattle and other species with encephalitis. Our objective was to determine the frequency of neurotropic bovine astrovirus (BoAstV) in cases of encephalitis in cattle ≥ 4-mo-old. Of 56 cases of idiopathic lymphocytic encephalitis examined retrospectively (1988-2019), fixed brain from 11 cases (19%) tested positive by semi-quantitative RT-PCR for BoAstV CH13/NeuroS1. None of the control cases tested positive, including 32 with other forms of encephalitis and 40 with no neurologic disease. Most astrovirus-positive cases were 1-2-y-old, with a range of 7 mo to 7 y, and affected both beef and dairy breeds with wide geographic distribution. BoAstV-positive cases had acute onset of neurologic signs of 12 h to 7 d before death or euthanasia. Affected cattle had lymphocytic inflammation throughout the brain including cerebrum, thalamus, midbrain, cerebellum, medulla oblongata, and spinal cord, and affecting gray and white matter. Further PCR testing identified a possible cause in 9 of the 45 (20%) remaining idiopathic cases of lymphocytic encephalitis, including eastern equine encephalitis virus, Listeria monocytogenes, bovine viral diarrhea virus, bovine alphaherpesvirus 1, and ovine gammaherpesvirus 2 (malignant catarrhal fever); we found no cases of infection by West Nile virus, rabies virus, or Chlamydia spp. No cause was identified in 36 of 56 (64%) cases of lymphocytic encephalitis. We frequently identified neurotropic BoAstV in cases of lymphocytic encephalitis that had no previously identified cause. Neurotropic BoAstV infections had gone undetected for decades, but the frequency of BoAstV infections has not increased among contemporary cases.
Assuntos
Infecções por Astroviridae , Doenças dos Bovinos , Animais , Bovinos , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Infecções por Astroviridae/epidemiologia , Doenças dos Bovinos/virologia , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/patologia , Estudos Retrospectivos , Ontário/epidemiologia , Feminino , Masculino , Encefalite Viral/veterinária , Encefalite Viral/virologia , Encefalite Viral/epidemiologia , Encefalite Viral/patologia , Astroviridae/isolamento & purificação , Astroviridae/genéticaRESUMO
Bone marrow (BM)-derived monocytes induce inflammation and tissue damage in a range of pathologies. In particular, in a mouse model of West Nile virus (WNV) encephalitis (WNE), nitric oxide-producing, Ly6Chi inflammatory monocytes from the BM are recruited to the central nervous system (CNS) and contribute to lethal immune pathology. Reducing the migration of these cells into the CNS using monoclonal antibody blockade, immune-modifying particles or CSF-1R inhibitors reduces neuroinflammation, improving survival and/or clinical outcomes. Macrophages can also be targeted more broadly by administration of clodronate-encapsulated liposomes, which induce apoptosis in phagocytes. In this study, clodronate reduced the inflammatory infiltrate by 70% in WNE, however, surprisingly, this had no effect on disease outcome. More detailed analysis demonstrated a compensatory increase in neutrophils and enhanced activation status of microglia in the brain. In addition, we observed increased numbers of Ly6Chi BM monocytes with an increased proliferative capacity and expression of SCA-1 and CD16/32, potentially indicating output of immature cells from the BM. Once in the brain, these cells were more phagocytic and had a reduced expression of antigen-presenting molecules. Lastly, we show that clodronate also reduces non-myeloid cells in the spleen and BM, as well as ablating red blood cells and their proliferation. These factors likely impeded the therapeutic potential of clodronate in WNE. Thus, while clodronate provides an excellent system to deplete macrophages in the body, it has larger and broader effects on the phagocytic and non-phagocytic system, which must be considered in the interpretation of data.
