Basal epithelial stem cells cross an alarmin checkpoint for postviral lung disease.

Epithelial cells are charged with protection at barrier sites, but whether this normally beneficial response might sometimes become dysfunctional still needs definition. Here, we recognized a pattern of imbalance marked by basal epithelial cell growth and differentiation that replaced normal airspaces in a mouse model of progressive postviral lung disease due to the Sendai virus. Single-cell and lineage-tracing technologies identified a distinct subset of basal epithelial stem cells (basal ESCs) that extended into gas-exchange tissue to form long-term bronchiolar-alveolar remodeling regions. Moreover, this cell subset was selectively expanded by crossing a cell-growth and survival checkpoint linked to the nuclear-localized alarmin IL-33 that was independent of IL-33 receptor signaling and instead connected to autocrine chromatin accessibility. This mechanism creates an activated stem-progenitor cell lineage with potential for physiological or pathological function. Thus, conditional loss of Il33 gene function in basal epithelial cells disrupted the homeostasis of the epithelial barrier at skin and gut sites but also markedly attenuated postviral disease in the lung based on the downregulation of remodeling and inflammation. Thus, we define a basal ESC strategy to deploy innate immune machinery that appears to overshoot the primordial goal of self-defense. Our findings reveal new targets to stratify and correct chronic and often deadly postviral disease.

Infection of calves with in-vivo passaged bovine parainfluenza-3 virus, alone or in combination with bovine respiratory syncytial virus and bovine coronavirus.

Bovine respiratory disease complex is etiologically complex and usually involves co-infection by several agents, including bovine parainfluenza virus-3 (BPIV-3), bovine respiratory syncytial virus (BRSV), and bovine coronavirus (BCoV). Traditionally, vaccines have been tested in seronegative calves infected with a single in vitro-passaged agent, often with little disease, resulting in unvaccinated subjects. To overcome the potential problem of attenuation coincident with in vitro culture of the viruses, cocktails of field isolates of BPIV-3s and BCoVs were passaged in the lungs of neonatal colostrum-deprived calves. Lung lavage fluids were used as inocula, alone and in combination with in-vivo passaged BRSV, and aerosolized into a trailer containing conventionally reared 9-week-old weaned Holstein calves with decayed, but still measurable, maternal antibodies. Calves developed acute respiratory disease of variable severity. Upon necropsy, there were characteristic gross and histologic lesions in the respiratory tract, associated immunohistochemically with BPIV-3, BRSV, and BCoV. In-vivo passage of viruses is an alternative to in vitro culture to produce inocula to better study the pathogenesis of infection and more rigorously and relevantly assess vaccine efficacy.

Le complexe des maladies respiratoires bovines possède une étiologie complexe et implique habituellement une co-infection par plusieurs agents, incluant le virus parainfluenza bovin 3 (BPIV-3), le virus respiratoire syncitial bovin (BRSV) et le coronavirus bovin (BCoV). Traditionnellement, les vaccins ont été testés chez des veaux séronégatifs infectés avec un seul agent cultivé in vitro, présentant souvent peu de maladie, résultant en des sujets non-vaccinés. Afin de contrecarrer le problème potentiel d'atténuation associé à la culture in vitro des virus, des cocktails d'isolats de champs de BPIV-3 et de BCoV furent passés dans des poumons de veaux nouveau-nés privés de colostrum. Les liquides de lavage pulmonaire furent utilisés comme inoculum, seul et en combinaison avec des BRSV passés in vivo, et aérosolisés dans une remorque contenant des veaux Holstein sevrés élevés de manière conventionnelle âgés de 9 semaines ayant des anticorps maternels en déclin mais toujours mesurables. Les veaux ont développé une maladie respiratoire aiguë de sévérité variable. Lors de la nécropsie, il y avait des lésions macroscopiques et histologiques caractéristiques dans le tractus respiratoire, associées immuno-histochimiquement avec BPIV-3, BRSV et BCoV. Le passage in vivo de virus est une alternative à la culture in vitro afin de produire un inoculum permettant de mieux étudier la pathogénie de l'infection et d'évaluer plus rigoureusement et plus pertinemment l'efficacité de vaccins.(Traduit par Docteur Serge Messier).

