Limits...
Wolbachia induces density-dependent inhibition to dengue virus in mosquito cells.

Lu P, Bian G, Pan X, Xi Z - PLoS Negl Trop Dis (2012)

Bottom Line: We then compared Wolbachia density between transinfected Ae. aegypti and naturally infected Ae. albopictus.The results show that Wolbachia density in midgut, fatbody and salivary gland of Ae. albopictus is 80-, 18-, and 24-fold less than that of Ae. aegypti, respectively.Our results will aid in understanding the mechanism of Wolbachia-mediated pathogen interference and developing novel methods to block disease transmission by mosquitoes carrying native Wolbachia infections.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA.

ABSTRACT
Wolbachia is a maternal transmitted endosymbiotic bacterium that is estimated to infect up to 65% of insect species. The ability of Wolbachia to both induce viral interference and spread into mosquito vector population makes it possible to develop Wolbachia as a biological control agent for dengue control. While Wolbachia induces resistance to dengue virus in the transinfected Aedes aegypti mosquitoes, a similar effect was not observed in Aedes albopictus, which naturally carries Wolbachia infection but still serves as a dengue vector. In order to understand the mechanism of this lack of Wolbachia-mediated viral interference, we used both Ae. albopictus cell line (Aa23) and mosquitoes to characterize the impact of Wolbachia on dengue infection. A serial of sub-lethal doses of antibiotic treatment was used to partially remove Wolbachia in Aa23 cells and generate cell cultures with Wolbachia at different densities. We show that there is a strong negative linear correlation between the genome copy of Wolbachia and dengue virus with a dengue infection completely removed when Wolbacha density reaches a certain level. We then compared Wolbachia density between transinfected Ae. aegypti and naturally infected Ae. albopictus. The results show that Wolbachia density in midgut, fatbody and salivary gland of Ae. albopictus is 80-, 18-, and 24-fold less than that of Ae. aegypti, respectively. We provide evidence that Wolbachia density in somatic tissues of Ae. albopictus is too low to induce resistance to dengue virus. Our results will aid in understanding the mechanism of Wolbachia-mediated pathogen interference and developing novel methods to block disease transmission by mosquitoes carrying native Wolbachia infections.

Show MeSH

Related in: MedlinePlus

The expression of DEFD was induced by Wolbachia in density-dependent manner in Aa23 cell lines.Seven days after rifampicin treatment, cells were collected to measure Wolbachia densities and DEFD expression. Because treatment with 5 µg/ml of rifampicin for 70 h resulted in both Wolbachia infection and DEFD expression at lowest level, it serves as a reference for all the other treatments to calculate a fold increase in both Wolbachia density and DEFD expression. Each point is the mean of at least three biological replicates.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3404113&req=5

pntd-0001754-g005: The expression of DEFD was induced by Wolbachia in density-dependent manner in Aa23 cell lines.Seven days after rifampicin treatment, cells were collected to measure Wolbachia densities and DEFD expression. Because treatment with 5 µg/ml of rifampicin for 70 h resulted in both Wolbachia infection and DEFD expression at lowest level, it serves as a reference for all the other treatments to calculate a fold increase in both Wolbachia density and DEFD expression. Each point is the mean of at least three biological replicates.

Mentions: We previously show that the boosted host immunity boosted plays important roles in Wolbachia-mediated viral inference and antimicrobial peptide defensin is involved in this anti-dengue resistance [17]. To test whether the above Wolbachia-density dependent viral inhibition in Aa23 cells relates to host immunity, we measured both Wolbachia density and the expression of DEFD in the antibiotic treated Aa23 cells. As shown in Fig. 5, there is a positive correlation between Wolbachia density and the amount of DEFD transcript (r = 0.92; P = 0.0001). This supports that host immune level could contribute to Wolbachia-density dependent viral inhibition.


Wolbachia induces density-dependent inhibition to dengue virus in mosquito cells.

Lu P, Bian G, Pan X, Xi Z - PLoS Negl Trop Dis (2012)

The expression of DEFD was induced by Wolbachia in density-dependent manner in Aa23 cell lines.Seven days after rifampicin treatment, cells were collected to measure Wolbachia densities and DEFD expression. Because treatment with 5 µg/ml of rifampicin for 70 h resulted in both Wolbachia infection and DEFD expression at lowest level, it serves as a reference for all the other treatments to calculate a fold increase in both Wolbachia density and DEFD expression. Each point is the mean of at least three biological replicates.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3404113&req=5

pntd-0001754-g005: The expression of DEFD was induced by Wolbachia in density-dependent manner in Aa23 cell lines.Seven days after rifampicin treatment, cells were collected to measure Wolbachia densities and DEFD expression. Because treatment with 5 µg/ml of rifampicin for 70 h resulted in both Wolbachia infection and DEFD expression at lowest level, it serves as a reference for all the other treatments to calculate a fold increase in both Wolbachia density and DEFD expression. Each point is the mean of at least three biological replicates.
Mentions: We previously show that the boosted host immunity boosted plays important roles in Wolbachia-mediated viral inference and antimicrobial peptide defensin is involved in this anti-dengue resistance [17]. To test whether the above Wolbachia-density dependent viral inhibition in Aa23 cells relates to host immunity, we measured both Wolbachia density and the expression of DEFD in the antibiotic treated Aa23 cells. As shown in Fig. 5, there is a positive correlation between Wolbachia density and the amount of DEFD transcript (r = 0.92; P = 0.0001). This supports that host immune level could contribute to Wolbachia-density dependent viral inhibition.

Bottom Line: We then compared Wolbachia density between transinfected Ae. aegypti and naturally infected Ae. albopictus.The results show that Wolbachia density in midgut, fatbody and salivary gland of Ae. albopictus is 80-, 18-, and 24-fold less than that of Ae. aegypti, respectively.Our results will aid in understanding the mechanism of Wolbachia-mediated pathogen interference and developing novel methods to block disease transmission by mosquitoes carrying native Wolbachia infections.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA.

ABSTRACT
Wolbachia is a maternal transmitted endosymbiotic bacterium that is estimated to infect up to 65% of insect species. The ability of Wolbachia to both induce viral interference and spread into mosquito vector population makes it possible to develop Wolbachia as a biological control agent for dengue control. While Wolbachia induces resistance to dengue virus in the transinfected Aedes aegypti mosquitoes, a similar effect was not observed in Aedes albopictus, which naturally carries Wolbachia infection but still serves as a dengue vector. In order to understand the mechanism of this lack of Wolbachia-mediated viral interference, we used both Ae. albopictus cell line (Aa23) and mosquitoes to characterize the impact of Wolbachia on dengue infection. A serial of sub-lethal doses of antibiotic treatment was used to partially remove Wolbachia in Aa23 cells and generate cell cultures with Wolbachia at different densities. We show that there is a strong negative linear correlation between the genome copy of Wolbachia and dengue virus with a dengue infection completely removed when Wolbacha density reaches a certain level. We then compared Wolbachia density between transinfected Ae. aegypti and naturally infected Ae. albopictus. The results show that Wolbachia density in midgut, fatbody and salivary gland of Ae. albopictus is 80-, 18-, and 24-fold less than that of Ae. aegypti, respectively. We provide evidence that Wolbachia density in somatic tissues of Ae. albopictus is too low to induce resistance to dengue virus. Our results will aid in understanding the mechanism of Wolbachia-mediated pathogen interference and developing novel methods to block disease transmission by mosquitoes carrying native Wolbachia infections.

Show MeSH
Related in: MedlinePlus