Assuntos
Encefalite Viral , Febre do Nilo Ocidental , Camundongos , Animais , Monócitos , Ácido Clodrônico/farmacologia , Sistema Nervoso Central/patologia , Macrófagos , Encefalite Viral/patologiaRESUMO
A diverse number of DNA and RNA viruses have the potential to invade the central nervous system (CNS), causing inflammation and injury to cells that have a limited capacity for repair and regeneration. While rare, viral encephalitis in humans is often fatal and survivors commonly suffer from permanent neurological sequelae including seizures. Established treatment options are extremely limited, predominantly relying on vaccines, antivirals, or supportive care. Many viral CNS infections are characterized by the presence of antiviral antibodies in the cerebral spinal fluid (CSF), indicating local maintenance of protective antibody secreting cells. However, the mechanisms maintaining these humoral responses are poorly characterized. Furthermore, while both viral and autoimmune encephalitis are associated with the recruitment of diverse B cell subsets to the CNS, their protective and pathogenic roles aside from antibody production are just beginning to be understood. This review will focus on the relevance of B cell responses to viral CNS infections, with an emphasis on the importance of intrathecal immunity and the potential contribution to autoimmunity. Specifically, it will summarize the newest data characterizing B cell activation, differentiation, migration, and localization in clinical samples as well as experimental models of acute and persistent viral encephalitis.
Assuntos
Viroses do Sistema Nervoso Central , Encefalite Viral , Antivirais , Linfócitos B , Sistema Nervoso Central , Viroses do Sistema Nervoso Central/patologia , Encefalite Viral/patologia , HumanosRESUMO
Disease associated with Nipah virus infection causes a devastating and often fatal spectrum of syndromes predominated by both respiratory and neurologic conditions. Additionally, neurologic sequelae may manifest months to years later after virus exposure or apparent recovery. In the two decades since this disease emerged, much work has been completed in an attempt to understand the pathogenesis and facilitate development of medical countermeasures. Here we provide detailed organ system-specific pathologic findings following exposure of four African green monkeys to 2.41×105 pfu of the Malaysian strain of Nipah virus. Our results further substantiate the African green monkey as a model of human Nipah virus disease, by demonstrating both the respiratory and neurologic components of disease. Additionally, we demonstrate that a chronic phase of disease exists in this model, that may provide an important opportunity to study the enigmatic late onset and relapse encephalitis as it is described in human disease.
Assuntos
Encefalite Viral/patologia , Infecções por Henipavirus/patologia , Pneumopatias/virologia , Vírus Nipah/patogenicidade , Animais , Chlorocebus aethiops , Modelos Animais de Doenças , Pneumopatias/patologia , Malásia , Masculino , Vírus Nipah/classificaçãoRESUMO
In 2021, three encephalitis cases due to the Borna disease virus 1 (BoDV-1) were diagnosed in the north and east of Germany. The patients were from the states of Thuringia, Saxony-Anhalt, and Lower Saxony. All were residents of known endemic areas for animal Borna disease but without prior diagnosed human cases. Except for one recently detected case in the state of Brandenburg, all >30 notified cases had occurred in, or were linked to, the southern state of Bavaria. Of the three detected cases described here, two infections were acute, while one infection was diagnosed retrospectively from archived brain autopsy tissue samples. One of the acute cases survived, but is permanently disabled. The cases were diagnosed by various techniques (serology, molecular assays, and immunohistology) following a validated testing scheme and adhering to a proposed case definition. Two cases were classified as confirmed BoDV-1 encephalitis, while one case was a probable infection with positive serology and typical brain magnetic resonance imaging, but without molecular confirmation. Of the three cases, one full virus genome sequence could be recovered. Our report highlights the need for awareness of a BoDV-1 etiology in cryptic encephalitis cases in all areas with known animal Borna disease endemicity in Europe, including virus-endemic regions in Austria, Liechtenstein, and Switzerland. BoDV-1 should be actively tested for in acute encephalitis cases with residence or rural exposure history in known Borna disease-endemic areas.