Fetal Pathology in an Aborted Holstein Fetus Infected With Bovine Parainfluenza Virus-3 Genotype A.

Bovine parainfluenza virus-3 (BPIV-3) is a recognized respiratory pathogen of cattle, and it has also been identified in aborted fetuses. However, little is known of this agent as a reproductive pathogen and detailed descriptions of fetal pathology on natural cases are lacking in the scientific literature. This article describes and illustrates lesions in a fetus spontaneously aborted by a first-calving Holstein heifer, naturally infected with BPIV-3 genotype A, broadening the current knowledge on fetal pathology by this virus. Fetal autopsy revealed diffusely reddened, rubbery and unexpanded lungs. Histologically, there was necrotizing bronchiolitis/alveolitis with intraluminal fibrin exudate and syncytial cells in the bronchiolar/alveolar spaces, and non-suppurative peribronchiolitis and perivascular interstitial pneumonia. In the small intestine there was multifocal necrotizing cryptitis and occasional necrotic syncytial enterocytes. Intralesional and extralesional BPIV-3 antigen was detected by immunohistochemistry in the lung and small intestine, and BPIV-3a was identified in fetal tissues by RT-PCR and sequencing.

Virus-induced asthma attack: The importance of allergic inflammation in response to viral antigen in an animal model of asthma.

Asthma exacerbation can be a life-threatening condition, and is most often triggered by common respiratory viruses. Poor asthma control and worsening of respiratory function is associated with increased airway inflammation, including eosinophilia. Prevention of asthma exacerbation relies on treatment with corticosteroids, which preferentially inhibit allergic inflammation like eosinophils. Human studies demonstrate that inactivated virus can trigger eosinophil activation in vitro through antigen presentation and memory CD4+ lymphocytes. We hypothesized that animals with immunologic memory to a respiratory virus would also develop airway hyperresponsiveness in response to a UV-inactivated form of the virus if they have pre-existing allergic airway inflammation. Guinea pigs were ovalbumin-sensitized, infected with live parainfluenza virus (PIV), aerosol-challenged with ovalbumin, and then re-inoculated 60 days later with live or UV-inactivated PIV. Some animals were either treated with dexamethasone prior to the second viral exposure. Lymphocytes were isolated from parabronchial lymph nodes to confirm immunologic memory to the virus. Airway reactivity was measured and inflammation was assessed using bronchoalveolar lavage and lung histology. The induction of viral immunologic memory was confirmed in infected animals. Allergen sensitized and challenged animals developed airway hyperreactivity with eosinophilic airway inflammation when re-exposed to UV-inactivated PIV, while non-sensitized animals did not. Airway hyperreactivity in the sensitized animals was inhibited by pre-treatment with dexamethasone. We suggest that the response of allergic inflammation to virus antigen is a significant factor causing asthma exacerbation. We propose that this is one mechanism explaining how corticosteroids prevent virus-induced asthma attack.

POL7085 or anti-CCL28 treatment inhibits development of post-paramyxoviral airway disease.

INTRODUCTION: Asthma is major health burden throughout the world, and there are no therapies that have been shown to be able to prevent the development of disease. A severe respiratory paramyxoviral infection early in life has been demonstrated to greatly increase the risk of developing asthma. We have a mouse model of a severe respiratory paramyxoviral infection (Sendai virus, SeV) that mimics human disease, and requires early expression of the cytokine CCL28 to drive the development of post-viral airway disease. The known receptors for CCL28 are CCR3 and CCR10. However, it is not known if blockade of these receptors will prevent the development of post-viral airway disease. The objective of this study was to determine if treatment with a protein epitope mimetic antagonist of CCR10, POL7085, will provide sufficient protection against the development of post-viral airway disease. METHODS: C57BL6 mice were inoculated with SeV or UV inactivated SeV. From day 3-19 post inoculation (PI), mice were subcutaneously administered daily POL7085 or saline, or every other day anti-CCL28 mAb. On days 8, 10, and 12 PI bronchoalveolar cytokines, serum IgE, and lung cellular constituents were measured. At day 21 PI airway hyper-reactivity to methacholine and mucous cell metaplasia was measured. RESULTS: Treatment with either anti-CCL28 or POL7085 significantly reduced development of airway hyper-reactivity and mucous cell metaplasia following SeV infection. The prevention of post-viral airway disease was associated with early reductions in innate immune cells, but did not appear to be due to a reduction in IL-13 or IgE. CONCLUSIONS: Blockade of CCL28 or CCR10 during an acute severe respiratory paramyxoviral infection is sufficient to prevent the development of post-viral airway disease. However, the mechanism of action is unclear and requires further exploration.

