Clinical aspects and detection of Zika virus RNA in several tissues of experimentally infected BALB/cAn mice / Aspectos clínicos e detecção de RNA do vírus Zika em diferentes tecidos de camundongos BALB/cAn infectados experimentalmente

Our group infected BALB/cAn mice with Zika virus to evaluate clinical signs and viral load in several tissues at three different kinetic points. We inoculated fifteen mice with a 100µl of a viral solution to collect nine different tissues, from each animal, for RNA extraction and quantification. Infections caused no lethality. Some of them, however, showed great agitation, hair bristling, and itchy skin. Viral RNA was detected in one sample of heart, eight of the spleen, and two of skeletal muscle. Seven positive detections were from the third day after infection. Only spleen yielded positive results at a later time.

Histopathological and ultrastructural studies of lung tissue of mice reinfected with dengue virus serotypes 1 or 2

Submitted by Sandra Infurna ([email protected]) on 2018-08-27T14:09:09Z No. of bitstreams: 1 enderson_silva_etal_IOC_2009.pdf: 405933 bytes, checksum: b6dbfa7e1119742c0d02559616ace815 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-08-27T14:17:42Z (GMT) No. of bitstreams: 1 enderson_silva_etal_IOC_2009.pdf: 405933 bytes, checksum: b6dbfa7e1119742c0d02559616ace815 (MD5)Made available in DSpace on 2018-08-27T14:17:42Z (GMT). No. of bitstreams: 1 enderson_silva_etal_IOC_2009.pdf: 405933 bytes, checksum: b6dbfa7e1119742c0d02559616ace815 (MD5) Previous issue date: 2009Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Instituto de Ciências Biomédicas. Departamento de Histologia e Embriologia,. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Flavivírus. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Flavivírus. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Histological and ultrastructural alterations in lung of BALB/c mice reinfected with heterologous DENV by the intravenous route with non-neuroadapted dengue viruses serotypes 1 and 2 were analyzed. The lung samples were processed following the standard techniques of photonic and transmission electron microscopy. Morphological studies showed breakdown of alveolocapilar barrier leading to alveolitis, focal zones of collapse, and intraalveolar hemorrhage. Inside alveolar septa, congested capillaries exhibited neutrophils and platelets. Alveolar capillary endothelial cells exhibited aspects of activation with exuberant phylopodia and intracytoplasmic vesicles and vacuoles. Morphometrical analyses demonstrated an increase of the surface density of interalveolar septa in all reinfected mice while alveolar space density was decreased. All these morphometrical data corroborated the histological features emphasizing the alveolocapilar breakdrown in dengue infected animals. Important is the fact that reinfection leads to intraalveolar fibrogenesis as demonstrated by histomorphometry and ultrastructural studies. DENV particles, antigens and RNA were observed 72 hours post-reinfection in mosquito cells (C6/36) inoculated with sera of the animals. The morphological alterations observed in lungs were similar to the observed in human cases of dengue fever and dengue hemorrhagic fever. The present study demonstrates that the BALB/c mice, during the secondary infection by a heterologous serotype of DENV, develop morphological alterations in lung tissue more severe than those observed in the primary infection

Morphological studies of hepatic tissue of mice reinfected with dengue virus serotypes 1 or 2

Submitted by Sandra Infurna ([email protected]) on 2018-04-26T10:48:54Z No. of bitstreams: 1 debora_vieira_etal_IOC_2011.pdf: 1565061 bytes, checksum: 0712963f06509eec67a0a67bacaa8696 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-04-26T10:59:30Z (GMT) No. of bitstreams: 1 debora_vieira_etal_IOC_2011.pdf: 1565061 bytes, checksum: 0712963f06509eec67a0a67bacaa8696 (MD5)Made available in DSpace on 2018-04-26T10:59:30Z (GMT). No. of bitstreams: 1 debora_vieira_etal_IOC_2011.pdf: 1565061 bytes, checksum: 0712963f06509eec67a0a67bacaa8696 (MD5) Previous issue date: 2010Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Instituto de Ciências Biológicas. Departamento de Histologia e Embriologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Flavivírus. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Flavivírus. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Morfologia e Morfogênese Viral. Rio de Janeiro, RJ. Brasil.Histopathological and ultrastructural aspects of liver of non-neuroadapted BALB/c mice reinfected by the intravenous route with dengue virus serotypes 1 and 2 were presented. The hepatic tissue was processed following the standard techniques for photonic and transmission electron microscopy. Morphological studies showed vacuolization of hepatocytes, inflammatory cells inside sinusoidal capillaries, enlargement of sinusoidal capillaries, foci of hemorrhage inside the interstitium, increase of surface density of reticular fibres, increase of numerical density of sinusoidal cells, decrease of surface density of hepatocytes, edema in the peri centrolobular vein space and presence of phyllopods and pseudopod-like extensions in endothelial cells. DENV particles, virus antigens and DENV RNA were observed in mosquito cells (C6/36) inoculated with sera of the animals 72 hours post-reinfection. The hepatic alterations observed in our experimental model were similar to those observed in human cases of dengue hemorrhagic fever. The present study shows that BALB/c mice reinfected with a heterologous serotype of DENV develop more severe lesions than those observed in mice in primary infection