Assuntos
Doença de Borna/diagnóstico , Vírus da Doença de Borna/isolamento & purificação , Encefalite Viral/diagnóstico , Idoso , Animais , Doença de Borna/epidemiologia , Doença de Borna/patologia , Doença de Borna/virologia , Vírus da Doença de Borna/classificação , Vírus da Doença de Borna/genética , Encéfalo/patologia , Encéfalo/virologia , Encefalite Viral/epidemiologia , Encefalite Viral/patologia , Encefalite Viral/virologia , Doenças Endêmicas , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , FilogeniaRESUMO
Human parechovirus type 3 (PeV-A3) infection has been recognized as an emerging etiologic factor causing severe nerve disease or sepsis in infants and young children. But the neuropathogenic mechanisms of PeV-A3 remain unknown. To understand the pathogenesis of PeV-A3 infection in the neuronal system, PeV-A3-mediated cytopathic effects were analyzed in human glioblastoma cells and neuroblastoma cells. PeV-A3 induced interferons and inflammatory cytokine expression in these neuronal cells. The pronounced cytopathic effects accompanied with activation of death signaling pathways of apoptosis, autophagy, and pyroptosis were detected. A new experimental disease model of parechovirus encephalitis was established. In the disease model, intracranial inoculation with PeV-A3 in C57BL/6 neonatal mice showed body weight loss, hindlimb paralysis, and approximately 20% mortality. PeV-A3 infection in the hippocampus and cortex regions of the neonatal mouse brain was revealed. Mechanistic assay supported the in vitro results, indicating detection of PeV-A3 replication, inflammatory cytokine expression, and death signaling transduction in mouse brain tissues. These in vitro and in vivo studies revealed that the activation of death signaling and inflammation responses is involved in PeV-A3-mediated neurological disorders. The present results might account for some of the PeV-A3-associated clinical manifestations.
Assuntos
Efeito Citopatogênico Viral , Modelos Animais de Doenças , Encefalite Viral/metabolismo , Parechovirus/patogenicidade , Infecções por Picornaviridae/metabolismo , Animais , Animais Recém-Nascidos , Apoptose , Autofagia , Linhagem Celular Tumoral , Córtex Cerebral/virologia , Chlorocebus aethiops , Citocinas/biossíntese , Citocinas/genética , Encefalite Viral/patologia , Encefalite Viral/virologia , Glioblastoma/patologia , Hipocampo/virologia , Humanos , Inflamação , Interferon Tipo I/biossíntese , Interferon Tipo I/genética , Interferon Tipo I/farmacologia , Interferons/biossíntese , Interferons/genética , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos C57BL , Neuroblastoma/patologia , Parechovirus/efeitos dos fármacos , Parechovirus/fisiologia , Infecções por Picornaviridae/patologia , Infecções por Picornaviridae/virologia , Piroptose , Células Vero , Replicação Viral/efeitos dos fármacos , Interferon lambdaRESUMO
A wide range of neurological manifestations have been associated with the development of COVID-19 following SARS-CoV-2 infection. However, the etiology of the neurological symptomatology is still largely unexplored. Here, we used state-of-the-art multiplexed immunostaining of human brains (n = 6 COVID-19, median age = 69.5 years; n = 7 control, median age = 68 years) and demonstrated that expression of the SARS-CoV-2 receptor ACE2 is restricted to a subset of neurovascular pericytes. Strikingly, neurological symptoms were exclusive to, and ubiquitous in, patients that exhibited moderate to high ACE2 expression in perivascular cells. Viral dsRNA was identified in the vascular wall and paralleled by perivascular inflammation, as signified by T cell and macrophage infiltration. Furthermore, fibrinogen leakage indicated compromised integrity of the blood-brain barrier. Notably, cerebrospinal fluid from additional 16 individuals (n = 8 COVID-19, median age = 67 years; n = 8 control, median age = 69.5 years) exhibited significantly lower levels of the pericyte marker PDGFRß in SARS-CoV-2-infected cases, indicative of disrupted pericyte homeostasis. We conclude that pericyte infection by SARS-CoV-2 underlies virus entry into the privileged central nervous system space, as well as neurological symptomatology due to perivascular inflammation and a locally compromised blood-brain barrier.
Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , Encéfalo/virologia , COVID-19/fisiopatologia , Encefalite Viral/virologia , Pericitos/virologia , Enzima de Conversão de Angiotensina 2/genética , Animais , Barreira Hematoencefálica , Encéfalo/patologia , COVID-19/etiologia , Estudos de Casos e Controles , Encefalite Viral/patologia , Fibrinogênio/metabolismo , Humanos , Imuno-Histoquímica/métodos , Camundongos , Pericitos/metabolismo , Pericitos/patologia , Receptor beta de Fator de Crescimento Derivado de Plaquetas/líquido cefalorraquidianoRESUMO
Infection with flaviviruses causes mild to severe diseases, including viral hemorrhagic fever, vascular shock syndrome, and viral encephalitis. Several animal models explore the pathogenesis of viral encephalitis, as shown by neuron destruction due to neurotoxicity after viral infection. While neuronal cells are injuries caused by inflammatory cytokine production following microglial/macrophage activation, the blockade of inflammatory cytokines can reduce neurotoxicity to improve the survival rate. This study investigated the involvement of macrophage phenotypes in facilitating CNS inflammation and neurotoxicity during flavivirus infection, including the Japanese encephalitis virus, dengue virus (DENV), and Zika virus. Mice infected with different flaviviruses presented encephalitis-like symptoms, including limbic seizure and paralysis. Histology indicated that brain lesions were identified in the hippocampus and surrounded by mononuclear cells. In those regions, both the infiltrated macrophages and resident microglia were significantly increased. RNA-seq analysis showed the gene profile shifting toward type 1 macrophage (M1) polarization, while M1 markers validated this phenomenon. Pharmacologically blocking C-C chemokine receptor 2 and tumor necrosis factor-α partly retarded DENV-induced M1 polarization. In summary, flavivirus infection, such as JEV and DENV, promoted type 1 macrophage polarization in the brain associated with encephalitic severity.
Assuntos
Polaridade Celular , Vírus da Dengue/fisiologia , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Encefalite Viral/patologia , Encefalite Viral/virologia , Macrófagos/patologia , Índice de Gravidade de Doença , Animais , Animais Lactentes , Linhagem Celular , Modelos Animais de Doenças , Encefalite Japonesa/imunologia , Encefalite Japonesa/patologia , Encefalite Japonesa/virologia , Encefalite Viral/imunologia , Hipocampo/patologia , Inflamação/patologia , Camundongos Endogâmicos ICR , Neurotoxinas/toxicidade , Receptores CCR2/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
We describe for the first time an child who demonstrated Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) after mumps infection in China. In this report, a 12-year-old boy came to Children's Hospital Affiliated to Zhengzhou University due to fever, swelling and pain under the earlobe for 4 days, and headache and vomiting for half of a day. Laboratory examinations showed a blood sodium level of 125mmol/L, both the Immunoglobulin M and Polymerase Chain Reaction results for the serum mumps virus were positive. Brain Magnetic Resonance Imaging (MRI) showed slight hypointense on T1 weighted images, hyperintense on T2-weighted images, fluid attenuated inversion recovery, diffusion-weighted images in the splenium of the corpus callosum indicative of MERS. On the 8th day, the patient no longer had swelling and pain around the parotid salivary glands, the sodium levels returned to normal. Onset of 14th d, follow-up brain MRI did not reveal any abnormalities. The case given to us indicates that MERS should be considered when patients after mumps infection presents with neurological symptoms and MRI should be performed to evaluate the splenium of the corpus callosum.