Air in All the Wrong Places.

Extraluminal air can occur through a wide variety of mechanisms. Often, the free air resides in isolated regions including the thorax, the peritoneum, or the mediastinum. We present a pediatric case where there was extensive extraluminal air simultaneously within several regions, one of which has never been reported in the literature.

Sendai Virus Induces Persistent Olfactory Dysfunction in a Murine Model of PVOD via Effects on Apoptosis, Cell Proliferation, and Response to Odorants.

BACKGROUND: Viral infection is a common cause of olfactory dysfunction. The complexities of studying post-viral olfactory loss in humans have impaired further progress in understanding the underlying mechanism. Recently, evidence from clinical studies has implicated Parainfluenza virus 3 as a causal agent. An animal model of post viral olfactory disorders (PVOD) would allow better understanding of disease pathogenesis and represent a major advance in the field. OBJECTIVE: To develop a mouse model of PVOD by evaluating the effects of Sendai virus (SeV), the murine counterpart of Parainfluenza virus, on olfactory function and regenerative ability of the olfactory epithelium. METHODS: C57BL/6 mice (6-8 months old) were inoculated intranasally with SeV or ultraviolet (UV)-inactivated virus (UV-SeV). On days 3, 10, 15, 30 and 60 post-infection, olfactory epithelium was harvested and analyzed by histopathology and immunohistochemical detection of S-phase nuclei. We also measured apoptosis by TUNEL assay and viral load by real-time PCR. The buried food test (BFT) was used to measure olfactory function of mice at day 60. In parallel, cultured murine olfactory sensory neurons (OSNs) infected with SeV or UV-SeV were tested for odorant-mixture response by measuring changes in intracellular calcium concentrations indicated by fura-4 AM assay. RESULTS: Mice infected with SeV suffered from olfactory dysfunction, peaking on day 15, with no loss observed with UV-SeV. At 60 days, four out of 12 mice infected with SeV still had not recovered, with continued normal function in controls. Viral copies of SeV persisted in both the olfactory epithelium (OE) and the olfactory bulb (OB) for at least 60 days. At day 10 and after, both unit length labeling index (ULLI) of apoptosis and ULLI of proliferation in the SeV group was markedly less than the UV-SeV group. In primary cultured OSNs infected by SeV, the percentage of cells responding to mixed odors was markedly lower in the SeV group compared to UV-SeV (P = 0.007). CONCLUSION: We demonstrate that SeV impairs olfaction, persists in OE and OB tissue, reduces their regenerative ability, and impairs the normal physiological function of OSNs without gross cytopathology. This mouse model shares key features of human post-viral olfactory loss, supporting its future use in studies of PVOD. Further testing and development of this model should allow us to clarify the pathophysiology of PVOD.

Study on JNK/AP-1 signaling pathway of airway mucus hypersecretion of severe pneumonia under RSV infection.

OBJECTIVE: To investigate the JNK/AP-1 signaling pathway of airway mucus hypersecretion of severe pneumonia under respiratory virus (RSV) infection. PATIENTS AND METHODS: Total of 56 severe pneumonia children under RSV infection were selected. Reverse transcription polymerase chain reaction (RT-PCR) was performed to measure the expression quantity of MUC5B mRNA and MUC5AC mRNA, and ELISA was used to measure the expression quantity of MUC5AC and MUC5B proteins. Following that, the children were divided into airway mucus hypersecretion group (n = 37) and non-hypersecretion group (n = 19). Western blotting was performed to detect the expression levels of JNK1/2, p-JNK1/2 and AP-1 proteins. RESULTS: Expression of MUC5AC and MUC5B proteins, and MUC5AC mRNA and MUC5B mRNA in the airway mucus hypersecretion group were significantly higher than those in the non-hypersecretion group (p < 0.05). The expression levels of JNK1/2, p-JNK1/2 and AP-1 proteins in airway mucus hypersecretion group were higher than those in the non-hypersecretion group (p < 0.05). CONCLUSIONS: MUC5AC and MUC5B can be used as marker molecules of airway mucus hypersecretion. Airway mucus hypersecretion of severe pneumonia induced by RSV might be related to the activation of JNK/AP-1 signaling pathway.

