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A novel orally infected hamster model for Coxsackievirus A16 hand-foot-and-mouth disease and encephalomyelitis

Hooi YT, Ong KC, Tan SH, Perera D, Wong KT

Lab Invest, 2020 Sep;100(9):1262-1275.
PMID: 32601355 DOI: 10.1038/s41374-020-0456-x

Coxsackievirus A16 (CV-A16) is one of the major causes of mild and self-limiting hand-foot-and-mouth disease (HFMD) in young children, which may occasionally leads to serious neurological complications. In this study, we had developed a novel, consistent, orally infected CV-A16 HFMD hamster model with encephalomyelitis. Four groups of 7-day-old hamsters in a kinetic study were orally infected with mouse-adapted CV-A16 strains and sacrificed at 1-4 days post infection (dpi), respectively. Tissues were studied by light microscopy, immunohistochemistry to detect viral antigens, in situ hybridization to detect viral RNA, and by viral titration. In a separate transmission experiment, orally infected index hamsters were housed together with contact hamsters to investigate oral and fecal viral shedding by virus culture and reverse transcription polymerase chain reaction (RT-PCR). At severe infection/death endpoints, index and contact hamster infection were also histopathologically analyzed. In the kinetic study, infected hamsters developed signs of infection at 4 dpi. Viral antigens/RNA were localized to brainstem (medulla/pons; reticular formation and motor trigeminal nucleus) and spinal cord anterior horn neurons, oral squamous epithelia and epidermis from 3 to 4 dpi. Salivary and lacrimal glands, myocardium, brown adipose tissue, intestinal smooth muscle, and skeletal muscle infection was also demonstrated. Viremia at 1 dpi and increasing viral titers in various tissues were observed from 2 dpi. In the transmission study, all contact hamsters developed disease 3-5 days later than index hamsters, but demonstrated similar histopathological findings at endpoint. Viral culture and RT-PCR positive oral washes and feces confirmed viral shedding. Our hamster model, orally infected by the natural route for human infection, confirmed CV-A16 neurotropism and demonstrated squamous epitheliotropism reminiscent of HFMD, attributes not found in other animal models. It should be useful to investigate neuropathogenesis, model person-to-person transmission, and for testing antiviral drugs and vaccines.

Matched MeSH terms: Encephalomyelitis/diagnosis; Encephalomyelitis/virology*
Fulltext Hormones in experimental autoimmune encephalomyelitis (EAE) animal models

Ghareghani M, Ghanbari A, Eid A, Shaito A, Mohamed W, Mondello S, et al.

Transl Neurosci, 2021 Jan 01;12(1):164-189.
PMID: 34046214 DOI: 10.1515/tnsci-2020-0169

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) in which activated immune cells attack the CNS and cause inflammation and demyelination. While the etiology of MS is still largely unknown, the interaction between hormones and the immune system plays a role in disease progression, but the mechanisms by which this occurs are incompletely understood. Several in vitro and in vivo experimental, but also clinical studies, have addressed the possible role of the endocrine system in susceptibility and severity of autoimmune diseases. Although there are several demyelinating models, experimental autoimmune encephalomyelitis (EAE) is the oldest and most commonly used model for MS in laboratory animals which enables researchers to translate their findings from EAE into human. Evidences imply that there is great heterogeneity in the susceptibility to the induction, the method of induction, and the response to various immunological or pharmacological interventions, which led to conflicting results on the role of specific hormones in the EAE model. In this review, we address the role of endocrine system in EAE model to provide a comprehensive view and a better understanding of the interactions between the endocrine and the immune systems in various models of EAE, to open up a ground for further detailed studies in this field by considering and comparing the results and models used in previous studies.

Matched MeSH terms: Encephalomyelitis, Autoimmune, Experimental
Fulltext Acute Disseminated Encephalomyelitis (ADEM) Presenting with Bilateral Optic Neuritis

Sapuan S, Basri H

Malays J Med Sci, 2007 Jan;14(1):71-4.
PMID: 22593657 MyJurnal

A 43-year old lady presented with progressive loss of vision in both eyes followed by rapid deterioration of consciousness within the next few days. This was preceded by a viral infection one week before her presentation. At presentation she had evidence of meningism and signs of bilateral upper motor neuron lesions and was managed initially as acute meningoencephalitis with antibiotics. The brain CT was within normal limits but subsequent MRI of the brain revealed multiple foci of hyperintense lesions on T2-weighted and FLAIR images. The cerebrospinal fluid examination revealed lymphocytosis, and normal protein and glucose levels. Cultures of the CSF were negative. She was managed as acute disseminated encephalomyelitis (ADEM) with high-dose of intravenous methlyprednisolone one gram/day for three consecutive days followed by oral prednisolone 60 mg/day. Despite the management she lapsed into coma and succumbed to her illness nine days after admission.

