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Differential replicative ability of clinical dengue virus isolates in an immunocompetent C57BL/6 mouse model.

Barros VE, dos Santos-Junior NN, Amarilla AA, Soares AM, Lourencini R, Trabuco AC, Aquino VH - BMC Microbiol. (2015)

Bottom Line: Enhancing antibodies did not influence on the infection of animals when macrophages were used, but the level of viremia was increased when they were used as a complex with a D3/BR/SL3/02 isolate.The main difference observed between the D3/BR/SL3/02 and D2/BR/RP/RMB/2009 clinical isolates was the neuroinvasive ability of the first one.Neuroinvasiveness has been described in some DENV infected cases and is common for other members of the Flavivirus genus.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Virology, Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Av do Café, s/n, CEP: 14040-903, Ribeirao Preto, Sao Paulo, Brazil. veridias@yahoo.com.br.

ABSTRACT

Background: Several experimental animal models have been used to study the pathogenesis of dengue disease; however, most of the studies used laboratory-adapted viruses, which lack the virulence of viruses circulating in humans. The aim of this study was to analyze the ability of clinical Dengue virus (DENV) isolates (D2/BR/RP/RMB/09 and D3/BR/SL3/02) to infect immunocompetent C57BL/6 mice.

Methods: Two strategies of intraperitoneal infection, which were based on the concept of the antibody dependent enhancement phenomenon, were used. In one strategy, the animals were inoculated with macrophages infected in vitro with dengue viruses, which were incubated with enhancing antibodies, and in the other strategy, the animals were inoculated with a complex of enhancing antibodies and dengue viruses.

Results: The D3/BR/SL3/08 isolate showed a higher ability of infection (virus RNA was more frequently detected in the serum and in several organs) in the experimental model compared to both the D2/BR/RP/RMB/2009 isolate and a laboratory adapted DENV-1 strain (Mochizuki strain), regardless of the infection strategy used. The main features of the D3/BR/SL3/08 isolate were its neuroinvasiveness and the induction of an extended period of viremia. Enhancing antibodies did not influence on the infection of animals when macrophages were used, but the level of viremia was increased when they were used as a complex with a D3/BR/SL3/02 isolate.

Discussion: We showed that DENV isolates could infect immunocompetent C57BL/6 mice, which have has been previously used to study some aspect of dengue disease when infected with laboratory adapted strains. DENV genome was detected in the same organs found in humans when autopsy and biopsy samples were analyzed, showing that C57BL/6 mice reproduce some aspects of the DENV tropism observed in humans. The main difference observed between the D3/BR/SL3/02 and D2/BR/RP/RMB/2009 clinical isolates was the neuroinvasive ability of the first one. Neuroinvasiveness has been described in some DENV infected cases and is common for other members of the Flavivirus genus.

Conclusions: These results suggest that C57BL/6 mice can be used as an experimental model to evaluate virulence differences among DENV clinical isolates.

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Related in: MedlinePlus

Susceptibility of C57BL/6 mice peritoneal macrophages to infection with DENV. Real-time RT-PCR for the detection and quantification of the virus genome in the supernatant of the culture of C57BL/6 mice macrophages after 1, 24 and 48 h of infection with the Mochizuki strain, the D3/BR/SL3/02 and the D2/BR/RP/RMB/2009 isolates
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Fig1: Susceptibility of C57BL/6 mice peritoneal macrophages to infection with DENV. Real-time RT-PCR for the detection and quantification of the virus genome in the supernatant of the culture of C57BL/6 mice macrophages after 1, 24 and 48 h of infection with the Mochizuki strain, the D3/BR/SL3/02 and the D2/BR/RP/RMB/2009 isolates

Mentions: To determine the susceptibility of C57BL/6 macrophages to infection by DENV, peritoneal macrophages were incubated in vitro with laboratory-adapted (DENV-1, Mochizuki strain) and clinical DENV isolates (DENV-2, D2/BR/RP/RMB/2009 and DENV-3, D3/BR/SL3/02). Cell infection was confirmed by detection of viral RNA genome in the cell culture supernatants with a real-time RT-PCR at 1, 24 and 48 h post inoculation (Fig. 1). The highest viral load in the cell culture supernatants was observed at 48 h post inoculation.Fig. 1


Differential replicative ability of clinical dengue virus isolates in an immunocompetent C57BL/6 mouse model.