Clinical and epidemiological characteristics of acute respiratory virus infections in Vietnamese children.

Information about viral acute respiratory infections (ARIs) is essential for prevention, diagnosis and treatment, but it is limited in tropical developing countries. This study described the clinical and epidemiological characteristics of ARIs in children hospitalized in Vietnam. Nasopharyngeal samples were collected from children with ARIs at Ho Chi Minh City Children's Hospital 2 between April 2010 and May 2011 in order to detect respiratory viruses by polymerase chain reaction. Viruses were found in 64% of 1082 patients, with 12% being co-infections. The leading detected viruses were human rhinovirus (HRV; 30%), respiratory syncytial virus (RSV; 23·8%), and human bocavirus (HBoV; 7·2%). HRV was detected all year round, while RSV epidemics occurred mainly in the rainy season. Influenza A (FluA) was found in both seasons. The other viruses were predominant in the dry season. HRV was identified in children of all age groups. RSV, parainfluenza virus (PIV) 1, PIV3 and HBoV, and FluA were detected predominantly in children aged 24 months, respectively. Significant associations were found between PIV1 with croup (P < 0·005) and RSV with bronchiolitis (P < 0·005). HBoV and HRV were associated with hypoxia (P < 0·05) and RSV with retraction (P < 0·05). HRV, RSV, and HBoV were detected most frequently and they may increase the severity of ARIs in children.

Vitamin A deficient mice exhibit increased viral antigens and enhanced cytokine/chemokine production in nasal tissues following respiratory virus infection despite the presence of FoxP3+ T cells.

The World Health Organization (WHO) estimates that 250 million children under the age of five suffer from vitamin A deficiencies (VAD). Individuals with VAD experience higher rates of mortality and increased morbidity during enteric and respiratory infections compared with those who are vitamin A sufficient. Previously, our laboratory has demonstrated that VAD mice have significantly impaired virus-specific IgA and CD8(+) T-cell responses in the airways. Here, we demonstrate that VAD mice experience enhanced cytokine/chemokine gene expression and release in the respiratory tract 10 days following virus infection compared with control vitamin A sufficient animals. Cytokines/chemokines that are reproducibly up-regulated at the gene expression and protein levels include IFNγ and IL-6. Despite previous indications that cytokine dysregulation in VAD animals might reflect low forkhead box P3 (FoxP3)-positive regulatory T-cell frequencies, we found no reduction in FoxP3(+) T cells in VAD respiratory tissues. As an alternative explanation for the high cytokine levels, we found that the extent of virus infection and the persistence of viral antigens were increased on day 10 post-infection in VAD animals compared with controls, and consequently that respiratory tract tissues had an increased potential to activate virus-specific T cells. Results encourage cautious management of viral infections in patients with VAD, as efforts to enhance FoxP3(+) T cell frequencies and quell immune effectors could potentially exacerbate disease if the virus has not been cleared.

[Severe acute disseminated encephalomyelitis associated with parainfluenza 3 infection: Case report]. / Encefalomielitis aguda diseminada grave: Comunicación de un caso asociado a infección por virus parainfluenza 3.

Disseminated encephalomyelitis (ADEM) is an infrequent condition with considerable morbidity and mortality in adult patients. It requires a high level of suspicion and diagnosis emerges by gathering clinical information, laboratory exams and images studies. ADEM is related to an immunological phenomena occurring after a bacterial/viral infection or recent vaccination. Glucocorticoids are the first line treatment, reserving immunoglobulins and plasmapheresis to refractory cases. We report a male patient aged 25, with ADEM associated to parainfluenza 3 virus respiratory infection that required mechanical ventilation and that had a complete recovery only after plasmapheresis.