Assuntos
Corpo Caloso/patologia , Encefalite Viral/patologia , Caxumba/complicações , Anti-Inflamatórios/uso terapêutico , Antivirais/uso terapêutico , Criança , China , Diuréticos Osmóticos/uso terapêutico , Encefalite Viral/virologia , Humanos , Masculino , Manitol/uso terapêutico , Metilprednisolona/uso terapêutico , Ribavirina/uso terapêuticoRESUMO
The activation of the sympathetic nervous system, release of norepinephrine (NE), and adrenergic receptor signaling participate in and regulate the complicated enterovirus 71 (EV71) brainstem encephalitis (BE). The neurotoxin 6-hydroxydopamine (6-OHDA) selectively ablates sympathetic nerves and markedly depletes NE in innervated organs. Changes in the plasma levels of NE, severity score, cytokine profiles, and percentages of immunophenotype expression in 7-day-old Bltw : CD1 (ICR) mice infected with EV71, with or without 6-OHDA treatment, were compared. The survival rate (76.9%) of EV71-infected and 6-OHDA (30 µg/g)-treated mice was increased significantly. The clinical scores were decreased markedly on days 8-12 in MP4-infected and 6-OHDA-treated mice compared to those without treatment. The results showed that the plasma levels of NE, epinephrine, and dopamine were decreased on days 4-8 after 6-OHDA treatment and at most on day 8. The plasma levels of interleukin (IL)-12p70, tumor necrosis factor, IL-6, and IL-10 did not change significantly after 6-OHDA treatment. Interferon-γ levels decreased evidently on days 4, 6, and 8 after 6-OHDA treatment. The absolute events of CD3+CD4+, CD3+CD8+, and CD3+NK1.1+ cells of peripheral blood mononuclear cells were increased significantly in MP4-infected and 6-OHDA-treated mice compared to those without treatment. In splenocytes, the absolute cells of CD3-NK1.1+, CD3+NK1.1+ and CD11b+Gr-1+ cells of EV71-infected mice were increased significantly after 6-OHDA treatment. These findings suggested that 6-OHDA may be used a probe to explore clinical improvements and immune responses in the complicated EV71 infection. Taken together, peripheral chemical sympathectomy contribute to further understand the immunopathogenesis of EV71 BE with autonomic nervous system dysregulation.
Assuntos
Encefalite Viral/imunologia , Infecções por Enterovirus/imunologia , Simpatectomia Química/métodos , Animais , Tronco Encefálico/imunologia , Tronco Encefálico/patologia , Encefalite Viral/patologia , Enterovirus Humano A , Infecções por Enterovirus/patologia , Camundongos , Camundongos Endogâmicos ICR , OxidopaminaRESUMO
Astrovirus infections are among the main causes of diarrhea in children, but their significance for animal health has remained underestimated and largely unknown. This is changing due to the increasing amount of newly identified neurotropic astroviruses in cases of nonsuppurative encephalitis and neurological disease in humans, pigs, ruminant species and minks. Neurological cases in ruminants and humans usually occur sporadically and as isolated cases. This contrasts with the situation in pigs and minks, in which diseases associated with neurotropic astroviruses are endemic and occur on the herd level. Affected animals show neurological signs such as mild ataxia to tetraplegia, loss of orientation or trembling, and the outcome is often fatal. Non-suppurative inflammation with perivascular cuffing, gliosis and neuronal necrosis are typical histological lesions of astrovirus encephalitis. Since astroviruses primarily target the gastrointestinal tract, it is assumed that they infect the brain through the circulatory system or retrograde following the nerves. The phylogenetic analysis of neurotropic astroviruses has revealed that they are genetically closely related, suggesting the presence of viral determinants for tissue tropism and neuroinvasion. In this review, we summarize the current knowledge on neurotropic astrovirus infections in animals and propose future research activities.