Matched MeSH terms: Encephalomyelitis, Acute Disseminated
Fulltext Evaluation of locomotor function and microscopic structure of the spinal cord in a mouse model of experimental autoimmune encephalomyelitis following treatment with syngeneic mesenchymal stem cells

Mitra NK, Bindal U, Eng Hwa W, Chua CL, Tan CY

Int J Clin Exp Pathol, 2015;8(10):12041-52.
PMID: 26722389

Out of the minor myelin proteins, most significant one is myelin oligodendrocyte glycoprotein (MOG). Mesenchymal stem cells (MSCs) have proven immunoregulatory capacity. The objective of this study was to investigate the effects of syngeneic MSCs on mouse model of experimental autoimmune encephalomyelitis (EAE) through observation of locomotion by footprint analysis, histological analysis of spinal cord and estimation IL-17. C57BL/6 mice (10 weeks, n = 16) were immunized with 300 µg of MOG35-55 and 200 µL of complete Freund's adjuvant (CFA) to produce EAE model. Sham-treated control (n = 8) were injected with CFA. Half of immunized mice were given 100 µL of PBS (n = 8) and next half (n = 8) received 1 × 10(5) MSCs on day 11 through the tail veins. Clinical scoring showed development of EAE (loss of tonicity of tail and weakness of hind limb) on day 10. Following MSC treatment, clinical scores and hindlimb stride length showed significant improvement on day 15 onwards, compared to day 10 (P < 0.05). Under LFB staining, while PBS-treated group of EAE mice showed pale and degenerated axons in anterolateral white column of lumbar spinal cord, MSC-treated group showed numerous normal-looking axons. H&E staining showed normal axons in anterolateral white column and reduction of macrophages in MSC-treated EAE mice group. A lower level of IL-17 was observed in MSC treated EAE mice, compared to PBS-treated EAE mice. Our results suggest that Intravenous MSC has the potential to improve the locomotion and regeneration of axons in spinal cord in MOG-induced EAE model.

Matched MeSH terms: Encephalomyelitis, Autoimmune, Experimental/therapy*
Gene Therapy Approaches in an Autoimmune Demyelinating Disease: Multiple Sclerosis

Islam MA, Kundu S, Hassan R

Curr Gene Ther, 2020;19(6):376-385.
PMID: 32141417 DOI: 10.2174/1566523220666200306092556

Multiple Sclerosis (MS) is the most common autoimmune demyelinating disease of the Central Nervous System (CNS). It is a multifactorial disease which develops in an immune-mediated way under the influences of both genetic and environmental factors. Demyelination is observed in the brain and spinal cord leading to neuro-axonal damage in patients with MS. Due to the infiltration of different immune cells such as T-cells, B-cells, monocytes and macrophages, focal lesions are observed in MS. Currently available medications treating MS are mainly based on two strategies; i) to ease specific symptoms or ii) to reduce disease progression. However, these medications tend to induce different adverse effects with limited therapeutic efficacy due to the protective function of the blood-brain barrier. Therefore, researchers have been working for the last four decades to discover better solutions by introducing gene therapy approaches in treating MS generally by following three strategies, i) prevention of specific symptoms, ii) halt or reverse disease progression and iii) heal CNS damage by promoting remyelination and axonal repair. In last two decades, there have been some remarkable successes of gene therapy approaches on the experimental mice model of MS - experimental autoimmune encephalomyelitis (EAE) which suggests that it is not far that the gene therapy approaches would start in human subjects ensuring the highest levels of safety and efficacy. In this review, we summarised the gene therapy approaches attempted in different animal models towards treating MS.