Encefalomielitis aguda diseminada grave: Comunicación de un caso asociado a infección por virus parainfluenza 3 / Severe acute disseminated encephalomyelitis associated with parainfluenza 3 infection: Case report

Disseminated encephalomyelitis (ADEM) is an infrequent condition with considerable morbidity and mortality in adult patients. It requires a high level of suspicion and diagnosis emerges by gathering clinical information, laboratory exams and images studies. ADEM is related to an immunological phenomena occurring after a bacterial/viral infection or recent vaccination. Glucocorticoids are the first line treatment, reserving immunoglobulins and plasmapheresis to refractory cases. We report a male patient aged 25, with ADEM associated to parainfluenza 3 virus respiratory infection that required mechanical ventilation and that had a complete recovery only after plasmapheresis.

La encefalomielitis aguda diseminada es una enfermedad infrecuente pero de elevada morbi-mortalidad en pacientes adultos. Demanda una sospecha y diagnóstico precoz que requiere el concurso de información clínica, pruebas de laboratorio y estudio de imágenes. De sustrato inmunológico, se puede relacionar a una infección viral, bacteriana o inmunización reciente. Los glucocorticoides son el tratamiento de elección, mientras que la inmunoglobulina intravenosa y la plasmaféresis se reservan para casos refractarios. Se presenta el caso de una encefalomielitis aguda diseminada grave, en un paciente de sexo masculino de 25 años, asociado a una infección respiratoria por virus parainfluenza 3. Requirió conexión a ventilación mecánica y tuvo una respuesta completa con plasmaféresis.

[THE VALUE OF RECURRENT BRONCHIAL OBSTRUCTION ASSOCIATED WITH RESPIRATORY INFECTIONS IN INFANTS].

It is shown that recurrent bronchial obstruction with nonallergic genesis is a significant problem for young children. Further researches of this disease are needed in order to develop differentiated therapies.

Fulminant type 1 diabetes mellitus and fulminant viral myocarditis. A case report and literature review.

A 35-year-old Japanese woman was admitted with coma following flu-like symptoms. She was diagnosed with diabetic ketoacidosis and fulminant type 1 diabetes (FT1D) and received intravenous infusion of insulin and saline. The next day, the ketoacidosis disappeared, and she recovered consciousness. However, extensive ST-segment elevations in the electrocardiogram appeared with a positive troponin test, and the patient developed pulmonary edema on day 3. An echocardiogram showed globally reduced wall motion of the left ventricle and mild pericardial effusion. Despite medical therapy with intravenous furosemide, carperitide, and catecholamines, her cardiac function deteriorated rapidly, with the left ventricular ejection fraction decreasing to 26% within 7 hours, and progressed to cardiogenic shock that afternoon. The patient received mechanical circulatory support for 4 days with intra-aortic balloon pumping and percutaneous cardiopulmonary support, and recovered fully from circulatory failure. A paired serum antibody test showed a significantly elevated titer against parainfluenza-3 virus, indicating a diagnosis of fulminant viral myocarditis. She was discharged on multiple daily insulin injection therapy, and her subsequent clinical course has been uneventful. In summary, we present a case of concurrent FT1D and fulminant viral myocarditis. Parainfluenza-3 viral infection was confirmed serologically and was considered to be a cause of both the FT1D and fulminant myocarditis.

ORMDL3 variants associated with bronchiolitis susceptibility in a Chinese population.

Recent studies revealed common genetic risks for both viral bronchiolitis and asthma. Genome-wide association studies revealed that rs7216389 in the ORMDL3 gene is associated with childhood asthma. We conducted a case-control study examining the associations between ORMDL3 polymorphisms (rs7216389, rs12603332, and rs11650680) and bronchiolitis susceptibility/viral findings among 247 infant bronchiolitis cases and 190 healthy controls. We genotyped single nucleotide polymorphisms by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry and detected respiratory viruses with multiplex reverse transcriptase-polymerase chain reaction. Only the genotype and allele frequencies of rs7216389 significantly differed between bronchiolitis and controls. The frequencies of the TT homozygote and the T allele of rs7216389 were significantly higher in the bronchiolitis patients (P = 0.0325; P = 0.0089, respectively). Polymorphisms were not associated with bronchiolitis severity. Cases were further stratified by viral infection, but no significant differences in the ORMDL3 genotype between the virus-detected group (e.g., respiratory syncytial virus alone, respiratory virus alone, virus detected) and no-virus-detected group were observed. Bronchiolitis is associated with the ORMDL3 gene in Chinese children, and there were no significant associations between genetic variations and disease severity or respiratory viruses. The TT homozygote and the T allele of rs7216389 in ORMDL3 increased bronchiolitis risk. The rs7216389 polymorphism may be a predictor for identifying infants with predisposition to virus-induced wheezing to persistent asthma.