First detection of dengue virus in the saliva of immunocompetent murine model

<div><p>The lack of an experimental animal model for the study of dengue pathogenesis is a limiting factor for the development of vaccines and drugs. In previous studies, our group demonstrated the susceptibility of BALB/c mice to infection by dengue virus (DENV) 1 and 2, and the virus was successfully isolated in several organs. In this study, BALB/c mice were experimentally infected intravenously with DENV-4, and samples of their saliva were collected. Viral RNA extracted from the saliva samples was subjected to qRT-PCR, with a detection limit of 0.002 PFU/mL. The presence of DENV-4 viral RNA was detected in the saliva of two mice, presenting viral titers of 109 RNA/mL. The detection of DENV RNA via saliva sampling is not a common practice in dengue diagnosis, due to the lower detection rates in human patients. However, the results observed in this study seem to indicate that, as in humans, detection rates of DENV RNA in mouse saliva are also low, correlating the infection in both cases. This study reports the first DENV detection in the saliva of BALB/c immunocompetent mice experimentally infected with non-neuroadapted DENV-4.</p></div

Immunocompetent Mice Infected by Two Lineages of Dengue Virus Type 2: Observations on the Pathology of the Lung, Heart and Skeletal Muscle

Dengue virus (DENV) infection by one of the four serotypes (DENV-1 to 4) may result in a wide spectrum of clinical manifestations, with unpredictable evolution and organ involvement. Due to its association with severe epidemics and clinical manifestations, DENV-2 has been substantially investigated. In fact, the first emergence of a new lineage of the DENV-2 Asian/American genotype in Brazil (Lineage II) in 2008 was associated with severe cases and increased mortality related to organ involvement. A major challenge for dengue pathogenesis studies has been a suitable animal model, but the use of immune-competent mice, although sometimes controversial, has proven to be useful, as histological observations in infected animals reveal tissue alterations consistent to those observed in dengue human cases. Here, we aimed to investigate the outcomes caused by two distinct lineages of the DENV-2 Asian/American genotype in the lung, heart and skeletal muscle tissues of infected BALB/c mice. Tissues were submitted to histopathology, immunohistochemistry, histomorphometry and transmission electron microscopy (TEM) analysis. The viral genome was detected in heart and skeletal muscle samples. The viral antigen was detected in cardiomyocytes and endothelial cells of heart tissue. Heart and lung tissue samples presented morphological alterations comparable to those seen in dengue human cases. Creatine kinase serum levels were higher in mice infected with both lineages of DENV-2. Additionally, statistically significant differences, concerning alveolar septa thickening and heart weight, were observed between BALB/c mice infected with both DENV-2 lineages, which was demonstrated to be an appropriate experimental model for dengue pathogenesis studies on lung, heart and skeletal muscle tissues

Structural investigation of C6/36 and Vero cell cultures infected with a Brazilian Zika virus - Fig 6

<p><b>C6/36 cells infected with ZIKV analyzed by transmission electron microscopy (TEM) at different time points post-infection (A-B: 48 hr p.i., C-D: 72 hr p.i.).</b> Several large viroplasm-like perinuclear compartments (V) (A-B) and ZIKV particles (*) measuring approximately 40–50 nm in diameter in the endoplasmic reticulum cisternae (RER) (A, B) and in lysosomes (L) (C-D) were observed. Nucleocapsids were observed inside the rER (D). Thickening of the nuclear membrane and rough endoplasmic reticulum cisternae (rER) (black head arrow) (C), numerous lysosomes (L) (C, D) and vesicular compartments associated with rER (arrow) (C) measuring approximately 100 nm in diameter were observed. Nucleus (N).</p

Detection of ZIKV RNA and viral load quantification from C6/36 and Vero cell supernatants at 24, 48 and 72 hr p.i. by quantitative real-time RT-PCR.

<p>Detection of ZIKV RNA and viral load quantification from C6/36 and Vero cell supernatants at 24, 48 and 72 hr p.i. by quantitative real-time RT-PCR.</p

Uninfected C6/36 cells (negative controls) at different time points in culture.

<p><b>No cellular ultrastructural alterations were observed.</b> (A–B) 24 hr of culture; (C) 48 hr of culture; (D) 72 hr of culture. Rough endoplasmic reticulum cisternae (rER), nucleus (N).</p

Immunolocalization of ZIKV E protein (4G2, green) [arrow] in the cytoplasm of Vero cells infected with ZIKV at different time points post-infection.

<p>(A) Uninfected cells; (B) 24 hr p.i; (C) 48 hr p.i.; (D) 72 hr p.i. The nuclei were counterstained with DAPI (blue). (E) The graph represents the mean ± standard deviation of the infection percentage (%). A higher number of infected cells was observed at 24 hr p.i.</p