Barros VE, dos Santos-Junior NN, Amarilla AA, Soares AM, Lourencini R, Trabuco AC, Aquino VH - BMC Microbiol. (2015)

Susceptibility of C57BL/6 mice peritoneal macrophages to infection with DENV. Real-time RT-PCR for the detection and quantification of the virus genome in the supernatant of the culture of C57BL/6 mice macrophages after 1, 24 and 48 h of infection with the Mochizuki strain, the D3/BR/SL3/02 and the D2/BR/RP/RMB/2009 isolates
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4587874&req=5

Fig1: Susceptibility of C57BL/6 mice peritoneal macrophages to infection with DENV. Real-time RT-PCR for the detection and quantification of the virus genome in the supernatant of the culture of C57BL/6 mice macrophages after 1, 24 and 48 h of infection with the Mochizuki strain, the D3/BR/SL3/02 and the D2/BR/RP/RMB/2009 isolates
Mentions: To determine the susceptibility of C57BL/6 macrophages to infection by DENV, peritoneal macrophages were incubated in vitro with laboratory-adapted (DENV-1, Mochizuki strain) and clinical DENV isolates (DENV-2, D2/BR/RP/RMB/2009 and DENV-3, D3/BR/SL3/02). Cell infection was confirmed by detection of viral RNA genome in the cell culture supernatants with a real-time RT-PCR at 1, 24 and 48 h post inoculation (Fig. 1). The highest viral load in the cell culture supernatants was observed at 48 h post inoculation.Fig. 1

Bottom Line: Enhancing antibodies did not influence on the infection of animals when macrophages were used, but the level of viremia was increased when they were used as a complex with a D3/BR/SL3/02 isolate.The main difference observed between the D3/BR/SL3/02 and D2/BR/RP/RMB/2009 clinical isolates was the neuroinvasive ability of the first one.Neuroinvasiveness has been described in some DENV infected cases and is common for other members of the Flavivirus genus.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Virology, Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Av do Café, s/n, CEP: 14040-903, Ribeirao Preto, Sao Paulo, Brazil. veridias@yahoo.com.br.

ABSTRACT

Background: Several experimental animal models have been used to study the pathogenesis of dengue disease; however, most of the studies used laboratory-adapted viruses, which lack the virulence of viruses circulating in humans. The aim of this study was to analyze the ability of clinical Dengue virus (DENV) isolates (D2/BR/RP/RMB/09 and D3/BR/SL3/02) to infect immunocompetent C57BL/6 mice.

Methods: Two strategies of intraperitoneal infection, which were based on the concept of the antibody dependent enhancement phenomenon, were used. In one strategy, the animals were inoculated with macrophages infected in vitro with dengue viruses, which were incubated with enhancing antibodies, and in the other strategy, the animals were inoculated with a complex of enhancing antibodies and dengue viruses.

Results: The D3/BR/SL3/08 isolate showed a higher ability of infection (virus RNA was more frequently detected in the serum and in several organs) in the experimental model compared to both the D2/BR/RP/RMB/2009 isolate and a laboratory adapted DENV-1 strain (Mochizuki strain), regardless of the infection strategy used. The main features of the D3/BR/SL3/08 isolate were its neuroinvasiveness and the induction of an extended period of viremia. Enhancing antibodies did not influence on the infection of animals when macrophages were used, but the level of viremia was increased when they were used as a complex with a D3/BR/SL3/02 isolate.

Discussion: We showed that DENV isolates could infect immunocompetent C57BL/6 mice, which have has been previously used to study some aspect of dengue disease when infected with laboratory adapted strains. DENV genome was detected in the same organs found in humans when autopsy and biopsy samples were analyzed, showing that C57BL/6 mice reproduce some aspects of the DENV tropism observed in humans. The main difference observed between the D3/BR/SL3/02 and D2/BR/RP/RMB/2009 clinical isolates was the neuroinvasive ability of the first one. Neuroinvasiveness has been described in some DENV infected cases and is common for other members of the Flavivirus genus.

Conclusions: These results suggest that C57BL/6 mice can be used as an experimental model to evaluate virulence differences among DENV clinical isolates.

Show MeSH
Related in: MedlinePlus