Acute disseminated encephalomyelitis (ADEM) following a H3N3 parainfluenza virus infection in a pregnant asthmatic woman with respiratory failure.

This case report relates to a 31-year-old pregnant woman, asthmatic, admitted to the intensive care unit with respiratory failure, secondary to a viral community-acquired pneumonia. A type 3 (H3N3) parainfluenza virus RNA was isolated in her throat swab. The patient developed neurological symptoms (behavioural changes, irritability, agitation and impaired consciousness) while being weaned off sedation and ventilatory support. Cerebrospinal fluid was clear with an opening pressure of 26 cm H2O. Brain MRI showed features compatible with acute disseminated encephalomyelitis. Immune screen and EEG were normal. She was treated with intravenous methylprednisolone followed by oral prednisolone. The patient made an almost full neurological recovery within 4 weeks after starting on steroids. The patient delivered a healthy baby at 38 weeks gestation. This case highlights the importance to keep in mind rare conditions that need early recognition and prompt treatment. Brain MRI is the key to early diagnosis and treatment.

Benign acute childhood myositis following human parainfluenza virus type-1 infection.

Benign acute childhood myositis (BACM) is a post-respiratory tract infection condition of school-age children. Presentation is typically with acute onset calf pain and tenderness and refusal to walk or altered gait during the convalescent period of an influenza A or B infection. We describe a unique cluster of children with BACM following infection with human parainfluenza 1 virus, with no evidence of influenza A or B infection. BACM is a commonly missed diagnosis of altered gait in children presenting to the emergency department. This is the first report to describe a cluster of human parainfluenza virus type-1 associated BACM. We discuss the presentation, clinical examination and investigation results of the children identified. Furthermore, we review the current research surrounding BACM, overview the clinical presentation to healthcare professionals, and present an interesting case of a child presenting for the second time with BACM.

Human parainfluenza type 3 virus impairs the efficacy of glucocorticoids to limit allergy-induced pulmonary inflammation in guinea-pigs.

Viral exacerbations of allergen-induced pulmonary inflammation in pre-clinical models reportedly reduce the efficacy of glucocorticoids to limit pulmonary inflammation and airways hyper-responsiveness to inhaled spasmogens. However, exacerbations of airway obstruction induced by allergen challenge have not yet been studied. hPIV-3 (human parainfluenza type 3 virus) inoculation of guinea-pigs increased inflammatory cell counts in BAL (bronchoalveolar lavage) fluid and caused hyper-responsiveness to inhaled histamine. Both responses were abolished by treatment with either dexamethasone (20 mg/kg of body weight, subcutaneous, once a day) or fluticasone propionate (a 0.5 mg/ml solution aerosolized and inhaled over 15 min, twice a day). In ovalbumin-sensitized guinea-pigs, allergen (ovalbumin) challenge caused two phases of airway obstruction [measured as changes in sGaw (specific airways conductance) using whole body plethysmography]: an immediate phase lasting between 4 and 6 h and a late phase at about 7 h. The late phase, airway hyper-responsiveness to histamine and inflammatory cell counts in BAL were all significantly reduced by either glucocorticoid. Inoculation of guinea-pigs sensitized to ovalbumin with hPIV-3 transformed the allergen-induced airway obstruction from two transient phases into a single sustained response lasting up to 12 h. This exacerbated airway obstruction and airway hyper-responsiveness to histamine were unaffected by treatment with either glucocorticoid whereas inflammatory cell counts in BAL were only partially inhibited. Virus- or allergen-induced pulmonary inflammation, individually, are glucocorticoid-sensitive, but in combination generate a phenotype where glucocorticoid efficacy is impaired. This suggests that during respiratory virus infection, glucocorticoids might be less effective in limiting pulmonary inflammation associated with asthma.