Matched MeSH terms: Encephalomyelitis, Autoimmune, Experimental/genetics*; Encephalomyelitis, Autoimmune, Experimental/therapy*
Unusual case of cerebral demyelination and bilateral optic neuritis in an infant with suppurative BCG lymphadenitis

Anandakrishnan P, Khoo TB

BMJ Case Rep, 2018 May 30;2018.
PMID: 29848532 DOI: 10.1136/bcr-2018-224496

Cerebral demyelination and optic neuritis are often seen in children with acute disseminated encephalomyelitis following various infections and immunisations. An eight month old girl presented with a left axillary lymph node swelling and an erythematous lace-like rash over her cheeks and trunk. She then developed acute encephalopathy, bilateral nystagmus, right hemiparesis and left facial nerve palsy. Her electroencephalogram showed an encephalopathic process and visual evoked response study were grossly abnormal. Her MRI brain showed hyperintensities in the midbrain, pons and bilateral cerebellar peduncles. She was treated as postinfectious cerebral demyelination with intravenous antibiotics, methylprednisolone and immunoglobulin. Left axillary lymph node excision biopsy and GeneXpert test detected Mycobacterium tuberculosis complex that prompted initiation of antituberculous therapy. Her chest X-ray and cerebrospinal fluid examinations for tuberculosis were normal. She showed significant recovery after 2 weeks. This case illustrates a rare presentation of cerebral demyelination and bilateral optic neuritis following suppurative BCG lymphadenitis.

Matched MeSH terms: Encephalomyelitis, Acute Disseminated/chemically induced*
Tonsillar crypt epithelium is an important extra-central nervous system site for viral replication in EV71 encephalomyelitis

He Y, Ong KC, Gao Z, Zhao X, Anderson VM, McNutt MA, et al.

Am J Pathol, 2014 Mar;184(3):714-20.
PMID: 24378407 DOI: 10.1016/j.ajpath.2013.11.009

Enterovirus 71 (EV71; family Picornaviridae, species human Enterovirus A) usually causes hand, foot, and mouth disease, which may rarely be complicated by fatal encephalomyelitis. We investigated extra-central nervous system (extra-CNS) tissues capable of supporting EV71 infection and replication, and have correlated tissue infection with expression of putative viral entry receptors, scavenger receptor B2 (SCARB2), and P-selectin glycoprotein ligand-1 (PSGL-1). Formalin-fixed, paraffin-embedded CNS and extra-CNS tissues from seven autopsy cases were examined by IHC and in situ hybridization to evaluate viral antigens and RNA. Viral receptors were identified with IHC. In all seven cases, the CNS showed stereotypical distribution of inflammation and neuronal localization of viral antigens and RNA, confirming the clinical diagnosis of EV71 encephalomyelitis. In six cases in which tonsillar tissues were available, viral antigens and/or RNA were localized to squamous epithelium lining the tonsillar crypts. Tissues from the gastrointestinal tract, pancreas, mesenteric nodes, spleen, and skin were all negative for viral antigens/RNA. Our novel findings strongly suggest that tonsillar crypt squamous epithelium supports active viral replication and represents an important source of viral shedding that facilitates person-to-person transmission by both the fecal-oral or oral-oral routes. It may also be a portal for viral entry. A correlation between viral infection and SCARB2 expression appears to be more significant than for PSGL-1 expression.

Matched MeSH terms: Encephalomyelitis/virology*
Development of the clinical assessment scale in autoimmune encephalitis

Lim JA, Lee ST, Moon J, Jun JS, Kim TJ, Shin YW, et al.

Ann Neurol, 2019 03;85(3):352-358.
PMID: 30675918 DOI: 10.1002/ana.25421

OBJECTIVE: There is no scale for rating the severity of autoimmune encephalitis (AE). In this study, we aimed to develop a novel scale for rating severity in patients with diverse AE syndromes and to verify the reliability and validity of the developed scale.
METHODS: The key items were generated by a panel of experts and selected according to content validity ratios. The developed scale was initially applied to 50 patients with AE (development cohort) to evaluate its acceptability, reproducibility, internal consistency, and construct validity. Then, the scale was applied to another independent cohort (validation cohort, n = 38).
RESULTS: A new scale consisting of 9 items (seizure, memory dysfunction, psychiatric symptoms, consciousness, language problems, dyskinesia/dystonia, gait instability and ataxia, brainstem dysfunction, and weakness) was developed. Each item was assigned a value of up to 3 points. The total score could therefore range from 0 to 27. We named the scale the Clinical Assessment Scale in Autoimmune Encephalitis (CASE). The new scale showed excellent interobserver (intraclass correlation coefficient [ICC] = 0.97) and intraobserver (ICC = 0.96) reliability for total scores, was highly correlated with modified Rankin scale (r = 0.86, p

Matched MeSH terms: Encephalomyelitis, Acute Disseminated/complications; Encephalomyelitis, Acute Disseminated/physiopathology; Encephalomyelitis, Acute Disseminated/psychology
Fulltext Potential health detriment from fruit-induced immunomodulation

Pei-Shin, Chai, Siti Zuleha Idris, Norfarazieda Hassan, Nur Ramziahrazana Jumat, Zainina Seman, Sharmili Vidyadaran, et al.