Assuntos
Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Astroviridae/isolamento & purificação , Doenças do Sistema Nervoso/veterinária , Doenças do Sistema Nervoso/virologia , Animais , Astroviridae/classificação , Astroviridae/genética , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/patologia , Encéfalo/patologia , Encéfalo/virologia , Encefalite Viral/diagnóstico , Encefalite Viral/patologia , Encefalite Viral/veterinária , Encefalite Viral/virologia , Genoma Viral , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/patologia , FilogeniaRESUMO
Neurotropic viruses target the brain and contribute to neurologic diseases. Caspase recruitment domain containing family member 9 (CARD9) controls protective immunity in a variety of infectious disorders. To investigate the effect of CARD9 in neurotropic virus infection, CARD9-/- and corresponding C57BL/6 wild-type control mice were infected with Theiler's murine encephalomyelitis virus (TMEV). Brain tissue was analyzed by histology, immunohistochemistry and molecular analyses, and spleens by flow cytometry. To determine the impact of CARD9 deficiency on T cell responses in vitro, antigen presentation assays were utilized. Genetic ablation of CARD9 enhanced early pro-inflammatory cytokine responses and accelerated infiltration of T and B cells in the brain, together with a transient increase in TMEV-infected cells in the hippocampus. CARD9-/- mice showed an increased loss of neuronal nuclear protein+ mature neurons and doublecortin+ neuronal precursor cells and an increase in ß-amyloid precursor protein+ damaged axons in the hippocampus. No effect of CARD9 deficiency was found on the initiation of CD8+ T cell responses by flow cytometry and co-culture experiments using virus-exposed dendritic cells or microglia-enriched glial cell mixtures, respectively. The present study indicates that CARD9 is dispensable for the initiation of early antiviral responses and TMEV elimination but may contribute to the modulation of neuroinflammation, thereby reducing hippocampal injury following neurotropic virus infection.
Assuntos
Proteínas Adaptadoras de Sinalização CARD/deficiência , Suscetibilidade a Doenças , Encefalite Viral/etiologia , Hipocampo/virologia , Infecções por Picornaviridae/etiologia , Picornaviridae/fisiologia , Animais , Biomarcadores , Modelos Animais de Doenças , Encefalite Viral/patologia , Predisposição Genética para Doença , Hipocampo/metabolismo , Hipocampo/patologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Imuno-Histoquímica , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Camundongos , Camundongos Knockout , Infecções por Picornaviridae/patologia , Carga ViralRESUMO
Viral encephalitis initiates a series of immunological events in the brain that can lead to brain damage and death. Astrocytes express IFN-ß in response to neurotropic infection, whereas activated microglia produce proinflammatory cytokines and accumulate at sites of infection. Here, we observed that neurotropic vesicular stomatitis virus (VSV) infection causes recruitment of leukocytes into the central nervous system (CNS), which requires MyD88, an adaptor of Toll-like receptor and interleukin-1 receptor signaling. Infiltrating leukocytes, and in particular CD8+ T cells, protected against lethal VSV infection of the CNS. Reconstitution of MyD88, specifically in neurons, restored chemokine production in the olfactory bulb as well as leukocyte recruitment into the infected CNS and enhanced survival. Comparative analysis of the translatome of neurons and astrocytes verified neurons as the critical source of chemokines, which regulated leukocyte infiltration of the infected brain and affected survival.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Quimiocinas/metabolismo , Encefalite Viral/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Infecções por Rhabdoviridae/imunologia , Proteínas Adaptadoras de Transporte Vesicular/genética , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Modelos Animais de Doenças , Encefalite Viral/patologia , Encefalite Viral/virologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Neurônios/metabolismo , Bulbo Olfatório/citologia , Bulbo Olfatório/imunologia , Bulbo Olfatório/patologia , Bulbo Olfatório/virologia , Infecções por Rhabdoviridae/patologia , Infecções por Rhabdoviridae/virologia , Transdução de Sinais/imunologia , Vesiculovirus/imunologiaRESUMO
The complexity of the central nervous system (CNS) is not recapitulated in cell culture models. Thin slicing and subsequent culture of CNS tissue has become a valued means to study neuronal and glial biology within the context of the physiologically relevant tissue milieu. Modern membrane-interface slice culturing methodology allows for straightforward access to both CNS tissue and feeding medium, enabling experimental manipulations and analyses that would otherwise be impossible in vivo. CNS slices can be successfully maintained in culture for up to several weeks for investigation of evolving pathology and long-term intervention in models of chronic neurologic disease.Herein, membrane-interface slice culture models for studying viral encephalitis and myelitis are detailed, with emphasis on the use of these models for investigation of pathogenesis and evaluation of novel treatment strategies. We describe techniques to (1) generate brain and spinal cord slices from rodent donors, (2) virally infect slices, (3) monitor viral replication, (4) assess virally induced injury/apoptosis, (5) characterize "CNS-specific" cytokine production, and, (6) treat slices with cytokines/pharmaceuticals. Although our focus is on CNS viral infection, we anticipate that the described methods can be adapted to address a wide range of investigations within the fields of neuropathology, neuroimmunology, and neuropharmacology.
Assuntos
Encéfalo/virologia , Encefalite Viral/virologia , Mielite/virologia , Medula Espinal/virologia , Animais , Animais Recém-Nascidos , Antivirais/farmacologia , Apoptose , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Citocinas/metabolismo , Encefalite Viral/tratamento farmacológico , Encefalite Viral/metabolismo , Encefalite Viral/patologia , Interações Hospedeiro-Patógeno , Mediadores da Inflamação/metabolismo , Camundongos , Mielite/tratamento farmacológico , Mielite/metabolismo , Mielite/patologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Medula Espinal/patologia , Técnicas de Cultura de Tecidos , Replicação ViralRESUMO
Porcine teschovirus (PTV) is a causative agent of reproductive disorders, encephalomyelitis, respiratory diseases, and diarrhea in swine, with a worldwide distribution. In this work, we identified PTV-associated nonsuppurative encephalitis as a potential cause of posterior paralysis in neonatal pigs in northeast China. Using indirect immunofluorescence assay, western blot, electron microscopy, and genome sequencing, we identified a neurotropic PTV strain, named CHN-NP1-2016, in the supernatants of pooled cerebrum and cerebellum samples from an affected piglet. Nucleotide sequence alignment revealed that the whole genome of CHN-NP1-2016 shared the highest sequence similarity (86.76% identity) with PTV 1 strain Talfan. A combination of phylogenetic and genetic divergence analysis was applied based on the deduced amino acid sequence of the P1 gene with a cutoff value of the genetic distance (0.102 ± 0.008) for defining PTV genotypes, and this showed that CHN-NP1-2016 is a variant of genotype 1. In total, 16 unique mutations and five mutant clusters were detected in the capsid proteins VP1 and VP2 of CHN-NP1-2016 when compared to other PTV1 isolates. Importantly, we detected three mutant clusters located in the exposed surface loops of the capsid protein, potentially indicating significant differences in major neutralization epitopes. Moreover, a potential recombination event in the P1 region of PTV CHN-NP1-2016 was detected. These findings provide valuable insights into the role of recombination in the evolution of teschoviruses. To our knowledge, this is the first case report of PTV-1-associated encephalitis in northeast China. Future investigations will narrow on the serology and pathogenicity of this novel isolate.
Assuntos
Encefalite Viral/veterinária , Infecções por Picornaviridae/veterinária , Doenças dos Suínos/virologia , Teschovirus/genética , Teschovirus/isolamento & purificação , Animais , Encéfalo/virologia , China/epidemiologia , Encefalite Viral/patologia , Encefalite Viral/virologia , Genoma Viral/genética , Genótipo , Mutação , Filogenia , Infecções por Picornaviridae/patologia , Infecções por Picornaviridae/virologia , RNA Viral/genética , Recombinação Genética , Suínos , Teschovirus/classificação , Proteínas Virais/genéticaRESUMO
Aerosol exposure to eastern equine encephalitis virus (EEEV) can trigger a lethal viral encephalitis in cynomolgus macaques which resembles severe human disease. Biomarkers indicative of central nervous system (CNS) infection by the virus and lethal outcome of disease would be useful in evaluating potential medical countermeasures, especially for therapeutic compounds. To meet requirements of the Animal Rule, a better understanding of the pathophysiology of EEEV-mediated disease in cynomolgus macaques is needed. In this study, macaques given a lethal dose of clone-derived EEEV strain V105 developed a fever between 2-3 days post infection (dpi) and succumbed to the disease by 6 dpi. At the peak of the febrile phase, there was a significant increase in the delta electroencephalography (EEG) power band associated with deep sleep as well as a sharp rise in intracranial pressure (ICP). Viremia peaked early after infection and was largely absent by the onset of fever. Granulocytosis and elevated plasma levels of IP-10 were found early after infection. At necropsy, there was a one hundred- to one thousand-fold increase in expression of traumatic brain injury genes (LIF, MMP-9) as well as inflammatory cytokines and chemokines (IFN-γ, IP-10, MCP-1, IL-8, IL-6) in the brain tissues. Phenotypic analysis of leukocytes entering the brain identified cells as primarily lymphoid (T, B, NK cells) with lower levels of infiltrating macrophages and activated microglia. Massive amounts of infectious virus were found in the brains of lethally-infected macaques. While no infectious virus was found in surviving macaques, quantitative PCR did find evidence of viral genomes in the brains of several survivors. These data are consistent with an overwhelming viral infection in the CNS coupled with a tremendous inflammatory response to the infection that may contribute to the disease outcome. Physiological monitoring of EEG and ICP represent novel methods for assessing efficacy of vaccines or therapeutics in the cynomolgus macaque model of EEEV encephalitis.