Malaysian Journal of Medicine and Health Sciences, 2019;15(108):11-11.
MyJurnal

The immune system responds to stimulus by activation/increase or inhibition/decrease in activities. These immu-nomodulatory effects may be triggered by various factors in the environment including cytokines, hormones and growth factors, as well as flavonoids, antioxidants and various antigens in food and the environment. Immunosup-pression has a direct effect on the capacity of the immune system to fight against infection and cancer formation. A pro-inflammatory response, however, may induce further progression of tumours that had formed. Inflammation is also associated with many chronic illnesses including pain. The suppressive effects from phytochemicals have been shown in the potential to reduce T-lymphocyte proliferation in vitro and in vivo. Studies have demonstrated inhibi-tion of pro-inflammatory cytokines from flavonoid such as naringenin, green tea polyphenol extract, encapsulated fruit and vegetable juice powder concentrate. Feijoa sellowiana Berg var. coolidge fruit juice consumption exerted anti-inflammatory activity on edema-induced mice within first hour of treatment while agipenin, a natural flavonoid reduced neuroinflammation by protection against damage from dendritic cells stimulated T cells in experimental autoimmune encephalomyelitis mouse models. Dietary polyphenols were found to exert a regulatory role on den-dritic cell function. Our own study showed immunosuppressive effect from increased T regulatory cells from papaya consumption. Increased regulatory cells are associated with cancer conditions. On the other hand, grape juice con-sumption mobilized gamma–delta T cells. Ginseng berry extract increased pro-inflammatory molecules in dendritic cells in the spleen while polysaccharide fractions from Momorica charantia, an edible medicinal vegetable increased various immune indexes. Fruits may also have endo-immunomodulatory function causing differential effects in male and female. Sex hormones can influence immune changes based on sex as seen in increased NK cells in males and antibodies in females. We observed a population of CD4-CD45RA-CD69+CD25- cells was significantly lower in males. However, none of these studies have been directly conducted on cancers. Investigation into this area may help improve decision making in cancer management.

Matched MeSH terms: Encephalomyelitis, Autoimmune, Experimental
Fulltext Modelling person-to-person transmission in an Enterovirus A71 orally infected hamster model of hand-foot-and-mouth disease and encephalomyelitis

Phyu WK, Ong KC, Wong KT

Emerg Microbes Infect, 2017 Jul 12;6(7):e62.
PMID: 28698666 DOI: 10.1038/emi.2017.49

Enterovirus A71 (EV-A71) causes hand-foot-and-mouth disease (HFMD), which may be complicated by fatal encephalomyelitis. Although fecal-oral or oral-oral routes are important in person-to-person transmission, how viral shedding and exposure may predispose individuals to infection remains unknown. We investigated person-to-person transmission by using a model of HFMD and encephalomyelitis based on EV-A71 oral infection of 2-week-old hamsters. Animals (index animals) infected with 104 50% cell culture infective doses of virus uniformly developed severe disease four days post-infection (dpi), whereas littermate contacts developed severe disease after six to seven days of exposure to index animals. Virus was detected in oral washes and feces at 3-4 dpi in index animals and at three to eight days after exposure to index animals in littermate contact animals. In a second experiment, non-littermate contact animals exposed for 8 or 12 h to index animals developed the disease six and four days post-exposure, respectively. Tissues from killed index and contact animals, studied by light microscopy, immunohistochemistry and in situ hybridization, exhibited mild inflammatory lesions and/or viral antigens/RNA in the squamous epithelia of the oral cavity, tongue, paws, skin, esophagus, gastric epithelium, salivary glands, lacrimal glands, central nervous system neurons, muscles (skeletal, cardiac and smooth muscles) and liver. Orally shed viruses were probably derived from infected oral mucosa and salivary glands, whereas fecal viruses may have derived from these sites as well as from esophageal and gastric epithelia. Asymptomatic seroconversion in exposed mother hamsters was demonstrated. Our hamster model should be useful in studying person-to-person EV-A71 transmission and how drugs and vaccines may interrupt transmission.

Matched MeSH terms: Encephalomyelitis/virology*

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