Assuntos
Aerossóis/efeitos adversos , Biomarcadores/análise , Encéfalo/imunologia , Encéfalo/patologia , Vírus da Encefalite Equina do Leste/patogenicidade , Encefalite Viral/imunologia , Febre/imunologia , Animais , Encéfalo/virologia , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalite Viral/patologia , Encefalite Viral/virologia , Feminino , Febre/patologia , Febre/virologia , Macaca fascicularis , MasculinoAssuntos
Encefalite Viral/complicações , Herpesvirus Humano 6/isolamento & purificação , Leucemia Mieloide Aguda/complicações , Aciclovir/uso terapêutico , Adulto , Antimetabólitos Antineoplásicos/uso terapêutico , Antivirais/uso terapêutico , Citarabina/uso terapêutico , Encefalite Viral/tratamento farmacológico , Encefalite Viral/patologia , Feminino , Herpesvirus Humano 6/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/patologiaRESUMO
A 2-year-old girl with fever and seizures was diagnosed as having clinically mild encephalitis/encephalopathy with a reversible splenial lesion, as indicated by magnetic resonance imaging. Virologic analysis identified human rhinovirus A49 in her serum. Although human rhinovirus rarely involves the central nervous system, such involvement could result in mild encephalitis/encephalopathy with a reversible splenial lesion.
Assuntos
Corpo Caloso/patologia , Encefalite Viral/virologia , Infecções por Picornaviridae/virologia , Rhinovirus , Baço/patologia , Anticonvulsivantes/uso terapêutico , Pré-Escolar , Corpo Caloso/virologia , Encefalite Viral/patologia , Feminino , Humanos , Midazolam/uso terapêutico , Fenitoína/análogos & derivados , Fenitoína/uso terapêutico , Infecções por Picornaviridae/patologiaRESUMO
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection can cause neurological disease in humans, but little is known about the pathogenesis of SARS-CoV-2 infection in the central nervous system (CNS). Herein, using K18-hACE2 mice, we demonstrate that SARS-CoV-2 neuroinvasion and encephalitis is associated with mortality in these mice. Intranasal infection of K18-hACE2 mice with 105 plaque-forming units of SARS-CoV-2 resulted in 100% mortality by day 6 after infection. The highest virus titers in the lungs were observed on day 3 and declined on days 5 and 6 after infection. By contrast, very high levels of infectious virus were uniformly detected in the brains of all the animals on days 5 and 6. Onset of severe disease in infected mice correlated with peak viral levels in the brain. SARS-CoV-2-infected mice exhibited encephalitis hallmarks characterized by production of cytokines and chemokines, leukocyte infiltration, hemorrhage and neuronal cell death. SARS-CoV-2 was also found to productively infect cells within the nasal turbinate, eye and olfactory bulb, suggesting SARS-CoV-2 entry into the brain by this route after intranasal infection. Our data indicate that direct infection of CNS cells together with the induced inflammatory response in the brain resulted in the severe disease observed in SARS-CoV-2-infected K18-hACE2 mice.